common/hush.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * sh.c -- a prototype Bourne shell grammar parser
   4  *      Intended to follow the original Thompson and Ritchie
   5  *      "small and simple is beautiful" philosophy, which
   6  *      incidentally is a good match to today's BusyBox.
   7  *
   8  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   9  *
  10  * Credits:
  11  *      The parser routines proper are all original material, first
  12  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  13  *      The execution engine, the builtins, and much of the underlying
  14  *      support has been adapted from busybox-0.49pre's lash,
  15  *      which is Copyright (C) 2000 by Lineo, Inc., and
  16  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  17  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  18  *      Erik W. Troan, which they placed in the public domain.  I don't know
  19  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  20  * Other credits:
  21  *      simple_itoa() was lifted from boa-0.93.15
  22  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  23  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  24  *        and many builtins derived from contributions by Erik Andersen
  25  *      miscellaneous bugfixes from Matt Kraai
  26  *
  27  * There are two big (and related) architecture differences between
  28  * this parser and the lash parser.  One is that this version is
  29  * actually designed from the ground up to understand nearly all
  30  * of the Bourne grammar.  The second, consequential change is that
  31  * the parser and input reader have been turned inside out.  Now,
  32  * the parser is in control, and asks for input as needed.  The old
  33  * way had the input reader in control, and it asked for parsing to
  34  * take place as needed.  The new way makes it much easier to properly
  35  * handle the recursion implicit in the various substitutions, especially
  36  * across continuation lines.
  37  *
  38  * Bash grammar not implemented: (how many of these were in original sh?)
  39  *      $@ (those sure look like weird quoting rules)
  40  *      $_
  41  *      ! negation operator for pipes
  42  *      &> and >& redirection of stdout+stderr
  43  *      Brace Expansion
  44  *      Tilde Expansion
  45  *      fancy forms of Parameter Expansion
  46  *      aliases
  47  *      Arithmetic Expansion
  48  *      <(list) and >(list) Process Substitution
  49  *      reserved words: case, esac, select, function
  50  *      Here Documents ( << word )
  51  *      Functions
  52  * Major bugs:
  53  *      job handling woefully incomplete and buggy
  54  *      reserved word execution woefully incomplete and buggy
  55  * to-do:
  56  *      port selected bugfixes from post-0.49 busybox lash - done?
  57  *      finish implementing reserved words: for, while, until, do, done
  58  *      change { and } from special chars to reserved words
  59  *      builtins: break, continue, eval, return, set, trap, ulimit
  60  *      test magic exec
  61  *      handle children going into background
  62  *      clean up recognition of null pipes
  63  *      check setting of global_argc and global_argv
  64  *      control-C handling, probably with longjmp
  65  *      follow IFS rules more precisely, including update semantics
  66  *      figure out what to do with backslash-newline
  67  *      explain why we use signal instead of sigaction
  68  *      propagate syntax errors, die on resource errors?
  69  *      continuation lines, both explicit and implicit - done?
  70  *      memory leak finding and plugging - done?
  71  *      more testing, especially quoting rules and redirection
  72  *      document how quoting rules not precisely followed for variable assignments
  73  *      maybe change map[] to use 2-bit entries
  74  *      (eventually) remove all the printf's
  75  *
  76  * This program is free software; you can redistribute it and/or modify
  77  * it under the terms of the GNU General Public License as published by
  78  * the Free Software Foundation; either version 2 of the License, or
  79  * (at your option) any later version.
  80  *
  81  * This program is distributed in the hope that it will be useful,
  82  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  83  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  84  * General Public License for more details.
  85  *
  86  * You should have received a copy of the GNU General Public License
  87  * along with this program; if not, write to the Free Software
  88  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  89  */
  90 #define __U_BOOT__
  91 #ifdef __U_BOOT__
  92 #include <malloc.h>         /* malloc, free, realloc*/
  93 #include <linux/ctype.h>    /* isalpha, isdigit */
  94 #include <common.h>        /* readline */
  95 #include <hush.h>
  96 #include <command.h>        /* find_cmd */
  97 /*cmd_boot.c*/
  98 extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);      /* do_bootd */
  99 #endif
 100 #ifdef CFG_HUSH_PARSER
 101 #ifndef __U_BOOT__
 102 #include <ctype.h>     /* isalpha, isdigit */
 103 #include <unistd.h>    /* getpid */
 104 #include <stdlib.h>    /* getenv, atoi */
 105 #include <string.h>    /* strchr */
 106 #include <stdio.h>     /* popen etc. */
 107 #include <glob.h>      /* glob, of course */
 108 #include <stdarg.h>    /* va_list */
 109 #include <errno.h>
 110 #include <fcntl.h>
 111 #include <getopt.h>    /* should be pretty obvious */
 112
 113 #include <sys/stat.h>  /* ulimit */
 114 #include <sys/types.h>
 115 #include <sys/wait.h>
 116 #include <signal.h>
 117
 118 /* #include <dmalloc.h> */
 119 /* #define DEBUG_SHELL */
 120
 121 #if 1
 122 #include "busybox.h"
 123 #include "cmdedit.h"
 124 #else
 125 #define applet_name "hush"
 126 #include "standalone.h"
 127 #define hush_main main
 128 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 129 #define BB_BANNER
 130 #endif
 131 #endif
 132 #define SPECIAL_VAR_SYMBOL 03
 133 #ifndef __U_BOOT__
 134 #define FLAG_EXIT_FROM_LOOP 1
 135 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 136 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 137
 138 #endif
 139
 140 #ifdef __U_BOOT__
 141 #define EXIT_SUCCESS 0
 142 #define EOF -1
 143 #define syntax() syntax_err()
 144 #define xstrdup strdup
 145 #define error_msg printf
 146 #else
 147 typedef enum {
 148         REDIRECT_INPUT     = 1,
 149         REDIRECT_OVERWRITE = 2,
 150         REDIRECT_APPEND    = 3,
 151         REDIRECT_HEREIS    = 4,
 152         REDIRECT_IO        = 5
 153 } redir_type;
 154
 155 /* The descrip member of this structure is only used to make debugging
 156  * output pretty */
 157 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 158         { 0,                         0, "()" },
 159         { O_RDONLY,                  0, "<"  },
 160         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 161         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 162         { O_RDONLY,                 -1, "<<" },
 163         { O_RDWR,                    1, "<>" }
 164 };
 165 #endif
 166
 167 typedef enum {
 168         PIPE_SEQ = 1,
 169         PIPE_AND = 2,
 170         PIPE_OR  = 3,
 171         PIPE_BG  = 4,
 172 } pipe_style;
 173
 174 /* might eventually control execution */
 175 typedef enum {
 176         RES_NONE  = 0,
 177         RES_IF    = 1,
 178         RES_THEN  = 2,
 179         RES_ELIF  = 3,
 180         RES_ELSE  = 4,
 181         RES_FI    = 5,
 182         RES_FOR   = 6,
 183         RES_WHILE = 7,
 184         RES_UNTIL = 8,
 185         RES_DO    = 9,
 186         RES_DONE  = 10,
 187         RES_XXXX  = 11,
 188         RES_IN    = 12,
 189         RES_SNTX  = 13
 190 } reserved_style;
 191 #define FLAG_END   (1<<RES_NONE)
 192 #define FLAG_IF    (1<<RES_IF)
 193 #define FLAG_THEN  (1<<RES_THEN)
 194 #define FLAG_ELIF  (1<<RES_ELIF)
 195 #define FLAG_ELSE  (1<<RES_ELSE)
 196 #define FLAG_FI    (1<<RES_FI)
 197 #define FLAG_FOR   (1<<RES_FOR)
 198 #define FLAG_WHILE (1<<RES_WHILE)
 199 #define FLAG_UNTIL (1<<RES_UNTIL)
 200 #define FLAG_DO    (1<<RES_DO)
 201 #define FLAG_DONE  (1<<RES_DONE)
 202 #define FLAG_IN    (1<<RES_IN)
 203 #define FLAG_START (1<<RES_XXXX)
 204
 205 /* This holds pointers to the various results of parsing */
 206 struct p_context {
 207         struct child_prog *child;
 208         struct pipe *list_head;
 209         struct pipe *pipe;
 210 #ifndef __U_BOOT__
 211         struct redir_struct *pending_redirect;
 212 #endif
 213         reserved_style w;
 214         int old_flag;                           /* for figuring out valid reserved words */
 215         struct p_context *stack;
 216         int type;                       /* define type of parser : ";$" common or special symbol */
 217         /* How about quoting status? */
 218 };
 219
 220 #ifndef __U_BOOT__
 221 struct redir_struct {
 222         redir_type type;                        /* type of redirection */
 223         int fd;                                         /* file descriptor being redirected */
 224         int dup;                                        /* -1, or file descriptor being duplicated */
 225         struct redir_struct *next;      /* pointer to the next redirect in the list */
 226         glob_t word;                            /* *word.gl_pathv is the filename */
 227 };
 228 #endif
 229
 230 struct child_prog {
 231 #ifndef __U_BOOT__
 232         pid_t pid;                                      /* 0 if exited */
 233 #endif
 234         char **argv;                            /* program name and arguments */
 235 #ifdef __U_BOOT__
 236         int    argc;                            /* number of program arguments */
 237 #endif
 238         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 239 #ifndef __U_BOOT__
 240         int subshell;                           /* flag, non-zero if group must be forked */
 241         struct redir_struct *redirects; /* I/O redirections */
