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 #ifndef CONFIG_SYS_PROMPT_HUSH_PS2
  96 #define CONFIG_SYS_PROMPT_HUSH_PS2      "> "
  97 #endif
  98 #endif
  99 #ifndef __U_BOOT__
 100 #include <ctype.h>     /* isalpha, isdigit */
 101 #include <unistd.h>    /* getpid */
 102 #include <stdlib.h>    /* getenv, atoi */
 103 #include <string.h>    /* strchr */
 104 #include <stdio.h>     /* popen etc. */
 105 #include <glob.h>      /* glob, of course */
 106 #include <stdarg.h>    /* va_list */
 107 #include <errno.h>
 108 #include <fcntl.h>
 109 #include <getopt.h>    /* should be pretty obvious */
 110
 111 #include <sys/stat.h>  /* ulimit */
 112 #include <sys/types.h>
 113 #include <sys/wait.h>
 114 #include <signal.h>
 115
 116 /* #include <dmalloc.h> */
 117
 118 #if 1
 119 #include "busybox.h"
 120 #include "cmdedit.h"
 121 #else
 122 #define applet_name "hush"
 123 #include "standalone.h"
 124 #define hush_main main
 125 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 126 #define BB_BANNER
 127 #endif
 128 #endif
 129 #define SPECIAL_VAR_SYMBOL 03
 130 #ifndef __U_BOOT__
 131 #define FLAG_EXIT_FROM_LOOP 1
 132 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 133 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 134
 135 #endif
 136
 137 #ifdef __U_BOOT__
 138 DECLARE_GLOBAL_DATA_PTR;
 139
 140 #define EXIT_SUCCESS 0
 141 #define EOF -1
 142 #define syntax() syntax_err()
 143 #define xstrdup strdup
 144 #define error_msg printf
 145 #else
 146 typedef enum {
 147         REDIRECT_INPUT     = 1,
 148         REDIRECT_OVERWRITE = 2,
 149         REDIRECT_APPEND    = 3,
 150         REDIRECT_HEREIS    = 4,
 151         REDIRECT_IO        = 5
 152 } redir_type;
 153
 154 /* The descrip member of this structure is only used to make debugging
 155  * output pretty */
 156 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 157         { 0,                         0, "()" },
 158         { O_RDONLY,                  0, "<"  },
 159         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 160         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 161         { O_RDONLY,                 -1, "<<" },
 162         { O_RDWR,                    1, "<>" }
 163 };
 164 #endif
 165
 166 typedef enum {
 167         PIPE_SEQ = 1,
 168         PIPE_AND = 2,
 169         PIPE_OR  = 3,
 170         PIPE_BG  = 4,
 171 } pipe_style;
 172
 173 /* might eventually control execution */
 174 typedef enum {
 175         RES_NONE  = 0,
 176         RES_IF    = 1,
 177         RES_THEN  = 2,
 178         RES_ELIF  = 3,
 179         RES_ELSE  = 4,
 180         RES_FI    = 5,
 181         RES_FOR   = 6,
 182         RES_WHILE = 7,
 183         RES_UNTIL = 8,
 184         RES_DO    = 9,
 185         RES_DONE  = 10,
 186         RES_XXXX  = 11,
 187         RES_IN    = 12,
 188         RES_SNTX  = 13
 189 } reserved_style;
 190 #define FLAG_END   (1<<RES_NONE)
 191 #define FLAG_IF    (1<<RES_IF)
 192 #define FLAG_THEN  (1<<RES_THEN)
 193 #define FLAG_ELIF  (1<<RES_ELIF)
 194 #define FLAG_ELSE  (1<<RES_ELSE)
 195 #define FLAG_FI    (1<<RES_FI)
 196 #define FLAG_FOR   (1<<RES_FOR)
 197 #define FLAG_WHILE (1<<RES_WHILE)
 198 #define FLAG_UNTIL (1<<RES_UNTIL)
 199 #define FLAG_DO    (1<<RES_DO)
 200 #define FLAG_DONE  (1<<RES_DONE)
 201 #define FLAG_IN    (1<<RES_IN)
 202 #define FLAG_START (1<<RES_XXXX)
 203
 204 /* This holds pointers to the various results of parsing */
 205 struct p_context {
 206         struct child_prog *child;
 207         struct pipe *list_head;
 208         struct pipe *pipe;
 209 #ifndef __U_BOOT__
 210         struct redir_struct *pending_redirect;
 211 #endif
 212         reserved_style w;
 213         int old_flag;                           /* for figuring out valid reserved words */
 214         struct p_context *stack;
 215         int type;                       /* define type of parser : ";$" common or special symbol */
 216         /* How about quoting status? */
 217 };
 218
 219 #ifndef __U_BOOT__
 220 struct redir_struct {
 221         redir_type type;                        /* type of redirection */
 222         int fd;                                         /* file descriptor being redirected */
 223         int dup;                                        /* -1, or file descriptor being duplicated */
 224         struct redir_struct *next;      /* pointer to the next redirect in the list */
 225         glob_t word;                            /* *word.gl_pathv is the filename */
 226 };
 227 #endif
 228
 229 struct child_prog {
 230 #ifndef __U_BOOT__
 231         pid_t pid;                                      /* 0 if exited */
 232 #endif
 233         char **argv;                            /* program name and arguments */
 234 #ifdef __U_BOOT__
 235         int    argc;                            /* number of program arguments */
 236 #endif
 237         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 238 #ifndef __U_BOOT__
 239         int subshell;                           /* flag, non-zero if group must be forked */
 240         struct redir_struct *redirects; /* I/O redirections */
 241         glob_t glob_result;                     /* result of parameter globbing */
 242         int is_stopped;                         /* is the program currently running? */
 243         struct pipe *family;            /* pointer back to the child's parent pipe */
 244 #endif
 245         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 246         int type;
 247 };
 248
 249 struct pipe {
 250 #ifndef __U_BOOT__
 251         int jobid;                                      /* job number */
 252 #endif
 253         int num_progs;                          /* total number of programs in job */
 254 #ifndef __U_BOOT__
 255         int running_progs;                      /* number of programs running */
 256         char *text;                                     /* name of job */
 257         char *cmdbuf;                           /* buffer various argv's point into */
 258         pid_t pgrp;                                     /* process group ID for the job */
 259 #endif
 260         struct child_prog *progs;       /* array of commands in pipe */
 261         struct pipe *next;                      /* to track background commands */
 262 #ifndef __U_BOOT__
 263         int stopped_progs;                      /* number of programs alive, but stopped */
 264         int job_context;                        /* bitmask defining current context */
 265 #endif
 266         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 267         reserved_style r_mode;          /* supports if, for, while, until */
 268 };
 269
 270 #ifndef __U_BOOT__
 271 struct close_me {
 272         int fd;
 273         struct close_me *next;
 274 };
 275 #endif
 276
 277 struct variables {
 278         char *name;
 279         char *value;
 280         int flg_export;
 281         int flg_read_only;
 282         struct variables *next;
 283 };
 284
 285 /* globals, connect us to the outside world
 286  * the first three support $?, $#, and $1 */
 287 #ifndef __U_BOOT__
 288 char **global_argv;
 289 unsigned int global_argc;
 290 #endif
 291 unsigned int last_return_code;
 292 int nesting_level;
 293 #ifndef __U_BOOT__
 294 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 295 #endif
 296
 297 /* "globals" within this file */
 298 static uchar *ifs;
 299 static char map[256];
 300 #ifndef __U_BOOT__
 301 static int fake_mode;
 302 static int interactive;
 303 static struct close_me *close_me_head;
 304 static const char *cwd;
 305 static struct pipe *job_list;
 306 static unsigned int last_bg_pid;
 307 static unsigned int last_jobid;
 308 static unsigned int shell_terminal;
 309 static char *PS1;
 310 static char *PS2;
 311 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 312 struct variables *top_vars = &shell_ver;
 313 #else
 314 static int flag_repeat = 0;
 315 static int do_repeat = 0;
 316 static struct variables *top_vars = NULL ;
 317 #endif /*__U_BOOT__ */
 318
 319 #define B_CHUNK (100)
 320 #define B_NOSPAC 1
 321
 322 typedef struct {
 323         char *data;
 324         int length;
 325         int maxlen;
 326         int quote;
 327         int nonnull;
 328 } o_string;
 329 #define NULL_O_STRING {NULL,0,0,0,0}
 330 /* used for initialization:
 331         o_string foo = NULL_O_STRING; */
 332
 333 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 334  * available?  Where is it documented? */
 335 struct in_str {
 336         const char *p;
 337 #ifndef __U_BOOT__
 338         char peek_buf[2];
 339 #endif
 340         int __promptme;
 341         int promptmode;
 342 #ifndef __U_BOOT__
 343         FILE *file;
 344 #endif
 345         int (*get) (struct in_str *);
 346         int (*peek) (struct in_str *);
 347 };
 348 #define b_getch(input) ((input)->get(input))
 349 #define b_peek(input) ((input)->peek(input))
 350
 351 #ifndef __U_BOOT__
 352 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 353
 354 struct built_in_command {
 355         char *cmd;                                      /* name */
 356         char *descr;                            /* description */
 357         int (*function) (struct child_prog *);  /* function ptr */
 358 };
 359 #endif
 360
 361 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 362 #if 0
 363 #define DEBUG_SHELL
 364 #endif
 365
 366 /* This should be in utility.c */
 367 #ifdef DEBUG_SHELL
 368 #ifndef __U_BOOT__
 369 static void debug_printf(const char *format, ...)
 370 {
 371         va_list args;
 372         va_start(args, format);
 373         vfprintf(stderr, format, args);
 374         va_end(args);
 375 }
 376 #else
 377 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 378 #endif
 379 #else
 380 static inline void debug_printf(const char *format, ...) { }
 381 #endif
 382 #define final_printf debug_printf
 383
 384 #ifdef __U_BOOT__
 385 static void syntax_err(void) {
 386          printf("syntax error\n");
 387 }
 388 #else
 389 static void __syntax(char *file, int line) {
 390         error_msg("syntax error %s:%d", file, line);
 391 }
 392 #define syntax() __syntax(__FILE__, __LINE__)
 393 #endif
 394
 395 #ifdef __U_BOOT__
 396 static void *xmalloc(size_t size);
 397 static void *xrealloc(void *ptr, size_t size);
 398 #else
 399 /* Index of subroutines: */
 400 /*   function prototypes for builtins */
 401 static int builtin_cd(struct child_prog *child);
 402 static int builtin_env(struct child_prog *child);
 403 static int builtin_eval(struct child_prog *child);
 404 static int builtin_exec(struct child_prog *child);
 405 static int builtin_exit(struct child_prog *child);
 406 static int builtin_export(struct child_prog *child);
 407 static int builtin_fg_bg(struct child_prog *child);
 408 static int builtin_help(struct child_prog *child);
 409 static int builtin_jobs(struct child_prog *child);
 410 static int builtin_pwd(struct child_prog *child);
 411 static int builtin_read(struct child_prog *child);
 412 static int builtin_set(struct child_prog *child);
 413 static int builtin_shift(struct child_prog *child);
 414 static int builtin_source(struct child_prog *child);
 415 static int builtin_umask(struct child_prog *child);
 416 static int builtin_unset(struct child_prog *child);
 417 static int builtin_not_written(struct child_prog *child);
 418 #endif
 419 /*   o_string manipulation: */
 420 static int b_check_space(o_string *o, int len);
 421 static int b_addchr(o_string *o, int ch);
 422 static void b_reset(o_string *o);
 423 static int b_addqchr(o_string *o, int ch, int quote);
 424 #ifndef __U_BOOT__
 425 static int b_adduint(o_string *o, unsigned int i);
 426 #endif
 427 /*  in_str manipulations: */
 428 static int static_get(struct in_str *i);
 429 static int static_peek(struct in_str *i);
 430 static int file_get(struct in_str *i);
 431 static int file_peek(struct in_str *i);
 432 #ifndef __U_BOOT__
 433 static void setup_file_in_str(struct in_str *i, FILE *f);
 434 #else
 435 static void setup_file_in_str(struct in_str *i);
 436 #endif
 437 static void setup_string_in_str(struct in_str *i, const char *s);
 438 #ifndef __U_BOOT__
 439 /*  close_me manipulations: */
 440 static void mark_open(int fd);
 441 static void mark_closed(int fd);
 442 static void close_all(void);
 443 #endif
 444 /*  "run" the final data structures: */
 445 static char *indenter(int i);
 446 static int free_pipe_list(struct pipe *head, int indent);
 447 static int free_pipe(struct pipe *pi, int indent);
 448 /*  really run the final data structures: */
 449 #ifndef __U_BOOT__
 450 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 451 #endif
 452 static int run_list_real(struct pipe *pi);
 453 #ifndef __U_BOOT__
 454 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 455 #endif
 456 static int run_pipe_real(struct pipe *pi);
 457 /*   extended glob support: */
 458 #ifndef __U_BOOT__
 459 static int globhack(const char *src, int flags, glob_t *pglob);
 460 static int glob_needed(const char *s);
 461 static int xglob(o_string *dest, int flags, glob_t *pglob);
 462 #endif
 463 /*   variable assignment: */
 464 static int is_assignment(const char *s);
 465 /*   data structure manipulation: */
 466 #ifndef __U_BOOT__
 467 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 468 #endif
 469 static void initialize_context(struct p_context *ctx);
 470 static int done_word(o_string *dest, struct p_context *ctx);
 471 static int done_command(struct p_context *ctx);
 472 static int done_pipe(struct p_context *ctx, pipe_style type);
 473 /*   primary string parsing: */
 474 #ifndef __U_BOOT__
 475 static int redirect_dup_num(struct in_str *input);
 476 static int redirect_opt_num(o_string *o);
 477 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 478 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 479 #endif
 480 static char *lookup_param(char *src);
 481 static char *make_string(char **inp);
 482 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 483 #ifndef __U_BOOT__
 484 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 485 #endif
 486 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 487 /*   setup: */
 488 static int parse_stream_outer(struct in_str *inp, int flag);
 489 #ifndef __U_BOOT__
 490 static int parse_string_outer(const char *s, int flag);
 491 static int parse_file_outer(FILE *f);
 492 #endif
 493 #ifndef __U_BOOT__
 494 /*   job management: */
 495 static int checkjobs(struct pipe* fg_pipe);
 496 static void insert_bg_job(struct pipe *pi);
 497 static void remove_bg_job(struct pipe *pi);
 498 #endif
 499 /*     local variable support */
 500 static char **make_list_in(char **inp, char *name);
 501 static char *insert_var_value(char *inp);
 502
 503 #ifndef __U_BOOT__
 504 /* Table of built-in functions.  They can be forked or not, depending on
 505  * context: within pipes, they fork.  As simple commands, they do not.
