common/hush.c

   1 /*
   2  * sh.c -- a prototype Bourne shell grammar parser
   3  *      Intended to follow the original Thompson and Ritchie
   4  *      "small and simple is beautiful" philosophy, which
   5  *      incidentally is a good match to today's BusyBox.
   6  *
   7  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   8  *
   9  * Credits:
  10  *      The parser routines proper are all original material, first
  11  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  12  *      The execution engine, the builtins, and much of the underlying
  13  *      support has been adapted from busybox-0.49pre's lash,
  14  *      which is Copyright (C) 2000 by Lineo, Inc., and
  15  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  16  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  17  *      Erik W. Troan, which they placed in the public domain.  I don't know
  18  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  19  * Other credits:
  20  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  21  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  22  *        and many builtins derived from contributions by Erik Andersen
  23  *      miscellaneous bugfixes from Matt Kraai
  24  *
  25  * There are two big (and related) architecture differences between
  26  * this parser and the lash parser.  One is that this version is
  27  * actually designed from the ground up to understand nearly all
  28  * of the Bourne grammar.  The second, consequential change is that
  29  * the parser and input reader have been turned inside out.  Now,
  30  * the parser is in control, and asks for input as needed.  The old
  31  * way had the input reader in control, and it asked for parsing to
  32  * take place as needed.  The new way makes it much easier to properly
  33  * handle the recursion implicit in the various substitutions, especially
  34  * across continuation lines.
  35  *
  36  * Bash grammar not implemented: (how many of these were in original sh?)
  37  *      $@ (those sure look like weird quoting rules)
  38  *      $_
  39  *      ! negation operator for pipes
  40  *      &> and >& redirection of stdout+stderr
  41  *      Brace Expansion
  42  *      Tilde Expansion
  43  *      fancy forms of Parameter Expansion
  44  *      aliases
  45  *      Arithmetic Expansion
  46  *      <(list) and >(list) Process Substitution
  47  *      reserved words: case, esac, select, function
  48  *      Here Documents ( << word )
  49  *      Functions
  50  * Major bugs:
  51  *      job handling woefully incomplete and buggy
  52  *      reserved word execution woefully incomplete and buggy
  53  * to-do:
  54  *      port selected bugfixes from post-0.49 busybox lash - done?
  55  *      finish implementing reserved words: for, while, until, do, done
  56  *      change { and } from special chars to reserved words
  57  *      builtins: break, continue, eval, return, set, trap, ulimit
  58  *      test magic exec
  59  *      handle children going into background
  60  *      clean up recognition of null pipes
  61  *      check setting of global_argc and global_argv
  62  *      control-C handling, probably with longjmp
  63  *      follow IFS rules more precisely, including update semantics
  64  *      figure out what to do with backslash-newline
  65  *      explain why we use signal instead of sigaction
  66  *      propagate syntax errors, die on resource errors?
  67  *      continuation lines, both explicit and implicit - done?
  68  *      memory leak finding and plugging - done?
  69  *      more testing, especially quoting rules and redirection
  70  *      document how quoting rules not precisely followed for variable assignments
  71  *      maybe change map[] to use 2-bit entries
  72  *      (eventually) remove all the printf's
  73  *
  74  * This program is free software; you can redistribute it and/or modify
  75  * it under the terms of the GNU General Public License as published by
  76  * the Free Software Foundation; either version 2 of the License, or
  77  * (at your option) any later version.
  78  *
  79  * This program is distributed in the hope that it will be useful,
  80  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  81  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  82  * General Public License for more details.
  83  *
  84  * You should have received a copy of the GNU General Public License
  85  * along with this program; if not, write to the Free Software
  86  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  87  */
  88 #define __U_BOOT__
  89 #ifdef __U_BOOT__
  90 #include <malloc.h>         /* malloc, free, realloc*/
  91 #include <linux/ctype.h>    /* isalpha, isdigit */
  92 #include <common.h>        /* readline */
  93 #include <hush.h>
  94 #include <command.h>        /* find_cmd */
  95 #endif
  96 #ifndef __U_BOOT__
  97 #include <ctype.h>     /* isalpha, isdigit */
  98 #include <unistd.h>    /* getpid */
  99 #include <stdlib.h>    /* getenv, atoi */
 100 #include <string.h>    /* strchr */
 101 #include <stdio.h>     /* popen etc. */
 102 #include <glob.h>      /* glob, of course */
 103 #include <stdarg.h>    /* va_list */
 104 #include <errno.h>
 105 #include <fcntl.h>
 106 #include <getopt.h>    /* should be pretty obvious */
 107
 108 #include <sys/stat.h>  /* ulimit */
 109 #include <sys/types.h>
 110 #include <sys/wait.h>
 111 #include <signal.h>
 112
 113 /* #include <dmalloc.h> */
 114
 115 #if 1
 116 #include "busybox.h"
 117 #include "cmdedit.h"
 118 #else
 119 #define applet_name "hush"
 120 #include "standalone.h"
 121 #define hush_main main
 122 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 123 #define BB_BANNER
 124 #endif
 125 #endif
 126 #define SPECIAL_VAR_SYMBOL 03
 127 #ifndef __U_BOOT__
 128 #define FLAG_EXIT_FROM_LOOP 1
 129 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 130 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 131
 132 #endif
 133
 134 #ifdef __U_BOOT__
 135 DECLARE_GLOBAL_DATA_PTR;
 136
 137 #define EXIT_SUCCESS 0
 138 #define EOF -1
 139 #define syntax() syntax_err()
 140 #define xstrdup strdup
 141 #define error_msg printf
 142 #else
 143 typedef enum {
 144         REDIRECT_INPUT     = 1,
 145         REDIRECT_OVERWRITE = 2,
 146         REDIRECT_APPEND    = 3,
 147         REDIRECT_HEREIS    = 4,
 148         REDIRECT_IO        = 5
 149 } redir_type;
 150
 151 /* The descrip member of this structure is only used to make debugging
 152  * output pretty */
 153 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 154         { 0,                         0, "()" },
 155         { O_RDONLY,                  0, "<"  },
 156         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 157         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 158         { O_RDONLY,                 -1, "<<" },
 159         { O_RDWR,                    1, "<>" }
 160 };
 161 #endif
 162
 163 typedef enum {
 164         PIPE_SEQ = 1,
 165         PIPE_AND = 2,
 166         PIPE_OR  = 3,
 167         PIPE_BG  = 4,
 168 } pipe_style;
 169
 170 /* might eventually control execution */
 171 typedef enum {
 172         RES_NONE  = 0,
 173         RES_IF    = 1,
 174         RES_THEN  = 2,
 175         RES_ELIF  = 3,
 176         RES_ELSE  = 4,
 177         RES_FI    = 5,
 178         RES_FOR   = 6,
 179         RES_WHILE = 7,
 180         RES_UNTIL = 8,
 181         RES_DO    = 9,
 182         RES_DONE  = 10,
 183         RES_XXXX  = 11,
 184         RES_IN    = 12,
 185         RES_SNTX  = 13
 186 } reserved_style;
 187 #define FLAG_END   (1<<RES_NONE)
 188 #define FLAG_IF    (1<<RES_IF)
 189 #define FLAG_THEN  (1<<RES_THEN)
 190 #define FLAG_ELIF  (1<<RES_ELIF)
 191 #define FLAG_ELSE  (1<<RES_ELSE)
 192 #define FLAG_FI    (1<<RES_FI)
 193 #define FLAG_FOR   (1<<RES_FOR)
 194 #define FLAG_WHILE (1<<RES_WHILE)
 195 #define FLAG_UNTIL (1<<RES_UNTIL)
 196 #define FLAG_DO    (1<<RES_DO)
 197 #define FLAG_DONE  (1<<RES_DONE)
 198 #define FLAG_IN    (1<<RES_IN)
 199 #define FLAG_START (1<<RES_XXXX)
 200
 201 /* This holds pointers to the various results of parsing */
 202 struct p_context {
 203         struct child_prog *child;
 204         struct pipe *list_head;
 205         struct pipe *pipe;
 206 #ifndef __U_BOOT__
 207         struct redir_struct *pending_redirect;
 208 #endif
 209         reserved_style w;
 210         int old_flag;                           /* for figuring out valid reserved words */
 211         struct p_context *stack;
 212         int type;                       /* define type of parser : ";$" common or special symbol */
 213         /* How about quoting status? */
 214 };
 215
 216 #ifndef __U_BOOT__
 217 struct redir_struct {
 218         redir_type type;                        /* type of redirection */
 219         int fd;                                         /* file descriptor being redirected */
 220         int dup;                                        /* -1, or file descriptor being duplicated */
 221         struct redir_struct *next;      /* pointer to the next redirect in the list */
 222         glob_t word;                            /* *word.gl_pathv is the filename */
 223 };
 224 #endif
 225
 226 struct child_prog {
 227 #ifndef __U_BOOT__
 228         pid_t pid;                                      /* 0 if exited */
 229 #endif
 230         char **argv;                            /* program name and arguments */
 231 #ifdef __U_BOOT__
 232         int    argc;                            /* number of program arguments */
 233 #endif
 234         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 235 #ifndef __U_BOOT__
 236         int subshell;                           /* flag, non-zero if group must be forked */
 237         struct redir_struct *redirects; /* I/O redirections */
 238         glob_t glob_result;                     /* result of parameter globbing */
 239         int is_stopped;                         /* is the program currently running? */
 240         struct pipe *family;            /* pointer back to the child's parent pipe */
 241 #endif
 242         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 243         int type;
 244 };
 245
 246 struct pipe {
 247 #ifndef __U_BOOT__
 248         int jobid;                                      /* job number */
 249 #endif
 250         int num_progs;                          /* total number of programs in job */
 251 #ifndef __U_BOOT__
 252         int running_progs;                      /* number of programs running */
 253         char *text;                                     /* name of job */
 254         char *cmdbuf;                           /* buffer various argv's point into */
 255         pid_t pgrp;                                     /* process group ID for the job */
 256 #endif
 257         struct child_prog *progs;       /* array of commands in pipe */
 258         struct pipe *next;                      /* to track background commands */
 259 #ifndef __U_BOOT__
 260         int stopped_progs;                      /* number of programs alive, but stopped */
 261         int job_context;                        /* bitmask defining current context */
 262 #endif
 263         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 264         reserved_style r_mode;          /* supports if, for, while, until */
 265 };
 266
 267 #ifndef __U_BOOT__
 268 struct close_me {
 269         int fd;
 270         struct close_me *next;
 271 };
 272 #endif
 273
 274 struct variables {
 275         char *name;
 276         char *value;
 277         int flg_export;
 278         int flg_read_only;
 279         struct variables *next;
 280 };
 281
 282 /* globals, connect us to the outside world
 283  * the first three support $?, $#, and $1 */
 284 #ifndef __U_BOOT__
 285 char **global_argv;
 286 unsigned int global_argc;
 287 #endif
 288 unsigned int last_return_code;
 289 int nesting_level;
 290 #ifndef __U_BOOT__
 291 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 292 #endif
 293
 294 /* "globals" within this file */
 295 static uchar *ifs;
 296 static char map[256];
 297 #ifndef __U_BOOT__
 298 static int fake_mode;
 299 static int interactive;
 300 static struct close_me *close_me_head;
 301 static const char *cwd;
 302 static struct pipe *job_list;
 303 static unsigned int last_bg_pid;
 304 static unsigned int last_jobid;
 305 static unsigned int shell_terminal;
 306 static char *PS1;
 307 static char *PS2;
 308 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 309 struct variables *top_vars = &shell_ver;
 310 #else
 311 static int flag_repeat = 0;
 312 static int do_repeat = 0;
 313 static struct variables *top_vars = NULL ;
 314 #endif /*__U_BOOT__ */
 315
 316 #define B_CHUNK (100)
 317 #define B_NOSPAC 1
 318
 319 typedef struct {
 320         char *data;
 321         int length;
 322         int maxlen;
 323         int quote;
 324         int nonnull;
 325 } o_string;
 326 #define NULL_O_STRING {NULL,0,0,0,0}
 327 /* used for initialization:
 328         o_string foo = NULL_O_STRING; */
 329
 330 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 331  * available?  Where is it documented? */
 332 struct in_str {
 333         const char *p;
 334 #ifndef __U_BOOT__
 335         char peek_buf[2];
 336 #endif
 337         int __promptme;
 338         int promptmode;
 339 #ifndef __U_BOOT__
 340         FILE *file;
 341 #endif
 342         int (*get) (struct in_str *);
 343         int (*peek) (struct in_str *);
 344 };
 345 #define b_getch(input) ((input)->get(input))
 346 #define b_peek(input) ((input)->peek(input))
 347
 348 #ifndef __U_BOOT__
 349 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 350
 351 struct built_in_command {
 352         char *cmd;                                      /* name */
 353         char *descr;                            /* description */
 354         int (*function) (struct child_prog *);  /* function ptr */
 355 };
 356 #endif
 357
 358 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 359 #if 0
 360 #define DEBUG_SHELL
 361 #endif
 362
 363 /* This should be in utility.c */
 364 #ifdef DEBUG_SHELL
 365 #ifndef __U_BOOT__
 366 static void debug_printf(const char *format, ...)