 242         glob_t glob_result;                     /* result of parameter globbing */
 243         int is_stopped;                         /* is the program currently running? */
 244         struct pipe *family;            /* pointer back to the child's parent pipe */
 245 #endif
 246         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 247         int type;
 248 };
 249
 250 struct pipe {
 251 #ifndef __U_BOOT__
 252         int jobid;                                      /* job number */
 253 #endif
 254         int num_progs;                          /* total number of programs in job */
 255 #ifndef __U_BOOT__
 256         int running_progs;                      /* number of programs running */
 257         char *text;                                     /* name of job */
 258         char *cmdbuf;                           /* buffer various argv's point into */
 259         pid_t pgrp;                                     /* process group ID for the job */
 260 #endif
 261         struct child_prog *progs;       /* array of commands in pipe */
 262         struct pipe *next;                      /* to track background commands */
 263 #ifndef __U_BOOT__
 264         int stopped_progs;                      /* number of programs alive, but stopped */
 265         int job_context;                        /* bitmask defining current context */
 266 #endif
 267         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 268         reserved_style r_mode;          /* supports if, for, while, until */
 269 };
 270
 271 #ifndef __U_BOOT__
 272 struct close_me {
 273         int fd;
 274         struct close_me *next;
 275 };
 276 #endif
 277
 278 struct variables {
 279         char *name;
 280         char *value;
 281         int flg_export;
 282         int flg_read_only;
 283         struct variables *next;
 284 };
 285
 286 /* globals, connect us to the outside world
 287  * the first three support $?, $#, and $1 */
 288 #ifndef __U_BOOT__
 289 char **global_argv;
 290 unsigned int global_argc;
 291 #endif
 292 unsigned int last_return_code;
 293 int nesting_level;
 294 #ifndef __U_BOOT__
 295 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 296 #endif
 297
 298 /* "globals" within this file */
 299 static char *ifs;
 300 static char map[256];
 301 #ifndef __U_BOOT__
 302 static int fake_mode;
 303 static int interactive;
 304 static struct close_me *close_me_head;
 305 static const char *cwd;
 306 static struct pipe *job_list;
 307 static unsigned int last_bg_pid;
 308 static unsigned int last_jobid;
 309 static unsigned int shell_terminal;
 310 static char *PS1;
 311 static char *PS2;
 312 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 313 struct variables *top_vars = &shell_ver;
 314 #else
 315 static int flag_repeat = 0;
 316 static int do_repeat = 0;
 317 static struct variables *top_vars = NULL ;
 318 #endif /*__U_BOOT__ */
 319
 320 #define B_CHUNK (100)
 321 #define B_NOSPAC 1
 322
 323 typedef struct {
 324         char *data;
 325         int length;
 326         int maxlen;
 327         int quote;
 328         int nonnull;
 329 } o_string;
 330 #define NULL_O_STRING {NULL,0,0,0,0}
 331 /* used for initialization:
 332         o_string foo = NULL_O_STRING; */
 333
 334 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 335  * available?  Where is it documented? */
 336 struct in_str {
 337         const char *p;
 338 #ifndef __U_BOOT__
 339         char peek_buf[2];
 340 #endif
 341         int __promptme;
 342         int promptmode;
 343 #ifndef __U_BOOT__
 344         FILE *file;
 345 #endif
 346         int (*get) (struct in_str *);
 347         int (*peek) (struct in_str *);
 348 };
 349 #define b_getch(input) ((input)->get(input))
 350 #define b_peek(input) ((input)->peek(input))
 351
 352 #ifndef __U_BOOT__
 353 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 354
 355 struct built_in_command {
 356         char *cmd;                                      /* name */
 357         char *descr;                            /* description */
 358         int (*function) (struct child_prog *);  /* function ptr */
 359 };
 360 #endif
 361
 362 /* This should be in utility.c */
 363 #ifdef DEBUG_SHELL
 364 #ifndef __U_BOOT__
 365 static void debug_printf(const char *format, ...)
 366 {
 367         va_list args;
 368         va_start(args, format);
 369         vfprintf(stderr, format, args);
 370         va_end(args);
 371 }
 372 #else
 373 #define debug_printf printf             /* U-Boot debug flag */
 374 #endif
 375 #else
 376 static inline void debug_printf(const char *format, ...) { }
 377 #endif
 378 #define final_printf debug_printf
 379
 380 #ifdef __U_BOOT__
 381 static void syntax_err(void) {
 382          printf("syntax error\n");
 383 }
 384 #else
 385 static void __syntax(char *file, int line) {
 386         error_msg("syntax error %s:%d", file, line);
 387 }
 388 #define syntax() __syntax(__FILE__, __LINE__)
 389 #endif
 390
 391 #ifdef __U_BOOT__
 392 static void *xmalloc(size_t size);
 393 static void *xrealloc(void *ptr, size_t size);
 394 #else
 395 /* Index of subroutines: */
 396 /*   function prototypes for builtins */
 397 static int builtin_cd(struct child_prog *child);
 398 static int builtin_env(struct child_prog *child);
 399 static int builtin_eval(struct child_prog *child);
 400 static int builtin_exec(struct child_prog *child);
 401 static int builtin_exit(struct child_prog *child);
 402 static int builtin_export(struct child_prog *child);
 403 static int builtin_fg_bg(struct child_prog *child);
 404 static int builtin_help(struct child_prog *child);
 405 static int builtin_jobs(struct child_prog *child);
 406 static int builtin_pwd(struct child_prog *child);
 407 static int builtin_read(struct child_prog *child);
 408 static int builtin_set(struct child_prog *child);
 409 static int builtin_shift(struct child_prog *child);
 410 static int builtin_source(struct child_prog *child);
 411 static int builtin_umask(struct child_prog *child);
 412 static int builtin_unset(struct child_prog *child);
 413 static int builtin_not_written(struct child_prog *child);
 414 #endif
 415 /*   o_string manipulation: */
 416 static int b_check_space(o_string *o, int len);
 417 static int b_addchr(o_string *o, int ch);
 418 static void b_reset(o_string *o);
 419 static int b_addqchr(o_string *o, int ch, int quote);
 420 #ifndef __U_BOOT__
 421 static int b_adduint(o_string *o, unsigned int i);
 422 #endif
 423 /*  in_str manipulations: */
 424 static int static_get(struct in_str *i);
 425 static int static_peek(struct in_str *i);
 426 static int file_get(struct in_str *i);
 427 static int file_peek(struct in_str *i);
 428 #ifndef __U_BOOT__
 429 static void setup_file_in_str(struct in_str *i, FILE *f);
 430 #else
 431 static void setup_file_in_str(struct in_str *i);
 432 #endif
 433 static void setup_string_in_str(struct in_str *i, const char *s);
 434 #ifndef __U_BOOT__
 435 /*  close_me manipulations: */
 436 static void mark_open(int fd);
 437 static void mark_closed(int fd);
 438 static void close_all(void);
 439 #endif
 440 /*  "run" the final data structures: */
 441 static char *indenter(int i);
 442 static int free_pipe_list(struct pipe *head, int indent);
 443 static int free_pipe(struct pipe *pi, int indent);
 444 /*  really run the final data structures: */
 445 #ifndef __U_BOOT__
 446 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 447 #endif
 448 static int run_list_real(struct pipe *pi);
 449 #ifndef __U_BOOT__
 450 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 451 #endif
 452 static int run_pipe_real(struct pipe *pi);
 453 /*   extended glob support: */
 454 #ifndef __U_BOOT__
 455 static int globhack(const char *src, int flags, glob_t *pglob);
 456 static int glob_needed(const char *s);
 457 static int xglob(o_string *dest, int flags, glob_t *pglob);
 458 #endif
 459 /*   variable assignment: */
 460 static int is_assignment(const char *s);
 461 /*   data structure manipulation: */
 462 #ifndef __U_BOOT__
 463 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 464 #endif
 465 static void initialize_context(struct p_context *ctx);
 466 static int done_word(o_string *dest, struct p_context *ctx);
 467 static int done_command(struct p_context *ctx);
 468 static int done_pipe(struct p_context *ctx, pipe_style type);
 469 /*   primary string parsing: */
 470 #ifndef __U_BOOT__
 471 static int redirect_dup_num(struct in_str *input);
 472 static int redirect_opt_num(o_string *o);
 473 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 474 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 475 #endif
 476 static char *lookup_param(char *src);
 477 static char *make_string(char **inp);
 478 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 479 #ifndef __U_BOOT__
 480 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 481 #endif
 482 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 483 /*   setup: */
 484 static int parse_stream_outer(struct in_str *inp, int flag);
 485 #ifndef __U_BOOT__
 486 static int parse_string_outer(const char *s, int flag);
 487 static int parse_file_outer(FILE *f);
 488 #endif
 489 #ifndef __U_BOOT__
 490 /*   job management: */
 491 static int checkjobs(struct pipe* fg_pipe);
 492 static void insert_bg_job(struct pipe *pi);
 493 static void remove_bg_job(struct pipe *pi);
 494 #endif
 495 /*     local variable support */
 496 static char **make_list_in(char **inp, char *name);
 497 static char *insert_var_value(char *inp);
 498 static char *get_local_var(const char *var);
 499 #ifndef __U_BOOT__
 500 static void  unset_local_var(const char *name);
 501 #endif
 502 static int set_local_var(const char *s, int flg_export);
 503
 504 #ifndef __U_BOOT__
 505 /* Table of built-in functions.  They can be forked or not, depending on
 506  * context: within pipes, they fork.  As simple commands, they do not.
 507  * When used in non-forking context, they can change global variables
 508  * in the parent shell process.  If forked, of course they can not.