 506  * When used in non-forking context, they can change global variables
 507  * in the parent shell process.  If forked, of course they can not.
 508  * For example, 'unset foo | whatever' will parse and run, but foo will
 509  * still be set at the end. */
 510 static struct built_in_command bltins[] = {
 511         {"bg", "Resume a job in the background", builtin_fg_bg},
 512         {"break", "Exit for, while or until loop", builtin_not_written},
 513         {"cd", "Change working directory", builtin_cd},
 514         {"continue", "Continue for, while or until loop", builtin_not_written},
 515         {"env", "Print all environment variables", builtin_env},
 516         {"eval", "Construct and run shell command", builtin_eval},
 517         {"exec", "Exec command, replacing this shell with the exec'd process",
 518                 builtin_exec},
 519         {"exit", "Exit from shell()", builtin_exit},
 520         {"export", "Set environment variable", builtin_export},
 521         {"fg", "Bring job into the foreground", builtin_fg_bg},
 522         {"jobs", "Lists the active jobs", builtin_jobs},
 523         {"pwd", "Print current directory", builtin_pwd},
 524         {"read", "Input environment variable", builtin_read},
 525         {"return", "Return from a function", builtin_not_written},
 526         {"set", "Set/unset shell local variables", builtin_set},
 527         {"shift", "Shift positional parameters", builtin_shift},
 528         {"trap", "Trap signals", builtin_not_written},
 529         {"ulimit","Controls resource limits", builtin_not_written},
 530         {"umask","Sets file creation mask", builtin_umask},
 531         {"unset", "Unset environment variable", builtin_unset},
 532         {".", "Source-in and run commands in a file", builtin_source},
 533         {"help", "List shell built-in commands", builtin_help},
 534         {NULL, NULL, NULL}
 535 };
 536
 537 static const char *set_cwd(void)
 538 {
 539         if(cwd==unknown)
 540                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 541         cwd = xgetcwd((char *)cwd);
 542         if (!cwd)
 543                 cwd = unknown;
 544         return cwd;
 545 }
 546
 547 /* built-in 'eval' handler */
 548 static int builtin_eval(struct child_prog *child)
 549 {
 550         char *str = NULL;
 551         int rcode = EXIT_SUCCESS;
 552
 553         if (child->argv[1]) {
 554                 str = make_string(child->argv + 1);
 555                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 556                                         FLAG_PARSE_SEMICOLON);
 557                 free(str);
 558                 rcode = last_return_code;
 559         }
 560         return rcode;
 561 }
 562
 563 /* built-in 'cd <path>' handler */
 564 static int builtin_cd(struct child_prog *child)
 565 {
 566         char *newdir;
 567         if (child->argv[1] == NULL)
 568                 newdir = getenv("HOME");
 569         else
 570                 newdir = child->argv[1];
 571         if (chdir(newdir)) {
 572                 printf("cd: %s: %s\n", newdir, strerror(errno));
 573                 return EXIT_FAILURE;
 574         }
 575         set_cwd();
 576         return EXIT_SUCCESS;
 577 }
 578
 579 /* built-in 'env' handler */
 580 static int builtin_env(struct child_prog *dummy)
 581 {
 582         char **e = environ;
 583         if (e == NULL) return EXIT_FAILURE;
 584         for (; *e; e++) {
 585                 puts(*e);
 586         }
 587         return EXIT_SUCCESS;
 588 }
 589
 590 /* built-in 'exec' handler */
 591 static int builtin_exec(struct child_prog *child)
 592 {
 593         if (child->argv[1] == NULL)
 594                 return EXIT_SUCCESS;   /* Really? */
 595         child->argv++;
 596         pseudo_exec(child);
 597         /* never returns */
 598 }
 599
 600 /* built-in 'exit' handler */
 601 static int builtin_exit(struct child_prog *child)
 602 {
 603         if (child->argv[1] == NULL)
 604                 exit(last_return_code);
 605         exit (atoi(child->argv[1]));
 606 }
 607
 608 /* built-in 'export VAR=value' handler */
 609 static int builtin_export(struct child_prog *child)
 610 {
 611         int res = 0;
 612         char *name = child->argv[1];
 613
 614         if (name == NULL) {
 615                 return (builtin_env(child));
 616         }
 617
 618         name = strdup(name);
 619
 620         if(name) {
 621                 char *value = strchr(name, '=');
 622
 623                 if (!value) {
 624                         char *tmp;
 625                         /* They are exporting something without an =VALUE */
 626
 627                         value = get_local_var(name);
 628                         if (value) {
 629                                 size_t ln = strlen(name);
 630
 631                                 tmp = realloc(name, ln+strlen(value)+2);
 632                                 if(tmp==NULL)
 633                                         res = -1;
 634                                 else {
 635                                         sprintf(tmp+ln, "=%s", value);
 636                                         name = tmp;
 637                                 }
 638                         } else {
 639                                 /* bash does not return an error when trying to export
 640                                  * an undefined variable.  Do likewise. */
 641                                 res = 1;
 642                         }
 643                 }
 644         }
 645         if (res<0)
 646                 perror_msg("export");
 647         else if(res==0)
 648                 res = set_local_var(name, 1);
 649         else
 650                 res = 0;
 651         free(name);
 652         return res;
 653 }
 654
 655 /* built-in 'fg' and 'bg' handler */
 656 static int builtin_fg_bg(struct child_prog *child)
 657 {
 658         int i, jobnum;
 659         struct pipe *pi=NULL;
 660
 661         if (!interactive)
 662                 return EXIT_FAILURE;
 663         /* If they gave us no args, assume they want the last backgrounded task */
 664         if (!child->argv[1]) {
 665                 for (pi = job_list; pi; pi = pi->next) {
 666                         if (pi->jobid == last_jobid) {
 667                                 break;
 668                         }
 669                 }
 670                 if (!pi) {
 671                         error_msg("%s: no current job", child->argv[0]);
 672                         return EXIT_FAILURE;
 673                 }
 674         } else {
 675                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 676                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 677                         return EXIT_FAILURE;
 678                 }
 679                 for (pi = job_list; pi; pi = pi->next) {
 680                         if (pi->jobid == jobnum) {
 681                                 break;
 682                         }
 683                 }
 684                 if (!pi) {
 685                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 686                         return EXIT_FAILURE;
 687                 }
 688         }
 689
 690         if (*child->argv[0] == 'f') {
 691                 /* Put the job into the foreground.  */
 692                 tcsetpgrp(shell_terminal, pi->pgrp);
 693         }
 694
 695         /* Restart the processes in the job */
 696         for (i = 0; i < pi->num_progs; i++)
 697                 pi->progs[i].is_stopped = 0;
 698
 699         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 700                 if (i == ESRCH) {
 701                         remove_bg_job(pi);
 702                 } else {
 703                         perror_msg("kill (SIGCONT)");
 704                 }
 705         }
 706
 707         pi->stopped_progs = 0;
 708         return EXIT_SUCCESS;
 709 }
 710
 711 /* built-in 'help' handler */
 712 static int builtin_help(struct child_prog *dummy)
 713 {
 714         struct built_in_command *x;
 715
 716         printf("\nBuilt-in commands:\n");
 717         printf("-------------------\n");
 718         for (x = bltins; x->cmd; x++) {
 719                 if (x->descr==NULL)
 720                         continue;
 721                 printf("%s\t%s\n", x->cmd, x->descr);
 722         }
 723         printf("\n\n");
 724         return EXIT_SUCCESS;
 725 }
 726
 727 /* built-in 'jobs' handler */
 728 static int builtin_jobs(struct child_prog *child)
 729 {
 730         struct pipe *job;
 731         char *status_string;
 732
 733         for (job = job_list; job; job = job->next) {
 734                 if (job->running_progs == job->stopped_progs)
 735                         status_string = "Stopped";
 736                 else
 737                         status_string = "Running";
 738
 739                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 740         }
 741         return EXIT_SUCCESS;
 742 }
 743
 744
 745 /* built-in 'pwd' handler */
 746 static int builtin_pwd(struct child_prog *dummy)
 747 {
 748         puts(set_cwd());
 749         return EXIT_SUCCESS;
 750 }
 751
 752 /* built-in 'read VAR' handler */
 753 static int builtin_read(struct child_prog *child)
 754 {
 755         int res;
 756
 757         if (child->argv[1]) {
 758                 char string[BUFSIZ];
 759                 char *var = 0;
 760
 761                 string[0] = 0;  /* In case stdin has only EOF */
 762                 /* read string */
 763                 fgets(string, sizeof(string), stdin);
 764                 chomp(string);
 765                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 766                 if(var) {
 767                         sprintf(var, "%s=%s", child->argv[1], string);
 768                         res = set_local_var(var, 0);
 769                 } else
 770                         res = -1;
 771                 if (res)
 772                         fprintf(stderr, "read: %m\n");
 773                 free(var);      /* So not move up to avoid breaking errno */
 774                 return res;
 775         } else {
 776                 do res=getchar(); while(res!='\n' && res!=EOF);
 777                 return 0;
 778         }
 779 }
 780
 781 /* built-in 'set VAR=value' handler */
 782 static int builtin_set(struct child_prog *child)
 783 {
 784         char *temp = child->argv[1];
 785         struct variables *e;
 786
 787         if (temp == NULL)
 788                 for(e = top_vars; e; e=e->next)
 789                         printf("%s=%s\n", e->name, e->value);
 790         else
 791                 set_local_var(temp, 0);
 792
 793                 return EXIT_SUCCESS;
 794 }
 795
 796
 797 /* Built-in 'shift' handler */
 798 static int builtin_shift(struct child_prog *child)
 799 {
 800         int n=1;
 801         if (child->argv[1]) {
 802                 n=atoi(child->argv[1]);
 803         }
 804         if (n>=0 && n<global_argc) {
 805                 /* XXX This probably breaks $0 */
 806                 global_argc -= n;
 807                 global_argv += n;
 808                 return EXIT_SUCCESS;
 809         } else {
 810                 return EXIT_FAILURE;
 811         }
 812 }
 813
 814 /* Built-in '.' handler (read-in and execute commands from file) */
 815 static int builtin_source(struct child_prog *child)
 816 {
 817         FILE *input;
 818         int status;
 819
 820         if (child->argv[1] == NULL)
 821                 return EXIT_FAILURE;
 822
 823         /* XXX search through $PATH is missing */
 824         input = fopen(child->argv[1], "r");
 825         if (!input) {
 826                 error_msg("Couldn't open file '%s'", child->argv[1]);
 827                 return EXIT_FAILURE;
 828         }
 829
 830         /* Now run the file */
 831         /* XXX argv and argc are broken; need to save old global_argv
 832          * (pointer only is OK!) on this stack frame,
 833          * set global_argv=child->argv+1, recurse, and restore. */
 834         mark_open(fileno(input));
 835         status = parse_file_outer(input);
 836         mark_closed(fileno(input));
 837         fclose(input);
 838         return (status);
 839 }
 840
 841 static int builtin_umask(struct child_prog *child)
 842 {
 843         mode_t new_umask;
 844         const char *arg = child->argv[1];
 845         char *end;
 846         if (arg) {
 847                 new_umask=strtoul(arg, &end, 8);
 848                 if (*end!='\0' || end == arg) {
 849                         return EXIT_FAILURE;
 850                 }
 851         } else {
 852                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 853         }
 854         umask(new_umask);
 855         return EXIT_SUCCESS;
 856 }
 857
 858 /* built-in 'unset VAR' handler */
 859 static int builtin_unset(struct child_prog *child)
 860 {
 861         /* bash returned already true */
 862         unset_local_var(child->argv[1]);
 863         return EXIT_SUCCESS;
 864 }
 865
 866 static int builtin_not_written(struct child_prog *child)
 867 {
 868         printf("builtin_%s not written\n",child->argv[0]);
 869         return EXIT_FAILURE;
 870 }
 871 #endif
 872
 873 static int b_check_space(o_string *o, int len)
 874 {
 875         /* It would be easy to drop a more restrictive policy
 876          * in here, such as setting a maximum string length */
 877         if (o->length + len > o->maxlen) {
 878                 char *old_data = o->data;
 879                 /* assert (data == NULL || o->maxlen != 0); */
 880                 o->maxlen += max(2*len, B_CHUNK);
 881                 o->data = realloc(o->data, 1 + o->maxlen);
 882                 if (o->data == NULL) {
 883                         free(old_data);
 884                 }
 885         }
 886         return o->data == NULL;
 887 }
 888
 889 static int b_addchr(o_string *o, int ch)
 890 {
 891         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 892         if (b_check_space(o, 1)) return B_NOSPAC;
 893         o->data[o->length] = ch;
 894         o->length++;
 895         o->data[o->length] = '\0';
 896         return 0;
 897 }
 898
 899 static void b_reset(o_string *o)
 900 {
 901         o->length = 0;
 902         o->nonnull = 0;
 903         if (o->data != NULL) *o->data = '\0';
 904 }
 905
 906 static void b_free(o_string *o)
 907 {
 908         b_reset(o);
 909         free(o->data);
 910         o->data = NULL;
 911         o->maxlen = 0;
 912 }
 913
 914 /* My analysis of quoting semantics tells me that state information
 915  * is associated with a destination, not a source.