 367 {
 368         va_list args;
 369         va_start(args, format);
 370         vfprintf(stderr, format, args);
 371         va_end(args);
 372 }
 373 #else
 374 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 375 #endif
 376 #else
 377 static inline void debug_printf(const char *format, ...) { }
 378 #endif
 379 #define final_printf debug_printf
 380
 381 #ifdef __U_BOOT__
 382 static void syntax_err(void) {
 383          printf("syntax error\n");
 384 }
 385 #else
 386 static void __syntax(char *file, int line) {
 387         error_msg("syntax error %s:%d", file, line);
 388 }
 389 #define syntax() __syntax(__FILE__, __LINE__)
 390 #endif
 391
 392 #ifdef __U_BOOT__
 393 static void *xmalloc(size_t size);
 394 static void *xrealloc(void *ptr, size_t size);
 395 #else
 396 /* Index of subroutines: */
 397 /*   function prototypes for builtins */
 398 static int builtin_cd(struct child_prog *child);
 399 static int builtin_env(struct child_prog *child);
 400 static int builtin_eval(struct child_prog *child);
 401 static int builtin_exec(struct child_prog *child);
 402 static int builtin_exit(struct child_prog *child);
 403 static int builtin_export(struct child_prog *child);
 404 static int builtin_fg_bg(struct child_prog *child);
 405 static int builtin_help(struct child_prog *child);
 406 static int builtin_jobs(struct child_prog *child);
 407 static int builtin_pwd(struct child_prog *child);
 408 static int builtin_read(struct child_prog *child);
 409 static int builtin_set(struct child_prog *child);
 410 static int builtin_shift(struct child_prog *child);
 411 static int builtin_source(struct child_prog *child);
 412 static int builtin_umask(struct child_prog *child);
 413 static int builtin_unset(struct child_prog *child);
 414 static int builtin_not_written(struct child_prog *child);
 415 #endif
 416 /*   o_string manipulation: */
 417 static int b_check_space(o_string *o, int len);
 418 static int b_addchr(o_string *o, int ch);
 419 static void b_reset(o_string *o);
 420 static int b_addqchr(o_string *o, int ch, int quote);
 421 #ifndef __U_BOOT__
 422 static int b_adduint(o_string *o, unsigned int i);
 423 #endif
 424 /*  in_str manipulations: */
 425 static int static_get(struct in_str *i);
 426 static int static_peek(struct in_str *i);
 427 static int file_get(struct in_str *i);
 428 static int file_peek(struct in_str *i);
 429 #ifndef __U_BOOT__
 430 static void setup_file_in_str(struct in_str *i, FILE *f);
 431 #else
 432 static void setup_file_in_str(struct in_str *i);
 433 #endif
 434 static void setup_string_in_str(struct in_str *i, const char *s);
 435 #ifndef __U_BOOT__
 436 /*  close_me manipulations: */
 437 static void mark_open(int fd);
 438 static void mark_closed(int fd);
 439 static void close_all(void);
 440 #endif
 441 /*  "run" the final data structures: */
 442 static char *indenter(int i);
 443 static int free_pipe_list(struct pipe *head, int indent);
 444 static int free_pipe(struct pipe *pi, int indent);
 445 /*  really run the final data structures: */
 446 #ifndef __U_BOOT__
 447 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 448 #endif
 449 static int run_list_real(struct pipe *pi);
 450 #ifndef __U_BOOT__
 451 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 452 #endif
 453 static int run_pipe_real(struct pipe *pi);
 454 /*   extended glob support: */
 455 #ifndef __U_BOOT__
 456 static int globhack(const char *src, int flags, glob_t *pglob);
 457 static int glob_needed(const char *s);
 458 static int xglob(o_string *dest, int flags, glob_t *pglob);
 459 #endif
 460 /*   variable assignment: */
 461 static int is_assignment(const char *s);
 462 /*   data structure manipulation: */
 463 #ifndef __U_BOOT__
 464 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 465 #endif
 466 static void initialize_context(struct p_context *ctx);
 467 static int done_word(o_string *dest, struct p_context *ctx);
 468 static int done_command(struct p_context *ctx);
 469 static int done_pipe(struct p_context *ctx, pipe_style type);
 470 /*   primary string parsing: */
 471 #ifndef __U_BOOT__
 472 static int redirect_dup_num(struct in_str *input);
 473 static int redirect_opt_num(o_string *o);
 474 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 475 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 476 #endif
 477 static char *lookup_param(char *src);
 478 static char *make_string(char **inp);
 479 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 480 #ifndef __U_BOOT__
 481 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 482 #endif
 483 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 484 /*   setup: */
 485 static int parse_stream_outer(struct in_str *inp, int flag);
 486 #ifndef __U_BOOT__
 487 static int parse_string_outer(const char *s, int flag);
 488 static int parse_file_outer(FILE *f);
 489 #endif
 490 #ifndef __U_BOOT__
 491 /*   job management: */
 492 static int checkjobs(struct pipe* fg_pipe);
 493 static void insert_bg_job(struct pipe *pi);
 494 static void remove_bg_job(struct pipe *pi);
 495 #endif
 496 /*     local variable support */
 497 static char **make_list_in(char **inp, char *name);
 498 static char *insert_var_value(char *inp);
 499
 500 #ifndef __U_BOOT__
 501 /* Table of built-in functions.  They can be forked or not, depending on
 502  * context: within pipes, they fork.  As simple commands, they do not.
 503  * When used in non-forking context, they can change global variables
 504  * in the parent shell process.  If forked, of course they can not.
 505  * For example, 'unset foo | whatever' will parse and run, but foo will
 506  * still be set at the end. */
 507 static struct built_in_command bltins[] = {
 508         {"bg", "Resume a job in the background", builtin_fg_bg},
 509         {"break", "Exit for, while or until loop", builtin_not_written},
 510         {"cd", "Change working directory", builtin_cd},
 511         {"continue", "Continue for, while or until loop", builtin_not_written},
 512         {"env", "Print all environment variables", builtin_env},
 513         {"eval", "Construct and run shell command", builtin_eval},
 514         {"exec", "Exec command, replacing this shell with the exec'd process",
 515                 builtin_exec},
 516         {"exit", "Exit from shell()", builtin_exit},
 517         {"export", "Set environment variable", builtin_export},
 518         {"fg", "Bring job into the foreground", builtin_fg_bg},
 519         {"jobs", "Lists the active jobs", builtin_jobs},
 520         {"pwd", "Print current directory", builtin_pwd},
 521         {"read", "Input environment variable", builtin_read},
 522         {"return", "Return from a function", builtin_not_written},
 523         {"set", "Set/unset shell local variables", builtin_set},
 524         {"shift", "Shift positional parameters", builtin_shift},
 525         {"trap", "Trap signals", builtin_not_written},
 526         {"ulimit","Controls resource limits", builtin_not_written},
 527         {"umask","Sets file creation mask", builtin_umask},
 528         {"unset", "Unset environment variable", builtin_unset},
 529         {".", "Source-in and run commands in a file", builtin_source},
 530         {"help", "List shell built-in commands", builtin_help},
 531         {NULL, NULL, NULL}
 532 };
 533
 534 static const char *set_cwd(void)
 535 {
 536         if(cwd==unknown)
 537                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 538         cwd = xgetcwd((char *)cwd);
 539         if (!cwd)
 540                 cwd = unknown;
 541         return cwd;
 542 }
 543
 544 /* built-in 'eval' handler */
 545 static int builtin_eval(struct child_prog *child)
 546 {
 547         char *str = NULL;
 548         int rcode = EXIT_SUCCESS;
 549
 550         if (child->argv[1]) {
 551                 str = make_string(child->argv + 1);
 552                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 553                                         FLAG_PARSE_SEMICOLON);
 554                 free(str);
 555                 rcode = last_return_code;
 556         }
 557         return rcode;
 558 }
 559
 560 /* built-in 'cd <path>' handler */
 561 static int builtin_cd(struct child_prog *child)
 562 {
 563         char *newdir;
 564         if (child->argv[1] == NULL)
 565                 newdir = getenv("HOME");
 566         else
 567                 newdir = child->argv[1];
 568         if (chdir(newdir)) {
 569                 printf("cd: %s: %s\n", newdir, strerror(errno));
 570                 return EXIT_FAILURE;
 571         }
 572         set_cwd();
 573         return EXIT_SUCCESS;
 574 }
 575
 576 /* built-in 'env' handler */
 577 static int builtin_env(struct child_prog *dummy)
 578 {
 579         char **e = environ;
 580         if (e == NULL) return EXIT_FAILURE;
 581         for (; *e; e++) {
 582                 puts(*e);
 583         }
 584         return EXIT_SUCCESS;
 585 }
 586
 587 /* built-in 'exec' handler */
 588 static int builtin_exec(struct child_prog *child)
 589 {
 590         if (child->argv[1] == NULL)
 591                 return EXIT_SUCCESS;   /* Really? */
 592         child->argv++;
 593         pseudo_exec(child);
 594         /* never returns */
 595 }
 596
 597 /* built-in 'exit' handler */
 598 static int builtin_exit(struct child_prog *child)
 599 {
 600         if (child->argv[1] == NULL)
 601                 exit(last_return_code);
 602         exit (atoi(child->argv[1]));
 603 }
 604
 605 /* built-in 'export VAR=value' handler */
 606 static int builtin_export(struct child_prog *child)
 607 {
 608         int res = 0;
 609         char *name = child->argv[1];
 610
 611         if (name == NULL) {
 612                 return (builtin_env(child));
 613         }
 614
 615         name = strdup(name);
 616
 617         if(name) {
 618                 char *value = strchr(name, '=');
 619
 620                 if (!value) {
 621                         char *tmp;
 622                         /* They are exporting something without an =VALUE */
 623
 624                         value = get_local_var(name);
 625                         if (value) {
 626                                 size_t ln = strlen(name);
 627
 628                                 tmp = realloc(name, ln+strlen(value)+2);
 629                                 if(tmp==NULL)
 630                                         res = -1;
 631                                 else {
 632                                         sprintf(tmp+ln, "=%s", value);
 633                                         name = tmp;
 634                                 }
 635                         } else {
 636                                 /* bash does not return an error when trying to export
 637                                  * an undefined variable.  Do likewise. */
 638                                 res = 1;
 639                         }
 640                 }
 641         }
 642         if (res<0)
 643                 perror_msg("export");
 644         else if(res==0)
 645                 res = set_local_var(name, 1);
 646         else
 647                 res = 0;
 648         free(name);
 649         return res;
 650 }
 651
 652 /* built-in 'fg' and 'bg' handler */
 653 static int builtin_fg_bg(struct child_prog *child)
 654 {
 655         int i, jobnum;
 656         struct pipe *pi=NULL;
 657
 658         if (!interactive)
 659                 return EXIT_FAILURE;
 660         /* If they gave us no args, assume they want the last backgrounded task */
 661         if (!child->argv[1]) {
 662                 for (pi = job_list; pi; pi = pi->next) {
 663                         if (pi->jobid == last_jobid) {
 664                                 break;
 665                         }
 666                 }
 667                 if (!pi) {
 668                         error_msg("%s: no current job", child->argv[0]);
 669                         return EXIT_FAILURE;
 670                 }
 671         } else {
 672                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 673                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 674                         return EXIT_FAILURE;
 675                 }
 676                 for (pi = job_list; pi; pi = pi->next) {
 677                         if (pi->jobid == jobnum) {
 678                                 break;
 679                         }
 680                 }
 681                 if (!pi) {
 682                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 683                         return EXIT_FAILURE;
 684                 }
 685         }
 686
 687         if (*child->argv[0] == 'f') {
 688                 /* Put the job into the foreground.  */
 689                 tcsetpgrp(shell_terminal, pi->pgrp);
 690         }
 691
 692         /* Restart the processes in the job */
 693         for (i = 0; i < pi->num_progs; i++)
 694                 pi->progs[i].is_stopped = 0;
 695
 696         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 697                 if (i == ESRCH) {
 698                         remove_bg_job(pi);
 699                 } else {
 700                         perror_msg("kill (SIGCONT)");
 701                 }
 702         }
 703
 704         pi->stopped_progs = 0;
 705         return EXIT_SUCCESS;
 706 }
 707
 708 /* built-in 'help' handler */
 709 static int builtin_help(struct child_prog *dummy)
 710 {
 711         struct built_in_command *x;
 712
 713         printf("\nBuilt-in commands:\n");
 714         printf("-------------------\n");
 715         for (x = bltins; x->cmd; x++) {
 716                 if (x->descr==NULL)
 717                         continue;
 718                 printf("%s\t%s\n", x->cmd, x->descr);
 719         }
 720         printf("\n\n");
 721         return EXIT_SUCCESS;
 722 }
 723
 724 /* built-in 'jobs' handler */
 725 static int builtin_jobs(struct child_prog *child)
 726 {
 727         struct pipe *job;
 728         char *status_string;
 729
 730         for (job = job_list; job; job = job->next) {
 731                 if (job->running_progs == job->stopped_progs)
 732                         status_string = "Stopped";
 733                 else
 734                         status_string = "Running";
 735
 736                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 737         }
 738         return EXIT_SUCCESS;
 739 }
 740
 741
 742 /* built-in 'pwd' handler */
 743 static int builtin_pwd(struct child_prog *dummy)
 744 {
 745         puts(set_cwd());
 746         return EXIT_SUCCESS;
 747 }
 748
 749 /* built-in 'read VAR' handler */
 750 static int builtin_read(struct child_prog *child)
 751 {
 752         int res;
 753
 754         if (child->argv[1]) {
 755                 char string[BUFSIZ];
 756                 char *var = 0;
 757
 758                 string[0] = 0;  /* In case stdin has only EOF */
 759                 /* read string */
 760                 fgets(string, sizeof(string), stdin);
 761                 chomp(string);
 762                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 763                 if(var) {
 764                         sprintf(var, "%s=%s", child->argv[1], string);
 765                         res = set_local_var(var, 0);
 766                 } else
 767                         res = -1;
 768                 if (res)
 769                         fprintf(stderr, "read: %m\n");
 770                 free(var);      /* So not move up to avoid breaking errno */
 771                 return res;
 772         } else {
 773                 do res=getchar(); while(res!='\n' && res!=EOF);
 774                 return 0;
 775         }
 776 }
 777
 778 /* built-in 'set VAR=value' handler */
 779 static int builtin_set(struct child_prog *child)
 780 {
 781         char *temp = child->argv[1];
 782         struct variables *e;
 783
 784         if (temp == NULL)
 785                 for(e = top_vars; e; e=e->next)
 786                         printf("%s=%s\n", e->name, e->value);
 787         else
 788                 set_local_var(temp, 0);
 789
 790                 return EXIT_SUCCESS;
 791 }
 792
 793
 794 /* Built-in 'shift' handler */
 795 static int builtin_shift(struct child_prog *child)
 796 {
 797         int n=1;
 798         if (child->argv[1]) {
 799                 n=atoi(child->argv[1]);
 800         }
 801         if (n>=0 && n<global_argc) {
 802                 /* XXX This probably breaks $0 */
 803                 global_argc -= n;
 804                 global_argv += n;
 805                 return EXIT_SUCCESS;
 806         } else {
 807                 return EXIT_FAILURE;
 808         }
 809 }
 810
 811 /* Built-in '.' handler (read-in and execute commands from file) */
 812 static int builtin_source(struct child_prog *child)
 813 {
 814         FILE *input;
 815         int status;
 816
 817         if (child->argv[1] == NULL)
 818                 return EXIT_FAILURE;
 819
 820         /* XXX search through $PATH is missing */
 821         input = fopen(child->argv[1], "r");
 822         if (!input) {
 823                 error_msg("Couldn't open file '%s'", child->argv[1]);
 824                 return EXIT_FAILURE;
 825         }
 826
 827         /* Now run the file */
 828         /* XXX argv and argc are broken; need to save old global_argv
 829          * (pointer only is OK!) on this stack frame,
 830          * set global_argv=child->argv+1, recurse, and restore. */
 831         mark_open(fileno(input));
 832         status = parse_file_outer(input);
 833         mark_closed(fileno(input));
 834         fclose(input);
 835         return (status);
 836 }
 837
 838 static int builtin_umask(struct child_prog *child)
 839 {
 840         mode_t new_umask;
 841         const char *arg = child->argv[1];
 842         char *end;
 843         if (arg) {
 844                 new_umask=strtoul(arg, &end, 8);
 845                 if (*end!='\0' || end == arg) {
 846                         return EXIT_FAILURE;
 847                 }
 848         } else {
 849                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 850         }
 851         umask(new_umask);
 852         return EXIT_SUCCESS;
 853 }
 854
 855 /* built-in 'unset VAR' handler */
 856 static int builtin_unset(struct child_prog *child)
 857 {
 858         /* bash returned already true */
 859         unset_local_var(child->argv[1]);
 860         return EXIT_SUCCESS;
 861 }
 862
 863 static int builtin_not_written(struct child_prog *child)
 864 {
 865         printf("builtin_%s not written\n",child->argv[0]);
 866         return EXIT_FAILURE;
 867 }
 868 #endif
 869
 870 static int b_check_space(o_string *o, int len)
 871 {
 872         /* It would be easy to drop a more restrictive policy
 873          * in here, such as setting a maximum string length */
 874         if (o->length + len > o->maxlen) {
 875                 char *old_data = o->data;
 876                 /* assert (data == NULL || o->maxlen != 0); */
 877                 o->maxlen += max(2*len, B_CHUNK);
 878                 o->data = realloc(o->data, 1 + o->maxlen);
 879                 if (o->data == NULL) {
 880                         free(old_data);
 881                 }
 882         }
 883         return o->data == NULL;
 884 }
 885
 886 static int b_addchr(o_string *o, int ch)
 887 {
 888         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 889         if (b_check_space(o, 1)) return B_NOSPAC;
 890         o->data[o->length] = ch;
 891         o->length++;
 892         o->data[o->length] = '\0';
 893         return 0;
 894 }
 895
 896 static void b_reset(o_string *o)
 897 {
 898         o->length = 0;
 899         o->nonnull = 0;
 900         if (o->data != NULL) *o->data = '\0';
 901 }
 902
 903 static void b_free(o_string *o)
 904 {
 905         b_reset(o);
 906         free(o->data);
 907         o->data = NULL;
 908         o->maxlen = 0;
 909 }
 910
 911 /* My analysis of quoting semantics tells me that state information
 912  * is associated with a destination, not a source.