 509  * For example, 'unset foo | whatever' will parse and run, but foo will
 510  * still be set at the end. */
 511 static struct built_in_command bltins[] = {
 512         {"bg", "Resume a job in the background", builtin_fg_bg},
 513         {"break", "Exit for, while or until loop", builtin_not_written},
 514         {"cd", "Change working directory", builtin_cd},
 515         {"continue", "Continue for, while or until loop", builtin_not_written},
 516         {"env", "Print all environment variables", builtin_env},
 517         {"eval", "Construct and run shell command", builtin_eval},
 518         {"exec", "Exec command, replacing this shell with the exec'd process",
 519                 builtin_exec},
 520         {"exit", "Exit from shell()", builtin_exit},
 521         {"export", "Set environment variable", builtin_export},
 522         {"fg", "Bring job into the foreground", builtin_fg_bg},
 523         {"jobs", "Lists the active jobs", builtin_jobs},
 524         {"pwd", "Print current directory", builtin_pwd},
 525         {"read", "Input environment variable", builtin_read},
 526         {"return", "Return from a function", builtin_not_written},
 527         {"set", "Set/unset shell local variables", builtin_set},
 528         {"shift", "Shift positional parameters", builtin_shift},
 529         {"trap", "Trap signals", builtin_not_written},
 530         {"ulimit","Controls resource limits", builtin_not_written},
 531         {"umask","Sets file creation mask", builtin_umask},
 532         {"unset", "Unset environment variable", builtin_unset},
 533         {".", "Source-in and run commands in a file", builtin_source},
 534         {"help", "List shell built-in commands", builtin_help},
 535         {NULL, NULL, NULL}
 536 };
 537
 538 static const char *set_cwd(void)
 539 {
 540         if(cwd==unknown)
 541                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 542         cwd = xgetcwd((char *)cwd);
 543         if (!cwd)
 544                 cwd = unknown;
 545         return cwd;
 546 }
 547
 548 /* built-in 'eval' handler */
 549 static int builtin_eval(struct child_prog *child)
 550 {
 551         char *str = NULL;
 552         int rcode = EXIT_SUCCESS;
 553
 554         if (child->argv[1]) {
 555                 str = make_string(child->argv + 1);
 556                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 557                                         FLAG_PARSE_SEMICOLON);
 558                 free(str);
 559                 rcode = last_return_code;
 560         }
 561         return rcode;
 562 }
 563
 564 /* built-in 'cd <path>' handler */
 565 static int builtin_cd(struct child_prog *child)
 566 {
 567         char *newdir;
 568         if (child->argv[1] == NULL)
 569                 newdir = getenv("HOME");
 570         else
 571                 newdir = child->argv[1];
 572         if (chdir(newdir)) {
 573                 printf("cd: %s: %s\n", newdir, strerror(errno));
 574                 return EXIT_FAILURE;
 575         }
 576         set_cwd();
 577         return EXIT_SUCCESS;
 578 }
 579
 580 /* built-in 'env' handler */
 581 static int builtin_env(struct child_prog *dummy)
 582 {
 583         char **e = environ;
 584         if (e == NULL) return EXIT_FAILURE;
 585         for (; *e; e++) {
 586                 puts(*e);
 587         }
 588         return EXIT_SUCCESS;
 589 }
 590
 591 /* built-in 'exec' handler */
 592 static int builtin_exec(struct child_prog *child)
 593 {
 594         if (child->argv[1] == NULL)
 595                 return EXIT_SUCCESS;   /* Really? */
 596         child->argv++;
 597         pseudo_exec(child);
 598         /* never returns */
 599 }
 600
 601 /* built-in 'exit' handler */
 602 static int builtin_exit(struct child_prog *child)
 603 {
 604         if (child->argv[1] == NULL)
 605                 exit(last_return_code);
 606         exit (atoi(child->argv[1]));
 607 }
 608
 609 /* built-in 'export VAR=value' handler */
 610 static int builtin_export(struct child_prog *child)
 611 {
 612         int res = 0;
 613         char *name = child->argv[1];
 614
 615         if (name == NULL) {
 616                 return (builtin_env(child));
 617         }
 618
 619         name = strdup(name);
 620
 621         if(name) {
 622                 char *value = strchr(name, '=');
 623
 624                 if (!value) {
 625                         char *tmp;
 626                         /* They are exporting something without an =VALUE */
 627
 628                         value = get_local_var(name);
 629                         if (value) {
 630                                 size_t ln = strlen(name);
 631
 632                                 tmp = realloc(name, ln+strlen(value)+2);
 633                                 if(tmp==NULL)
 634                                         res = -1;
 635                                 else {
 636                                         sprintf(tmp+ln, "=%s", value);
 637                                         name = tmp;
 638                                 }
 639                         } else {
 640                                 /* bash does not return an error when trying to export
 641                                  * an undefined variable.  Do likewise. */
 642                                 res = 1;
 643                         }
 644                 }
 645         }
 646         if (res<0)
 647                 perror_msg("export");
 648         else if(res==0)
 649                 res = set_local_var(name, 1);
 650         else
 651                 res = 0;
 652         free(name);
 653         return res;
 654 }
 655
 656 /* built-in 'fg' and 'bg' handler */
 657 static int builtin_fg_bg(struct child_prog *child)
 658 {
 659         int i, jobnum;
 660         struct pipe *pi=NULL;
 661
 662         if (!interactive)
 663                 return EXIT_FAILURE;
 664         /* If they gave us no args, assume they want the last backgrounded task */
 665         if (!child->argv[1]) {
 666                 for (pi = job_list; pi; pi = pi->next) {
 667                         if (pi->jobid == last_jobid) {
 668                                 break;
 669                         }
 670                 }
 671                 if (!pi) {
 672                         error_msg("%s: no current job", child->argv[0]);
 673                         return EXIT_FAILURE;
 674                 }
 675         } else {
 676                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 677                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 678                         return EXIT_FAILURE;
 679                 }
 680                 for (pi = job_list; pi; pi = pi->next) {
 681                         if (pi->jobid == jobnum) {
 682                                 break;
 683                         }
 684                 }
 685                 if (!pi) {
 686                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 687                         return EXIT_FAILURE;
 688                 }
 689         }
 690
 691         if (*child->argv[0] == 'f') {
 692                 /* Put the job into the foreground.  */
 693                 tcsetpgrp(shell_terminal, pi->pgrp);
 694         }
 695
 696         /* Restart the processes in the job */
 697         for (i = 0; i < pi->num_progs; i++)
 698                 pi->progs[i].is_stopped = 0;
 699
 700         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 701                 if (i == ESRCH) {
 702                         remove_bg_job(pi);
 703                 } else {
 704                         perror_msg("kill (SIGCONT)");
 705                 }
 706         }
 707
 708         pi->stopped_progs = 0;
 709         return EXIT_SUCCESS;
 710 }
 711
 712 /* built-in 'help' handler */
 713 static int builtin_help(struct child_prog *dummy)
 714 {
 715         struct built_in_command *x;
 716
 717         printf("\nBuilt-in commands:\n");
 718         printf("-------------------\n");
 719         for (x = bltins; x->cmd; x++) {
 720                 if (x->descr==NULL)
 721                         continue;
 722                 printf("%s\t%s\n", x->cmd, x->descr);
 723         }
 724         printf("\n\n");
 725         return EXIT_SUCCESS;
 726 }
 727
 728 /* built-in 'jobs' handler */
 729 static int builtin_jobs(struct child_prog *child)
 730 {
 731         struct pipe *job;
 732         char *status_string;
 733
 734         for (job = job_list; job; job = job->next) {
 735                 if (job->running_progs == job->stopped_progs)
 736                         status_string = "Stopped";
 737                 else
 738                         status_string = "Running";
 739
 740                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 741         }
 742         return EXIT_SUCCESS;
 743 }
 744
 745
 746 /* built-in 'pwd' handler */
 747 static int builtin_pwd(struct child_prog *dummy)
 748 {
 749         puts(set_cwd());
 750         return EXIT_SUCCESS;
 751 }
 752
 753 /* built-in 'read VAR' handler */
 754 static int builtin_read(struct child_prog *child)
 755 {
 756         int res;
 757
 758         if (child->argv[1]) {
 759                 char string[BUFSIZ];
 760                 char *var = 0;
 761
 762                 string[0] = 0;  /* In case stdin has only EOF */
 763                 /* read string */
 764                 fgets(string, sizeof(string), stdin);
 765                 chomp(string);
 766                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 767                 if(var) {
 768                         sprintf(var, "%s=%s", child->argv[1], string);
 769                         res = set_local_var(var, 0);
 770                 } else
 771                         res = -1;
 772                 if (res)
 773                         fprintf(stderr, "read: %m\n");
 774                 free(var);      /* So not move up to avoid breaking errno */
 775                 return res;
 776         } else {
 777                 do res=getchar(); while(res!='\n' && res!=EOF);
 778                 return 0;
 779         }
 780 }
 781
 782 /* built-in 'set VAR=value' handler */
 783 static int builtin_set(struct child_prog *child)
 784 {
 785         char *temp = child->argv[1];
 786         struct variables *e;
 787
 788         if (temp == NULL)
 789                 for(e = top_vars; e; e=e->next)
 790                         printf("%s=%s\n", e->name, e->value);
 791         else
 792                 set_local_var(temp, 0);
 793
 794                 return EXIT_SUCCESS;
 795 }
 796
 797
 798 /* Built-in 'shift' handler */
 799 static int builtin_shift(struct child_prog *child)
 800 {
 801         int n=1;
 802         if (child->argv[1]) {
 803                 n=atoi(child->argv[1]);
 804         }
 805         if (n>=0 && n<global_argc) {
 806                 /* XXX This probably breaks $0 */
 807                 global_argc -= n;
 808                 global_argv += n;
 809                 return EXIT_SUCCESS;
 810         } else {
 811                 return EXIT_FAILURE;
 812         }
 813 }
 814
 815 /* Built-in '.' handler (read-in and execute commands from file) */
 816 static int builtin_source(struct child_prog *child)
 817 {
 818         FILE *input;
 819         int status;
 820
 821         if (child->argv[1] == NULL)
 822                 return EXIT_FAILURE;
 823
 824         /* XXX search through $PATH is missing */
 825         input = fopen(child->argv[1], "r");
 826         if (!input) {
 827                 error_msg("Couldn't open file '%s'", child->argv[1]);