 916  */
 917 static int b_addqchr(o_string *o, int ch, int quote)
 918 {
 919         if (quote && strchr("*?[\\",ch)) {
 920                 int rc;
 921                 rc = b_addchr(o, '\\');
 922                 if (rc) return rc;
 923         }
 924         return b_addchr(o, ch);
 925 }
 926
 927 #ifndef __U_BOOT__
 928 static int b_adduint(o_string *o, unsigned int i)
 929 {
 930         int r;
 931         char *p = simple_itoa(i);
 932         /* no escape checking necessary */
 933         do r=b_addchr(o, *p++); while (r==0 && *p);
 934         return r;
 935 }
 936 #endif
 937
 938 static int static_get(struct in_str *i)
 939 {
 940         int ch = *i->p++;
 941         if (ch=='\0') return EOF;
 942         return ch;
 943 }
 944
 945 static int static_peek(struct in_str *i)
 946 {
 947         return *i->p;
 948 }
 949
 950 #ifndef __U_BOOT__
 951 static inline void cmdedit_set_initial_prompt(void)
 952 {
 953 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 954         PS1 = NULL;
 955 #else
 956         PS1 = getenv("PS1");
 957         if(PS1==0)
 958                 PS1 = "\\w \\$ ";
 959 #endif
 960 }
 961
 962 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 963 {
 964         debug_printf("setup_prompt_string %d ",promptmode);
 965 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 966         /* Set up the prompt */
 967         if (promptmode == 1) {
 968                 free(PS1);
 969                 PS1=xmalloc(strlen(cwd)+4);
 970                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 971                 *prompt_str = PS1;
 972         } else {
 973                 *prompt_str = PS2;
 974         }
 975 #else
 976         *prompt_str = (promptmode==1)? PS1 : PS2;
 977 #endif
 978         debug_printf("result %s\n",*prompt_str);
 979 }
 980 #endif
 981
 982 static void get_user_input(struct in_str *i)
 983 {
 984 #ifndef __U_BOOT__
 985         char *prompt_str;
 986         static char the_command[BUFSIZ];
 987
 988         setup_prompt_string(i->promptmode, &prompt_str);
 989 #ifdef CONFIG_FEATURE_COMMAND_EDITING
 990         /*
 991          ** enable command line editing only while a command line
 992          ** is actually being read; otherwise, we'll end up bequeathing
 993          ** atexit() handlers and other unwanted stuff to our
 994          ** child processes (rob@sysgo.de)
 995          */
 996         cmdedit_read_input(prompt_str, the_command);
 997 #else
 998         fputs(prompt_str, stdout);
 999         fflush(stdout);
1000         the_command[0]=fgetc(i->file);
1001         the_command[1]='\0';
1002 #endif
1003         fflush(stdout);
1004         i->p = the_command;
1005 #else
1006         int n;
1007         static char the_command[CONFIG_SYS_CBSIZE];
1008
1009 #ifdef CONFIG_BOOT_RETRY_TIME
1010 #  ifndef CONFIG_RESET_TO_RETRY
1011 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1012 #  endif
1013         reset_cmd_timeout();
1014 #endif
1015         i->__promptme = 1;
1016         if (i->promptmode == 1) {
1017                 n = readline(CONFIG_SYS_PROMPT);
1018         } else {
1019                 n = readline(CONFIG_SYS_PROMPT_HUSH_PS2);
1020         }
1021 #ifdef CONFIG_BOOT_RETRY_TIME
1022         if (n == -2) {
1023           puts("\nTimeout waiting for command\n");
1024 #  ifdef CONFIG_RESET_TO_RETRY
1025           do_reset(NULL, 0, 0, NULL);
1026 #  else
1027 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1028 #  endif
1029         }
1030 #endif
1031         if (n == -1 ) {
1032                 flag_repeat = 0;
1033                 i->__promptme = 0;
1034         }
1035         n = strlen(console_buffer);
1036         console_buffer[n] = '\n';
1037         console_buffer[n+1]= '\0';
1038         if (had_ctrlc()) flag_repeat = 0;
1039         clear_ctrlc();
1040         do_repeat = 0;
1041         if (i->promptmode == 1) {
1042                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1043                         strcpy(the_command,console_buffer);
1044                 }
1045                 else {
1046                         if (console_buffer[0] != '\n') {
1047                                 strcpy(the_command,console_buffer);
1048                                 flag_repeat = 1;
1049                         }
1050                         else {
1051                                 do_repeat = 1;
1052                         }
1053                 }
1054                 i->p = the_command;
1055         }
1056         else {
1057                 if (console_buffer[0] != '\n') {
1058                         if (strlen(the_command) + strlen(console_buffer)
1059                             < CONFIG_SYS_CBSIZE) {
1060                                 n = strlen(the_command);
1061                                 the_command[n-1] = ' ';
1062                                 strcpy(&the_command[n],console_buffer);
1063                         }
1064                         else {
1065                                 the_command[0] = '\n';
1066                                 the_command[1] = '\0';
1067                                 flag_repeat = 0;
1068                         }
1069                 }
1070                 if (i->__promptme == 0) {
1071                         the_command[0] = '\n';
1072                         the_command[1] = '\0';
1073                 }
1074                 i->p = console_buffer;
1075         }
1076 #endif
1077 }
1078
1079 /* This is the magic location that prints prompts
1080  * and gets data back from the user */
1081 static int file_get(struct in_str *i)
1082 {
1083         int ch;
1084
1085         ch = 0;
1086         /* If there is data waiting, eat it up */
1087         if (i->p && *i->p) {
1088                 ch = *i->p++;
1089         } else {
1090                 /* need to double check i->file because we might be doing something
1091                  * more complicated by now, like sourcing or substituting. */
1092 #ifndef __U_BOOT__
1093                 if (i->__promptme && interactive && i->file == stdin) {
1094                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1095 #else
1096                         while(! i->p  || strlen(i->p)==0 ) {
1097 #endif
1098                                 get_user_input(i);
1099                         }
1100                         i->promptmode=2;
1101 #ifndef __U_BOOT__
1102                         i->__promptme = 0;
1103 #endif
1104                         if (i->p && *i->p) {
1105                                 ch = *i->p++;
1106                         }
1107 #ifndef __U_BOOT__
1108                 } else {
1109                         ch = fgetc(i->file);
1110                 }
1111
1112 #endif
1113                 debug_printf("b_getch: got a %d\n", ch);
1114         }
1115 #ifndef __U_BOOT__
1116         if (ch == '\n') i->__promptme=1;
1117 #endif
1118         return ch;
1119 }
1120
1121 /* All the callers guarantee this routine will never be
1122  * used right after a newline, so prompting is not needed.
1123  */
1124 static int file_peek(struct in_str *i)
1125 {
1126 #ifndef __U_BOOT__
1127         if (i->p && *i->p) {
1128 #endif
1129                 return *i->p;
1130 #ifndef __U_BOOT__
1131         } else {
1132                 i->peek_buf[0] = fgetc(i->file);
1133                 i->peek_buf[1] = '\0';
1134                 i->p = i->peek_buf;
1135                 debug_printf("b_peek: got a %d\n", *i->p);
1136                 return *i->p;
1137         }
1138 #endif
1139 }
1140
1141 #ifndef __U_BOOT__
1142 static void setup_file_in_str(struct in_str *i, FILE *f)
1143 #else
1144 static void setup_file_in_str(struct in_str *i)
1145 #endif
1146 {
1147         i->peek = file_peek;
1148         i->get = file_get;
1149         i->__promptme=1;
1150         i->promptmode=1;
1151 #ifndef __U_BOOT__
1152         i->file = f;
1153 #endif
1154         i->p = NULL;
1155 }
1156
1157 static void setup_string_in_str(struct in_str *i, const char *s)
1158 {
1159         i->peek = static_peek;
1160         i->get = static_get;
1161         i->__promptme=1;
1162         i->promptmode=1;
1163         i->p = s;
1164 }
1165
1166 #ifndef __U_BOOT__
1167 static void mark_open(int fd)
1168 {
1169         struct close_me *new = xmalloc(sizeof(struct close_me));
1170         new->fd = fd;
1171         new->next = close_me_head;
1172         close_me_head = new;
1173 }
1174
1175 static void mark_closed(int fd)
1176 {
1177         struct close_me *tmp;
1178         if (close_me_head == NULL || close_me_head->fd != fd)
1179                 error_msg_and_die("corrupt close_me");
1180         tmp = close_me_head;
1181         close_me_head = close_me_head->next;
1182         free(tmp);
1183 }
1184
1185 static void close_all(void)
1186 {
1187         struct close_me *c;
1188         for (c=close_me_head; c; c=c->next) {
1189                 close(c->fd);
1190         }
1191         close_me_head = NULL;
1192 }
1193
1194 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1195  * and stderr if they are redirected. */
1196 static int setup_redirects(struct child_prog *prog, int squirrel[])
1197 {
1198         int openfd, mode;
1199         struct redir_struct *redir;
1200
1201         for (redir=prog->redirects; redir; redir=redir->next) {
1202                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1203                         /* something went wrong in the parse.  Pretend it didn't happen */
1204                         continue;
1205                 }
1206                 if (redir->dup == -1) {
1207                         mode=redir_table[redir->type].mode;
1208                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1209                         if (openfd < 0) {
1210                         /* this could get lost if stderr has been redirected, but
1211                            bash and ash both lose it as well (though zsh doesn't!) */
1212                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1213                                 return 1;
1214                         }
1215                 } else {
1216                         openfd = redir->dup;
1217                 }
1218
1219                 if (openfd != redir->fd) {
1220                         if (squirrel && redir->fd < 3) {
1221                                 squirrel[redir->fd] = dup(redir->fd);
1222                         }
1223                         if (openfd == -3) {
1224                                 close(openfd);
1225                         } else {
1226                                 dup2(openfd, redir->fd);
1227                                 if (redir->dup == -1)
1228                                         close (openfd);
1229                         }
1230                 }
1231         }
1232         return 0;
1233 }
1234
1235 static void restore_redirects(int squirrel[])
1236 {
1237         int i, fd;
1238         for (i=0; i<3; i++) {
1239                 fd = squirrel[i];
1240                 if (fd != -1) {
1241                         /* No error checking.  I sure wouldn't know what
1242                          * to do with an error if I found one! */
1243                         dup2(fd, i);
1244                         close(fd);
1245                 }
1246         }
1247 }
1248
1249 /* never returns */
1250 /* XXX no exit() here.  If you don't exec, use _exit instead.
1251  * The at_exit handlers apparently confuse the calling process,
1252  * in particular stdin handling.  Not sure why? */
1253 static void pseudo_exec(struct child_prog *child)
1254 {
1255         int i, rcode;
1256         char *p;
1257         struct built_in_command *x;
1258         if (child->argv) {
1259                 for (i=0; is_assignment(child->argv[i]); i++) {
1260                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1261                         p = insert_var_value(child->argv[i]);
1262                         putenv(strdup(p));
1263                         if (p != child->argv[i]) free(p);
1264                 }
1265                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1266                                         to exit, and therefore don't need to keep data
1267                                         structures consistent for free() use. */
1268                 /* If a variable is assigned in a forest, and nobody listens,
1269                  * was it ever really set?
1270                  */
1271                 if (child->argv[0] == NULL) {
1272                         _exit(EXIT_SUCCESS);
1273                 }
1274
1275                 /*
1276                  * Check if the command matches any of the builtins.
1277                  * Depending on context, this might be redundant.  But it's
1278                  * easier to waste a few CPU cycles than it is to figure out
1279                  * if this is one of those cases.
1280                  */
1281                 for (x = bltins; x->cmd; x++) {
1282                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1283                                 debug_printf("builtin exec %s\n", child->argv[0]);
1284                                 rcode = x->function(child);
1285                                 fflush(stdout);
1286                                 _exit(rcode);
1287                         }
1288                 }
1289
1290                 /* Check if the command matches any busybox internal commands
1291                  * ("applets") here.
1292                  * FIXME: This feature is not 100% safe, since
1293                  * BusyBox is not fully reentrant, so we have no guarantee the things
1294                  * from the .bss are still zeroed, or that things from .data are still
1295                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1296                  * really dislike relying on /proc for things.  We could exec ourself
1297                  * from global_argv[0], but if we are in a chroot, we may not be able
1298                  * to find ourself... */
1299 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1300                 {
1301                         int argc_l;
1302                         char** argv_l=child->argv;
1303                         char *name = child->argv[0];
1304
1305 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1306                         /* Following discussions from November 2000 on the busybox mailing
1307                          * list, the default configuration, (without
1308                          * get_last_path_component()) lets the user force use of an
1309                          * external command by specifying the full (with slashes) filename.
1310                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1311                          * _aways_ override external commands, so if you want to run
1312                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1313                          * filesystem and is _not_ busybox.  Some systems may want this,
1314                          * most do not.  */
1315                         name = get_last_path_component(name);
1316 #endif
1317                         /* Count argc for use in a second... */
1318                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1319                         optind = 1;
1320                         debug_printf("running applet %s\n", name);
1321                         run_applet_by_name(name, argc_l, child->argv);
1322                 }
1323 #endif
1324                 debug_printf("exec of %s\n",child->argv[0]);
1325                 execvp(child->argv[0],child->argv);
1326                 perror_msg("couldn't exec: %s",child->argv[0]);
1327                 _exit(1);
1328         } else if (child->group) {
1329                 debug_printf("runtime nesting to group\n");
1330                 interactive=0;    /* crucial!!!! */
1331                 rcode = run_list_real(child->group);
1332                 /* OK to leak memory by not calling free_pipe_list,
1333                  * since this process is about to exit */
1334                 _exit(rcode);
1335         } else {
1336                 /* Can happen.  See what bash does with ">foo" by itself. */
1337                 debug_printf("trying to pseudo_exec null command\n");
1338                 _exit(EXIT_SUCCESS);
1339         }
1340 }
1341
1342 static void insert_bg_job(struct pipe *pi)
1343 {
1344         struct pipe *thejob;
1345
1346         /* Linear search for the ID of the job to use */
1347         pi->jobid = 1;
1348         for (thejob = job_list; thejob; thejob = thejob->next)
1349                 if (thejob->jobid >= pi->jobid)
1350                         pi->jobid = thejob->jobid + 1;
1351
1352         /* add thejob to the list of running jobs */
1353         if (!job_list) {
1354                 thejob = job_list = xmalloc(sizeof(*thejob));
1355         } else {
1356                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1357                 thejob->next = xmalloc(sizeof(*thejob));
1358                 thejob = thejob->next;
1359         }
1360
1361         /* physically copy the struct job */
1362         memcpy(thejob, pi, sizeof(struct pipe));
1363         thejob->next = NULL;
1364         thejob->running_progs = thejob->num_progs;
1365         thejob->stopped_progs = 0;
1366         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1367
1368         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1369         {
1370                 char *bar=thejob->text;
1371                 char **foo=pi->progs[0].argv;
1372                 while(foo && *foo) {
1373                         bar += sprintf(bar, "%s ", *foo++);
1374                 }
1375         }
1376
1377         /* we don't wait for background thejobs to return -- append it
1378            to the list of backgrounded thejobs and leave it alone */
1379         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1380         last_bg_pid = thejob->progs[0].pid;
1381         last_jobid = thejob->jobid;
1382 }
1383
1384 /* remove a backgrounded job */
1385 static void remove_bg_job(struct pipe *pi)
1386 {
1387         struct pipe *prev_pipe;
1388
1389         if (pi == job_list) {
1390                 job_list = pi->next;
1391         } else {
1392                 prev_pipe = job_list;
1393                 while (prev_pipe->next != pi)
1394                         prev_pipe = prev_pipe->next;
1395                 prev_pipe->next = pi->next;
1396         }
1397         if (job_list)
1398                 last_jobid = job_list->jobid;
1399         else
1400                 last_jobid = 0;
1401
1402         pi->stopped_progs = 0;
1403         free_pipe(pi, 0);
1404         free(pi);
1405 }
1406
1407 /* Checks to see if any processes have exited -- if they
1408    have, figure out why and see if a job has completed */
1409 static int checkjobs(struct pipe* fg_pipe)
1410 {
1411         int attributes;
1412         int status;
1413         int prognum = 0;
1414         struct pipe *pi;
1415         pid_t childpid;
1416
1417         attributes = WUNTRACED;
1418         if (fg_pipe==NULL) {
1419                 attributes |= WNOHANG;
1420         }
1421
1422         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1423                 if (fg_pipe) {
1424                         int i, rcode = 0;
1425                         for (i=0; i < fg_pipe->num_progs; i++) {
1426                                 if (fg_pipe->progs[i].pid == childpid) {
1427                                         if (i==fg_pipe->num_progs-1)
1428                                                 rcode=WEXITSTATUS(status);
1429                                         (fg_pipe->num_progs)--;
1430                                         return(rcode);
1431                                 }
1432                         }
1433                 }
1434
1435                 for (pi = job_list; pi; pi = pi->next) {
1436                         prognum = 0;
1437                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1438                                 prognum++;
1439                         }
1440                         if (prognum < pi->num_progs)
1441                                 break;
1442                 }
1443
1444                 if(pi==NULL) {
1445                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1446                         continue;
1447                 }
1448
1449                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1450                         /* child exited */
1451                         pi->running_progs--;
1452                         pi->progs[prognum].pid = 0;
1453
1454                         if (!pi->running_progs) {
1455                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1456                                 remove_bg_job(pi);
1457                         }
1458                 } else {
1459                         /* child stopped */
1460                         pi->stopped_progs++;
1461                         pi->progs[prognum].is_stopped = 1;
1462
1463 #if 0
1464                         /* Printing this stuff is a pain, since it tends to
1465                          * overwrite the prompt an inconveinient moments.  So
1466                          * don't do that.  */
1467                         if (pi->stopped_progs == pi->num_progs) {
1468                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1469                         }
1470 #endif
1471                 }
1472         }
1473
1474         if (childpid == -1 && errno != ECHILD)
1475                 perror_msg("waitpid");
1476
1477         /* move the shell to the foreground */
1478         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1479         /*      perror_msg("tcsetpgrp-2"); */
1480         return -1;
1481 }
1482
1483 /* Figure out our controlling tty, checking in order stderr,
1484  * stdin, and stdout.  If check_pgrp is set, also check that
1485  * we belong to the foreground process group associated with
1486  * that tty.  The value of shell_terminal is needed in order to call
1487  * tcsetpgrp(shell_terminal, ...); */
1488 void controlling_tty(int check_pgrp)
1489 {
1490         pid_t curpgrp;
1491
1492         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1493                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1494                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1495                 goto shell_terminal_error;
1496
1497         if (check_pgrp && curpgrp != getpgid(0))
1498                 goto shell_terminal_error;
1499
1500         return;
1501
1502 shell_terminal_error:
1503                 shell_terminal = -1;
1504                 return;
1505 }
1506 #endif
1507
1508 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1509  * to finish.  See checkjobs().