 913  */
 914 static int b_addqchr(o_string *o, int ch, int quote)
 915 {
 916         if (quote && strchr("*?[\\",ch)) {
 917                 int rc;
 918                 rc = b_addchr(o, '\\');
 919                 if (rc) return rc;
 920         }
 921         return b_addchr(o, ch);
 922 }
 923
 924 #ifndef __U_BOOT__
 925 static int b_adduint(o_string *o, unsigned int i)
 926 {
 927         int r;
 928         char *p = simple_itoa(i);
 929         /* no escape checking necessary */
 930         do r=b_addchr(o, *p++); while (r==0 && *p);
 931         return r;
 932 }
 933 #endif
 934
 935 static int static_get(struct in_str *i)
 936 {
 937         int ch = *i->p++;
 938         if (ch=='\0') return EOF;
 939         return ch;
 940 }
 941
 942 static int static_peek(struct in_str *i)
 943 {
 944         return *i->p;
 945 }
 946
 947 #ifndef __U_BOOT__
 948 static inline void cmdedit_set_initial_prompt(void)
 949 {
 950 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 951         PS1 = NULL;
 952 #else
 953         PS1 = getenv("PS1");
 954         if(PS1==0)
 955                 PS1 = "\\w \\$ ";
 956 #endif
 957 }
 958
 959 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 960 {
 961         debug_printf("setup_prompt_string %d ",promptmode);
 962 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 963         /* Set up the prompt */
 964         if (promptmode == 1) {
 965                 free(PS1);
 966                 PS1=xmalloc(strlen(cwd)+4);
 967                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 968                 *prompt_str = PS1;
 969         } else {
 970                 *prompt_str = PS2;
 971         }
 972 #else
 973         *prompt_str = (promptmode==1)? PS1 : PS2;
 974 #endif
 975         debug_printf("result %s\n",*prompt_str);
 976 }
 977 #endif
 978
 979 static void get_user_input(struct in_str *i)
 980 {
 981 #ifndef __U_BOOT__
 982         char *prompt_str;
 983         static char the_command[BUFSIZ];
 984
 985         setup_prompt_string(i->promptmode, &prompt_str);
 986 #ifdef CONFIG_FEATURE_COMMAND_EDITING
 987         /*
 988          ** enable command line editing only while a command line
 989          ** is actually being read; otherwise, we'll end up bequeathing
 990          ** atexit() handlers and other unwanted stuff to our
 991          ** child processes (rob@sysgo.de)
 992          */
 993         cmdedit_read_input(prompt_str, the_command);
 994 #else
 995         fputs(prompt_str, stdout);
 996         fflush(stdout);
 997         the_command[0]=fgetc(i->file);
 998         the_command[1]='\0';
 999 #endif
1000         fflush(stdout);
1001         i->p = the_command;
1002 #else
1003         extern char console_buffer[];
1004         int n;
1005         static char the_command[CONFIG_SYS_CBSIZE];
1006
1007 #ifdef CONFIG_BOOT_RETRY_TIME
1008 #  ifndef CONFIG_RESET_TO_RETRY
1009 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1010 #  endif
1011         reset_cmd_timeout();
1012 #endif
1013         i->__promptme = 1;
1014         if (i->promptmode == 1) {
1015                 n = readline(CONFIG_SYS_PROMPT);
1016         } else {
1017                 n = readline(CONFIG_SYS_PROMPT_HUSH_PS2);
1018         }
1019 #ifdef CONFIG_BOOT_RETRY_TIME
1020         if (n == -2) {
1021           puts("\nTimeout waiting for command\n");
1022 #  ifdef CONFIG_RESET_TO_RETRY
1023           do_reset(NULL, 0, 0, NULL);
1024 #  else
1025 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1026 #  endif
1027         }
1028 #endif
1029         if (n == -1 ) {
1030                 flag_repeat = 0;
1031                 i->__promptme = 0;
1032         }
1033         n = strlen(console_buffer);
1034         console_buffer[n] = '\n';
1035         console_buffer[n+1]= '\0';
1036         if (had_ctrlc()) flag_repeat = 0;
1037         clear_ctrlc();
1038         do_repeat = 0;
1039         if (i->promptmode == 1) {
1040                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1041                         strcpy(the_command,console_buffer);
1042                 }
1043                 else {
1044                         if (console_buffer[0] != '\n') {
1045                                 strcpy(the_command,console_buffer);
1046                                 flag_repeat = 1;
1047                         }
1048                         else {
1049                                 do_repeat = 1;
1050                         }
1051                 }
1052                 i->p = the_command;
1053         }
1054         else {
1055                 if (console_buffer[0] != '\n') {
1056                         if (strlen(the_command) + strlen(console_buffer)
1057                             < CONFIG_SYS_CBSIZE) {
1058                                 n = strlen(the_command);
1059                                 the_command[n-1] = ' ';
1060                                 strcpy(&the_command[n],console_buffer);
1061                         }
1062                         else {
1063                                 the_command[0] = '\n';
1064                                 the_command[1] = '\0';
1065                                 flag_repeat = 0;
1066                         }
1067                 }
1068                 if (i->__promptme == 0) {
1069                         the_command[0] = '\n';
1070                         the_command[1] = '\0';
1071                 }
1072                 i->p = console_buffer;
1073         }
1074 #endif
1075 }
1076
1077 /* This is the magic location that prints prompts
1078  * and gets data back from the user */
1079 static int file_get(struct in_str *i)
1080 {
1081         int ch;
1082
1083         ch = 0;
1084         /* If there is data waiting, eat it up */
1085         if (i->p && *i->p) {
1086                 ch = *i->p++;
1087         } else {
1088                 /* need to double check i->file because we might be doing something
1089                  * more complicated by now, like sourcing or substituting. */
1090 #ifndef __U_BOOT__
1091                 if (i->__promptme && interactive && i->file == stdin) {
1092                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1093 #else
1094                         while(! i->p  || strlen(i->p)==0 ) {
1095 #endif
1096                                 get_user_input(i);
1097                         }
1098                         i->promptmode=2;
1099 #ifndef __U_BOOT__
1100                         i->__promptme = 0;
1101 #endif
1102                         if (i->p && *i->p) {
1103                                 ch = *i->p++;
1104                         }
1105 #ifndef __U_BOOT__
1106                 } else {
1107                         ch = fgetc(i->file);
1108                 }
1109
1110 #endif
1111                 debug_printf("b_getch: got a %d\n", ch);
1112         }
1113 #ifndef __U_BOOT__
1114         if (ch == '\n') i->__promptme=1;
1115 #endif
1116         return ch;
1117 }
1118
1119 /* All the callers guarantee this routine will never be
1120  * used right after a newline, so prompting is not needed.
1121  */
1122 static int file_peek(struct in_str *i)
1123 {
1124 #ifndef __U_BOOT__
1125         if (i->p && *i->p) {
1126 #endif
1127                 return *i->p;
1128 #ifndef __U_BOOT__
1129         } else {
1130                 i->peek_buf[0] = fgetc(i->file);
1131                 i->peek_buf[1] = '\0';
1132                 i->p = i->peek_buf;
1133                 debug_printf("b_peek: got a %d\n", *i->p);
1134                 return *i->p;
1135         }
1136 #endif
1137 }
1138
1139 #ifndef __U_BOOT__
1140 static void setup_file_in_str(struct in_str *i, FILE *f)
1141 #else
1142 static void setup_file_in_str(struct in_str *i)
1143 #endif
1144 {
1145         i->peek = file_peek;
1146         i->get = file_get;
1147         i->__promptme=1;
1148         i->promptmode=1;
1149 #ifndef __U_BOOT__
1150         i->file = f;
1151 #endif
1152         i->p = NULL;
1153 }
1154
1155 static void setup_string_in_str(struct in_str *i, const char *s)
1156 {
1157         i->peek = static_peek;
1158         i->get = static_get;
1159         i->__promptme=1;
1160         i->promptmode=1;
1161         i->p = s;
1162 }
1163
1164 #ifndef __U_BOOT__
1165 static void mark_open(int fd)
1166 {
1167         struct close_me *new = xmalloc(sizeof(struct close_me));
1168         new->fd = fd;
1169         new->next = close_me_head;
1170         close_me_head = new;
1171 }
1172
1173 static void mark_closed(int fd)
1174 {
1175         struct close_me *tmp;
1176         if (close_me_head == NULL || close_me_head->fd != fd)
1177                 error_msg_and_die("corrupt close_me");
1178         tmp = close_me_head;
1179         close_me_head = close_me_head->next;
1180         free(tmp);
1181 }
1182
1183 static void close_all(void)
1184 {
1185         struct close_me *c;
1186         for (c=close_me_head; c; c=c->next) {
1187                 close(c->fd);
1188         }
1189         close_me_head = NULL;
1190 }
1191
1192 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1193  * and stderr if they are redirected. */
1194 static int setup_redirects(struct child_prog *prog, int squirrel[])
1195 {
1196         int openfd, mode;
1197         struct redir_struct *redir;
1198
1199         for (redir=prog->redirects; redir; redir=redir->next) {
1200                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1201                         /* something went wrong in the parse.  Pretend it didn't happen */
1202                         continue;
1203                 }
1204                 if (redir->dup == -1) {
1205                         mode=redir_table[redir->type].mode;
1206                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1207                         if (openfd < 0) {
1208                         /* this could get lost if stderr has been redirected, but
1209                            bash and ash both lose it as well (though zsh doesn't!) */
1210                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1211                                 return 1;
1212                         }
1213                 } else {
1214                         openfd = redir->dup;
1215                 }
1216
1217                 if (openfd != redir->fd) {
1218                         if (squirrel && redir->fd < 3) {
1219                                 squirrel[redir->fd] = dup(redir->fd);
1220                         }
1221                         if (openfd == -3) {
1222                                 close(openfd);
1223                         } else {
1224                                 dup2(openfd, redir->fd);
1225                                 if (redir->dup == -1)
1226                                         close (openfd);
1227                         }
1228                 }
1229         }
1230         return 0;
1231 }
1232
1233 static void restore_redirects(int squirrel[])
1234 {
1235         int i, fd;
1236         for (i=0; i<3; i++) {
1237                 fd = squirrel[i];
1238                 if (fd != -1) {
1239                         /* No error checking.  I sure wouldn't know what
1240                          * to do with an error if I found one! */
1241                         dup2(fd, i);
1242                         close(fd);
1243                 }
1244         }
1245 }
1246
1247 /* never returns */
1248 /* XXX no exit() here.  If you don't exec, use _exit instead.
1249  * The at_exit handlers apparently confuse the calling process,
1250  * in particular stdin handling.  Not sure why? */
1251 static void pseudo_exec(struct child_prog *child)
1252 {
1253         int i, rcode;
1254         char *p;
1255         struct built_in_command *x;
1256         if (child->argv) {
1257                 for (i=0; is_assignment(child->argv[i]); i++) {
1258                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1259                         p = insert_var_value(child->argv[i]);
1260                         putenv(strdup(p));
1261                         if (p != child->argv[i]) free(p);
1262                 }
1263                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1264                                         to exit, and therefore don't need to keep data
1265                                         structures consistent for free() use. */
1266                 /* If a variable is assigned in a forest, and nobody listens,
1267                  * was it ever really set?
1268                  */
1269                 if (child->argv[0] == NULL) {
1270                         _exit(EXIT_SUCCESS);
1271                 }
1272
1273                 /*
1274                  * Check if the command matches any of the builtins.
1275                  * Depending on context, this might be redundant.  But it's
1276                  * easier to waste a few CPU cycles than it is to figure out
1277                  * if this is one of those cases.
1278                  */
1279                 for (x = bltins; x->cmd; x++) {
1280                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1281                                 debug_printf("builtin exec %s\n", child->argv[0]);
1282                                 rcode = x->function(child);
1283                                 fflush(stdout);
1284                                 _exit(rcode);
1285                         }
1286                 }
1287
1288                 /* Check if the command matches any busybox internal commands
1289                  * ("applets") here.
1290                  * FIXME: This feature is not 100% safe, since
1291                  * BusyBox is not fully reentrant, so we have no guarantee the things
1292                  * from the .bss are still zeroed, or that things from .data are still
1293                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1294                  * really dislike relying on /proc for things.  We could exec ourself
1295                  * from global_argv[0], but if we are in a chroot, we may not be able
1296                  * to find ourself... */
1297 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1298                 {
1299                         int argc_l;
1300                         char** argv_l=child->argv;
1301                         char *name = child->argv[0];
1302
1303 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1304                         /* Following discussions from November 2000 on the busybox mailing
1305                          * list, the default configuration, (without
1306                          * get_last_path_component()) lets the user force use of an
1307                          * external command by specifying the full (with slashes) filename.