 828                 return EXIT_FAILURE;
 829         }
 830
 831         /* Now run the file */
 832         /* XXX argv and argc are broken; need to save old global_argv
 833          * (pointer only is OK!) on this stack frame,
 834          * set global_argv=child->argv+1, recurse, and restore. */
 835         mark_open(fileno(input));
 836         status = parse_file_outer(input);
 837         mark_closed(fileno(input));
 838         fclose(input);
 839         return (status);
 840 }
 841
 842 static int builtin_umask(struct child_prog *child)
 843 {
 844         mode_t new_umask;
 845         const char *arg = child->argv[1];
 846         char *end;
 847         if (arg) {
 848                 new_umask=strtoul(arg, &end, 8);
 849                 if (*end!='\0' || end == arg) {
 850                         return EXIT_FAILURE;
 851                 }
 852         } else {
 853                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 854         }
 855         umask(new_umask);
 856         return EXIT_SUCCESS;
 857 }
 858
 859 /* built-in 'unset VAR' handler */
 860 static int builtin_unset(struct child_prog *child)
 861 {
 862         /* bash returned already true */
 863         unset_local_var(child->argv[1]);
 864         return EXIT_SUCCESS;
 865 }
 866
 867 static int builtin_not_written(struct child_prog *child)
 868 {
 869         printf("builtin_%s not written\n",child->argv[0]);
 870         return EXIT_FAILURE;
 871 }
 872 #endif
 873
 874 static int b_check_space(o_string *o, int len)
 875 {
 876         /* It would be easy to drop a more restrictive policy
 877          * in here, such as setting a maximum string length */
 878         if (o->length + len > o->maxlen) {
 879                 char *old_data = o->data;
 880                 /* assert (data == NULL || o->maxlen != 0); */
 881                 o->maxlen += max(2*len, B_CHUNK);
 882                 o->data = realloc(o->data, 1 + o->maxlen);
 883                 if (o->data == NULL) {
 884                         free(old_data);
 885                 }
 886         }
 887         return o->data == NULL;
 888 }
 889
 890 static int b_addchr(o_string *o, int ch)
 891 {
 892         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 893         if (b_check_space(o, 1)) return B_NOSPAC;
 894         o->data[o->length] = ch;
 895         o->length++;
 896         o->data[o->length] = '\0';
 897         return 0;
 898 }
 899
 900 static void b_reset(o_string *o)
 901 {
 902         o->length = 0;
 903         o->nonnull = 0;
 904         if (o->data != NULL) *o->data = '\0';
 905 }
 906
 907 static void b_free(o_string *o)
 908 {
 909         b_reset(o);
 910         free(o->data);
 911         o->data = NULL;
 912         o->maxlen = 0;
 913 }
 914
 915 /* My analysis of quoting semantics tells me that state information
 916  * is associated with a destination, not a source.
 917  */
 918 static int b_addqchr(o_string *o, int ch, int quote)
 919 {
 920         if (quote && strchr("*?[\\",ch)) {
 921                 int rc;
 922                 rc = b_addchr(o, '\\');
 923                 if (rc) return rc;
 924         }
 925         return b_addchr(o, ch);
 926 }
 927
 928 /* belongs in utility.c */
 929 char *simple_itoa(unsigned int i)
 930 {
 931         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 932         static char local[22];
 933         char *p = &local[21];
 934         *p-- = '\0';
 935         do {
 936                 *p-- = '0' + i % 10;
 937                 i /= 10;
 938         } while (i > 0);
 939         return p + 1;
 940 }
 941
 942 #ifndef __U_BOOT__
 943 static int b_adduint(o_string *o, unsigned int i)
 944 {
 945         int r;
 946         char *p = simple_itoa(i);
 947         /* no escape checking necessary */
 948         do r=b_addchr(o, *p++); while (r==0 && *p);
 949         return r;
 950 }
 951 #endif
 952
 953 static int static_get(struct in_str *i)
 954 {
 955         int ch=*i->p++;
 956         if (ch=='\0') return EOF;
 957         return ch;
 958 }
 959
 960 static int static_peek(struct in_str *i)
 961 {
 962         return *i->p;
 963 }
 964
 965 #ifndef __U_BOOT__
 966 static inline void cmdedit_set_initial_prompt(void)
 967 {
 968 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 969         PS1 = NULL;
 970 #else
 971         PS1 = getenv("PS1");
 972         if(PS1==0)
 973                 PS1 = "\\w \\$ ";
 974 #endif
 975 }
 976
 977 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 978 {
 979         debug_printf("setup_prompt_string %d ",promptmode);
 980 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 981         /* Set up the prompt */
 982         if (promptmode == 1) {
 983                 free(PS1);
 984                 PS1=xmalloc(strlen(cwd)+4);
 985                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 986                 *prompt_str = PS1;
 987         } else {
 988                 *prompt_str = PS2;
 989         }
 990 #else
 991         *prompt_str = (promptmode==1)? PS1 : PS2;
 992 #endif
 993         debug_printf("result %s\n",*prompt_str);
 994 }
 995 #endif
 996
 997 static void get_user_input(struct in_str *i)
 998 {
 999 #ifndef __U_BOOT__
1000         char *prompt_str;
1001         static char the_command[BUFSIZ];
1002
1003         setup_prompt_string(i->promptmode, &prompt_str);
1004 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1005         /*
1006          ** enable command line editing only while a command line
1007          ** is actually being read; otherwise, we'll end up bequeathing
1008          ** atexit() handlers and other unwanted stuff to our
1009          ** child processes (rob@sysgo.de)
1010          */
1011         cmdedit_read_input(prompt_str, the_command);
1012 #else
1013         fputs(prompt_str, stdout);
1014         fflush(stdout);
1015         the_command[0]=fgetc(i->file);
1016         the_command[1]='\0';
1017 #endif
1018         fflush(stdout);
1019         i->p = the_command;
1020 #else
1021         extern char console_buffer[CFG_CBSIZE];
1022         int n;
1023         static char the_command[CFG_CBSIZE];
1024
1025         i->__promptme = 1;
1026         if (i->promptmode == 1) {
1027                 n = readline(CFG_PROMPT);
1028         } else {
1029                 n = readline(CFG_PROMPT_HUSH_PS2);
1030         }
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                             < CFG_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         cmd_tbl_t *cmdtp;
1545         char *p;
1546 # if __GNUC__
1547         /* Avoid longjmp clobbering */
1548         (void) &i;
1549         (void) &nextin;
1550         (void) &child;
1551 # endif
1552 #endif  /* __U_BOOT__ */
1553
1554         nextin = 0;
1555 #ifndef __U_BOOT__
1556         pi->pgrp = -1;
1557 #endif
1558
1559         /* Check if this is a simple builtin (not part of a pipe).
1560          * Builtins within pipes have to fork anyway, and are handled in
1561          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1562          */
1563         if (pi->num_progs == 1) child = & (pi->progs[0]);
1564 #ifndef __U_BOOT__
1565         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1566                 int squirrel[] = {-1, -1, -1};
1567                 int rcode;
1568                 debug_printf("non-subshell grouping\n");
1569                 setup_redirects(child, squirrel);
1570                 /* XXX could we merge code with following builtin case,
1571                  * by creating a pseudo builtin that calls run_list_real? */
1572                 rcode = run_list_real(child->group);
1573                 restore_redirects(squirrel);
1574 #else
1575                 if (pi->num_progs == 1 && child->group) {
1576                 int rcode;
1577                 debug_printf("non-subshell grouping\n");
1578                 rcode = run_list_real(child->group);
1579 #endif
1580                 return rcode;
1581         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1582                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1583                 if (i!=0 && child->argv[i]==NULL) {
1584                         /* assignments, but no command: set the local environment */
1585                         for (i=0; child->argv[i]!=NULL; i++) {
1586
1587                                 /* Ok, this case is tricky.  We have to decide if this is a
1588                                  * local variable, or an already exported variable.  If it is
1589                                  * already exported, we have to export the new value.  If it is
1590                                  * not exported, we need only set this as a local variable.
1591                                  * This junk is all to decide whether or not to export this
1592                                  * variable. */
1593                                 int export_me=0;
1594                                 char *name, *value;
1595                                 name = xstrdup(child->argv[i]);
1596                                 debug_printf("Local environment set: %s\n", name);
1597                                 value = strchr(name, '=');
1598                                 if (value)
1599                                         *value=0;
1600 #ifndef __U_BOOT__
1601                                 if ( get_local_var(name)) {
1602                                         export_me=1;
1603                                 }
1604 #endif
1605                                 free(name);
1606                                 p = insert_var_value(child->argv[i]);
1607                                 set_local_var(p, export_me);
1608                                 if (p != child->argv[i]) free(p);
1609                         }
1610                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1611                 }
1612                 for (i = 0; is_assignment(child->argv[i]); i++) {
1613                         p = insert_var_value(child->argv[i]);
1614 #ifndef __U_BOOT__
1615                         putenv(strdup(p));
1616 #else
1617                         set_local_var(p, 0);
1618 #endif
1619                         if (p != child->argv[i]) {
1620                                 child->sp--;
1621                                 free(p);
1622                         }
1623                 }
1624                 if (child->sp) {
1625                         char * str = NULL;
1626
1627                         str = make_string((child->argv + i));
1628                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1629                         free(str);
1630                         return last_return_code;
1631                 }
1632 #ifndef __U_BOOT__
1633                 for (x = bltins; x->cmd; x++) {
1634                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1635                                 int squirrel[] = {-1, -1, -1};
1636                                 int rcode;
1637                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1638                                         debug_printf("magic exec\n");
1639                                         setup_redirects(child,NULL);
1640                                         return EXIT_SUCCESS;
1641                                 }
1642                                 debug_printf("builtin inline %s\n", child->argv[0]);
1643                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1644                                  * This is perfect for work that comes after exec().