1510  *
1511  * return code is normally -1, when the caller has to wait for children
1512  * to finish to determine the exit status of the pipe.  If the pipe
1513  * is a simple builtin command, however, the action is done by the
1514  * time run_pipe_real returns, and the exit code is provided as the
1515  * return value.
1516  *
1517  * The input of the pipe is always stdin, the output is always
1518  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1519  * because it tries to avoid running the command substitution in
1520  * subshell, when that is in fact necessary.  The subshell process
1521  * now has its stdout directed to the input of the appropriate pipe,
1522  * so this routine is noticeably simpler.
1523  */
1524 static int run_pipe_real(struct pipe *pi)
1525 {
1526         int i;
1527 #ifndef __U_BOOT__
1528         int nextin, nextout;
1529         int pipefds[2];                         /* pipefds[0] is for reading */
1530         struct child_prog *child;
1531         struct built_in_command *x;
1532         char *p;
1533 # if __GNUC__
1534         /* Avoid longjmp clobbering */
1535         (void) &i;
1536         (void) &nextin;
1537         (void) &nextout;
1538         (void) &child;
1539 # endif
1540 #else
1541         int nextin;
1542         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1543         struct child_prog *child;
1544         char *p;
1545 # if __GNUC__
1546         /* Avoid longjmp clobbering */
1547         (void) &i;
1548         (void) &nextin;
1549         (void) &child;
1550 # endif
1551 #endif  /* __U_BOOT__ */
1552
1553         nextin = 0;
1554 #ifndef __U_BOOT__
1555         pi->pgrp = -1;
1556 #endif
1557
1558         /* Check if this is a simple builtin (not part of a pipe).
1559          * Builtins within pipes have to fork anyway, and are handled in
1560          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1561          */
1562         if (pi->num_progs == 1) child = & (pi->progs[0]);
1563 #ifndef __U_BOOT__
1564         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1565                 int squirrel[] = {-1, -1, -1};
1566                 int rcode;
1567                 debug_printf("non-subshell grouping\n");
1568                 setup_redirects(child, squirrel);
1569                 /* XXX could we merge code with following builtin case,
1570                  * by creating a pseudo builtin that calls run_list_real? */
1571                 rcode = run_list_real(child->group);
1572                 restore_redirects(squirrel);
1573 #else
1574                 if (pi->num_progs == 1 && child->group) {
1575                 int rcode;
1576                 debug_printf("non-subshell grouping\n");
1577                 rcode = run_list_real(child->group);
1578 #endif
1579                 return rcode;
1580         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1581                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1582                 if (i!=0 && child->argv[i]==NULL) {
1583                         /* assignments, but no command: set the local environment */
1584                         for (i=0; child->argv[i]!=NULL; i++) {
1585
1586                                 /* Ok, this case is tricky.  We have to decide if this is a
1587                                  * local variable, or an already exported variable.  If it is
1588                                  * already exported, we have to export the new value.  If it is
1589                                  * not exported, we need only set this as a local variable.
1590                                  * This junk is all to decide whether or not to export this
1591                                  * variable. */
1592                                 int export_me=0;
1593                                 char *name, *value;
1594                                 name = xstrdup(child->argv[i]);
1595                                 debug_printf("Local environment set: %s\n", name);
1596                                 value = strchr(name, '=');
1597                                 if (value)
1598                                         *value=0;
1599 #ifndef __U_BOOT__
1600                                 if ( get_local_var(name)) {
1601                                         export_me=1;
1602                                 }
1603 #endif
1604                                 free(name);
1605                                 p = insert_var_value(child->argv[i]);
1606                                 set_local_var(p, export_me);
1607                                 if (p != child->argv[i]) free(p);
1608                         }
1609                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1610                 }
1611                 for (i = 0; is_assignment(child->argv[i]); i++) {
1612                         p = insert_var_value(child->argv[i]);
1613 #ifndef __U_BOOT__
1614                         putenv(strdup(p));
1615 #else
1616                         set_local_var(p, 0);
1617 #endif
1618                         if (p != child->argv[i]) {
1619                                 child->sp--;
1620                                 free(p);
1621                         }
1622                 }
1623                 if (child->sp) {
1624                         char * str = NULL;
1625
1626                         str = make_string((child->argv + i));
1627                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1628                         free(str);
1629                         return last_return_code;
1630                 }
1631 #ifndef __U_BOOT__
1632                 for (x = bltins; x->cmd; x++) {
1633                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1634                                 int squirrel[] = {-1, -1, -1};
1635                                 int rcode;
1636                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1637                                         debug_printf("magic exec\n");
1638                                         setup_redirects(child,NULL);
1639                                         return EXIT_SUCCESS;
1640                                 }
1641                                 debug_printf("builtin inline %s\n", child->argv[0]);
1642                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1643                                  * This is perfect for work that comes after exec().
1644                                  * Is it really safe for inline use?  Experimentally,
1645                                  * things seem to work with glibc. */
1646                                 setup_redirects(child, squirrel);
1647
1648                                 child->argv += i;  /* XXX horrible hack */
1649                                 rcode = x->function(child);
1650                                 /* XXX restore hack so free() can work right */
1651                                 child->argv -= i;
1652                                 restore_redirects(squirrel);
1653                         }
1654                         return rcode;
1655                 }
1656 #else
1657                 /* check ";", because ,example , argv consist from
1658                  * "help;flinfo" must not execute
1659                  */
1660                 if (strchr(child->argv[i], ';')) {
1661                         printf("Unknown command '%s' - try 'help' or use "
1662                                         "'run' command\n", child->argv[i]);
1663                         return -1;
1664                 }
1665                 /* Process the command */
1666                 return cmd_process(flag, child->argc, child->argv,
1667                                    &flag_repeat);
1668 #endif
1669         }
1670 #ifndef __U_BOOT__
1671
1672         for (i = 0; i < pi->num_progs; i++) {
1673                 child = & (pi->progs[i]);
1674
1675                 /* pipes are inserted between pairs of commands */
1676                 if ((i + 1) < pi->num_progs) {
1677                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1678                         nextout = pipefds[1];
1679                 } else {
1680                         nextout=1;
1681                         pipefds[0] = -1;
1682                 }
1683
1684                 /* XXX test for failed fork()? */
1685                 if (!(child->pid = fork())) {
1686                         /* Set the handling for job control signals back to the default.  */
1687                         signal(SIGINT, SIG_DFL);
1688                         signal(SIGQUIT, SIG_DFL);
1689                         signal(SIGTERM, SIG_DFL);
1690                         signal(SIGTSTP, SIG_DFL);
1691                         signal(SIGTTIN, SIG_DFL);
1692                         signal(SIGTTOU, SIG_DFL);
1693                         signal(SIGCHLD, SIG_DFL);
1694
1695                         close_all();
1696
1697                         if (nextin != 0) {
1698                                 dup2(nextin, 0);
1699                                 close(nextin);
1700                         }
1701                         if (nextout != 1) {
1702                                 dup2(nextout, 1);
1703                                 close(nextout);
1704                         }
1705                         if (pipefds[0]!=-1) {
1706                                 close(pipefds[0]);  /* opposite end of our output pipe */
1707                         }
1708
1709                         /* Like bash, explicit redirects override pipes,
1710                          * and the pipe fd is available for dup'ing. */
1711                         setup_redirects(child,NULL);
1712
1713                         if (interactive && pi->followup!=PIPE_BG) {
1714                                 /* If we (the child) win the race, put ourselves in the process
1715                                  * group whose leader is the first process in this pipe. */
1716                                 if (pi->pgrp < 0) {
1717                                         pi->pgrp = getpid();
1718                                 }
1719                                 if (setpgid(0, pi->pgrp) == 0) {
1720                                         tcsetpgrp(2, pi->pgrp);
1721                                 }
1722                         }
1723
1724                         pseudo_exec(child);
1725                 }
1726
1727
1728                 /* put our child in the process group whose leader is the
1729                    first process in this pipe */
1730                 if (pi->pgrp < 0) {
1731                         pi->pgrp = child->pid;
1732                 }
1733                 /* Don't check for errors.  The child may be dead already,
1734                  * in which case setpgid returns error code EACCES. */
1735                 setpgid(child->pid, pi->pgrp);
1736
1737                 if (nextin != 0)
1738                         close(nextin);
1739                 if (nextout != 1)
1740                         close(nextout);
1741
1742                 /* If there isn't another process, nextin is garbage
1743                    but it doesn't matter */
1744                 nextin = pipefds[0];
1745         }
1746 #endif
1747         return -1;
1748 }
1749
1750 static int run_list_real(struct pipe *pi)
1751 {
1752         char *save_name = NULL;
1753         char **list = NULL;
1754         char **save_list = NULL;
1755         struct pipe *rpipe;
1756         int flag_rep = 0;
1757 #ifndef __U_BOOT__
1758         int save_num_progs;
1759 #endif
1760         int rcode=0, flag_skip=1;
1761         int flag_restore = 0;
1762         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1763         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1764         /* check syntax for "for" */
1765         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1766                 if ((rpipe->r_mode == RES_IN ||
1767                     rpipe->r_mode == RES_FOR) &&
1768                     (rpipe->next == NULL)) {
1769                                 syntax();
1770 #ifdef __U_BOOT__
1771                                 flag_repeat = 0;
1772 #endif
1773                                 return 1;
1774                 }
1775                 if ((rpipe->r_mode == RES_IN &&
1776                         (rpipe->next->r_mode == RES_IN &&
1777                         rpipe->next->progs->argv != NULL))||
1778                         (rpipe->r_mode == RES_FOR &&
1779                         rpipe->next->r_mode != RES_IN)) {
1780                                 syntax();
1781 #ifdef __U_BOOT__
1782                                 flag_repeat = 0;
1783 #endif
1784                                 return 1;
1785                 }
1786         }
1787         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1788                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1789                         pi->r_mode == RES_FOR) {
1790 #ifdef __U_BOOT__
1791                                 /* check Ctrl-C */
1792                                 ctrlc();
1793                                 if ((had_ctrlc())) {
1794                                         return 1;
1795                                 }
1796 #endif
1797                                 flag_restore = 0;
1798                                 if (!rpipe) {
1799                                         flag_rep = 0;
1800                                         rpipe = pi;
1801                                 }
1802                 }
1803                 rmode = pi->r_mode;
1804                 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);
1805                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1806                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1807                         continue;
1808                 }
1809                 flag_skip = 1;
1810                 skip_more_in_this_rmode = RES_XXXX;
1811                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1812                 if (rmode == RES_THEN &&  if_code) continue;
1813                 if (rmode == RES_ELSE && !if_code) continue;
1814                 if (rmode == RES_ELIF && !if_code) break;
1815                 if (rmode == RES_FOR && pi->num_progs) {
1816                         if (!list) {
1817                                 /* if no variable values after "in" we skip "for" */
1818                                 if (!pi->next->progs->argv) continue;
1819                                 /* create list of variable values */
1820                                 list = make_list_in(pi->next->progs->argv,
1821                                         pi->progs->argv[0]);
1822                                 save_list = list;
1823                                 save_name = pi->progs->argv[0];
1824                                 pi->progs->argv[0] = NULL;
1825                                 flag_rep = 1;
1826                         }
1827                         if (!(*list)) {
1828                                 free(pi->progs->argv[0]);
1829                                 free(save_list);
1830                                 list = NULL;
1831                                 flag_rep = 0;
1832                                 pi->progs->argv[0] = save_name;
1833 #ifndef __U_BOOT__
1834                                 pi->progs->glob_result.gl_pathv[0] =
1835                                         pi->progs->argv[0];
1836 #endif
1837                                 continue;
1838                         } else {
1839                                 /* insert new value from list for variable */
1840                                 if (pi->progs->argv[0])
1841                                         free(pi->progs->argv[0]);
1842                                 pi->progs->argv[0] = *list++;
1843 #ifndef __U_BOOT__
1844                                 pi->progs->glob_result.gl_pathv[0] =
1845                                         pi->progs->argv[0];
1846 #endif
1847                         }
1848                 }
1849                 if (rmode == RES_IN) continue;
1850                 if (rmode == RES_DO) {
1851                         if (!flag_rep) continue;
1852                 }
1853                 if ((rmode == RES_DONE)) {
1854                         if (flag_rep) {
1855                                 flag_restore = 1;
1856                         } else {
1857                                 rpipe = NULL;
1858                         }
1859                 }
1860                 if (pi->num_progs == 0) continue;
1861 #ifndef __U_BOOT__
1862                 save_num_progs = pi->num_progs; /* save number of programs */