1308                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1309                          * _aways_ override external commands, so if you want to run
1310                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1311                          * filesystem and is _not_ busybox.  Some systems may want this,
1312                          * most do not.  */
1313                         name = get_last_path_component(name);
1314 #endif
1315                         /* Count argc for use in a second... */
1316                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1317                         optind = 1;
1318                         debug_printf("running applet %s\n", name);
1319                         run_applet_by_name(name, argc_l, child->argv);
1320                 }
1321 #endif
1322                 debug_printf("exec of %s\n",child->argv[0]);
1323                 execvp(child->argv[0],child->argv);
1324                 perror_msg("couldn't exec: %s",child->argv[0]);
1325                 _exit(1);
1326         } else if (child->group) {
1327                 debug_printf("runtime nesting to group\n");
1328                 interactive=0;    /* crucial!!!! */
1329                 rcode = run_list_real(child->group);
1330                 /* OK to leak memory by not calling free_pipe_list,
1331                  * since this process is about to exit */
1332                 _exit(rcode);
1333         } else {
1334                 /* Can happen.  See what bash does with ">foo" by itself. */
1335                 debug_printf("trying to pseudo_exec null command\n");
1336                 _exit(EXIT_SUCCESS);
1337         }
1338 }
1339
1340 static void insert_bg_job(struct pipe *pi)
1341 {
1342         struct pipe *thejob;
1343
1344         /* Linear search for the ID of the job to use */
1345         pi->jobid = 1;
1346         for (thejob = job_list; thejob; thejob = thejob->next)
1347                 if (thejob->jobid >= pi->jobid)
1348                         pi->jobid = thejob->jobid + 1;
1349
1350         /* add thejob to the list of running jobs */
1351         if (!job_list) {
1352                 thejob = job_list = xmalloc(sizeof(*thejob));
1353         } else {
1354                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1355                 thejob->next = xmalloc(sizeof(*thejob));
1356                 thejob = thejob->next;
1357         }
1358
1359         /* physically copy the struct job */
1360         memcpy(thejob, pi, sizeof(struct pipe));
1361         thejob->next = NULL;
1362         thejob->running_progs = thejob->num_progs;
1363         thejob->stopped_progs = 0;
1364         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1365
1366         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1367         {
1368                 char *bar=thejob->text;
1369                 char **foo=pi->progs[0].argv;
1370                 while(foo && *foo) {
1371                         bar += sprintf(bar, "%s ", *foo++);
1372                 }
1373         }
1374
1375         /* we don't wait for background thejobs to return -- append it
1376            to the list of backgrounded thejobs and leave it alone */
1377         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1378         last_bg_pid = thejob->progs[0].pid;
1379         last_jobid = thejob->jobid;
1380 }
1381
1382 /* remove a backgrounded job */
1383 static void remove_bg_job(struct pipe *pi)
1384 {
1385         struct pipe *prev_pipe;
1386
1387         if (pi == job_list) {
1388                 job_list = pi->next;
1389         } else {
1390                 prev_pipe = job_list;
1391                 while (prev_pipe->next != pi)
1392                         prev_pipe = prev_pipe->next;
1393                 prev_pipe->next = pi->next;
1394         }
1395         if (job_list)
1396                 last_jobid = job_list->jobid;
1397         else
1398                 last_jobid = 0;
1399
1400         pi->stopped_progs = 0;
1401         free_pipe(pi, 0);
1402         free(pi);
1403 }
1404
1405 /* Checks to see if any processes have exited -- if they
1406    have, figure out why and see if a job has completed */
1407 static int checkjobs(struct pipe* fg_pipe)
1408 {
1409         int attributes;
1410         int status;
1411         int prognum = 0;
1412         struct pipe *pi;
1413         pid_t childpid;
1414
1415         attributes = WUNTRACED;
1416         if (fg_pipe==NULL) {
1417                 attributes |= WNOHANG;
1418         }
1419
1420         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1421                 if (fg_pipe) {
1422                         int i, rcode = 0;
1423                         for (i=0; i < fg_pipe->num_progs; i++) {
1424                                 if (fg_pipe->progs[i].pid == childpid) {
1425                                         if (i==fg_pipe->num_progs-1)
1426                                                 rcode=WEXITSTATUS(status);
1427                                         (fg_pipe->num_progs)--;
1428                                         return(rcode);
1429                                 }
1430                         }
1431                 }
1432
1433                 for (pi = job_list; pi; pi = pi->next) {
1434                         prognum = 0;
1435                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1436                                 prognum++;
1437                         }
1438                         if (prognum < pi->num_progs)
1439                                 break;
1440                 }
1441
1442                 if(pi==NULL) {
1443                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1444                         continue;
1445                 }
1446
1447                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1448                         /* child exited */
1449                         pi->running_progs--;
1450                         pi->progs[prognum].pid = 0;
1451
1452                         if (!pi->running_progs) {
1453                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1454                                 remove_bg_job(pi);
1455                         }
1456                 } else {
1457                         /* child stopped */
1458                         pi->stopped_progs++;
1459                         pi->progs[prognum].is_stopped = 1;
1460
1461 #if 0
1462                         /* Printing this stuff is a pain, since it tends to
1463                          * overwrite the prompt an inconveinient moments.  So
1464                          * don't do that.  */
1465                         if (pi->stopped_progs == pi->num_progs) {
1466                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1467                         }
1468 #endif
1469                 }
1470         }
1471
1472         if (childpid == -1 && errno != ECHILD)
1473                 perror_msg("waitpid");
1474
1475         /* move the shell to the foreground */
1476         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1477         /*      perror_msg("tcsetpgrp-2"); */
1478         return -1;
1479 }
1480
1481 /* Figure out our controlling tty, checking in order stderr,
1482  * stdin, and stdout.  If check_pgrp is set, also check that
1483  * we belong to the foreground process group associated with
1484  * that tty.  The value of shell_terminal is needed in order to call
1485  * tcsetpgrp(shell_terminal, ...); */
1486 void controlling_tty(int check_pgrp)
1487 {
1488         pid_t curpgrp;
1489
1490         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1491                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1492                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1493                 goto shell_terminal_error;
1494
1495         if (check_pgrp && curpgrp != getpgid(0))
1496                 goto shell_terminal_error;
1497
1498         return;
1499
1500 shell_terminal_error:
1501                 shell_terminal = -1;
1502                 return;
1503 }
1504 #endif
1505
1506 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1507  * to finish.  See checkjobs().
1508  *
1509  * return code is normally -1, when the caller has to wait for children
1510  * to finish to determine the exit status of the pipe.  If the pipe
1511  * is a simple builtin command, however, the action is done by the
1512  * time run_pipe_real returns, and the exit code is provided as the
1513  * return value.
1514  *
1515  * The input of the pipe is always stdin, the output is always
1516  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1517  * because it tries to avoid running the command substitution in
1518  * subshell, when that is in fact necessary.  The subshell process
1519  * now has its stdout directed to the input of the appropriate pipe,
1520  * so this routine is noticeably simpler.
1521  */
1522 static int run_pipe_real(struct pipe *pi)
1523 {
1524         int i;
1525 #ifndef __U_BOOT__
1526         int nextin, nextout;
1527         int pipefds[2];                         /* pipefds[0] is for reading */
1528         struct child_prog *child;
1529         struct built_in_command *x;
1530         char *p;
1531 # if __GNUC__
1532         /* Avoid longjmp clobbering */
1533         (void) &i;
1534         (void) &nextin;
1535         (void) &nextout;
1536         (void) &child;
1537 # endif
1538 #else
1539         int nextin;
1540         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1541         struct child_prog *child;
1542         cmd_tbl_t *cmdtp;
1543         char *p;
1544 # if __GNUC__
1545         /* Avoid longjmp clobbering */
1546         (void) &i;
1547         (void) &nextin;
1548         (void) &child;
1549 # endif
1550 #endif  /* __U_BOOT__ */
1551
1552         nextin = 0;
1553 #ifndef __U_BOOT__
1554         pi->pgrp = -1;
1555 #endif
1556
1557         /* Check if this is a simple builtin (not part of a pipe).
1558          * Builtins within pipes have to fork anyway, and are handled in
1559          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1560          */
1561         if (pi->num_progs == 1) child = & (pi->progs[0]);
1562 #ifndef __U_BOOT__
1563         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1564                 int squirrel[] = {-1, -1, -1};
1565                 int rcode;
1566                 debug_printf("non-subshell grouping\n");
1567                 setup_redirects(child, squirrel);
1568                 /* XXX could we merge code with following builtin case,
1569                  * by creating a pseudo builtin that calls run_list_real? */
1570                 rcode = run_list_real(child->group);
1571                 restore_redirects(squirrel);
1572 #else
1573                 if (pi->num_progs == 1 && child->group) {
1574                 int rcode;
1575                 debug_printf("non-subshell grouping\n");
1576                 rcode = run_list_real(child->group);
1577 #endif
1578                 return rcode;
1579         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1580                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1581                 if (i!=0 && child->argv[i]==NULL) {
1582                         /* assignments, but no command: set the local environment */
1583                         for (i=0; child->argv[i]!=NULL; i++) {
1584
1585                                 /* Ok, this case is tricky.  We have to decide if this is a
1586                                  * local variable, or an already exported variable.  If it is
1587                                  * already exported, we have to export the new value.  If it is
1588                                  * not exported, we need only set this as a local variable.
1589                                  * This junk is all to decide whether or not to export this
1590                                  * variable. */
1591                                 int export_me=0;
1592                                 char *name, *value;
1593                                 name = xstrdup(child->argv[i]);
1594                                 debug_printf("Local environment set: %s\n", name);
1595                                 value = strchr(name, '=');
1596                                 if (value)
1597                                         *value=0;
1598 #ifndef __U_BOOT__
1599                                 if ( get_local_var(name)) {
1600                                         export_me=1;
1601                                 }
1602 #endif
1603                                 free(name);
1604                                 p = insert_var_value(child->argv[i]);
1605                                 set_local_var(p, export_me);
1606                                 if (p != child->argv[i]) free(p);
1607                         }
1608                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1609                 }
1610                 for (i = 0; is_assignment(child->argv[i]); i++) {
1611                         p = insert_var_value(child->argv[i]);
1612 #ifndef __U_BOOT__
1613                         putenv(strdup(p));
1614 #else
1615                         set_local_var(p, 0);
1616 #endif
1617                         if (p != child->argv[i]) {
1618                                 child->sp--;
1619                                 free(p);
1620                         }
1621                 }
1622                 if (child->sp) {
1623                         char * str = NULL;
1624
1625                         str = make_string((child->argv + i));
1626                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1627                         free(str);
1628                         return last_return_code;
1629                 }
1630 #ifndef __U_BOOT__
1631                 for (x = bltins; x->cmd; x++) {
1632                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1633                                 int squirrel[] = {-1, -1, -1};
1634                                 int rcode;
1635                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1636                                         debug_printf("magic exec\n");
1637                                         setup_redirects(child,NULL);
1638                                         return EXIT_SUCCESS;
1639                                 }
1640                                 debug_printf("builtin inline %s\n", child->argv[0]);
1641                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1642                                  * This is perfect for work that comes after exec().
1643                                  * Is it really safe for inline use?  Experimentally,
1644                                  * things seem to work with glibc. */
1645                                 setup_redirects(child, squirrel);
1646 #else
1647                         /* check ";", because ,example , argv consist from
1648                          * "help;flinfo" must not execute
1649                          */
1650                         if (strchr(child->argv[i], ';')) {
1651                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1652                                         child->argv[i]);
1653                                 return -1;
1654                         }
1655                         /* Look up command in command table */
1656
1657
1658                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1659                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1660                                 return -1;      /* give up after bad command */
1661                         } else {
1662                                 int rcode;
1663 #if defined(CONFIG_CMD_BOOTD)
1664                                 /* avoid "bootd" recursion */
1665                                 if (cmdtp->cmd == do_bootd) {
1666                                         if (flag & CMD_FLAG_BOOTD) {
1667                                                 printf ("'bootd' recursion detected\n");
1668                                                 return -1;
1669                                         }
1670                                 else
1671                                         flag |= CMD_FLAG_BOOTD;
1672                                 }
1673 #endif
1674                                 /* found - check max args */
1675                                 if ((child->argc - i) > cmdtp->maxargs)
1676                                         return cmd_usage(cmdtp);
1677 #endif
1678                                 child->argv+=i;  /* XXX horrible hack */
1679 #ifndef __U_BOOT__
1680                                 rcode = x->function(child);
1681 #else
1682                                 /* OK - call function to do the command */
1683
1684                                 rcode = (cmdtp->cmd)
1685 (cmdtp, flag,child->argc-i,&child->argv[i]);
1686                                 if ( !cmdtp->repeatable )
1687                                         flag_repeat = 0;
1688
1689
1690 #endif
1691                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1692 #ifndef __U_BOOT__
1693
1694                                 restore_redirects(squirrel);
1695 #endif
1696
1697                                 return rcode;
1698                         }
1699                 }
1700 #ifndef __U_BOOT__
1701         }
1702
1703         for (i = 0; i < pi->num_progs; i++) {
1704                 child = & (pi->progs[i]);
1705
1706                 /* pipes are inserted between pairs of commands */
1707                 if ((i + 1) < pi->num_progs) {
1708                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1709                         nextout = pipefds[1];
1710                 } else {
1711                         nextout=1;
1712                         pipefds[0] = -1;
1713                 }
1714
1715                 /* XXX test for failed fork()? */
1716                 if (!(child->pid = fork())) {
1717                         /* Set the handling for job control signals back to the default.  */
1718                         signal(SIGINT, SIG_DFL);
1719                         signal(SIGQUIT, SIG_DFL);
1720                         signal(SIGTERM, SIG_DFL);
1721                         signal(SIGTSTP, SIG_DFL);
1722                         signal(SIGTTIN, SIG_DFL);
1723                         signal(SIGTTOU, SIG_DFL);
1724                         signal(SIGCHLD, SIG_DFL);
1725
1726                         close_all();
1727
1728                         if (nextin != 0) {
1729                                 dup2(nextin, 0);
1730                                 close(nextin);
1731                         }
1732                         if (nextout != 1) {
1733                                 dup2(nextout, 1);
1734                                 close(nextout);
1735                         }
1736                         if (pipefds[0]!=-1) {
1737                                 close(pipefds[0]);  /* opposite end of our output pipe */
1738                         }
1739
1740                         /* Like bash, explicit redirects override pipes,
1741                          * and the pipe fd is available for dup'ing. */
1742                         setup_redirects(child,NULL);
1743
1744                         if (interactive && pi->followup!=PIPE_BG) {
1745                                 /* If we (the child) win the race, put ourselves in the process
1746                                  * group whose leader is the first process in this pipe. */
1747                                 if (pi->pgrp < 0) {
1748                                         pi->pgrp = getpid();
1749                                 }
1750                                 if (setpgid(0, pi->pgrp) == 0) {
1751                                         tcsetpgrp(2, pi->pgrp);
1752                                 }
1753                         }
1754
1755                         pseudo_exec(child);
1756                 }
1757
1758
1759                 /* put our child in the process group whose leader is the
1760                    first process in this pipe */
1761                 if (pi->pgrp < 0) {
1762                         pi->pgrp = child->pid;
1763                 }
1764                 /* Don't check for errors.  The child may be dead already,
1765                  * in which case setpgid returns error code EACCES. */
1766                 setpgid(child->pid, pi->pgrp);
1767
1768                 if (nextin != 0)
1769                         close(nextin);
1770                 if (nextout != 1)
1771                         close(nextout);
1772
1773                 /* If there isn't another process, nextin is garbage
1774                    but it doesn't matter */
1775                 nextin = pipefds[0];
1776         }
1777 #endif
1778         return -1;
1779 }
1780
1781 static int run_list_real(struct pipe *pi)
1782 {
1783         char *save_name = NULL;
1784         char **list = NULL;
1785         char **save_list = NULL;
1786         struct pipe *rpipe;
1787         int flag_rep = 0;
1788 #ifndef __U_BOOT__
1789         int save_num_progs;
1790 #endif
1791         int rcode=0, flag_skip=1;
1792         int flag_restore = 0;
1793         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1794         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1795         /* check syntax for "for" */
1796         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1797                 if ((rpipe->r_mode == RES_IN ||