1645                                  * Is it really safe for inline use?  Experimentally,
1646                                  * things seem to work with glibc. */
1647                                 setup_redirects(child, squirrel);
1648 #else
1649                         /* check ";", because ,example , argv consist from
1650                          * "help;flinfo" must not execute
1651                          */
1652                         if (strchr(child->argv[i], ';')) {
1653                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1654                                         child->argv[i]);
1655                                 return -1;
1656                         }
1657                         /* Look up command in command table */
1658
1659
1660                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1661                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1662                                 return -1;      /* give up after bad command */
1663                         } else {
1664                                 int rcode;
1665 #if (CONFIG_COMMANDS & CFG_CMD_BOOTD)
1666             extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1667
1668                                 /* avoid "bootd" recursion */
1669                                 if (cmdtp->cmd == do_bootd) {
1670                                         if (flag & CMD_FLAG_BOOTD) {
1671                                                 printf ("'bootd' recursion detected\n");
1672                                                 return -1;
1673                                         }
1674                                 else
1675                                         flag |= CMD_FLAG_BOOTD;
1676                                 }
1677 #endif  /* CFG_CMD_BOOTD */
1678                                 /* found - check max args */
1679                                 if ((child->argc - i) > cmdtp->maxargs) {
1680                                         printf ("Usage:\n%s\n", cmdtp->usage);
1681                                         return -1;
1682                                 }
1683 #endif
1684                                 child->argv+=i;  /* XXX horrible hack */
1685 #ifndef __U_BOOT__
1686                                 rcode = x->function(child);
1687 #else
1688                                 /* OK - call function to do the command */
1689
1690                                 rcode = (cmdtp->cmd)
1691 (cmdtp, flag,child->argc-i,&child->argv[i]);
1692                                 if ( !cmdtp->repeatable )
1693                                         flag_repeat = 0;
1694
1695
1696 #endif
1697                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1698 #ifndef __U_BOOT__
1699
1700                                 restore_redirects(squirrel);
1701 #endif
1702
1703                                 return rcode;
1704                         }
1705                 }
1706 #ifndef __U_BOOT__
1707         }
1708
1709         for (i = 0; i < pi->num_progs; i++) {
1710                 child = & (pi->progs[i]);
1711
1712                 /* pipes are inserted between pairs of commands */
1713                 if ((i + 1) < pi->num_progs) {
1714                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1715                         nextout = pipefds[1];
1716                 } else {
1717                         nextout=1;
1718                         pipefds[0] = -1;
1719                 }
1720
1721                 /* XXX test for failed fork()? */
1722                 if (!(child->pid = fork())) {
1723                         /* Set the handling for job control signals back to the default.  */
1724                         signal(SIGINT, SIG_DFL);
1725                         signal(SIGQUIT, SIG_DFL);
1726                         signal(SIGTERM, SIG_DFL);
1727                         signal(SIGTSTP, SIG_DFL);
1728                         signal(SIGTTIN, SIG_DFL);
1729                         signal(SIGTTOU, SIG_DFL);
1730                         signal(SIGCHLD, SIG_DFL);
1731
1732                         close_all();
1733
1734                         if (nextin != 0) {
1735                                 dup2(nextin, 0);
1736                                 close(nextin);
1737                         }
1738                         if (nextout != 1) {
1739                                 dup2(nextout, 1);
1740                                 close(nextout);
1741                         }
1742                         if (pipefds[0]!=-1) {
1743                                 close(pipefds[0]);  /* opposite end of our output pipe */
1744                         }
1745
1746                         /* Like bash, explicit redirects override pipes,
1747                          * and the pipe fd is available for dup'ing. */
1748                         setup_redirects(child,NULL);
1749
1750                         if (interactive && pi->followup!=PIPE_BG) {
1751                                 /* If we (the child) win the race, put ourselves in the process
1752                                  * group whose leader is the first process in this pipe. */
1753                                 if (pi->pgrp < 0) {
1754                                         pi->pgrp = getpid();
1755                                 }
1756                                 if (setpgid(0, pi->pgrp) == 0) {
1757                                         tcsetpgrp(2, pi->pgrp);
1758                                 }
1759                         }
1760
1761                         pseudo_exec(child);
1762                 }
1763
1764
1765                 /* put our child in the process group whose leader is the
1766                    first process in this pipe */
1767                 if (pi->pgrp < 0) {
1768                         pi->pgrp = child->pid;
1769                 }
1770                 /* Don't check for errors.  The child may be dead already,
1771                  * in which case setpgid returns error code EACCES. */
1772                 setpgid(child->pid, pi->pgrp);
1773
1774                 if (nextin != 0)
1775                         close(nextin);
1776                 if (nextout != 1)
1777                         close(nextout);
1778
1779                 /* If there isn't another process, nextin is garbage
1780                    but it doesn't matter */
1781                 nextin = pipefds[0];
1782         }
1783 #endif
1784         return -1;
1785 }
1786
1787 static int run_list_real(struct pipe *pi)
1788 {
1789         char *save_name = NULL;
1790         char **list = NULL;
1791         char **save_list = NULL;
1792         struct pipe *rpipe;
1793         int flag_rep = 0;
1794 #ifndef __U_BOOT__
1795         int save_num_progs;
1796 #endif
1797         int rcode=0, flag_skip=1;
1798         int flag_restore = 0;
1799         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1800         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1801         /* check syntax for "for" */
1802         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1803                 if ((rpipe->r_mode == RES_IN ||
1804                     rpipe->r_mode == RES_FOR) &&
1805                     (rpipe->next == NULL)) {
1806                                 syntax();
1807 #ifdef __U_BOOT__
1808                                 flag_repeat = 0;
1809 #endif
1810                                 return 1;
1811                 }
1812                 if ((rpipe->r_mode == RES_IN &&
1813                         (rpipe->next->r_mode == RES_IN &&
1814                         rpipe->next->progs->argv != NULL))||
1815                         (rpipe->r_mode == RES_FOR &&
1816                         rpipe->next->r_mode != RES_IN)) {
1817                                 syntax();
1818 #ifdef __U_BOOT__
1819                                 flag_repeat = 0;
1820 #endif
1821                                 return 1;
1822                 }
1823         }
1824         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1825                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1826                         pi->r_mode == RES_FOR) {
1827 #ifdef __U_BOOT__
1828                                 /* check Ctrl-C */
1829                                 ctrlc();
1830                                 if ((had_ctrlc())) {
1831                                         return 1;
1832                                 }
1833 #endif
1834                                 flag_restore = 0;
1835                                 if (!rpipe) {
1836                                         flag_rep = 0;
1837                                         rpipe = pi;
1838                                 }
1839                 }
1840                 rmode = pi->r_mode;
1841                 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);
1842                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1843                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1844                         continue;
1845                 }
1846                 flag_skip = 1;
1847                 skip_more_in_this_rmode = RES_XXXX;
1848                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1849                 if (rmode == RES_THEN &&  if_code) continue;
1850                 if (rmode == RES_ELSE && !if_code) continue;
1851                 if (rmode == RES_ELIF && !if_code) break;
1852                 if (rmode == RES_FOR && pi->num_progs) {
1853                         if (!list) {
1854                                 /* if no variable values after "in" we skip "for" */
1855                                 if (!pi->next->progs->argv) continue;
1856                                 /* create list of variable values */
1857                                 list = make_list_in(pi->next->progs->argv,
1858                                         pi->progs->argv[0]);
1859                                 save_list = list;
1860                                 save_name = pi->progs->argv[0];
1861                                 pi->progs->argv[0] = NULL;
1862                                 flag_rep = 1;
1863                         }
1864                         if (!(*list)) {
1865                                 free(pi->progs->argv[0]);
1866                                 free(save_list);
1867                                 list = NULL;
1868                                 flag_rep = 0;
1869                                 pi->progs->argv[0] = save_name;
1870 #ifndef __U_BOOT__
1871                                 pi->progs->glob_result.gl_pathv[0] =
1872                                         pi->progs->argv[0];
1873 #endif
1874                                 continue;
1875                         } else {
1876                                 /* insert new value from list for variable */
1877                                 if (pi->progs->argv[0])
1878                                         free(pi->progs->argv[0]);
1879                                 pi->progs->argv[0] = *list++;
1880 #ifndef __U_BOOT__
1881                                 pi->progs->glob_result.gl_pathv[0] =
1882                                         pi->progs->argv[0];
1883 #endif
1884                         }
1885                 }
1886                 if (rmode == RES_IN) continue;
1887                 if (rmode == RES_DO) {
1888                         if (!flag_rep) continue;
1889                 }
1890                 if ((rmode == RES_DONE)) {
1891                         if (flag_rep) {
1892                                 flag_restore = 1;
1893                         } else {
1894                                 rpipe = NULL;