1863 #endif
1864                 rcode = run_pipe_real(pi);
1865                 debug_printf("run_pipe_real returned %d\n",rcode);
1866 #ifndef __U_BOOT__
1867                 if (rcode!=-1) {
1868                         /* We only ran a builtin: rcode was set by the return value
1869                          * of run_pipe_real(), and we don't need to wait for anything. */
1870                 } else if (pi->followup==PIPE_BG) {
1871                         /* XXX check bash's behavior with nontrivial pipes */
1872                         /* XXX compute jobid */
1873                         /* XXX what does bash do with attempts to background builtins? */
1874                         insert_bg_job(pi);
1875                         rcode = EXIT_SUCCESS;
1876                 } else {
1877                         if (interactive) {
1878                                 /* move the new process group into the foreground */
1879                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1880                                         perror_msg("tcsetpgrp-3");
1881                                 rcode = checkjobs(pi);
1882                                 /* move the shell to the foreground */
1883                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1884                                         perror_msg("tcsetpgrp-4");
1885                         } else {
1886                                 rcode = checkjobs(pi);
1887                         }
1888                         debug_printf("checkjobs returned %d\n",rcode);
1889                 }
1890                 last_return_code=rcode;
1891 #else
1892                 if (rcode < -1) {
1893                         last_return_code = -rcode - 2;
1894                         return -2;      /* exit */
1895                 }
1896                 last_return_code=(rcode == 0) ? 0 : 1;
1897 #endif
1898 #ifndef __U_BOOT__
1899                 pi->num_progs = save_num_progs; /* restore number of programs */
1900 #endif
1901                 if ( rmode == RES_IF || rmode == RES_ELIF )
1902                         next_if_code=rcode;  /* can be overwritten a number of times */
1903                 if (rmode == RES_WHILE)
1904                         flag_rep = !last_return_code;
1905                 if (rmode == RES_UNTIL)
1906                         flag_rep = last_return_code;
1907                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1908                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1909                         skip_more_in_this_rmode=rmode;
1910 #ifndef __U_BOOT__
1911                 checkjobs(NULL);
1912 #endif
1913         }
1914         return rcode;
1915 }
1916
1917 /* broken, of course, but OK for testing */
1918 static char *indenter(int i)
1919 {
1920         static char blanks[]="                                    ";
1921         return &blanks[sizeof(blanks)-i-1];
1922 }
1923
1924 /* return code is the exit status of the pipe */
1925 static int free_pipe(struct pipe *pi, int indent)
1926 {
1927         char **p;
1928         struct child_prog *child;
1929 #ifndef __U_BOOT__
1930         struct redir_struct *r, *rnext;
1931 #endif
1932         int a, i, ret_code=0;
1933         char *ind = indenter(indent);
1934
1935 #ifndef __U_BOOT__
1936         if (pi->stopped_progs > 0)
1937                 return ret_code;
1938         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1939 #endif
1940         for (i=0; i<pi->num_progs; i++) {
1941                 child = &pi->progs[i];
1942                 final_printf("%s  command %d:\n",ind,i);
1943                 if (child->argv) {
1944                         for (a=0,p=child->argv; *p; a++,p++) {
1945                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1946                         }
1947 #ifndef __U_BOOT__
1948                         globfree(&child->glob_result);
1949 #else
1950                         for (a = 0; a < child->argc; a++) {
1951                                 free(child->argv[a]);
1952                         }
1953                                         free(child->argv);
1954                         child->argc = 0;
1955 #endif
1956                         child->argv=NULL;
1957                 } else if (child->group) {
1958 #ifndef __U_BOOT__
1959                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1960 #endif
1961                         ret_code = free_pipe_list(child->group,indent+3);
1962                         final_printf("%s   end group\n",ind);
1963                 } else {
1964                         final_printf("%s   (nil)\n",ind);
1965                 }
1966 #ifndef __U_BOOT__
1967                 for (r=child->redirects; r; r=rnext) {
1968                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
1969                         if (r->dup == -1) {
1970                                 /* guard against the case >$FOO, where foo is unset or blank */
1971                                 if (r->word.gl_pathv) {
1972                                         final_printf(" %s\n", *r->word.gl_pathv);
1973                                         globfree(&r->word);
1974                                 }
1975                         } else {
1976                                 final_printf("&%d\n", r->dup);
1977                         }
1978                         rnext=r->next;
1979                         free(r);
1980                 }
1981                 child->redirects=NULL;
1982 #endif
1983         }
1984         free(pi->progs);   /* children are an array, they get freed all at once */
1985         pi->progs=NULL;
1986         return ret_code;
1987 }
1988
1989 static int free_pipe_list(struct pipe *head, int indent)
1990 {
1991         int rcode=0;   /* if list has no members */
1992         struct pipe *pi, *next;
1993         char *ind = indenter(indent);
1994         for (pi=head; pi; pi=next) {
1995                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
1996                 rcode = free_pipe(pi, indent);
1997                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
1998                 next=pi->next;
1999                 pi->next=NULL;
2000                 free(pi);
2001         }
2002         return rcode;
2003 }
2004
2005 /* Select which version we will use */
2006 static int run_list(struct pipe *pi)
2007 {
2008         int rcode=0;
2009 #ifndef __U_BOOT__
2010         if (fake_mode==0) {
2011 #endif
2012                 rcode = run_list_real(pi);
2013 #ifndef __U_BOOT__
2014         }
2015 #endif
2016         /* free_pipe_list has the side effect of clearing memory
2017          * In the long run that function can be merged with run_list_real,
2018          * but doing that now would hobble the debugging effort. */
2019         free_pipe_list(pi,0);
2020         return rcode;
2021 }
2022
2023 /* The API for glob is arguably broken.  This routine pushes a non-matching
2024  * string into the output structure, removing non-backslashed backslashes.
2025  * If someone can prove me wrong, by performing this function within the
2026  * original glob(3) api, feel free to rewrite this routine into oblivion.
2027  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2028  * XXX broken if the last character is '\\', check that before calling.
2029  */
2030 #ifndef __U_BOOT__
2031 static int globhack(const char *src, int flags, glob_t *pglob)
2032 {
2033         int cnt=0, pathc;
2034         const char *s;
2035         char *dest;
2036         for (cnt=1, s=src; s && *s; s++) {
2037                 if (*s == '\\') s++;
2038                 cnt++;
2039         }
2040         dest = malloc(cnt);
2041         if (!dest) return GLOB_NOSPACE;
2042         if (!(flags & GLOB_APPEND)) {
2043                 pglob->gl_pathv=NULL;
2044                 pglob->gl_pathc=0;
2045                 pglob->gl_offs=0;
2046                 pglob->gl_offs=0;
2047         }
2048         pathc = ++pglob->gl_pathc;
2049         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2050         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2051         pglob->gl_pathv[pathc-1]=dest;
2052         pglob->gl_pathv[pathc]=NULL;
2053         for (s=src; s && *s; s++, dest++) {
2054                 if (*s == '\\') s++;
2055                 *dest = *s;
2056         }
2057         *dest='\0';
2058         return 0;
2059 }
2060
2061 /* XXX broken if the last character is '\\', check that before calling */
2062 static int glob_needed(const char *s)
2063 {
2064         for (; *s; s++) {
2065                 if (*s == '\\') s++;
2066                 if (strchr("*[?",*s)) return 1;
2067         }
2068         return 0;
2069 }
2070
2071 #if 0
2072 static void globprint(glob_t *pglob)
2073 {
2074         int i;
2075         debug_printf("glob_t at %p:\n", pglob);
2076         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2077                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2078         for (i=0; i<pglob->gl_pathc; i++)
2079                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2080                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2081 }
2082 #endif
2083
2084 static int xglob(o_string *dest, int flags, glob_t *pglob)
2085 {
2086         int gr;
2087
2088         /* short-circuit for null word */
2089         /* we can code this better when the debug_printf's are gone */
2090         if (dest->length == 0) {
2091                 if (dest->nonnull) {
2092                         /* bash man page calls this an "explicit" null */
2093                         gr = globhack(dest->data, flags, pglob);
2094                         debug_printf("globhack returned %d\n",gr);
2095                 } else {
2096                         return 0;
2097                 }
2098         } else if (glob_needed(dest->data)) {
2099                 gr = glob(dest->data, flags, NULL, pglob);
2100                 debug_printf("glob returned %d\n",gr);
2101                 if (gr == GLOB_NOMATCH) {
2102                         /* quote removal, or more accurately, backslash removal */
2103                         gr = globhack(dest->data, flags, pglob);
2104                         debug_printf("globhack returned %d\n",gr);
2105                 }
2106         } else {
2107                 gr = globhack(dest->data, flags, pglob);
2108                 debug_printf("globhack returned %d\n",gr);
2109         }
2110         if (gr == GLOB_NOSPACE)
2111                 error_msg_and_die("out of memory during glob");
2112         if (gr != 0) { /* GLOB_ABORTED ? */
2113                 error_msg("glob(3) error %d",gr);
2114         }
2115         /* globprint(glob_target); */
2116         return gr;
2117 }
2118 #endif
2119
2120 #ifdef __U_BOOT__
2121 static char *get_dollar_var(char ch);
2122 #endif
2123
2124 /* This is used to get/check local shell variables */
2125 char *get_local_var(const char *s)
2126 {
2127         struct variables *cur;
2128
2129         if (!s)
2130                 return NULL;
2131
2132 #ifdef __U_BOOT__
2133         if (*s == '$')
2134                 return get_dollar_var(s[1]);
2135 #endif
2136
2137         for (cur = top_vars; cur; cur=cur->next)
2138                 if(strcmp(cur->name, s)==0)
2139                         return cur->value;
2140         return NULL;
2141 }
2142
2143 /* This is used to set local shell variables
2144    flg_export==0 if only local (not exporting) variable
2145    flg_export==1 if "new" exporting environ
2146    flg_export>1  if current startup environ (not call putenv()) */
2147 int set_local_var(const char *s, int flg_export)
2148 {
2149         char *name, *value;
2150         int result=0;
2151         struct variables *cur;
2152
2153 #ifdef __U_BOOT__
2154         /* might be possible! */
2155         if (!isalpha(*s))
2156                 return -1;
2157 #endif
2158
2159         name=strdup(s);
2160
2161 #ifdef __U_BOOT__
2162         if (getenv(name) != NULL) {
2163                 printf ("ERROR: "
2164                                 "There is a global environment variable with the same name.\n");
2165                 free(name);
2166                 return -1;
2167         }
2168 #endif
2169         /* Assume when we enter this function that we are already in
2170          * NAME=VALUE format.  So the first order of business is to
2171          * split 's' on the '=' into 'name' and 'value' */
2172         value = strchr(name, '=');
2173         if (value==0 && ++value==0) {
2174                 free(name);
2175                 return -1;
2176         }
2177         *value++ = 0;
2178
2179         for(cur = top_vars; cur; cur = cur->next) {
2180                 if(strcmp(cur->name, name)==0)
2181                         break;
2182         }
2183
2184         if(cur) {
2185                 if(strcmp(cur->value, value)==0) {
2186                         if(flg_export>0 && cur->flg_export==0)
2187                                 cur->flg_export=flg_export;
2188                         else
2189                                 result++;
2190                 } else {
2191                         if(cur->flg_read_only) {
2192                                 error_msg("%s: readonly variable", name);
2193                                 result = -1;
2194                         } else {
2195                                 if(flg_export>0 || cur->flg_export>1)
2196                                         cur->flg_export=1;
2197                                 free(cur->value);
2198
2199                                 cur->value = strdup(value);
2200                         }
2201                 }
2202         } else {
2203                 cur = malloc(sizeof(struct variables));
2204                 if(!cur) {
2205                         result = -1;
2206                 } else {
2207                         cur->name = strdup(name);
2208                         if(cur->name == 0) {
2209                                 free(cur);
2210                                 result = -1;
2211                         } else {
2212                                 struct variables *bottom = top_vars;
2213                                 cur->value = strdup(value);
2214                                 cur->next = 0;
2215                                 cur->flg_export = flg_export;
2216                                 cur->flg_read_only = 0;
2217                                 while(bottom->next) bottom=bottom->next;
2218                                 bottom->next = cur;
2219                         }
2220                 }
2221         }
2222
2223 #ifndef __U_BOOT__
2224         if(result==0 && cur->flg_export==1) {
2225                 *(value-1) = '=';
2226                 result = putenv(name);
2227         } else {
2228 #endif
2229                 free(name);
2230 #ifndef __U_BOOT__
2231                 if(result>0)            /* equivalent to previous set */
2232                         result = 0;
2233         }
2234 #endif
2235         return result;
2236 }
2237
2238 void unset_local_var(const char *name)
2239 {
2240         struct variables *cur;
2241
2242         if (name) {
2243                 for (cur = top_vars; cur; cur=cur->next) {
2244                         if(strcmp(cur->name, name)==0)
2245                                 break;
2246                 }
2247                 if(cur!=0) {
2248                         struct variables *next = top_vars;
2249                         if(cur->flg_read_only) {
2250                                 error_msg("%s: readonly variable", name);
2251                                 return;
2252                         } else {
2253 #ifndef __U_BOOT__
2254                                 if(cur->flg_export)
2255                                         unsetenv(cur->name);
2256 #endif
2257                                 free(cur->name);
2258                                 free(cur->value);
2259                                 while (next->next != cur)
2260                                         next = next->next;
2261                                 next->next = cur->next;
2262                         }
2263                         free(cur);
2264                 }
2265         }
2266 }
2267
2268 static int is_assignment(const char *s)
2269 {
2270         if (s == NULL)
2271                 return 0;
2272
2273         if (!isalpha(*s)) return 0;
2274         ++s;
2275         while(isalnum(*s) || *s=='_') ++s;
2276         return *s=='=';
2277 }
2278
2279 #ifndef __U_BOOT__
2280 /* the src parameter allows us to peek forward to a possible &n syntax
2281  * for file descriptor duplication, e.g., "2>&1".