1798                     rpipe->r_mode == RES_FOR) &&
1799                     (rpipe->next == NULL)) {
1800                                 syntax();
1801 #ifdef __U_BOOT__
1802                                 flag_repeat = 0;
1803 #endif
1804                                 return 1;
1805                 }
1806                 if ((rpipe->r_mode == RES_IN &&
1807                         (rpipe->next->r_mode == RES_IN &&
1808                         rpipe->next->progs->argv != NULL))||
1809                         (rpipe->r_mode == RES_FOR &&
1810                         rpipe->next->r_mode != RES_IN)) {
1811                                 syntax();
1812 #ifdef __U_BOOT__
1813                                 flag_repeat = 0;
1814 #endif
1815                                 return 1;
1816                 }
1817         }
1818         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1819                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1820                         pi->r_mode == RES_FOR) {
1821 #ifdef __U_BOOT__
1822                                 /* check Ctrl-C */
1823                                 ctrlc();
1824                                 if ((had_ctrlc())) {
1825                                         return 1;
1826                                 }
1827 #endif
1828                                 flag_restore = 0;
1829                                 if (!rpipe) {
1830                                         flag_rep = 0;
1831                                         rpipe = pi;
1832                                 }
1833                 }
1834                 rmode = pi->r_mode;
1835                 debug_printf("rmode=%d  if_code=%d  next_if_code=%d skip_more=%d\n", rmode, if_code, next_if_code, skip_more_in_this_rmode);
1836                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1837                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1838                         continue;
1839                 }
1840                 flag_skip = 1;
1841                 skip_more_in_this_rmode = RES_XXXX;
1842                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1843                 if (rmode == RES_THEN &&  if_code) continue;
1844                 if (rmode == RES_ELSE && !if_code) continue;
1845                 if (rmode == RES_ELIF && !if_code) break;
1846                 if (rmode == RES_FOR && pi->num_progs) {
1847                         if (!list) {
1848                                 /* if no variable values after "in" we skip "for" */
1849                                 if (!pi->next->progs->argv) continue;
1850                                 /* create list of variable values */
1851                                 list = make_list_in(pi->next->progs->argv,
1852                                         pi->progs->argv[0]);
1853                                 save_list = list;
1854                                 save_name = pi->progs->argv[0];
1855                                 pi->progs->argv[0] = NULL;
1856                                 flag_rep = 1;
1857                         }
1858                         if (!(*list)) {
1859                                 free(pi->progs->argv[0]);
1860                                 free(save_list);
1861                                 list = NULL;
1862                                 flag_rep = 0;
1863                                 pi->progs->argv[0] = save_name;
1864 #ifndef __U_BOOT__
1865                                 pi->progs->glob_result.gl_pathv[0] =
1866                                         pi->progs->argv[0];
1867 #endif
1868                                 continue;
1869                         } else {
1870                                 /* insert new value from list for variable */
1871                                 if (pi->progs->argv[0])
1872                                         free(pi->progs->argv[0]);
1873                                 pi->progs->argv[0] = *list++;
1874 #ifndef __U_BOOT__
1875                                 pi->progs->glob_result.gl_pathv[0] =
1876                                         pi->progs->argv[0];
1877 #endif
1878                         }
1879                 }
1880                 if (rmode == RES_IN) continue;
1881                 if (rmode == RES_DO) {
1882                         if (!flag_rep) continue;
1883                 }
1884                 if ((rmode == RES_DONE)) {
1885                         if (flag_rep) {
1886                                 flag_restore = 1;
1887                         } else {
1888                                 rpipe = NULL;
1889                         }
1890                 }
1891                 if (pi->num_progs == 0) continue;
1892 #ifndef __U_BOOT__
1893                 save_num_progs = pi->num_progs; /* save number of programs */
1894 #endif
1895                 rcode = run_pipe_real(pi);
1896                 debug_printf("run_pipe_real returned %d\n",rcode);
1897 #ifndef __U_BOOT__
1898                 if (rcode!=-1) {
1899                         /* We only ran a builtin: rcode was set by the return value
1900                          * of run_pipe_real(), and we don't need to wait for anything. */
1901                 } else if (pi->followup==PIPE_BG) {
1902                         /* XXX check bash's behavior with nontrivial pipes */
1903                         /* XXX compute jobid */
1904                         /* XXX what does bash do with attempts to background builtins? */
1905                         insert_bg_job(pi);
1906                         rcode = EXIT_SUCCESS;
1907                 } else {
1908                         if (interactive) {
1909                                 /* move the new process group into the foreground */
1910                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1911                                         perror_msg("tcsetpgrp-3");
1912                                 rcode = checkjobs(pi);
1913                                 /* move the shell to the foreground */
1914                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1915                                         perror_msg("tcsetpgrp-4");
1916                         } else {
1917                                 rcode = checkjobs(pi);
1918                         }
1919                         debug_printf("checkjobs returned %d\n",rcode);
1920                 }
1921                 last_return_code=rcode;
1922 #else
1923                 if (rcode < -1) {
1924                         last_return_code = -rcode - 2;
1925                         return -2;      /* exit */
1926                 }
1927                 last_return_code=(rcode == 0) ? 0 : 1;
1928 #endif
1929 #ifndef __U_BOOT__
1930                 pi->num_progs = save_num_progs; /* restore number of programs */
1931 #endif
1932                 if ( rmode == RES_IF || rmode == RES_ELIF )
1933                         next_if_code=rcode;  /* can be overwritten a number of times */
1934                 if (rmode == RES_WHILE)
1935                         flag_rep = !last_return_code;
1936                 if (rmode == RES_UNTIL)
1937                         flag_rep = last_return_code;
1938                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1939                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1940                         skip_more_in_this_rmode=rmode;
1941 #ifndef __U_BOOT__
1942                 checkjobs(NULL);
1943 #endif
1944         }
1945         return rcode;
1946 }
1947
1948 /* broken, of course, but OK for testing */
1949 static char *indenter(int i)
1950 {
1951         static char blanks[]="                                    ";
1952         return &blanks[sizeof(blanks)-i-1];
1953 }
1954
1955 /* return code is the exit status of the pipe */
1956 static int free_pipe(struct pipe *pi, int indent)
1957 {
1958         char **p;
1959         struct child_prog *child;
1960 #ifndef __U_BOOT__
1961         struct redir_struct *r, *rnext;
1962 #endif
1963         int a, i, ret_code=0;
1964         char *ind = indenter(indent);
1965
1966 #ifndef __U_BOOT__
1967         if (pi->stopped_progs > 0)
1968                 return ret_code;
1969         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1970 #endif
1971         for (i=0; i<pi->num_progs; i++) {
1972                 child = &pi->progs[i];
1973                 final_printf("%s  command %d:\n",ind,i);
1974                 if (child->argv) {
1975                         for (a=0,p=child->argv; *p; a++,p++) {
1976                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1977                         }
1978 #ifndef __U_BOOT__
1979                         globfree(&child->glob_result);
1980 #else
1981                         for (a = 0; a < child->argc; a++) {
1982                                 free(child->argv[a]);
1983                         }
1984                                         free(child->argv);
1985                         child->argc = 0;
1986 #endif
1987                         child->argv=NULL;
1988                 } else if (child->group) {
1989 #ifndef __U_BOOT__
1990                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1991 #endif
1992                         ret_code = free_pipe_list(child->group,indent+3);
1993                         final_printf("%s   end group\n",ind);
1994                 } else {
1995                         final_printf("%s   (nil)\n",ind);
1996                 }
1997 #ifndef __U_BOOT__
1998                 for (r=child->redirects; r; r=rnext) {
1999                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2000                         if (r->dup == -1) {
2001                                 /* guard against the case >$FOO, where foo is unset or blank */
2002                                 if (r->word.gl_pathv) {
2003                                         final_printf(" %s\n", *r->word.gl_pathv);
2004                                         globfree(&r->word);
2005                                 }
2006                         } else {
2007                                 final_printf("&%d\n", r->dup);
2008                         }
2009                         rnext=r->next;
2010                         free(r);
2011                 }
2012                 child->redirects=NULL;
2013 #endif
2014         }
2015         free(pi->progs);   /* children are an array, they get freed all at once */
2016         pi->progs=NULL;
2017         return ret_code;
2018 }
2019
2020 static int free_pipe_list(struct pipe *head, int indent)
2021 {
2022         int rcode=0;   /* if list has no members */
2023         struct pipe *pi, *next;
2024         char *ind = indenter(indent);
2025         for (pi=head; pi; pi=next) {
2026                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2027                 rcode = free_pipe(pi, indent);
2028                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2029                 next=pi->next;
2030                 pi->next=NULL;
2031                 free(pi);
2032         }
2033         return rcode;
2034 }
2035
2036 /* Select which version we will use */
2037 static int run_list(struct pipe *pi)
2038 {
2039         int rcode=0;
2040 #ifndef __U_BOOT__
2041         if (fake_mode==0) {
2042 #endif
2043                 rcode = run_list_real(pi);
2044 #ifndef __U_BOOT__
2045         }
2046 #endif
2047         /* free_pipe_list has the side effect of clearing memory
2048          * In the long run that function can be merged with run_list_real,
2049          * but doing that now would hobble the debugging effort. */
2050         free_pipe_list(pi,0);
2051         return rcode;
2052 }
2053
2054 /* The API for glob is arguably broken.  This routine pushes a non-matching
2055  * string into the output structure, removing non-backslashed backslashes.
2056  * If someone can prove me wrong, by performing this function within the
2057  * original glob(3) api, feel free to rewrite this routine into oblivion.
2058  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2059  * XXX broken if the last character is '\\', check that before calling.
2060  */
2061 #ifndef __U_BOOT__
2062 static int globhack(const char *src, int flags, glob_t *pglob)
2063 {
2064         int cnt=0, pathc;
2065         const char *s;
2066         char *dest;
2067         for (cnt=1, s=src; s && *s; s++) {
2068                 if (*s == '\\') s++;
2069                 cnt++;
2070         }
2071         dest = malloc(cnt);
2072         if (!dest) return GLOB_NOSPACE;
2073         if (!(flags & GLOB_APPEND)) {
2074                 pglob->gl_pathv=NULL;
2075                 pglob->gl_pathc=0;
2076                 pglob->gl_offs=0;
2077                 pglob->gl_offs=0;
2078         }
2079         pathc = ++pglob->gl_pathc;
2080         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2081         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2082         pglob->gl_pathv[pathc-1]=dest;
2083         pglob->gl_pathv[pathc]=NULL;
2084         for (s=src; s && *s; s++, dest++) {
2085                 if (*s == '\\') s++;
2086                 *dest = *s;
2087         }
2088         *dest='\0';
2089         return 0;
2090 }
2091
2092 /* XXX broken if the last character is '\\', check that before calling */
2093 static int glob_needed(const char *s)
2094 {
2095         for (; *s; s++) {
2096                 if (*s == '\\') s++;
2097                 if (strchr("*[?",*s)) return 1;
2098         }
2099         return 0;
2100 }
2101
2102 #if 0
2103 static void globprint(glob_t *pglob)
2104 {
2105         int i;
2106         debug_printf("glob_t at %p:\n", pglob);
2107         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2108                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2109         for (i=0; i<pglob->gl_pathc; i++)
2110                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2111                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2112 }
2113 #endif
2114
2115 static int xglob(o_string *dest, int flags, glob_t *pglob)
2116 {
2117         int gr;
2118
2119         /* short-circuit for null word */
2120         /* we can code this better when the debug_printf's are gone */
2121         if (dest->length == 0) {
2122                 if (dest->nonnull) {
2123                         /* bash man page calls this an "explicit" null */
2124                         gr = globhack(dest->data, flags, pglob);
2125                         debug_printf("globhack returned %d\n",gr);
2126                 } else {
2127                         return 0;
2128                 }
2129         } else if (glob_needed(dest->data)) {
2130                 gr = glob(dest->data, flags, NULL, pglob);
2131                 debug_printf("glob returned %d\n",gr);
2132                 if (gr == GLOB_NOMATCH) {
2133                         /* quote removal, or more accurately, backslash removal */
2134                         gr = globhack(dest->data, flags, pglob);
2135                         debug_printf("globhack returned %d\n",gr);
2136                 }
2137         } else {
2138                 gr = globhack(dest->data, flags, pglob);
2139                 debug_printf("globhack returned %d\n",gr);
2140         }
2141         if (gr == GLOB_NOSPACE)
2142                 error_msg_and_die("out of memory during glob");
2143         if (gr != 0) { /* GLOB_ABORTED ? */
2144                 error_msg("glob(3) error %d",gr);
2145         }
2146         /* globprint(glob_target); */
2147         return gr;
2148 }
2149 #endif
2150
2151 #ifdef __U_BOOT__
2152 static char *get_dollar_var(char ch);
2153 #endif
2154
2155 /* This is used to get/check local shell variables */
2156 char *get_local_var(const char *s)
2157 {
2158         struct variables *cur;
2159
2160         if (!s)
2161                 return NULL;
2162
2163 #ifdef __U_BOOT__
2164         if (*s == '$')
2165                 return get_dollar_var(s[1]);
2166 #endif
2167
2168         for (cur = top_vars; cur; cur=cur->next)
2169                 if(strcmp(cur->name, s)==0)
2170                         return cur->value;
2171         return NULL;
2172 }
2173
2174 /* This is used to set local shell variables
2175    flg_export==0 if only local (not exporting) variable
2176    flg_export==1 if "new" exporting environ
2177    flg_export>1  if current startup environ (not call putenv()) */
2178 int set_local_var(const char *s, int flg_export)
2179 {
2180         char *name, *value;
2181         int result=0;
2182         struct variables *cur;
2183
2184 #ifdef __U_BOOT__
2185         /* might be possible! */
2186         if (!isalpha(*s))
2187                 return -1;
2188 #endif
2189
2190         name=strdup(s);
2191
2192 #ifdef __U_BOOT__
2193         if (getenv(name) != NULL) {
2194                 printf ("ERROR: "
2195                                 "There is a global environment variable with the same name.\n");
2196                 free(name);
2197                 return -1;
2198         }
2199 #endif
2200         /* Assume when we enter this function that we are already in
2201          * NAME=VALUE format.  So the first order of business is to
2202          * split 's' on the '=' into 'name' and 'value' */
2203         value = strchr(name, '=');
2204         if (value==0 && ++value==0) {
2205                 free(name);
2206                 return -1;
2207         }
2208         *value++ = 0;
2209
2210         for(cur = top_vars; cur; cur = cur->next) {
2211                 if(strcmp(cur->name, name)==0)
2212                         break;
2213         }
2214
2215         if(cur) {
2216                 if(strcmp(cur->value, value)==0) {
2217                         if(flg_export>0 && cur->flg_export==0)
2218                                 cur->flg_export=flg_export;
2219                         else
2220                                 result++;
2221                 } else {
2222                         if(cur->flg_read_only) {
2223                                 error_msg("%s: readonly variable", name);
2224                                 result = -1;
2225                         } else {
2226                                 if(flg_export>0 || cur->flg_export>1)
2227                                         cur->flg_export=1;
2228                                 free(cur->value);
2229
2230                                 cur->value = strdup(value);
2231                         }
2232                 }
2233         } else {
2234                 cur = malloc(sizeof(struct variables));
2235                 if(!cur) {
2236                         result = -1;
2237                 } else {
2238                         cur->name = strdup(name);
2239                         if(cur->name == 0) {
2240                                 free(cur);
2241                                 result = -1;
2242                         } else {
2243                                 struct variables *bottom = top_vars;
2244                                 cur->value = strdup(value);
2245                                 cur->next = 0;
2246                                 cur->flg_export = flg_export;
2247                                 cur->flg_read_only = 0;
2248                                 while(bottom->next) bottom=bottom->next;
2249                                 bottom->next = cur;
2250                         }
2251                 }
2252         }
2253
2254 #ifndef __U_BOOT__
2255         if(result==0 && cur->flg_export==1) {
2256                 *(value-1) = '=';
2257                 result = putenv(name);
2258         } else {
2259 #endif
2260                 free(name);
2261 #ifndef __U_BOOT__
2262                 if(result>0)            /* equivalent to previous set */
2263                         result = 0;
2264         }
2265 #endif
2266         return result;
2267 }
2268
2269 void unset_local_var(const char *name)
2270 {
2271         struct variables *cur;
2272
2273         if (name) {
2274                 for (cur = top_vars; cur; cur=cur->next) {
2275                         if(strcmp(cur->name, name)==0)
2276                                 break;
2277                 }
2278                 if(cur!=0) {
2279                         struct variables *next = top_vars;
2280                         if(cur->flg_read_only) {
2281                                 error_msg("%s: readonly variable", name);
2282                                 return;
2283                         } else {
2284 #ifndef __U_BOOT__
2285                                 if(cur->flg_export)
2286                                         unsetenv(cur->name);
2287 #endif
2288                                 free(cur->name);
2289                                 free(cur->value);
2290                                 while (next->next != cur)
2291                                         next = next->next;
2292                                 next->next = cur->next;
2293                         }
2294                         free(cur);
2295                 }
2296         }
2297 }
2298
2299 static int is_assignment(const char *s)
2300 {
2301         if (s == NULL)
2302                 return 0;
2303
2304         if (!isalpha(*s)) return 0;
2305         ++s;
2306         while(isalnum(*s) || *s=='_') ++s;
2307         return *s=='=';
2308 }
2309
2310 #ifndef __U_BOOT__
2311 /* the src parameter allows us to peek forward to a possible &n syntax
2312  * for file descriptor duplication, e.g., "2>&1".