1895                         }
1896                 }
1897                 if (pi->num_progs == 0) continue;
1898 #ifndef __U_BOOT__
1899                 save_num_progs = pi->num_progs; /* save number of programs */
1900 #endif
1901                 rcode = run_pipe_real(pi);
1902                 debug_printf("run_pipe_real returned %d\n",rcode);
1903 #ifndef __U_BOOT__
1904                 if (rcode!=-1) {
1905                         /* We only ran a builtin: rcode was set by the return value
1906                          * of run_pipe_real(), and we don't need to wait for anything. */
1907                 } else if (pi->followup==PIPE_BG) {
1908                         /* XXX check bash's behavior with nontrivial pipes */
1909                         /* XXX compute jobid */
1910                         /* XXX what does bash do with attempts to background builtins? */
1911                         insert_bg_job(pi);
1912                         rcode = EXIT_SUCCESS;
1913                 } else {
1914                         if (interactive) {
1915                                 /* move the new process group into the foreground */
1916                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1917                                         perror_msg("tcsetpgrp-3");
1918                                 rcode = checkjobs(pi);
1919                                 /* move the shell to the foreground */
1920                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1921                                         perror_msg("tcsetpgrp-4");
1922                         } else {
1923                                 rcode = checkjobs(pi);
1924                         }
1925                         debug_printf("checkjobs returned %d\n",rcode);
1926                 }
1927                 last_return_code=rcode;
1928 #else
1929                 if (rcode < -1) {
1930                         last_return_code = -rcode - 2;
1931                         return -2;      /* exit */
1932                 }
1933                 last_return_code=(rcode == 0) ? 0 : 1;
1934 #endif
1935 #ifndef __U_BOOT__
1936                 pi->num_progs = save_num_progs; /* restore number of programs */
1937 #endif
1938                 if ( rmode == RES_IF || rmode == RES_ELIF )
1939                         next_if_code=rcode;  /* can be overwritten a number of times */
1940                 if (rmode == RES_WHILE)
1941                         flag_rep = !last_return_code;
1942                 if (rmode == RES_UNTIL)
1943                         flag_rep = last_return_code;
1944                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1945                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1946                         skip_more_in_this_rmode=rmode;
1947 #ifndef __U_BOOT__
1948                 checkjobs(NULL);
1949 #endif
1950         }
1951         return rcode;
1952 }
1953
1954 /* broken, of course, but OK for testing */
1955 static char *indenter(int i)
1956 {
1957         static char blanks[]="                                    ";
1958         return &blanks[sizeof(blanks)-i-1];
1959 }
1960
1961 /* return code is the exit status of the pipe */
1962 static int free_pipe(struct pipe *pi, int indent)
1963 {
1964         char **p;
1965         struct child_prog *child;
1966 #ifndef __U_BOOT__
1967         struct redir_struct *r, *rnext;
1968 #endif
1969         int a, i, ret_code=0;
1970         char *ind = indenter(indent);
1971
1972 #ifndef __U_BOOT__
1973         if (pi->stopped_progs > 0)
1974                 return ret_code;
1975         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1976 #endif
1977         for (i=0; i<pi->num_progs; i++) {
1978                 child = &pi->progs[i];
1979                 final_printf("%s  command %d:\n",ind,i);
1980                 if (child->argv) {
1981                         for (a=0,p=child->argv; *p; a++,p++) {
1982                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1983                         }
1984 #ifndef __U_BOOT__
1985                         globfree(&child->glob_result);
1986 #else
1987                         for (a = child->argc;a >= 0;a--) {
1988                                 free(child->argv[a]);
1989                         }
1990                                         free(child->argv);
1991                         child->argc = 0;
1992 #endif
1993                         child->argv=NULL;
1994                 } else if (child->group) {
1995 #ifndef __U_BOOT__
1996                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
1997 #endif
1998                         ret_code = free_pipe_list(child->group,indent+3);
1999                         final_printf("%s   end group\n",ind);
2000                 } else {
2001                         final_printf("%s   (nil)\n",ind);
2002                 }
2003 #ifndef __U_BOOT__
2004                 for (r=child->redirects; r; r=rnext) {
2005                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2006                         if (r->dup == -1) {
2007                                 /* guard against the case >$FOO, where foo is unset or blank */
2008                                 if (r->word.gl_pathv) {
2009                                         final_printf(" %s\n", *r->word.gl_pathv);
2010                                         globfree(&r->word);
2011                                 }
2012                         } else {
2013                                 final_printf("&%d\n", r->dup);
2014                         }
2015                         rnext=r->next;
2016                         free(r);
2017                 }
2018                 child->redirects=NULL;
2019 #endif
2020         }
2021         free(pi->progs);   /* children are an array, they get freed all at once */
2022         pi->progs=NULL;
2023         return ret_code;
2024 }
2025
2026 static int free_pipe_list(struct pipe *head, int indent)
2027 {
2028         int rcode=0;   /* if list has no members */
2029         struct pipe *pi, *next;
2030         char *ind = indenter(indent);
2031         for (pi=head; pi; pi=next) {
2032                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2033                 rcode = free_pipe(pi, indent);
2034                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2035                 next=pi->next;
2036                 pi->next=NULL;
2037                 free(pi);
2038         }
2039         return rcode;
2040 }
2041
2042 /* Select which version we will use */
2043 static int run_list(struct pipe *pi)
2044 {
2045         int rcode=0;
2046 #ifndef __U_BOOT__
2047         if (fake_mode==0) {
2048 #endif
2049                 rcode = run_list_real(pi);
2050 #ifndef __U_BOOT__
2051         }
2052 #endif
2053         /* free_pipe_list has the side effect of clearing memory
2054          * In the long run that function can be merged with run_list_real,
2055          * but doing that now would hobble the debugging effort. */
2056         free_pipe_list(pi,0);
2057         return rcode;
2058 }
2059
2060 /* The API for glob is arguably broken.  This routine pushes a non-matching
2061  * string into the output structure, removing non-backslashed backslashes.
2062  * If someone can prove me wrong, by performing this function within the
2063  * original glob(3) api, feel free to rewrite this routine into oblivion.
2064  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2065  * XXX broken if the last character is '\\', check that before calling.
2066  */
2067 #ifndef __U_BOOT__
2068 static int globhack(const char *src, int flags, glob_t *pglob)
2069 {
2070         int cnt=0, pathc;
2071         const char *s;
2072         char *dest;
2073         for (cnt=1, s=src; s && *s; s++) {
2074                 if (*s == '\\') s++;
2075                 cnt++;
2076         }
2077         dest = malloc(cnt);
2078         if (!dest) return GLOB_NOSPACE;
2079         if (!(flags & GLOB_APPEND)) {
2080                 pglob->gl_pathv=NULL;
2081                 pglob->gl_pathc=0;
2082                 pglob->gl_offs=0;
2083                 pglob->gl_offs=0;
2084         }
2085         pathc = ++pglob->gl_pathc;
2086         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2087         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2088         pglob->gl_pathv[pathc-1]=dest;
2089         pglob->gl_pathv[pathc]=NULL;
2090         for (s=src; s && *s; s++, dest++) {
2091                 if (*s == '\\') s++;
2092                 *dest = *s;
2093         }
2094         *dest='\0';
2095         return 0;
2096 }
2097
2098 /* XXX broken if the last character is '\\', check that before calling */
2099 static int glob_needed(const char *s)
2100 {
2101         for (; *s; s++) {
2102                 if (*s == '\\') s++;
2103                 if (strchr("*[?",*s)) return 1;
2104         }
2105         return 0;
2106 }
2107
2108 #if 0
2109 static void globprint(glob_t *pglob)
2110 {
2111         int i;
2112         debug_printf("glob_t at %p:\n", pglob);
2113         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2114                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2115         for (i=0; i<pglob->gl_pathc; i++)
2116                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2117                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2118 }
2119 #endif
2120
2121 static int xglob(o_string *dest, int flags, glob_t *pglob)
2122 {
2123         int gr;
2124
2125         /* short-circuit for null word */
2126         /* we can code this better when the debug_printf's are gone */
2127         if (dest->length == 0) {
2128                 if (dest->nonnull) {
2129                         /* bash man page calls this an "explicit" null */
2130                         gr = globhack(dest->data, flags, pglob);
2131                         debug_printf("globhack returned %d\n",gr);
2132                 } else {
2133                         return 0;
2134                 }
2135         } else if (glob_needed(dest->data)) {
2136                 gr = glob(dest->data, flags, NULL, pglob);
2137                 debug_printf("glob returned %d\n",gr);
2138                 if (gr == GLOB_NOMATCH) {
2139                         /* quote removal, or more accurately, backslash removal */
2140                         gr = globhack(dest->data, flags, pglob);
2141                         debug_printf("globhack returned %d\n",gr);
2142                 }
2143         } else {
2144                 gr = globhack(dest->data, flags, pglob);
2145                 debug_printf("globhack returned %d\n",gr);
2146         }
2147         if (gr == GLOB_NOSPACE)
2148                 error_msg_and_die("out of memory during glob");
2149         if (gr != 0) { /* GLOB_ABORTED ? */
2150                 error_msg("glob(3) error %d",gr);
2151         }
2152         /* globprint(glob_target); */
2153         return gr;
2154 }
2155 #endif
2156
2157 #ifdef __U_BOOT__
2158 static char *get_dollar_var(char ch);
2159 #endif
2160
2161 /* This is used to get/check local shell variables */
2162 static char *get_local_var(const char *s)
2163 {
2164         struct variables *cur;
2165
2166         if (!s)
2167                 return NULL;
2168
2169 #ifdef __U_BOOT__
2170         if (*s == '$')
2171                 return get_dollar_var(s[1]);
2172 #endif
2173
2174         for (cur = top_vars; cur; cur=cur->next)
2175                 if(strcmp(cur->name, s)==0)
2176                         return cur->value;
2177         return NULL;
2178 }
2179
2180 /* This is used to set local shell variables
2181    flg_export==0 if only local (not exporting) variable