2282  * Return code is 0 normally, 1 if a syntax error is detected in src.
2283  * Resource errors (in xmalloc) cause the process to exit */
2284 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2285         struct in_str *input)
2286 {
2287         struct child_prog *child=ctx->child;
2288         struct redir_struct *redir = child->redirects;
2289         struct redir_struct *last_redir=NULL;
2290
2291         /* Create a new redir_struct and drop it onto the end of the linked list */
2292         while(redir) {
2293                 last_redir=redir;
2294                 redir=redir->next;
2295         }
2296         redir = xmalloc(sizeof(struct redir_struct));
2297         redir->next=NULL;
2298         redir->word.gl_pathv=NULL;
2299         if (last_redir) {
2300                 last_redir->next=redir;
2301         } else {
2302                 child->redirects=redir;
2303         }
2304
2305         redir->type=style;
2306         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2307
2308         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2309
2310         /* Check for a '2>&1' type redirect */
2311         redir->dup = redirect_dup_num(input);
2312         if (redir->dup == -2) return 1;  /* syntax error */
2313         if (redir->dup != -1) {
2314                 /* Erik had a check here that the file descriptor in question
2315                  * is legit; I postpone that to "run time"
2316                  * A "-" representation of "close me" shows up as a -3 here */
2317                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2318         } else {
2319                 /* We do _not_ try to open the file that src points to,
2320                  * since we need to return and let src be expanded first.
2321                  * Set ctx->pending_redirect, so we know what to do at the
2322                  * end of the next parsed word.
2323                  */
2324                 ctx->pending_redirect = redir;
2325         }
2326         return 0;
2327 }
2328 #endif
2329
2330 struct pipe *new_pipe(void) {
2331         struct pipe *pi;
2332         pi = xmalloc(sizeof(struct pipe));
2333         pi->num_progs = 0;
2334         pi->progs = NULL;
2335         pi->next = NULL;
2336         pi->followup = 0;  /* invalid */
2337         pi->r_mode = RES_NONE;
2338         return pi;
2339 }
2340
2341 static void initialize_context(struct p_context *ctx)
2342 {
2343         ctx->pipe=NULL;
2344 #ifndef __U_BOOT__
2345         ctx->pending_redirect=NULL;
2346 #endif
2347         ctx->child=NULL;
2348         ctx->list_head=new_pipe();
2349         ctx->pipe=ctx->list_head;
2350         ctx->w=RES_NONE;
2351         ctx->stack=NULL;
2352 #ifdef __U_BOOT__
2353         ctx->old_flag=0;
2354 #endif
2355         done_command(ctx);   /* creates the memory for working child */
2356 }
2357
2358 /* normal return is 0
2359  * if a reserved word is found, and processed, return 1
2360  * should handle if, then, elif, else, fi, for, while, until, do, done.
2361  * case, function, and select are obnoxious, save those for later.
2362  */
2363 struct reserved_combo {
2364         char *literal;
2365         int code;
2366         long flag;
2367 };
2368 /* Mostly a list of accepted follow-up reserved words.
2369  * FLAG_END means we are done with the sequence, and are ready
2370  * to turn the compound list into a command.
2371  * FLAG_START means the word must start a new compound list.
2372  */
2373 static struct reserved_combo reserved_list[] = {
2374         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2375         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2376         { "elif",  RES_ELIF,  FLAG_THEN },
2377         { "else",  RES_ELSE,  FLAG_FI   },
2378         { "fi",    RES_FI,    FLAG_END  },
2379         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2380         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2381         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2382         { "in",    RES_IN,    FLAG_DO   },
2383         { "do",    RES_DO,    FLAG_DONE },
2384         { "done",  RES_DONE,  FLAG_END  }
2385 };
2386 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2387
2388 int reserved_word(o_string *dest, struct p_context *ctx)
2389 {
2390         struct reserved_combo *r;
2391         for (r=reserved_list;
2392                 r<reserved_list+NRES; r++) {
2393                 if (strcmp(dest->data, r->literal) == 0) {
2394                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2395                         if (r->flag & FLAG_START) {
2396                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2397                                 debug_printf("push stack\n");
2398                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2399                                         syntax();
2400                                         free(new);
2401                                         ctx->w = RES_SNTX;
2402                                         b_reset(dest);
2403                                         return 1;
2404                                 }
2405                                 *new = *ctx;   /* physical copy */
2406                                 initialize_context(ctx);
2407                                 ctx->stack=new;
2408                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2409                                 syntax();
2410                                 ctx->w = RES_SNTX;
2411                                 b_reset(dest);
2412                                 return 1;
2413                         }
2414                         ctx->w=r->code;
2415                         ctx->old_flag = r->flag;
2416                         if (ctx->old_flag & FLAG_END) {
2417                                 struct p_context *old;
2418                                 debug_printf("pop stack\n");
2419                                 done_pipe(ctx,PIPE_SEQ);
2420                                 old = ctx->stack;
2421                                 old->child->group = ctx->list_head;
2422 #ifndef __U_BOOT__
2423                                 old->child->subshell = 0;
2424 #endif
2425                                 *ctx = *old;   /* physical copy */
2426                                 free(old);
2427                         }
2428                         b_reset (dest);
2429                         return 1;
2430                 }
2431         }
2432         return 0;
2433 }
2434
2435 /* normal return is 0.
2436  * Syntax or xglob errors return 1. */
2437 static int done_word(o_string *dest, struct p_context *ctx)
2438 {
2439         struct child_prog *child=ctx->child;
2440 #ifndef __U_BOOT__
2441         glob_t *glob_target;
2442         int gr, flags = 0;
2443 #else
2444         char *str, *s;
2445         int argc, cnt;
2446 #endif
2447
2448         debug_printf("done_word: %s %p\n", dest->data, child);
2449         if (dest->length == 0 && !dest->nonnull) {
2450                 debug_printf("  true null, ignored\n");
2451                 return 0;
2452         }
2453 #ifndef __U_BOOT__
2454         if (ctx->pending_redirect) {
2455                 glob_target = &ctx->pending_redirect->word;
2456         } else {
2457 #endif
2458                 if (child->group) {
2459                         syntax();
2460                         return 1;  /* syntax error, groups and arglists don't mix */
2461                 }
2462                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2463                         debug_printf("checking %s for reserved-ness\n",dest->data);
2464                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2465                 }
2466 #ifndef __U_BOOT__
2467                 glob_target = &child->glob_result;
2468                 if (child->argv) flags |= GLOB_APPEND;
2469 #else
2470                 for (cnt = 1, s = dest->data; s && *s; s++) {
2471                         if (*s == '\\') s++;
2472                         cnt++;
2473                 }
2474                 str = malloc(cnt);
2475                 if (!str) return 1;
2476                 if ( child->argv == NULL) {
2477                         child->argc=0;
2478                 }
2479                 argc = ++child->argc;
2480                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2481                 if (child->argv == NULL) return 1;
2482                 child->argv[argc-1]=str;
2483                 child->argv[argc]=NULL;
2484                 for (s = dest->data; s && *s; s++,str++) {
2485                         if (*s == '\\') s++;
2486                         *str = *s;
2487                 }
2488                 *str = '\0';
2489 #endif
2490 #ifndef __U_BOOT__
2491         }
2492         gr = xglob(dest, flags, glob_target);
2493         if (gr != 0) return 1;
2494 #endif
2495
2496         b_reset(dest);
2497 #ifndef __U_BOOT__
2498         if (ctx->pending_redirect) {
2499                 ctx->pending_redirect=NULL;
2500                 if (glob_target->gl_pathc != 1) {
2501                         error_msg("ambiguous redirect");
2502                         return 1;
2503                 }
2504         } else {
2505                 child->argv = glob_target->gl_pathv;
2506         }
2507 #endif
2508         if (ctx->w == RES_FOR) {
2509                 done_word(dest,ctx);
2510                 done_pipe(ctx,PIPE_SEQ);
2511         }
2512         return 0;
2513 }
2514
2515 /* The only possible error here is out of memory, in which case
2516  * xmalloc exits. */
2517 static int done_command(struct p_context *ctx)
2518 {
2519         /* The child is really already in the pipe structure, so
2520          * advance the pipe counter and make a new, null child.
2521          * Only real trickiness here is that the uncommitted
2522          * child structure, to which ctx->child points, is not
2523          * counted in pi->num_progs. */
2524         struct pipe *pi=ctx->pipe;
2525         struct child_prog *prog=ctx->child;
2526
2527         if (prog && prog->group == NULL
2528                  && prog->argv == NULL
2529 #ifndef __U_BOOT__
2530                  && prog->redirects == NULL) {
2531 #else
2532                                                                                 ) {
2533 #endif
2534                 debug_printf("done_command: skipping null command\n");
2535                 return 0;
2536         } else if (prog) {
2537                 pi->num_progs++;
2538                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2539         } else {
2540                 debug_printf("done_command: initializing\n");
2541         }
2542         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2543
2544         prog = pi->progs + pi->num_progs;
2545 #ifndef __U_BOOT__
2546         prog->redirects = NULL;
2547 #endif
2548         prog->argv = NULL;
2549 #ifndef __U_BOOT__
2550         prog->is_stopped = 0;
2551 #endif
2552         prog->group = NULL;
2553 #ifndef __U_BOOT__
2554         prog->glob_result.gl_pathv = NULL;
2555         prog->family = pi;
2556 #endif
2557         prog->sp = 0;
2558         ctx->child = prog;
2559         prog->type = ctx->type;
2560
2561         /* but ctx->pipe and ctx->list_head remain unchanged */
2562         return 0;
2563 }
2564
2565 static int done_pipe(struct p_context *ctx, pipe_style type)
2566 {
2567         struct pipe *new_p;
2568         done_command(ctx);  /* implicit closure of previous command */
2569         debug_printf("done_pipe, type %d\n", type);
2570         ctx->pipe->followup = type;
2571         ctx->pipe->r_mode = ctx->w;
2572         new_p=new_pipe();
2573         ctx->pipe->next = new_p;
2574         ctx->pipe = new_p;
2575         ctx->child = NULL;
2576         done_command(ctx);  /* set up new pipe to accept commands */
2577         return 0;
2578 }
2579
2580 #ifndef __U_BOOT__
2581 /* peek ahead in the in_str to find out if we have a "&n" construct,
2582  * as in "2>&1", that represents duplicating a file descriptor.
2583  * returns either -2 (syntax error), -1 (no &), or the number found.
2584  */
2585 static int redirect_dup_num(struct in_str *input)
2586 {
2587         int ch, d=0, ok=0;
2588         ch = b_peek(input);
2589         if (ch != '&') return -1;
2590
2591         b_getch(input);  /* get the & */
2592         ch=b_peek(input);
2593         if (ch == '-') {
2594                 b_getch(input);
2595                 return -3;  /* "-" represents "close me" */
2596         }
2597         while (isdigit(ch)) {
2598                 d = d*10+(ch-'0');
2599                 ok=1;
2600                 b_getch(input);
2601                 ch = b_peek(input);
2602         }
2603         if (ok) return d;
2604
2605         error_msg("ambiguous redirect");
2606         return -2;
2607 }
2608
2609 /* If a redirect is immediately preceded by a number, that number is
2610  * supposed to tell which file descriptor to redirect.  This routine
2611  * looks for such preceding numbers.  In an ideal world this routine
2612  * needs to handle all the following classes of redirects...
2613  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2614  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2615  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2616  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2617  * A -1 output from this program means no valid number was found, so the
2618  * caller should use the appropriate default for this redirection.
2619  */
2620 static int redirect_opt_num(o_string *o)
2621 {
2622         int num;
2623
2624         if (o->length==0) return -1;
2625         for(num=0; num<o->length; num++) {
2626                 if (!isdigit(*(o->data+num))) {
2627                         return -1;
2628                 }
2629         }
2630         /* reuse num (and save an int) */
2631         num=atoi(o->data);
2632         b_reset(o);
2633         return num;
2634 }
2635
2636 FILE *generate_stream_from_list(struct pipe *head)
2637 {
2638         FILE *pf;
2639 #if 1
2640         int pid, channel[2];
2641         if (pipe(channel)<0) perror_msg_and_die("pipe");
2642         pid=fork();
2643         if (pid<0) {
2644                 perror_msg_and_die("fork");
2645         } else if (pid==0) {
2646                 close(channel[0]);
2647                 if (channel[1] != 1) {
2648                         dup2(channel[1],1);
2649                         close(channel[1]);
2650                 }
2651 #if 0
2652 #define SURROGATE "surrogate response"
2653                 write(1,SURROGATE,sizeof(SURROGATE));
2654                 _exit(run_list(head));
2655 #else
2656                 _exit(run_list_real(head));   /* leaks memory */
2657 #endif
2658         }
2659         debug_printf("forked child %d\n",pid);
2660         close(channel[1]);
2661         pf = fdopen(channel[0],"r");
2662         debug_printf("pipe on FILE *%p\n",pf);
2663 #else
2664         free_pipe_list(head,0);
2665         pf=popen("echo surrogate response","r");
2666         debug_printf("started fake pipe on FILE *%p\n",pf);
2667 #endif
2668         return pf;
2669 }
2670
2671 /* this version hacked for testing purposes */
2672 /* return code is exit status of the process that is run. */
2673 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2674 {
2675         int retcode;
2676         o_string result=NULL_O_STRING;
2677         struct p_context inner;
2678         FILE *p;
2679         struct in_str pipe_str;
2680         initialize_context(&inner);
2681
2682         /* recursion to generate command */
2683         retcode = parse_stream(&result, &inner, input, subst_end);
2684         if (retcode != 0) return retcode;  /* syntax error or EOF */
2685         done_word(&result, &inner);
2686         done_pipe(&inner, PIPE_SEQ);
2687         b_free(&result);
2688
2689         p=generate_stream_from_list(inner.list_head);
2690         if (p==NULL) return 1;
2691         mark_open(fileno(p));
2692         setup_file_in_str(&pipe_str, p);
2693
2694         /* now send results of command back into original context */
2695         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2696         /* XXX In case of a syntax error, should we try to kill the child?