2313  * Return code is 0 normally, 1 if a syntax error is detected in src.
2314  * Resource errors (in xmalloc) cause the process to exit */
2315 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2316         struct in_str *input)
2317 {
2318         struct child_prog *child=ctx->child;
2319         struct redir_struct *redir = child->redirects;
2320         struct redir_struct *last_redir=NULL;
2321
2322         /* Create a new redir_struct and drop it onto the end of the linked list */
2323         while(redir) {
2324                 last_redir=redir;
2325                 redir=redir->next;
2326         }
2327         redir = xmalloc(sizeof(struct redir_struct));
2328         redir->next=NULL;
2329         redir->word.gl_pathv=NULL;
2330         if (last_redir) {
2331                 last_redir->next=redir;
2332         } else {
2333                 child->redirects=redir;
2334         }
2335
2336         redir->type=style;
2337         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2338
2339         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2340
2341         /* Check for a '2>&1' type redirect */
2342         redir->dup = redirect_dup_num(input);
2343         if (redir->dup == -2) return 1;  /* syntax error */
2344         if (redir->dup != -1) {
2345                 /* Erik had a check here that the file descriptor in question
2346                  * is legit; I postpone that to "run time"
2347                  * A "-" representation of "close me" shows up as a -3 here */
2348                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2349         } else {
2350                 /* We do _not_ try to open the file that src points to,
2351                  * since we need to return and let src be expanded first.
2352                  * Set ctx->pending_redirect, so we know what to do at the
2353                  * end of the next parsed word.
2354                  */
2355                 ctx->pending_redirect = redir;
2356         }
2357         return 0;
2358 }
2359 #endif
2360
2361 struct pipe *new_pipe(void) {
2362         struct pipe *pi;
2363         pi = xmalloc(sizeof(struct pipe));
2364         pi->num_progs = 0;
2365         pi->progs = NULL;
2366         pi->next = NULL;
2367         pi->followup = 0;  /* invalid */
2368         pi->r_mode = RES_NONE;
2369         return pi;
2370 }
2371
2372 static void initialize_context(struct p_context *ctx)
2373 {
2374         ctx->pipe=NULL;
2375 #ifndef __U_BOOT__
2376         ctx->pending_redirect=NULL;
2377 #endif
2378         ctx->child=NULL;
2379         ctx->list_head=new_pipe();
2380         ctx->pipe=ctx->list_head;
2381         ctx->w=RES_NONE;
2382         ctx->stack=NULL;
2383 #ifdef __U_BOOT__
2384         ctx->old_flag=0;
2385 #endif
2386         done_command(ctx);   /* creates the memory for working child */
2387 }
2388
2389 /* normal return is 0
2390  * if a reserved word is found, and processed, return 1
2391  * should handle if, then, elif, else, fi, for, while, until, do, done.
2392  * case, function, and select are obnoxious, save those for later.
2393  */
2394 struct reserved_combo {
2395         char *literal;
2396         int code;
2397         long flag;
2398 };
2399 /* Mostly a list of accepted follow-up reserved words.
2400  * FLAG_END means we are done with the sequence, and are ready
2401  * to turn the compound list into a command.
2402  * FLAG_START means the word must start a new compound list.
2403  */
2404 static struct reserved_combo reserved_list[] = {
2405         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2406         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2407         { "elif",  RES_ELIF,  FLAG_THEN },
2408         { "else",  RES_ELSE,  FLAG_FI   },
2409         { "fi",    RES_FI,    FLAG_END  },
2410         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2411         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2412         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2413         { "in",    RES_IN,    FLAG_DO   },
2414         { "do",    RES_DO,    FLAG_DONE },
2415         { "done",  RES_DONE,  FLAG_END  }
2416 };
2417 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2418
2419 int reserved_word(o_string *dest, struct p_context *ctx)
2420 {
2421         struct reserved_combo *r;
2422         for (r=reserved_list;
2423                 r<reserved_list+NRES; r++) {
2424                 if (strcmp(dest->data, r->literal) == 0) {
2425                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2426                         if (r->flag & FLAG_START) {
2427                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2428                                 debug_printf("push stack\n");
2429                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2430                                         syntax();
2431                                         free(new);
2432                                         ctx->w = RES_SNTX;
2433                                         b_reset(dest);
2434                                         return 1;
2435                                 }
2436                                 *new = *ctx;   /* physical copy */
2437                                 initialize_context(ctx);
2438                                 ctx->stack=new;
2439                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2440                                 syntax();
2441                                 ctx->w = RES_SNTX;
2442                                 b_reset(dest);
2443                                 return 1;
2444                         }
2445                         ctx->w=r->code;
2446                         ctx->old_flag = r->flag;
2447                         if (ctx->old_flag & FLAG_END) {
2448                                 struct p_context *old;
2449                                 debug_printf("pop stack\n");
2450                                 done_pipe(ctx,PIPE_SEQ);
2451                                 old = ctx->stack;
2452                                 old->child->group = ctx->list_head;
2453 #ifndef __U_BOOT__
2454                                 old->child->subshell = 0;
2455 #endif
2456                                 *ctx = *old;   /* physical copy */
2457                                 free(old);
2458                         }
2459                         b_reset (dest);
2460                         return 1;
2461                 }
2462         }
2463         return 0;
2464 }
2465
2466 /* normal return is 0.
2467  * Syntax or xglob errors return 1. */
2468 static int done_word(o_string *dest, struct p_context *ctx)
2469 {
2470         struct child_prog *child=ctx->child;
2471 #ifndef __U_BOOT__
2472         glob_t *glob_target;
2473         int gr, flags = 0;
2474 #else
2475         char *str, *s;
2476         int argc, cnt;
2477 #endif
2478
2479         debug_printf("done_word: %s %p\n", dest->data, child);
2480         if (dest->length == 0 && !dest->nonnull) {
2481                 debug_printf("  true null, ignored\n");
2482                 return 0;
2483         }
2484 #ifndef __U_BOOT__
2485         if (ctx->pending_redirect) {
2486                 glob_target = &ctx->pending_redirect->word;
2487         } else {
2488 #endif
2489                 if (child->group) {
2490                         syntax();
2491                         return 1;  /* syntax error, groups and arglists don't mix */
2492                 }
2493                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2494                         debug_printf("checking %s for reserved-ness\n",dest->data);
2495                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2496                 }
2497 #ifndef __U_BOOT__
2498                 glob_target = &child->glob_result;
2499                 if (child->argv) flags |= GLOB_APPEND;
2500 #else
2501                 for (cnt = 1, s = dest->data; s && *s; s++) {
2502                         if (*s == '\\') s++;
2503                         cnt++;
2504                 }
2505                 str = malloc(cnt);
2506                 if (!str) return 1;
2507                 if ( child->argv == NULL) {
2508                         child->argc=0;
2509                 }
2510                 argc = ++child->argc;
2511                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2512                 if (child->argv == NULL) return 1;
2513                 child->argv[argc-1]=str;
2514                 child->argv[argc]=NULL;
2515                 for (s = dest->data; s && *s; s++,str++) {
2516                         if (*s == '\\') s++;
2517                         *str = *s;
2518                 }
2519                 *str = '\0';
2520 #endif
2521 #ifndef __U_BOOT__
2522         }
2523         gr = xglob(dest, flags, glob_target);
2524         if (gr != 0) return 1;
2525 #endif
2526
2527         b_reset(dest);
2528 #ifndef __U_BOOT__
2529         if (ctx->pending_redirect) {
2530                 ctx->pending_redirect=NULL;
2531                 if (glob_target->gl_pathc != 1) {
2532                         error_msg("ambiguous redirect");
2533                         return 1;
2534                 }
2535         } else {
2536                 child->argv = glob_target->gl_pathv;
2537         }
2538 #endif
2539         if (ctx->w == RES_FOR) {
2540                 done_word(dest,ctx);
2541                 done_pipe(ctx,PIPE_SEQ);
2542         }
2543         return 0;
2544 }
2545
2546 /* The only possible error here is out of memory, in which case
2547  * xmalloc exits. */
2548 static int done_command(struct p_context *ctx)
2549 {
2550         /* The child is really already in the pipe structure, so
2551          * advance the pipe counter and make a new, null child.
2552          * Only real trickiness here is that the uncommitted
2553          * child structure, to which ctx->child points, is not
2554          * counted in pi->num_progs. */
2555         struct pipe *pi=ctx->pipe;
2556         struct child_prog *prog=ctx->child;
2557
2558         if (prog && prog->group == NULL
2559                  && prog->argv == NULL
2560 #ifndef __U_BOOT__
2561                  && prog->redirects == NULL) {
2562 #else
2563                                                                                 ) {
2564 #endif
2565                 debug_printf("done_command: skipping null command\n");
2566                 return 0;
2567         } else if (prog) {
2568                 pi->num_progs++;
2569                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2570         } else {
2571                 debug_printf("done_command: initializing\n");
2572         }
2573         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2574
2575         prog = pi->progs + pi->num_progs;
2576 #ifndef __U_BOOT__
2577         prog->redirects = NULL;
2578 #endif
2579         prog->argv = NULL;
2580 #ifndef __U_BOOT__
2581         prog->is_stopped = 0;
2582 #endif
2583         prog->group = NULL;
2584 #ifndef __U_BOOT__
2585         prog->glob_result.gl_pathv = NULL;
2586         prog->family = pi;
2587 #endif
2588         prog->sp = 0;
2589         ctx->child = prog;
2590         prog->type = ctx->type;
2591
2592         /* but ctx->pipe and ctx->list_head remain unchanged */
2593         return 0;
2594 }
2595
2596 static int done_pipe(struct p_context *ctx, pipe_style type)
2597 {
2598         struct pipe *new_p;
2599         done_command(ctx);  /* implicit closure of previous command */
2600         debug_printf("done_pipe, type %d\n", type);
2601         ctx->pipe->followup = type;
2602         ctx->pipe->r_mode = ctx->w;
2603         new_p=new_pipe();
2604         ctx->pipe->next = new_p;
2605         ctx->pipe = new_p;
2606         ctx->child = NULL;
2607         done_command(ctx);  /* set up new pipe to accept commands */
2608         return 0;
2609 }
2610
2611 #ifndef __U_BOOT__
2612 /* peek ahead in the in_str to find out if we have a "&n" construct,
2613  * as in "2>&1", that represents duplicating a file descriptor.
2614  * returns either -2 (syntax error), -1 (no &), or the number found.
2615  */
2616 static int redirect_dup_num(struct in_str *input)
2617 {
2618         int ch, d=0, ok=0;
2619         ch = b_peek(input);
2620         if (ch != '&') return -1;
2621
2622         b_getch(input);  /* get the & */
2623         ch=b_peek(input);
2624         if (ch == '-') {
2625                 b_getch(input);
2626                 return -3;  /* "-" represents "close me" */
2627         }
2628         while (isdigit(ch)) {
2629                 d = d*10+(ch-'0');
2630                 ok=1;
2631                 b_getch(input);
2632                 ch = b_peek(input);
2633         }
2634         if (ok) return d;
2635
2636         error_msg("ambiguous redirect");
2637         return -2;
2638 }
2639
2640 /* If a redirect is immediately preceded by a number, that number is
2641  * supposed to tell which file descriptor to redirect.  This routine
2642  * looks for such preceding numbers.  In an ideal world this routine
2643  * needs to handle all the following classes of redirects...
2644  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2645  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2646  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2647  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2648  * A -1 output from this program means no valid number was found, so the
2649  * caller should use the appropriate default for this redirection.