2182    flg_export==1 if "new" exporting environ
2183    flg_export>1  if current startup environ (not call putenv()) */
2184 static int set_local_var(const char *s, int flg_export)
2185 {
2186         char *name, *value;
2187         int result=0;
2188         struct variables *cur;
2189
2190 #ifdef __U_BOOT__
2191         /* might be possible! */
2192         if (!isalpha(*s))
2193                 return -1;
2194 #endif
2195
2196         name=strdup(s);
2197
2198 #ifdef __U_BOOT__
2199         if (getenv(name) != NULL) {
2200                 printf ("ERROR: "
2201                                 "There is a global environment variable with the same name.\n");
2202                 free(name);
2203                 return -1;
2204         }
2205 #endif
2206         /* Assume when we enter this function that we are already in
2207          * NAME=VALUE format.  So the first order of business is to
2208          * split 's' on the '=' into 'name' and 'value' */
2209         value = strchr(name, '=');
2210         if (value==0 && ++value==0) {
2211                 free(name);
2212                 return -1;
2213         }
2214         *value++ = 0;
2215
2216         for(cur = top_vars; cur; cur = cur->next) {
2217                 if(strcmp(cur->name, name)==0)
2218                         break;
2219         }
2220
2221         if(cur) {
2222                 if(strcmp(cur->value, value)==0) {
2223                         if(flg_export>0 && cur->flg_export==0)
2224                                 cur->flg_export=flg_export;
2225                         else
2226                                 result++;
2227                 } else {
2228                         if(cur->flg_read_only) {
2229                                 error_msg("%s: readonly variable", name);
2230                                 result = -1;
2231                         } else {
2232                                 if(flg_export>0 || cur->flg_export>1)
2233                                         cur->flg_export=1;
2234                                 free(cur->value);
2235
2236                                 cur->value = strdup(value);
2237                         }
2238                 }
2239         } else {
2240                 cur = malloc(sizeof(struct variables));
2241                 if(!cur) {
2242                         result = -1;
2243                 } else {
2244                         cur->name = strdup(name);
2245                         if(cur->name == 0) {
2246                                 free(cur);
2247                                 result = -1;
2248                         } else {
2249                                 struct variables *bottom = top_vars;
2250                                 cur->value = strdup(value);
2251                                 cur->next = 0;
2252                                 cur->flg_export = flg_export;
2253                                 cur->flg_read_only = 0;
2254                                 while(bottom->next) bottom=bottom->next;
2255                                 bottom->next = cur;
2256                         }
2257                 }
2258         }
2259
2260 #ifndef __U_BOOT__
2261         if(result==0 && cur->flg_export==1) {
2262                 *(value-1) = '=';
2263                 result = putenv(name);
2264         } else {
2265 #endif
2266                 free(name);
2267 #ifndef __U_BOOT__
2268                 if(result>0)            /* equivalent to previous set */
2269                         result = 0;
2270         }
2271 #endif
2272         return result;
2273 }
2274
2275 #ifndef __U_BOOT__
2276 static void unset_local_var(const char *name)
2277 {
2278         struct variables *cur;
2279
2280         if (name) {
2281                 for (cur = top_vars; cur; cur=cur->next) {
2282                         if(strcmp(cur->name, name)==0)
2283                                 break;
2284                 }
2285                 if(cur!=0) {
2286                         struct variables *next = top_vars;
2287                         if(cur->flg_read_only) {
2288                                 error_msg("%s: readonly variable", name);
2289                                 return;
2290                         } else {
2291                                 if(cur->flg_export)
2292                                         unsetenv(cur->name);
2293                                 free(cur->name);
2294                                 free(cur->value);
2295                                 while (next->next != cur)
2296                                         next = next->next;
2297                                 next->next = cur->next;
2298                         }
2299                         free(cur);
2300                 }
2301         }
2302 }
2303 #endif
2304
2305 static int is_assignment(const char *s)
2306 {
2307         if (s == NULL)
2308                 return 0;
2309
2310         if (!isalpha(*s)) return 0;
2311         ++s;
2312         while(isalnum(*s) || *s=='_') ++s;
2313         return *s=='=';
2314 }
2315
2316 #ifndef __U_BOOT__
2317 /* the src parameter allows us to peek forward to a possible &n syntax
2318  * for file descriptor duplication, e.g., "2>&1".
2319  * Return code is 0 normally, 1 if a syntax error is detected in src.
2320  * Resource errors (in xmalloc) cause the process to exit */
2321 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2322         struct in_str *input)
2323 {
2324         struct child_prog *child=ctx->child;
2325         struct redir_struct *redir = child->redirects;
2326         struct redir_struct *last_redir=NULL;
2327
2328         /* Create a new redir_struct and drop it onto the end of the linked list */
2329         while(redir) {
2330                 last_redir=redir;
2331                 redir=redir->next;
2332         }
2333         redir = xmalloc(sizeof(struct redir_struct));
2334         redir->next=NULL;
2335         redir->word.gl_pathv=NULL;
2336         if (last_redir) {
2337                 last_redir->next=redir;
2338         } else {
2339                 child->redirects=redir;
2340         }
2341
2342         redir->type=style;
2343         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2344
2345         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2346
2347         /* Check for a '2>&1' type redirect */
2348         redir->dup = redirect_dup_num(input);
2349         if (redir->dup == -2) return 1;  /* syntax error */
2350         if (redir->dup != -1) {
2351                 /* Erik had a check here that the file descriptor in question
2352                  * is legit; I postpone that to "run time"
2353                  * A "-" representation of "close me" shows up as a -3 here */
2354                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2355         } else {
2356                 /* We do _not_ try to open the file that src points to,
2357                  * since we need to return and let src be expanded first.
2358                  * Set ctx->pending_redirect, so we know what to do at the
2359                  * end of the next parsed word.
2360                  */
2361                 ctx->pending_redirect = redir;
2362         }
2363         return 0;
2364 }
2365 #endif
2366
2367 struct pipe *new_pipe(void) {
2368         struct pipe *pi;
2369         pi = xmalloc(sizeof(struct pipe));
2370         pi->num_progs = 0;
2371         pi->progs = NULL;
2372         pi->next = NULL;
2373         pi->followup = 0;  /* invalid */
2374         return pi;
2375 }
2376
2377 static void initialize_context(struct p_context *ctx)
2378 {
2379         ctx->pipe=NULL;
2380 #ifndef __U_BOOT__
2381         ctx->pending_redirect=NULL;
2382 #endif
2383         ctx->child=NULL;
2384         ctx->list_head=new_pipe();
2385         ctx->pipe=ctx->list_head;
2386         ctx->w=RES_NONE;
2387         ctx->stack=NULL;
2388 #ifdef __U_BOOT__
2389         ctx->old_flag=0;
2390 #endif
2391         done_command(ctx);   /* creates the memory for working child */
2392 }
2393
2394 /* normal return is 0
2395  * if a reserved word is found, and processed, return 1
2396  * should handle if, then, elif, else, fi, for, while, until, do, done.
2397  * case, function, and select are obnoxious, save those for later.
2398  */
2399 struct reserved_combo {
2400         char *literal;
2401         int code;
2402         long flag;
2403 };
2404 /* Mostly a list of accepted follow-up reserved words.
2405  * FLAG_END means we are done with the sequence, and are ready
2406  * to turn the compound list into a command.
2407  * FLAG_START means the word must start a new compound list.
2408  */
2409 static struct reserved_combo reserved_list[] = {
2410         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2411         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2412         { "elif",  RES_ELIF,  FLAG_THEN },
2413         { "else",  RES_ELSE,  FLAG_FI   },
2414         { "fi",    RES_FI,    FLAG_END  },
2415         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2416         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2417         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2418         { "in",    RES_IN,    FLAG_DO   },
2419         { "do",    RES_DO,    FLAG_DONE },
2420         { "done",  RES_DONE,  FLAG_END  }
2421 };
2422 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2423
2424 int reserved_word(o_string *dest, struct p_context *ctx)
2425 {
2426         struct reserved_combo *r;
2427         for (r=reserved_list;
2428                 r<reserved_list+NRES; r++) {
2429                 if (strcmp(dest->data, r->literal) == 0) {
2430                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2431                         if (r->flag & FLAG_START) {
2432                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2433                                 debug_printf("push stack\n");
2434                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2435                                         syntax();
2436                                         free(new);
2437                                         ctx->w = RES_SNTX;
2438                                         b_reset(dest);
2439                                         return 1;
2440                                 }
2441                                 *new = *ctx;   /* physical copy */
2442                                 initialize_context(ctx);
2443                                 ctx->stack=new;
2444                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2445                                 syntax();
2446                                 ctx->w = RES_SNTX;
2447                                 b_reset(dest);
2448                                 return 1;
2449                         }
2450                         ctx->w=r->code;
2451                         ctx->old_flag = r->flag;
2452                         if (ctx->old_flag & FLAG_END) {
2453                                 struct p_context *old;
2454                                 debug_printf("pop stack\n");
2455                                 done_pipe(ctx,PIPE_SEQ);
2456                                 old = ctx->stack;
2457                                 old->child->group = ctx->list_head;
2458 #ifndef __U_BOOT__
2459                                 old->child->subshell = 0;
2460 #endif
2461                                 *ctx = *old;   /* physical copy */
2462                                 free(old);
2463                         }
2464                         b_reset (dest);
2465                         return 1;
2466                 }
2467         }
2468         return 0;
2469 }
2470
2471 /* normal return is 0.