2697          * That would be tough to do right, so just read until EOF. */
2698         if (retcode == 1) {
2699                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2700         }
2701
2702         debug_printf("done reading from pipe, pclose()ing\n");
2703         /* This is the step that wait()s for the child.  Should be pretty
2704          * safe, since we just read an EOF from its stdout.  We could try
2705          * to better, by using wait(), and keeping track of background jobs
2706          * at the same time.  That would be a lot of work, and contrary
2707          * to the KISS philosophy of this program. */
2708         mark_closed(fileno(p));
2709         retcode=pclose(p);
2710         free_pipe_list(inner.list_head,0);
2711         debug_printf("pclosed, retcode=%d\n",retcode);
2712         /* XXX this process fails to trim a single trailing newline */
2713         return retcode;
2714 }
2715
2716 static int parse_group(o_string *dest, struct p_context *ctx,
2717         struct in_str *input, int ch)
2718 {
2719         int rcode, endch=0;
2720         struct p_context sub;
2721         struct child_prog *child = ctx->child;
2722         if (child->argv) {
2723                 syntax();
2724                 return 1;  /* syntax error, groups and arglists don't mix */
2725         }
2726         initialize_context(&sub);
2727         switch(ch) {
2728                 case '(': endch=')'; child->subshell=1; break;
2729                 case '{': endch='}'; break;
2730                 default: syntax();   /* really logic error */
2731         }
2732         rcode=parse_stream(dest,&sub,input,endch);
2733         done_word(dest,&sub); /* finish off the final word in the subcontext */
2734         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2735         child->group = sub.list_head;
2736         return rcode;
2737         /* child remains "open", available for possible redirects */
2738 }
2739 #endif
2740
2741 /* basically useful version until someone wants to get fancier,
2742  * see the bash man page under "Parameter Expansion" */
2743 static char *lookup_param(char *src)
2744 {
2745         char *p;
2746         char *sep;
2747         char *default_val = NULL;
2748         int assign = 0;
2749         int expand_empty = 0;
2750
2751         if (!src)
2752                 return NULL;
2753
2754         sep = strchr(src, ':');
2755
2756         if (sep) {
2757                 *sep = '\0';
2758                 if (*(sep + 1) == '-')
2759                         default_val = sep+2;
2760                 if (*(sep + 1) == '=') {
2761                         default_val = sep+2;
2762                         assign = 1;
2763                 }
2764                 if (*(sep + 1) == '+') {
2765                         default_val = sep+2;
2766                         expand_empty = 1;
2767                 }
2768         }
2769
2770         p = getenv(src);
2771         if (!p)
2772                 p = get_local_var(src);
2773
2774         if (!p || strlen(p) == 0) {
2775                 p = default_val;
2776                 if (assign) {
2777                         char *var = malloc(strlen(src)+strlen(default_val)+2);
2778                         if (var) {
2779                                 sprintf(var, "%s=%s", src, default_val);
2780                                 set_local_var(var, 0);
2781                         }
2782                         free(var);
2783                 }
2784         } else if (expand_empty) {
2785                 p += strlen(p);
2786         }
2787
2788         if (sep)
2789                 *sep = ':';
2790
2791         return p;
2792 }
2793
2794 #ifdef __U_BOOT__
2795 static char *get_dollar_var(char ch)
2796 {
2797         static char buf[40];
2798
2799         buf[0] = '\0';
2800         switch (ch) {
2801                 case '?':
2802                         sprintf(buf, "%u", (unsigned int)last_return_code);
2803                         break;
2804                 default:
2805                         return NULL;
2806         }
2807         return buf;
2808 }
2809 #endif
2810
2811 /* return code: 0 for OK, 1 for syntax error */
2812 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2813 {
2814 #ifndef __U_BOOT__
2815         int i, advance=0;
2816 #else
2817         int advance=0;
2818 #endif
2819 #ifndef __U_BOOT__
2820         char sep[]=" ";
2821 #endif
2822         int ch = input->peek(input);  /* first character after the $ */
2823         debug_printf("handle_dollar: ch=%c\n",ch);
2824         if (isalpha(ch)) {
2825                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2826                 ctx->child->sp++;
2827                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2828                         b_getch(input);
2829                         b_addchr(dest,ch);
2830                 }
2831                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2832 #ifndef __U_BOOT__
2833         } else if (isdigit(ch)) {
2834                 i = ch-'0';  /* XXX is $0 special? */
2835                 if (i<global_argc) {
2836                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2837                 }
2838                 advance = 1;
2839 #endif
2840         } else switch (ch) {
2841 #ifndef __U_BOOT__
2842                 case '$':
2843                         b_adduint(dest,getpid());
2844                         advance = 1;
2845                         break;
2846                 case '!':
2847                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2848                         advance = 1;
2849                         break;
2850 #endif
2851                 case '?':
2852 #ifndef __U_BOOT__
2853                         b_adduint(dest,last_return_code);
2854 #else
2855                         ctx->child->sp++;
2856                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2857                         b_addchr(dest, '$');
2858                         b_addchr(dest, '?');
2859                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2860 #endif
2861                         advance = 1;
2862                         break;
2863 #ifndef __U_BOOT__
2864                 case '#':
2865                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2866                         advance = 1;
2867                         break;
2868 #endif
2869                 case '{':
2870                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2871                         ctx->child->sp++;
2872                         b_getch(input);
2873                         /* XXX maybe someone will try to escape the '}' */
2874                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2875                                 b_addchr(dest,ch);
2876                         }
2877                         if (ch != '}') {
2878                                 syntax();
2879                                 return 1;
2880                         }
2881                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2882                         break;
2883 #ifndef __U_BOOT__
2884                 case '(':
2885                         b_getch(input);
2886                         process_command_subs(dest, ctx, input, ')');
2887                         break;
2888                 case '*':
2889                         sep[0]=ifs[0];
2890                         for (i=1; i<global_argc; i++) {
2891                                 parse_string(dest, ctx, global_argv[i]);
2892                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2893                         }
2894                         break;
2895                 case '@':
2896                 case '-':
2897                 case '_':
2898                         /* still unhandled, but should be eventually */
2899                         error_msg("unhandled syntax: $%c",ch);
2900                         return 1;
2901                         break;
2902 #endif
2903                 default:
2904                         b_addqchr(dest,'$',dest->quote);
2905         }
2906         /* Eat the character if the flag was set.  If the compiler
2907          * is smart enough, we could substitute "b_getch(input);"
2908          * for all the "advance = 1;" above, and also end up with
2909          * a nice size-optimized program.  Hah!  That'll be the day.
2910          */
2911         if (advance) b_getch(input);
2912         return 0;
2913 }
2914
2915 #ifndef __U_BOOT__
2916 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2917 {
2918         struct in_str foo;
2919         setup_string_in_str(&foo, src);
2920         return parse_stream(dest, ctx, &foo, '\0');
2921 }
2922 #endif
2923
2924 /* return code is 0 for normal exit, 1 for syntax error */
2925 int parse_stream(o_string *dest, struct p_context *ctx,
2926         struct in_str *input, int end_trigger)
2927 {
2928         unsigned int ch, m;
2929 #ifndef __U_BOOT__
2930         int redir_fd;
2931         redir_type redir_style;
2932 #endif
2933         int next;
2934
2935         /* Only double-quote state is handled in the state variable dest->quote.
2936          * A single-quote triggers a bypass of the main loop until its mate is
2937          * found.  When recursing, quote state is passed in via dest->quote. */
2938
2939         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2940         while ((ch=b_getch(input))!=EOF) {
2941                 m = map[ch];
2942 #ifdef __U_BOOT__
2943                 if (input->__promptme == 0) return 1;
2944 #endif
2945                 next = (ch == '\n') ? 0 : b_peek(input);
2946
2947                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2948                         ch >= ' ' ? ch : '.', ch, m,
2949                         dest->quote, ctx->stack == NULL ? '*' : '.');
2950
2951                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2952                         b_addqchr(dest, ch, dest->quote);
2953                 } else {
2954                         if (m==2) {  /* unquoted IFS */
2955                                 if (done_word(dest, ctx)) {
2956                                         return 1;
2957                                 }
2958                                 /* If we aren't performing a substitution, treat a newline as a
2959                                  * command separator.  */
2960                                 if (end_trigger != '\0' && ch=='\n')
2961                                         done_pipe(ctx,PIPE_SEQ);
2962                         }
2963                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2964                                 debug_printf("leaving parse_stream (triggered)\n");
2965                                 return 0;
2966                         }
2967 #if 0
2968                         if (ch=='\n') {
2969                                 /* Yahoo!  Time to run with it! */
2970                                 done_pipe(ctx,PIPE_SEQ);
2971                                 run_list(ctx->list_head);
2972                                 initialize_context(ctx);
2973                         }
2974 #endif
2975                         if (m!=2) switch (ch) {
2976                 case '#':
2977                         if (dest->length == 0 && !dest->quote) {
2978                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2979                         } else {
2980                                 b_addqchr(dest, ch, dest->quote);
2981                         }
2982                         break;
2983                 case '\\':
2984                         if (next == EOF) {
2985                                 syntax();
2986                                 return 1;
2987                         }
2988                         b_addqchr(dest, '\\', dest->quote);
2989                         b_addqchr(dest, b_getch(input), dest->quote);
2990                         break;
2991                 case '$':
2992                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2993                         break;
2994                 case '\'':
2995                         dest->nonnull = 1;
2996                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2997 #ifdef __U_BOOT__
2998                                 if(input->__promptme == 0) return 1;
2999 #endif
3000                                 b_addchr(dest,ch);
3001                         }
3002                         if (ch==EOF) {
3003                                 syntax();
3004                                 return 1;
3005                         }
3006                         break;
3007                 case '"':
3008                         dest->nonnull = 1;
3009                         dest->quote = !dest->quote;
3010                         break;
3011 #ifndef __U_BOOT__
3012                 case '`':
3013                         process_command_subs(dest, ctx, input, '`');
3014                         break;
3015                 case '>':
3016                         redir_fd = redirect_opt_num(dest);
3017                         done_word(dest, ctx);
3018                         redir_style=REDIRECT_OVERWRITE;
3019                         if (next == '>') {
3020                                 redir_style=REDIRECT_APPEND;
3021                                 b_getch(input);
3022                         } else if (next == '(') {
3023                                 syntax();   /* until we support >(list) Process Substitution */
3024                                 return 1;
3025                         }
3026                         setup_redirect(ctx, redir_fd, redir_style, input);
3027                         break;
3028                 case '<':
3029                         redir_fd = redirect_opt_num(dest);
3030                         done_word(dest, ctx);
3031                         redir_style=REDIRECT_INPUT;
3032                         if (next == '<') {
3033                                 redir_style=REDIRECT_HEREIS;
3034                                 b_getch(input);
3035                         } else if (next == '>') {
3036                                 redir_style=REDIRECT_IO;
3037                                 b_getch(input);
3038                         } else if (next == '(') {
3039                                 syntax();   /* until we support <(list) Process Substitution */
3040                                 return 1;
3041                         }
3042                         setup_redirect(ctx, redir_fd, redir_style, input);
3043                         break;
3044 #endif
3045                 case ';':
3046                         done_word(dest, ctx);
3047                         done_pipe(ctx,PIPE_SEQ);
3048                         break;
3049                 case '&':
3050                         done_word(dest, ctx);
3051                         if (next=='&') {
3052                                 b_getch(input);
3053                                 done_pipe(ctx,PIPE_AND);
3054                         } else {
3055 #ifndef __U_BOOT__
3056                                 done_pipe(ctx,PIPE_BG);
3057 #else
3058                                 syntax_err();
3059                                 return 1;
3060 #endif
3061                         }
3062                         break;
3063                 case '|':
3064                         done_word(dest, ctx);
3065                         if (next=='|') {
3066                                 b_getch(input);
3067                                 done_pipe(ctx,PIPE_OR);
3068                         } else {
3069                                 /* we could pick up a file descriptor choice here
3070                                  * with redirect_opt_num(), but bash doesn't do it.
3071                                  * "echo foo 2| cat" yields "foo 2". */
3072 #ifndef __U_BOOT__
3073                                 done_command(ctx);
3074 #else
3075                                 syntax_err();
3076                                 return 1;
3077 #endif
3078                         }
3079                         break;
3080 #ifndef __U_BOOT__
3081                 case '(':
3082                 case '{':
3083                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3084                         break;
3085                 case ')':
3086                 case '}':
3087                         syntax();   /* Proper use of this character caught by end_trigger */
3088                         return 1;
3089                         break;
3090 #endif
3091                 default:
3092                         syntax();   /* this is really an internal logic error */
3093                         return 1;
3094                         }
3095                 }
3096         }
3097         /* complain if quote?  No, maybe we just finished a command substitution
3098          * that was quoted.  Example:
3099          * $ echo "`cat foo` plus more"
3100          * and we just got the EOF generated by the subshell that ran "cat foo"
3101          * The only real complaint is if we got an EOF when end_trigger != '\0',
3102          * that is, we were really supposed to get end_trigger, and never got
3103          * one before the EOF.  Can't use the standard "syntax error" return code,
3104          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3105         debug_printf("leaving parse_stream (EOF)\n");
3106         if (end_trigger != '\0') return -1;
3107         return 0;
3108 }
3109
3110 void mapset(const unsigned char *set, int code)
3111 {
3112         const unsigned char *s;
3113         for (s=set; *s; s++) map[*s] = code;
3114 }
3115
3116 void update_ifs_map(void)
3117 {
3118         /* char *ifs and char map[256] are both globals. */
3119         ifs = (uchar *)getenv("IFS");
3120         if (ifs == NULL) ifs=(uchar *)" \t\n";
3121         /* Precompute a list of 'flow through' behavior so it can be treated
3122          * quickly up front.  Computation is necessary because of IFS.
3123          * Special case handling of IFS == " \t\n" is not implemented.
3124          * The map[] array only really needs two bits each, and on most machines
3125          * that would be faster because of the reduced L1 cache footprint.