2650  */
2651 static int redirect_opt_num(o_string *o)
2652 {
2653         int num;
2654
2655         if (o->length==0) return -1;
2656         for(num=0; num<o->length; num++) {
2657                 if (!isdigit(*(o->data+num))) {
2658                         return -1;
2659                 }
2660         }
2661         /* reuse num (and save an int) */
2662         num=atoi(o->data);
2663         b_reset(o);
2664         return num;
2665 }
2666
2667 FILE *generate_stream_from_list(struct pipe *head)
2668 {
2669         FILE *pf;
2670 #if 1
2671         int pid, channel[2];
2672         if (pipe(channel)<0) perror_msg_and_die("pipe");
2673         pid=fork();
2674         if (pid<0) {
2675                 perror_msg_and_die("fork");
2676         } else if (pid==0) {
2677                 close(channel[0]);
2678                 if (channel[1] != 1) {
2679                         dup2(channel[1],1);
2680                         close(channel[1]);
2681                 }
2682 #if 0
2683 #define SURROGATE "surrogate response"
2684                 write(1,SURROGATE,sizeof(SURROGATE));
2685                 _exit(run_list(head));
2686 #else
2687                 _exit(run_list_real(head));   /* leaks memory */
2688 #endif
2689         }
2690         debug_printf("forked child %d\n",pid);
2691         close(channel[1]);
2692         pf = fdopen(channel[0],"r");
2693         debug_printf("pipe on FILE *%p\n",pf);
2694 #else
2695         free_pipe_list(head,0);
2696         pf=popen("echo surrogate response","r");
2697         debug_printf("started fake pipe on FILE *%p\n",pf);
2698 #endif
2699         return pf;
2700 }
2701
2702 /* this version hacked for testing purposes */
2703 /* return code is exit status of the process that is run. */
2704 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2705 {
2706         int retcode;
2707         o_string result=NULL_O_STRING;
2708         struct p_context inner;
2709         FILE *p;
2710         struct in_str pipe_str;
2711         initialize_context(&inner);
2712
2713         /* recursion to generate command */
2714         retcode = parse_stream(&result, &inner, input, subst_end);
2715         if (retcode != 0) return retcode;  /* syntax error or EOF */
2716         done_word(&result, &inner);
2717         done_pipe(&inner, PIPE_SEQ);
2718         b_free(&result);
2719
2720         p=generate_stream_from_list(inner.list_head);
2721         if (p==NULL) return 1;
2722         mark_open(fileno(p));
2723         setup_file_in_str(&pipe_str, p);
2724
2725         /* now send results of command back into original context */
2726         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2727         /* XXX In case of a syntax error, should we try to kill the child?
2728          * That would be tough to do right, so just read until EOF. */
2729         if (retcode == 1) {
2730                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2731         }
2732
2733         debug_printf("done reading from pipe, pclose()ing\n");
2734         /* This is the step that wait()s for the child.  Should be pretty
2735          * safe, since we just read an EOF from its stdout.  We could try
2736          * to better, by using wait(), and keeping track of background jobs
2737          * at the same time.  That would be a lot of work, and contrary
2738          * to the KISS philosophy of this program. */
2739         mark_closed(fileno(p));
2740         retcode=pclose(p);
2741         free_pipe_list(inner.list_head,0);
2742         debug_printf("pclosed, retcode=%d\n",retcode);
2743         /* XXX this process fails to trim a single trailing newline */
2744         return retcode;
2745 }
2746
2747 static int parse_group(o_string *dest, struct p_context *ctx,
2748         struct in_str *input, int ch)
2749 {
2750         int rcode, endch=0;
2751         struct p_context sub;
2752         struct child_prog *child = ctx->child;
2753         if (child->argv) {
2754                 syntax();
2755                 return 1;  /* syntax error, groups and arglists don't mix */
2756         }
2757         initialize_context(&sub);
2758         switch(ch) {
2759                 case '(': endch=')'; child->subshell=1; break;
2760                 case '{': endch='}'; break;
2761                 default: syntax();   /* really logic error */
2762         }
2763         rcode=parse_stream(dest,&sub,input,endch);
2764         done_word(dest,&sub); /* finish off the final word in the subcontext */
2765         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2766         child->group = sub.list_head;
2767         return rcode;
2768         /* child remains "open", available for possible redirects */
2769 }
2770 #endif
2771
2772 /* basically useful version until someone wants to get fancier,
2773  * see the bash man page under "Parameter Expansion" */
2774 static char *lookup_param(char *src)
2775 {
2776         char *p;
2777
2778         if (!src)
2779                 return NULL;
2780
2781                 p = getenv(src);
2782                 if (!p)
2783                         p = get_local_var(src);
2784
2785         return p;
2786 }
2787
2788 #ifdef __U_BOOT__
2789 static char *get_dollar_var(char ch)
2790 {
2791         static char buf[40];
2792
2793         buf[0] = '\0';
2794         switch (ch) {
2795                 case '?':
2796                         sprintf(buf, "%u", (unsigned int)last_return_code);
2797                         break;
2798                 default:
2799                         return NULL;
2800         }
2801         return buf;
2802 }
2803 #endif
2804
2805 /* return code: 0 for OK, 1 for syntax error */
2806 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2807 {
2808 #ifndef __U_BOOT__
2809         int i, advance=0;
2810 #else
2811         int advance=0;
2812 #endif
2813 #ifndef __U_BOOT__
2814         char sep[]=" ";
2815 #endif
2816         int ch = input->peek(input);  /* first character after the $ */
2817         debug_printf("handle_dollar: ch=%c\n",ch);
2818         if (isalpha(ch)) {
2819                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2820                 ctx->child->sp++;
2821                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2822                         b_getch(input);
2823                         b_addchr(dest,ch);
2824                 }
2825                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2826 #ifndef __U_BOOT__
2827         } else if (isdigit(ch)) {
2828                 i = ch-'0';  /* XXX is $0 special? */
2829                 if (i<global_argc) {
2830                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2831                 }
2832                 advance = 1;
2833 #endif
2834         } else switch (ch) {
2835 #ifndef __U_BOOT__
2836                 case '$':
2837                         b_adduint(dest,getpid());
2838                         advance = 1;
2839                         break;
2840                 case '!':
2841                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2842                         advance = 1;
2843                         break;
2844 #endif
2845                 case '?':
2846 #ifndef __U_BOOT__
2847                         b_adduint(dest,last_return_code);
2848 #else
2849                         ctx->child->sp++;
2850                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2851                         b_addchr(dest, '$');
2852                         b_addchr(dest, '?');
2853                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2854 #endif
2855                         advance = 1;
2856                         break;
2857 #ifndef __U_BOOT__
2858                 case '#':
2859                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2860                         advance = 1;
2861                         break;
2862 #endif
2863                 case '{':
2864                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2865                         ctx->child->sp++;
2866                         b_getch(input);
2867                         /* XXX maybe someone will try to escape the '}' */
2868                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2869                                 b_addchr(dest,ch);
2870                         }
2871                         if (ch != '}') {
2872                                 syntax();
2873                                 return 1;
2874                         }
2875                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2876                         break;
2877 #ifndef __U_BOOT__
2878                 case '(':
2879                         b_getch(input);
2880                         process_command_subs(dest, ctx, input, ')');
2881                         break;
2882                 case '*':
2883                         sep[0]=ifs[0];
2884                         for (i=1; i<global_argc; i++) {
2885                                 parse_string(dest, ctx, global_argv[i]);
2886                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2887                         }
2888                         break;
2889                 case '@':
2890                 case '-':
2891                 case '_':
2892                         /* still unhandled, but should be eventually */
2893                         error_msg("unhandled syntax: $%c",ch);
2894                         return 1;
2895                         break;
2896 #endif
2897                 default:
2898                         b_addqchr(dest,'$',dest->quote);
2899         }
2900         /* Eat the character if the flag was set.  If the compiler
2901          * is smart enough, we could substitute "b_getch(input);"
2902          * for all the "advance = 1;" above, and also end up with
2903          * a nice size-optimized program.  Hah!  That'll be the day.
2904          */
2905         if (advance) b_getch(input);
2906         return 0;
2907 }
2908
2909 #ifndef __U_BOOT__
2910 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2911 {
2912         struct in_str foo;
2913         setup_string_in_str(&foo, src);
2914         return parse_stream(dest, ctx, &foo, '\0');
2915 }
2916 #endif
2917
2918 /* return code is 0 for normal exit, 1 for syntax error */
2919 int parse_stream(o_string *dest, struct p_context *ctx,
2920         struct in_str *input, int end_trigger)
2921 {
2922         unsigned int ch, m;
2923 #ifndef __U_BOOT__
2924         int redir_fd;
2925         redir_type redir_style;
2926 #endif
2927         int next;
2928
2929         /* Only double-quote state is handled in the state variable dest->quote.
2930          * A single-quote triggers a bypass of the main loop until its mate is
2931          * found.  When recursing, quote state is passed in via dest->quote. */
2932
2933         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2934         while ((ch=b_getch(input))!=EOF) {
2935                 m = map[ch];
2936 #ifdef __U_BOOT__
2937                 if (input->__promptme == 0) return 1;
2938 #endif
2939                 next = (ch == '\n') ? 0 : b_peek(input);
2940
2941                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2942                         ch >= ' ' ? ch : '.', ch, m,
2943                         dest->quote, ctx->stack == NULL ? '*' : '.');
2944
2945                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2946                         b_addqchr(dest, ch, dest->quote);
2947                 } else {
2948                         if (m==2) {  /* unquoted IFS */
2949                                 if (done_word(dest, ctx)) {
2950                                         return 1;
2951                                 }
2952                                 /* If we aren't performing a substitution, treat a newline as a
2953                                  * command separator.  */
2954                                 if (end_trigger != '\0' && ch=='\n')
2955                                         done_pipe(ctx,PIPE_SEQ);
2956                         }
2957                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2958                                 debug_printf("leaving parse_stream (triggered)\n");
2959                                 return 0;
2960                         }
2961 #if 0
2962                         if (ch=='\n') {
2963                                 /* Yahoo!  Time to run with it! */
2964                                 done_pipe(ctx,PIPE_SEQ);
2965                                 run_list(ctx->list_head);
2966                                 initialize_context(ctx);
2967                         }
2968 #endif
2969                         if (m!=2) switch (ch) {
2970                 case '#':
2971                         if (dest->length == 0 && !dest->quote) {
2972                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2973                         } else {
2974                                 b_addqchr(dest, ch, dest->quote);
2975                         }
2976                         break;
2977                 case '\\':
2978                         if (next == EOF) {
2979                                 syntax();
2980                                 return 1;
2981                         }
2982                         b_addqchr(dest, '\\', dest->quote);
2983                         b_addqchr(dest, b_getch(input), dest->quote);
2984                         break;
2985                 case '$':
2986                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2987                         break;
2988                 case '\'':
2989                         dest->nonnull = 1;
2990                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2991 #ifdef __U_BOOT__
2992                                 if(input->__promptme == 0) return 1;
2993 #endif
2994                                 b_addchr(dest,ch);
2995                         }
2996                         if (ch==EOF) {
2997                                 syntax();
2998                                 return 1;
2999                         }
3000                         break;
3001                 case '"':
3002                         dest->nonnull = 1;
3003                         dest->quote = !dest->quote;
3004                         break;
3005 #ifndef __U_BOOT__
3006                 case '`':
3007                         process_command_subs(dest, ctx, input, '`');
3008                         break;
3009                 case '>':
3010                         redir_fd = redirect_opt_num(dest);
3011                         done_word(dest, ctx);
3012                         redir_style=REDIRECT_OVERWRITE;
3013                         if (next == '>') {
3014                                 redir_style=REDIRECT_APPEND;
3015                                 b_getch(input);
3016                         } else if (next == '(') {
3017                                 syntax();   /* until we support >(list) Process Substitution */
3018                                 return 1;
3019                         }
3020                         setup_redirect(ctx, redir_fd, redir_style, input);
3021                         break;
3022                 case '<':
3023                         redir_fd = redirect_opt_num(dest);
3024                         done_word(dest, ctx);
3025                         redir_style=REDIRECT_INPUT;
3026                         if (next == '<') {
3027                                 redir_style=REDIRECT_HEREIS;
3028                                 b_getch(input);
3029                         } else if (next == '>') {
3030                                 redir_style=REDIRECT_IO;
3031                                 b_getch(input);
3032                         } else if (next == '(') {
3033                                 syntax();   /* until we support <(list) Process Substitution */
3034                                 return 1;
3035                         }
3036                         setup_redirect(ctx, redir_fd, redir_style, input);
3037                         break;
3038 #endif
3039                 case ';':
3040                         done_word(dest, ctx);
3041                         done_pipe(ctx,PIPE_SEQ);
3042                         break;
3043                 case '&':
3044                         done_word(dest, ctx);
3045                         if (next=='&') {
3046                                 b_getch(input);
3047                                 done_pipe(ctx,PIPE_AND);
3048                         } else {
3049 #ifndef __U_BOOT__
3050                                 done_pipe(ctx,PIPE_BG);
3051 #else
3052                                 syntax_err();
3053                                 return 1;
3054 #endif
3055                         }
3056                         break;
3057                 case '|':
3058                         done_word(dest, ctx);
3059                         if (next=='|') {
3060                                 b_getch(input);
3061                                 done_pipe(ctx,PIPE_OR);
3062                         } else {
3063                                 /* we could pick up a file descriptor choice here
3064                                  * with redirect_opt_num(), but bash doesn't do it.
3065                                  * "echo foo 2| cat" yields "foo 2". */
3066 #ifndef __U_BOOT__
3067                                 done_command(ctx);
3068 #else
3069                                 syntax_err();
3070                                 return 1;
3071 #endif
3072                         }
3073                         break;
3074 #ifndef __U_BOOT__
3075                 case '(':
3076                 case '{':
3077                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3078                         break;
3079                 case ')':
3080                 case '}':
3081                         syntax();   /* Proper use of this character caught by end_trigger */
3082                         return 1;
3083                         break;
3084 #endif
3085                 default:
3086                         syntax();   /* this is really an internal logic error */
3087                         return 1;
3088                         }
3089                 }
3090         }
3091         /* complain if quote?  No, maybe we just finished a command substitution
3092          * that was quoted.  Example:
3093          * $ echo "`cat foo` plus more"
3094          * and we just got the EOF generated by the subshell that ran "cat foo"
3095          * The only real complaint is if we got an EOF when end_trigger != '\0',
3096          * that is, we were really supposed to get end_trigger, and never got
3097          * one before the EOF.  Can't use the standard "syntax error" return code,
3098          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3099         debug_printf("leaving parse_stream (EOF)\n");
3100         if (end_trigger != '\0') return -1;
3101         return 0;
3102 }
3103
3104 void mapset(const unsigned char *set, int code)
3105 {
3106         const unsigned char *s;
3107         for (s=set; *s; s++) map[*s] = code;
3108 }
3109
3110 void update_ifs_map(void)
3111 {
3112         /* char *ifs and char map[256] are both globals. */
3113         ifs = (uchar *)getenv("IFS");
3114         if (ifs == NULL) ifs=(uchar *)" \t\n";
3115         /* Precompute a list of 'flow through' behavior so it can be treated
3116          * quickly up front.  Computation is necessary because of IFS.
3117          * Special case handling of IFS == " \t\n" is not implemented.
3118          * The map[] array only really needs two bits each, and on most machines
3119          * that would be faster because of the reduced L1 cache footprint.
3120          */
3121         memset(map,0,sizeof(map)); /* most characters flow through always */
3122 #ifndef __U_BOOT__
3123         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3124         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3125 #else
3126         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3127         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3128 #endif
3129         mapset(ifs, 2);            /* also flow through if quoted */
3130 }
3131
3132 /* most recursion does not come through here, the exeception is
3133  * from builtin_source() */
3134 int parse_stream_outer(struct in_str *inp, int flag)
3135 {
3136
3137         struct p_context ctx;
3138         o_string temp=NULL_O_STRING;
3139         int rcode;
3140 #ifdef __U_BOOT__
3141         int code = 0;
3142 #endif
3143         do {
3144                 ctx.type = flag;
3145                 initialize_context(&ctx);
3146                 update_ifs_map();
3147                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3148                 inp->promptmode=1;
3149                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3150 #ifdef __U_BOOT__
3151                 if (rcode == 1) flag_repeat = 0;
3152 #endif
3153                 if (rcode != 1 && ctx.old_flag != 0) {
3154                         syntax();
3155 #ifdef __U_BOOT__
3156                         flag_repeat = 0;
3157 #endif
3158                 }
3159                 if (rcode != 1 && ctx.old_flag == 0) {
3160                         done_word(&temp, &ctx);
3161                         done_pipe(&ctx,PIPE_SEQ);
3162 #ifndef __U_BOOT__
3163                         run_list(ctx.list_head);
3164 #else
3165                         code = run_list(ctx.list_head);
3166                         if (code == -2) {       /* exit */
3167                                 b_free(&temp);
3168                                 code = 0;
3169                                 /* XXX hackish way to not allow exit from main loop */
3170                                 if (inp->peek == file_peek) {
3171                                         printf("exit not allowed from main input shell.\n");
3172                                         continue;
3173                                 }
3174                                 break;
3175                         }
3176                         if (code == -1)
3177                             flag_repeat = 0;
3178 #endif
3179                 } else {
3180                         if (ctx.old_flag != 0) {
3181                                 free(ctx.stack);
3182                                 b_reset(&temp);
3183                         }
3184 #ifdef __U_BOOT__
3185                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3186                         inp->__promptme = 1;
3187 #endif
3188                         temp.nonnull = 0;
3189                         temp.quote = 0;
3190                         inp->p = NULL;
3191                         free_pipe_list(ctx.list_head,0);
3192                 }
3193                 b_free(&temp);
3194         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3195 #ifndef __U_BOOT__
3196         return 0;
3197 #else
3198         return (code != 0) ? 1 : 0;
3199 #endif /* __U_BOOT__ */
3200 }
3201
3202 #ifndef __U_BOOT__
3203 static int parse_string_outer(const char *s, int flag)
3204 #else
3205 int parse_string_outer(const char *s, int flag)
3206 #endif  /* __U_BOOT__ */
3207 {
3208         struct in_str input;
3209 #ifdef __U_BOOT__
3210         char *p = NULL;
3211         int rcode;
3212         if ( !s || !*s)
3213                 return 1;
3214         if (!(p = strchr(s, '\n')) || *++p) {
3215                 p = xmalloc(strlen(s) + 2);
3216                 strcpy(p, s);
3217                 strcat(p, "\n");
3218                 setup_string_in_str(&input, p);
3219                 rcode = parse_stream_outer(&input, flag);
3220                 free(p);
3221                 return rcode;
3222         } else {
3223 #endif
3224         setup_string_in_str(&input, s);
3225         return parse_stream_outer(&input, flag);
3226 #ifdef __U_BOOT__
3227         }
3228 #endif
3229 }
3230
3231 #ifndef __U_BOOT__
3232 static int parse_file_outer(FILE *f)
3233 #else
3234 int parse_file_outer(void)
3235 #endif
3236 {
3237         int rcode;
3238         struct in_str input;
3239 #ifndef __U_BOOT__
3240         setup_file_in_str(&input, f);
3241 #else
3242         setup_file_in_str(&input);
3243 #endif
3244         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3245         return rcode;
3246 }
3247
3248 #ifdef __U_BOOT__
3249 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3250 static void u_boot_hush_reloc(void)
3251 {
3252         unsigned long addr;
3253         struct reserved_combo *r;
3254
3255         for (r=reserved_list; r<reserved_list+NRES; r++) {
3256                 addr = (ulong) (r->literal) + gd->reloc_off;
3257                 r->literal = (char *)addr;
3258         }
3259 }
3260 #endif
3261
3262 int u_boot_hush_start(void)
3263 {
3264         if (top_vars == NULL) {
3265                 top_vars = malloc(sizeof(struct variables));
3266                 top_vars->name = "HUSH_VERSION";
3267                 top_vars->value = "0.01";
3268                 top_vars->next = 0;
3269                 top_vars->flg_export = 0;
3270                 top_vars->flg_read_only = 1;
3271 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3272                 u_boot_hush_reloc();
3273 #endif
3274         }
3275         return 0;
3276 }
3277
3278 static void *xmalloc(size_t size)
3279 {
3280         void *p = NULL;
3281
3282         if (!(p = malloc(size))) {
3283             printf("ERROR : memory not allocated\n");
3284             for(;;);
3285         }
3286         return p;
3287 }
3288
3289 static void *xrealloc(void *ptr, size_t size)
3290 {
3291         void *p = NULL;
3292
3293         if (!(p = realloc(ptr, size))) {
3294             printf("ERROR : memory not allocated\n");
3295             for(;;);
3296         }
3297         return p;
3298 }
3299 #endif /* __U_BOOT__ */
3300
3301 #ifndef __U_BOOT__
3302 /* Make sure we have a controlling tty.  If we get started under a job
3303  * aware app (like bash for example), make sure we are now in charge so
3304  * we don't fight over who gets the foreground */
3305 static void setup_job_control(void)
3306 {
3307         static pid_t shell_pgrp;
3308         /* Loop until we are in the foreground.  */
3309         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3310                 kill (- shell_pgrp, SIGTTIN);
3311
3312         /* Ignore interactive and job-control signals.  */
3313         signal(SIGINT, SIG_IGN);
3314         signal(SIGQUIT, SIG_IGN);
3315         signal(SIGTERM, SIG_IGN);
3316         signal(SIGTSTP, SIG_IGN);
3317         signal(SIGTTIN, SIG_IGN);
3318         signal(SIGTTOU, SIG_IGN);
3319         signal(SIGCHLD, SIG_IGN);
3320
3321         /* Put ourselves in our own process group.  */
3322         setsid();
3323         shell_pgrp = getpid ();
3324         setpgid (shell_pgrp, shell_pgrp);
3325
3326         /* Grab control of the terminal.  */
3327         tcsetpgrp(shell_terminal, shell_pgrp);
3328 }
3329
3330 int hush_main(int argc, char * const *argv)
3331 {
3332         int opt;
3333         FILE *input;
3334         char **e = environ;
3335
3336         /* XXX what should these be while sourcing /etc/profile? */
3337         global_argc = argc;
3338         global_argv = argv;
3339
3340         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3341          * hush_main(), therefore we cannot rely on the BSS to zero out this
3342          * stuff.  Reset these to 0 every time. */
3343         ifs = NULL;
3344         /* map[] is taken care of with call to update_ifs_map() */
3345         fake_mode = 0;
3346         interactive = 0;
3347         close_me_head = NULL;
3348         last_bg_pid = 0;
3349         job_list = NULL;
3350         last_jobid = 0;
3351
3352         /* Initialize some more globals to non-zero values */
3353         set_cwd();
3354 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3355         cmdedit_set_initial_prompt();
3356 #else
3357         PS1 = NULL;
3358 #endif
3359         PS2 = "> ";
3360
3361         /* initialize our shell local variables with the values
3362          * currently living in the environment */
3363         if (e) {
3364                 for (; *e; e++)
3365                         set_local_var(*e, 2);   /* without call putenv() */
3366         }
3367
3368         last_return_code=EXIT_SUCCESS;
3369
3370
3371         if (argv[0] && argv[0][0] == '-') {
3372                 debug_printf("\nsourcing /etc/profile\n");
3373                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3374                         mark_open(fileno(input));
3375                         parse_file_outer(input);
3376                         mark_closed(fileno(input));
3377                         fclose(input);
3378                 }
3379         }
3380         input=stdin;
3381
3382         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3383                 switch (opt) {
3384                         case 'c':
3385                                 {
3386                                         global_argv = argv+optind;
3387                                         global_argc = argc-optind;
3388                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3389                                         goto final_return;
3390                                 }
3391                                 break;
3392                         case 'i':
3393                                 interactive++;
3394                                 break;
3395                         case 'f':
3396                                 fake_mode++;
3397                                 break;
3398                         default:
3399 #ifndef BB_VER
3400                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3401                                                 "   or: sh -c command [args]...\n\n");
3402                                 exit(EXIT_FAILURE);
3403 #else
3404                                 show_usage();
3405 #endif
3406                 }
3407         }
3408         /* A shell is interactive if the `-i' flag was given, or if all of
3409          * the following conditions are met:
3410          *        no -c command
3411          *    no arguments remaining or the -s flag given
3412          *    standard input is a terminal
3413          *    standard output is a terminal
3414          *    Refer to Posix.2, the description of the `sh' utility. */
3415         if (argv[optind]==NULL && input==stdin &&
3416                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3417                 interactive++;
3418         }
3419
3420         debug_printf("\ninteractive=%d\n", interactive);
3421         if (interactive) {
3422                 /* Looks like they want an interactive shell */
3423 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3424                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3425                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3426 #endif
3427                 setup_job_control();
3428         }
3429
3430         if (argv[optind]==NULL) {
3431                 opt=parse_file_outer(stdin);
3432                 goto final_return;
3433         }
3434
3435         debug_printf("\nrunning script '%s'\n", argv[optind]);
3436         global_argv = argv+optind;
3437         global_argc = argc-optind;
3438         input = xfopen(argv[optind], "r");
3439         opt = parse_file_outer(input);
3440
3441 #ifdef CONFIG_FEATURE_CLEAN_UP
3442         fclose(input);
3443         if (cwd && cwd != unknown)
3444                 free((char*)cwd);
3445         {
3446                 struct variables *cur, *tmp;
3447                 for(cur = top_vars; cur; cur = tmp) {
3448                         tmp = cur->next;
3449                         if (!cur->flg_read_only) {
3450                                 free(cur->name);
3451                                 free(cur->value);
3452                                 free(cur);
3453                         }
3454                 }
3455         }
3456 #endif
3457
3458 final_return:
3459         return(opt?opt:last_return_code);
3460 }
3461 #endif
3462
3463 static char *insert_var_value(char *inp)
3464 {
3465         int res_str_len = 0;
3466         int len;
3467         int done = 0;
3468         char *p, *p1, *res_str = NULL;
3469
3470         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3471                 if (p != inp) {
3472                         len = p - inp;
3473                         res_str = xrealloc(res_str, (res_str_len + len));
3474                         strncpy((res_str + res_str_len), inp, len);
3475                         res_str_len += len;
3476                 }
3477                 inp = ++p;
3478                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3479                 *p = '\0';
3480                 if ((p1 = lookup_param(inp))) {
3481                         len = res_str_len + strlen(p1);
3482                         res_str = xrealloc(res_str, (1 + len));
3483                         strcpy((res_str + res_str_len), p1);
3484                         res_str_len = len;
3485                 }
3486                 *p = SPECIAL_VAR_SYMBOL;
3487                 inp = ++p;
3488                 done = 1;
3489         }
3490         if (done) {
3491                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3492                 strcpy((res_str + res_str_len), inp);
3493                 while ((p = strchr(res_str, '\n'))) {
3494                         *p = ' ';
3495                 }
3496         }
3497         return (res_str == NULL) ? inp : res_str;
3498 }
3499
3500 static char **make_list_in(char **inp, char *name)
3501 {
3502         int len, i;
3503         int name_len = strlen(name);
3504         int n = 0;
3505         char **list;
3506         char *p1, *p2, *p3;
3507
3508         /* create list of variable values */
3509         list = xmalloc(sizeof(*list));
3510         for (i = 0; inp[i]; i++) {
3511                 p3 = insert_var_value(inp[i]);
3512                 p1 = p3;
3513                 while (*p1) {
3514                         if ((*p1 == ' ')) {
3515                                 p1++;
3516                                 continue;
3517                         }
3518                         if ((p2 = strchr(p1, ' '))) {
3519                                 len = p2 - p1;
3520                         } else {
3521                                 len = strlen(p1);
3522                                 p2 = p1 + len;
3523                         }
3524                         /* we use n + 2 in realloc for list,because we add
3525                          * new element and then we will add NULL element */
3526                         list = xrealloc(list, sizeof(*list) * (n + 2));
3527                         list[n] = xmalloc(2 + name_len + len);
3528                         strcpy(list[n], name);
3529                         strcat(list[n], "=");
3530                         strncat(list[n], p1, len);
3531                         list[n++][name_len + len + 1] = '\0';
3532                         p1 = p2;
3533                 }
3534                 if (p3 != inp[i]) free(p3);
3535         }
3536         list[n] = NULL;
3537         return list;
3538 }
3539
3540 /* Make new string for parser */
3541 static char * make_string(char ** inp)
3542 {
3543         char *p;
3544         char *str = NULL;
3545         int n;
3546         int len = 2;
3547
3548         for (n = 0; inp[n]; n++) {
3549                 p = insert_var_value(inp[n]);
3550                 str = xrealloc(str, (len + strlen(p)));
3551                 if (n) {
3552                         strcat(str, " ");
3553                 } else {
3554                         *str = '\0';
3555                 }
3556                 strcat(str, p);
3557                 len = strlen(str) + 3;
3558                 if (p != inp[n]) free(p);
3559         }
3560         len = strlen(str);
3561         *(str + len) = '\n';
3562         *(str + len + 1) = '\0';
3563         return str;
3564 }
3565
3566 #ifdef __U_BOOT__
3567 int do_showvar (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
3568 {
3569         int i, k;
3570         int rcode = 0;
3571         struct variables *cur;
3572
3573         if (argc == 1) {                /* Print all env variables      */
3574                 for (cur = top_vars; cur; cur = cur->next) {
3575                         printf ("%s=%s\n", cur->name, cur->value);
3576                         if (ctrlc ()) {
3577                                 puts ("\n ** Abort\n");
3578                                 return 1;
3579                         }
3580                 }
3581                 return 0;
3582         }
3583         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3584                 char *name = argv[i];
3585
3586                 k = -1;
3587                 for (cur = top_vars; cur; cur = cur->next) {
3588                         if(strcmp (cur->name, name) == 0) {
3589                                 k = 0;
3590                                 printf ("%s=%s\n", cur->name, cur->value);
3591                         }
3592                         if (ctrlc ()) {
3593                                 puts ("\n ** Abort\n");
3594                                 return 1;
3595                         }
3596                 }
3597                 if (k < 0) {
3598                         printf ("## Error: \"%s\" not defined\n", name);
3599                         rcode ++;
3600                 }
3601         }
3602         return rcode;
3603 }
3604
3605 U_BOOT_CMD(
3606         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3607         "print local hushshell variables",
3608         "\n    - print values of all hushshell variables\n"
3609         "showvar name ...\n"
3610         "    - print value of hushshell variable 'name'"
3611 );
3612
3613 #endif
3614 /****************************************************************************/