3126          */
3127         memset(map,0,sizeof(map)); /* most characters flow through always */
3128 #ifndef __U_BOOT__
3129         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3130         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3131 #else
3132         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3133         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3134 #endif
3135         mapset(ifs, 2);            /* also flow through if quoted */
3136 }
3137
3138 /* most recursion does not come through here, the exeception is
3139  * from builtin_source() */
3140 int parse_stream_outer(struct in_str *inp, int flag)
3141 {
3142
3143         struct p_context ctx;
3144         o_string temp=NULL_O_STRING;
3145         int rcode;
3146 #ifdef __U_BOOT__
3147         int code = 0;
3148 #endif
3149         do {
3150                 ctx.type = flag;
3151                 initialize_context(&ctx);
3152                 update_ifs_map();
3153                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3154                 inp->promptmode=1;
3155                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3156 #ifdef __U_BOOT__
3157                 if (rcode == 1) flag_repeat = 0;
3158 #endif
3159                 if (rcode != 1 && ctx.old_flag != 0) {
3160                         syntax();
3161 #ifdef __U_BOOT__
3162                         flag_repeat = 0;
3163 #endif
3164                 }
3165                 if (rcode != 1 && ctx.old_flag == 0) {
3166                         done_word(&temp, &ctx);
3167                         done_pipe(&ctx,PIPE_SEQ);
3168 #ifndef __U_BOOT__
3169                         run_list(ctx.list_head);
3170 #else
3171                         code = run_list(ctx.list_head);
3172                         if (code == -2) {       /* exit */
3173                                 b_free(&temp);
3174                                 code = 0;
3175                                 /* XXX hackish way to not allow exit from main loop */
3176                                 if (inp->peek == file_peek) {
3177                                         printf("exit not allowed from main input shell.\n");
3178                                         continue;
3179                                 }
3180                                 break;
3181                         }
3182                         if (code == -1)
3183                             flag_repeat = 0;
3184 #endif
3185                 } else {
3186                         if (ctx.old_flag != 0) {
3187                                 free(ctx.stack);
3188                                 b_reset(&temp);
3189                         }
3190 #ifdef __U_BOOT__
3191                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3192                         inp->__promptme = 1;
3193 #endif
3194                         temp.nonnull = 0;
3195                         temp.quote = 0;
3196                         inp->p = NULL;
3197                         free_pipe_list(ctx.list_head,0);
3198                 }
3199                 b_free(&temp);
3200         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3201 #ifndef __U_BOOT__
3202         return 0;
3203 #else
3204         return (code != 0) ? 1 : 0;
3205 #endif /* __U_BOOT__ */
3206 }
3207
3208 #ifndef __U_BOOT__
3209 static int parse_string_outer(const char *s, int flag)
3210 #else
3211 int parse_string_outer(const char *s, int flag)
3212 #endif  /* __U_BOOT__ */
3213 {
3214         struct in_str input;
3215 #ifdef __U_BOOT__
3216         char *p = NULL;
3217         int rcode;
3218         if ( !s || !*s)
3219                 return 1;
3220         if (!(p = strchr(s, '\n')) || *++p) {
3221                 p = xmalloc(strlen(s) + 2);
3222                 strcpy(p, s);
3223                 strcat(p, "\n");
3224                 setup_string_in_str(&input, p);
3225                 rcode = parse_stream_outer(&input, flag);
3226                 free(p);
3227                 return rcode;
3228         } else {
3229 #endif
3230         setup_string_in_str(&input, s);
3231         return parse_stream_outer(&input, flag);
3232 #ifdef __U_BOOT__
3233         }
3234 #endif
3235 }
3236
3237 #ifndef __U_BOOT__
3238 static int parse_file_outer(FILE *f)
3239 #else
3240 int parse_file_outer(void)
3241 #endif
3242 {
3243         int rcode;
3244         struct in_str input;
3245 #ifndef __U_BOOT__
3246         setup_file_in_str(&input, f);
3247 #else
3248         setup_file_in_str(&input);
3249 #endif
3250         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3251         return rcode;
3252 }
3253
3254 #ifdef __U_BOOT__
3255 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3256 static void u_boot_hush_reloc(void)
3257 {
3258         unsigned long addr;
3259         struct reserved_combo *r;
3260
3261         for (r=reserved_list; r<reserved_list+NRES; r++) {
3262                 addr = (ulong) (r->literal) + gd->reloc_off;
3263                 r->literal = (char *)addr;
3264         }
3265 }
3266 #endif
3267
3268 int u_boot_hush_start(void)
3269 {
3270         if (top_vars == NULL) {
3271                 top_vars = malloc(sizeof(struct variables));
3272                 top_vars->name = "HUSH_VERSION";
3273                 top_vars->value = "0.01";
3274                 top_vars->next = 0;
3275                 top_vars->flg_export = 0;
3276                 top_vars->flg_read_only = 1;
3277 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3278                 u_boot_hush_reloc();
3279 #endif
3280         }
3281         return 0;
3282 }
3283
3284 static void *xmalloc(size_t size)
3285 {
3286         void *p = NULL;
3287
3288         if (!(p = malloc(size))) {
3289             printf("ERROR : memory not allocated\n");
3290             for(;;);
3291         }
3292         return p;
3293 }
3294
3295 static void *xrealloc(void *ptr, size_t size)
3296 {
3297         void *p = NULL;
3298
3299         if (!(p = realloc(ptr, size))) {
3300             printf("ERROR : memory not allocated\n");
3301             for(;;);
3302         }
3303         return p;
3304 }
3305 #endif /* __U_BOOT__ */
3306
3307 #ifndef __U_BOOT__
3308 /* Make sure we have a controlling tty.  If we get started under a job
3309  * aware app (like bash for example), make sure we are now in charge so
3310  * we don't fight over who gets the foreground */
3311 static void setup_job_control(void)
3312 {
3313         static pid_t shell_pgrp;
3314         /* Loop until we are in the foreground.  */
3315         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3316                 kill (- shell_pgrp, SIGTTIN);
3317
3318         /* Ignore interactive and job-control signals.  */
3319         signal(SIGINT, SIG_IGN);
3320         signal(SIGQUIT, SIG_IGN);
3321         signal(SIGTERM, SIG_IGN);
3322         signal(SIGTSTP, SIG_IGN);
3323         signal(SIGTTIN, SIG_IGN);
3324         signal(SIGTTOU, SIG_IGN);
3325         signal(SIGCHLD, SIG_IGN);
3326
3327         /* Put ourselves in our own process group.  */
3328         setsid();
3329         shell_pgrp = getpid ();
3330         setpgid (shell_pgrp, shell_pgrp);
3331
3332         /* Grab control of the terminal.  */
3333         tcsetpgrp(shell_terminal, shell_pgrp);
3334 }
3335
3336 int hush_main(int argc, char * const *argv)
3337 {
3338         int opt;
3339         FILE *input;
3340         char **e = environ;
3341
3342         /* XXX what should these be while sourcing /etc/profile? */
3343         global_argc = argc;
3344         global_argv = argv;
3345
3346         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3347          * hush_main(), therefore we cannot rely on the BSS to zero out this
3348          * stuff.  Reset these to 0 every time. */
3349         ifs = NULL;
3350         /* map[] is taken care of with call to update_ifs_map() */
3351         fake_mode = 0;
3352         interactive = 0;
3353         close_me_head = NULL;
3354         last_bg_pid = 0;
3355         job_list = NULL;
3356         last_jobid = 0;
3357
3358         /* Initialize some more globals to non-zero values */
3359         set_cwd();
3360 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3361         cmdedit_set_initial_prompt();
3362 #else
3363         PS1 = NULL;
3364 #endif
3365         PS2 = "> ";
3366
3367         /* initialize our shell local variables with the values
3368          * currently living in the environment */
3369         if (e) {
3370                 for (; *e; e++)
3371                         set_local_var(*e, 2);   /* without call putenv() */
3372         }
3373
3374         last_return_code=EXIT_SUCCESS;
3375
3376
3377         if (argv[0] && argv[0][0] == '-') {
3378                 debug_printf("\nsourcing /etc/profile\n");
3379                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3380                         mark_open(fileno(input));
3381                         parse_file_outer(input);
3382                         mark_closed(fileno(input));
3383                         fclose(input);
3384                 }
3385         }
3386         input=stdin;
3387
3388         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3389                 switch (opt) {
3390                         case 'c':
3391                                 {
3392                                         global_argv = argv+optind;
3393                                         global_argc = argc-optind;
3394                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3395                                         goto final_return;
3396                                 }
3397                                 break;
3398                         case 'i':
3399                                 interactive++;
3400                                 break;
3401                         case 'f':
3402                                 fake_mode++;
3403                                 break;
3404                         default:
3405 #ifndef BB_VER
3406                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3407                                                 "   or: sh -c command [args]...\n\n");
3408                                 exit(EXIT_FAILURE);
3409 #else
3410                                 show_usage();
3411 #endif
3412                 }
3413         }
3414         /* A shell is interactive if the `-i' flag was given, or if all of
3415          * the following conditions are met:
3416          *        no -c command
3417          *    no arguments remaining or the -s flag given
3418          *    standard input is a terminal
3419          *    standard output is a terminal
3420          *    Refer to Posix.2, the description of the `sh' utility. */
3421         if (argv[optind]==NULL && input==stdin &&
3422                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3423                 interactive++;
3424         }
3425
3426         debug_printf("\ninteractive=%d\n", interactive);
3427         if (interactive) {
3428                 /* Looks like they want an interactive shell */
3429 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3430                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3431                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3432 #endif
3433                 setup_job_control();
3434         }
3435
3436         if (argv[optind]==NULL) {
3437                 opt=parse_file_outer(stdin);
3438                 goto final_return;
3439         }
3440
3441         debug_printf("\nrunning script '%s'\n", argv[optind]);
3442         global_argv = argv+optind;
3443         global_argc = argc-optind;
3444         input = xfopen(argv[optind], "r");
3445         opt = parse_file_outer(input);
3446
3447 #ifdef CONFIG_FEATURE_CLEAN_UP
3448         fclose(input);
3449         if (cwd && cwd != unknown)
3450                 free((char*)cwd);
3451         {
3452                 struct variables *cur, *tmp;
3453                 for(cur = top_vars; cur; cur = tmp) {
3454                         tmp = cur->next;
3455                         if (!cur->flg_read_only) {
3456                                 free(cur->name);
3457                                 free(cur->value);
3458                                 free(cur);
3459                         }
3460                 }
3461         }
3462 #endif
3463
3464 final_return:
3465         return(opt?opt:last_return_code);
3466 }
3467 #endif
3468
3469 static char *insert_var_value(char *inp)
3470 {
3471         int res_str_len = 0;
3472         int len;
3473         int done = 0;
3474         char *p, *p1, *res_str = NULL;
3475
3476         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3477                 if (p != inp) {
3478                         len = p - inp;
3479                         res_str = xrealloc(res_str, (res_str_len + len));
3480                         strncpy((res_str + res_str_len), inp, len);
3481                         res_str_len += len;
3482                 }
3483                 inp = ++p;
3484                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3485                 *p = '\0';
3486                 if ((p1 = lookup_param(inp))) {
3487                         len = res_str_len + strlen(p1);
3488                         res_str = xrealloc(res_str, (1 + len));
3489                         strcpy((res_str + res_str_len), p1);
3490                         res_str_len = len;
3491                 }
3492                 *p = SPECIAL_VAR_SYMBOL;
3493                 inp = ++p;
3494                 done = 1;
3495         }
3496         if (done) {
3497                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3498                 strcpy((res_str + res_str_len), inp);
3499                 while ((p = strchr(res_str, '\n'))) {
3500                         *p = ' ';
3501                 }
3502         }
3503         return (res_str == NULL) ? inp : res_str;
3504 }
3505
3506 static char **make_list_in(char **inp, char *name)
3507 {
3508         int len, i;
3509         int name_len = strlen(name);
3510         int n = 0;
3511         char **list;
3512         char *p1, *p2, *p3;
3513
3514         /* create list of variable values */
3515         list = xmalloc(sizeof(*list));
3516         for (i = 0; inp[i]; i++) {
3517                 p3 = insert_var_value(inp[i]);
3518                 p1 = p3;
3519                 while (*p1) {
3520                         if ((*p1 == ' ')) {
3521                                 p1++;
3522                                 continue;
3523                         }
3524                         if ((p2 = strchr(p1, ' '))) {
3525                                 len = p2 - p1;
3526                         } else {
3527                                 len = strlen(p1);
3528                                 p2 = p1 + len;
3529                         }
3530                         /* we use n + 2 in realloc for list,because we add
3531                          * new element and then we will add NULL element */
3532                         list = xrealloc(list, sizeof(*list) * (n + 2));
3533                         list[n] = xmalloc(2 + name_len + len);
3534                         strcpy(list[n], name);
3535                         strcat(list[n], "=");
3536                         strncat(list[n], p1, len);
3537                         list[n++][name_len + len + 1] = '\0';
3538                         p1 = p2;
3539                 }
3540                 if (p3 != inp[i]) free(p3);
3541         }
3542         list[n] = NULL;
3543         return list;
3544 }
3545
3546 /* Make new string for parser */
3547 static char * make_string(char ** inp)
3548 {
3549         char *p;
3550         char *str = NULL;
3551         int n;
3552         int len = 2;
3553
3554         for (n = 0; inp[n]; n++) {
3555                 p = insert_var_value(inp[n]);
3556                 str = xrealloc(str, (len + strlen(p)));
3557                 if (n) {
3558                         strcat(str, " ");
3559                 } else {
3560                         *str = '\0';
3561                 }
3562                 strcat(str, p);
3563                 len = strlen(str) + 3;
3564                 if (p != inp[n]) free(p);
3565         }
3566         len = strlen(str);
3567         *(str + len) = '\n';
3568         *(str + len + 1) = '\0';
3569         return str;
3570 }
3571
3572 #ifdef __U_BOOT__
3573 int do_showvar (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
3574 {
3575         int i, k;
3576         int rcode = 0;
3577         struct variables *cur;
3578
3579         if (argc == 1) {                /* Print all env variables      */
3580                 for (cur = top_vars; cur; cur = cur->next) {
3581                         printf ("%s=%s\n", cur->name, cur->value);
3582                         if (ctrlc ()) {
3583                                 puts ("\n ** Abort\n");
3584                                 return 1;
3585                         }
3586                 }
3587                 return 0;
3588         }
3589         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3590                 char *name = argv[i];
3591
3592                 k = -1;
3593                 for (cur = top_vars; cur; cur = cur->next) {
3594                         if(strcmp (cur->name, name) == 0) {
3595                                 k = 0;
3596                                 printf ("%s=%s\n", cur->name, cur->value);
3597                         }
3598                         if (ctrlc ()) {
3599                                 puts ("\n ** Abort\n");
3600                                 return 1;
3601                         }
3602                 }
3603                 if (k < 0) {
3604                         printf ("## Error: \"%s\" not defined\n", name);
3605                         rcode ++;
3606                 }
3607         }
3608         return rcode;
3609 }
3610
3611 U_BOOT_CMD(
3612         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3613         "print local hushshell variables",
3614         "\n    - print values of all hushshell variables\n"
3615         "showvar name ...\n"
3616         "    - print value of hushshell variable 'name'"
3617 );
3618
3619 #endif
3620 /****************************************************************************/