2472  * Syntax or xglob errors return 1. */
2473 static int done_word(o_string *dest, struct p_context *ctx)
2474 {
2475         struct child_prog *child=ctx->child;
2476 #ifndef __U_BOOT__
2477         glob_t *glob_target;
2478         int gr, flags = 0;
2479 #else
2480         char *str, *s;
2481         int argc, cnt;
2482 #endif
2483
2484         debug_printf("done_word: %s %p\n", dest->data, child);
2485         if (dest->length == 0 && !dest->nonnull) {
2486                 debug_printf("  true null, ignored\n");
2487                 return 0;
2488         }
2489 #ifndef __U_BOOT__
2490         if (ctx->pending_redirect) {
2491                 glob_target = &ctx->pending_redirect->word;
2492         } else {
2493 #endif
2494                 if (child->group) {
2495                         syntax();
2496                         return 1;  /* syntax error, groups and arglists don't mix */
2497                 }
2498                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2499                         debug_printf("checking %s for reserved-ness\n",dest->data);
2500                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2501                 }
2502 #ifndef __U_BOOT__
2503                 glob_target = &child->glob_result;
2504                 if (child->argv) flags |= GLOB_APPEND;
2505 #else
2506                 for (cnt = 1, s = dest->data; s && *s; s++) {
2507                         if (*s == '\\') s++;
2508                         cnt++;
2509                 }
2510                 str = malloc(cnt);
2511                 if (!str) return 1;
2512                 if ( child->argv == NULL) {
2513                         child->argc=0;
2514                 }
2515                 argc = ++child->argc;
2516                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2517                 if (child->argv == NULL) return 1;
2518                 child->argv[argc-1]=str;
2519                 child->argv[argc]=NULL;
2520                 for (s = dest->data; s && *s; s++,str++) {
2521                         if (*s == '\\') s++;
2522                         *str = *s;
2523                 }
2524                 *str = '\0';
2525 #endif
2526 #ifndef __U_BOOT__
2527         }
2528         gr = xglob(dest, flags, glob_target);
2529         if (gr != 0) return 1;
2530 #endif
2531
2532         b_reset(dest);
2533 #ifndef __U_BOOT__
2534         if (ctx->pending_redirect) {
2535                 ctx->pending_redirect=NULL;
2536                 if (glob_target->gl_pathc != 1) {
2537                         error_msg("ambiguous redirect");
2538                         return 1;
2539                 }
2540         } else {
2541                 child->argv = glob_target->gl_pathv;
2542         }
2543 #endif
2544         if (ctx->w == RES_FOR) {
2545                 done_word(dest,ctx);
2546                 done_pipe(ctx,PIPE_SEQ);
2547         }
2548         return 0;
2549 }
2550
2551 /* The only possible error here is out of memory, in which case
2552  * xmalloc exits. */
2553 static int done_command(struct p_context *ctx)
2554 {
2555         /* The child is really already in the pipe structure, so
2556          * advance the pipe counter and make a new, null child.
2557          * Only real trickiness here is that the uncommitted
2558          * child structure, to which ctx->child points, is not
2559          * counted in pi->num_progs. */
2560         struct pipe *pi=ctx->pipe;
2561         struct child_prog *prog=ctx->child;
2562
2563         if (prog && prog->group == NULL
2564                  && prog->argv == NULL
2565 #ifndef __U_BOOT__
2566                  && prog->redirects == NULL) {
2567 #else
2568                                                                                 ) {
2569 #endif
2570                 debug_printf("done_command: skipping null command\n");
2571                 return 0;
2572         } else if (prog) {
2573                 pi->num_progs++;
2574                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2575         } else {
2576                 debug_printf("done_command: initializing\n");
2577         }
2578         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2579
2580         prog = pi->progs + pi->num_progs;
2581 #ifndef __U_BOOT__
2582         prog->redirects = NULL;
2583 #endif
2584         prog->argv = NULL;
2585 #ifndef __U_BOOT__
2586         prog->is_stopped = 0;
2587 #endif
2588         prog->group = NULL;
2589 #ifndef __U_BOOT__
2590         prog->glob_result.gl_pathv = NULL;
2591         prog->family = pi;
2592 #endif
2593         prog->sp = 0;
2594         ctx->child = prog;
2595         prog->type = ctx->type;
2596
2597         /* but ctx->pipe and ctx->list_head remain unchanged */
2598         return 0;
2599 }
2600
2601 static int done_pipe(struct p_context *ctx, pipe_style type)
2602 {
2603         struct pipe *new_p;
2604         done_command(ctx);  /* implicit closure of previous command */
2605         debug_printf("done_pipe, type %d\n", type);
2606         ctx->pipe->followup = type;
2607         ctx->pipe->r_mode = ctx->w;
2608         new_p=new_pipe();
2609         ctx->pipe->next = new_p;
2610         ctx->pipe = new_p;
2611         ctx->child = NULL;
2612         done_command(ctx);  /* set up new pipe to accept commands */
2613         return 0;
2614 }
2615
2616 #ifndef __U_BOOT__
2617 /* peek ahead in the in_str to find out if we have a "&n" construct,
2618  * as in "2>&1", that represents duplicating a file descriptor.
2619  * returns either -2 (syntax error), -1 (no &), or the number found.
2620  */
2621 static int redirect_dup_num(struct in_str *input)
2622 {
2623         int ch, d=0, ok=0;
2624         ch = b_peek(input);
2625         if (ch != '&') return -1;
2626
2627         b_getch(input);  /* get the & */
2628         ch=b_peek(input);
2629         if (ch == '-') {
2630                 b_getch(input);
2631                 return -3;  /* "-" represents "close me" */
2632         }
2633         while (isdigit(ch)) {
2634                 d = d*10+(ch-'0');
2635                 ok=1;
2636                 b_getch(input);
2637                 ch = b_peek(input);
2638         }
2639         if (ok) return d;
2640
2641         error_msg("ambiguous redirect");
2642         return -2;
2643 }
2644
2645 /* If a redirect is immediately preceded by a number, that number is
2646  * supposed to tell which file descriptor to redirect.  This routine
2647  * looks for such preceding numbers.  In an ideal world this routine
2648  * needs to handle all the following classes of redirects...
2649  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2650  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2651  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2652  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2653  * A -1 output from this program means no valid number was found, so the
2654  * caller should use the appropriate default for this redirection.
2655  */
2656 static int redirect_opt_num(o_string *o)
2657 {
2658         int num;
2659
2660         if (o->length==0) return -1;
2661         for(num=0; num<o->length; num++) {
2662                 if (!isdigit(*(o->data+num))) {
2663                         return -1;
2664                 }
2665         }
2666         /* reuse num (and save an int) */
2667         num=atoi(o->data);
2668         b_reset(o);
2669         return num;
2670 }
2671
2672 FILE *generate_stream_from_list(struct pipe *head)
2673 {
2674         FILE *pf;
2675 #if 1
2676         int pid, channel[2];
2677         if (pipe(channel)<0) perror_msg_and_die("pipe");
2678         pid=fork();
2679         if (pid<0) {
2680                 perror_msg_and_die("fork");
2681         } else if (pid==0) {
2682                 close(channel[0]);
2683                 if (channel[1] != 1) {
2684                         dup2(channel[1],1);
2685                         close(channel[1]);
2686                 }
2687 #if 0
2688 #define SURROGATE "surrogate response"
2689                 write(1,SURROGATE,sizeof(SURROGATE));
2690                 _exit(run_list(head));
2691 #else
2692                 _exit(run_list_real(head));   /* leaks memory */
2693 #endif
2694         }
2695         debug_printf("forked child %d\n",pid);
2696         close(channel[1]);
2697         pf = fdopen(channel[0],"r");
2698         debug_printf("pipe on FILE *%p\n",pf);
2699 #else
2700         free_pipe_list(head,0);
2701         pf=popen("echo surrogate response","r");
2702         debug_printf("started fake pipe on FILE *%p\n",pf);
2703 #endif
2704         return pf;
2705 }
2706
2707 /* this version hacked for testing purposes */
2708 /* return code is exit status of the process that is run. */
2709 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2710 {
2711         int retcode;
2712         o_string result=NULL_O_STRING;
2713         struct p_context inner;
2714         FILE *p;
2715         struct in_str pipe_str;
2716         initialize_context(&inner);
2717
2718         /* recursion to generate command */
2719         retcode = parse_stream(&result, &inner, input, subst_end);
2720         if (retcode != 0) return retcode;  /* syntax error or EOF */
2721         done_word(&result, &inner);
2722         done_pipe(&inner, PIPE_SEQ);
2723         b_free(&result);
2724
2725         p=generate_stream_from_list(inner.list_head);
2726         if (p==NULL) return 1;
2727         mark_open(fileno(p));
2728         setup_file_in_str(&pipe_str, p);
2729
2730         /* now send results of command back into original context */
2731         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2732         /* XXX In case of a syntax error, should we try to kill the child?
2733          * That would be tough to do right, so just read until EOF. */
2734         if (retcode == 1) {
2735                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2736         }
2737
2738         debug_printf("done reading from pipe, pclose()ing\n");
2739         /* This is the step that wait()s for the child.  Should be pretty
2740          * safe, since we just read an EOF from its stdout.  We could try
2741          * to better, by using wait(), and keeping track of background jobs
2742          * at the same time.  That would be a lot of work, and contrary
2743          * to the KISS philosophy of this program. */
2744         mark_closed(fileno(p));
2745         retcode=pclose(p);
2746         free_pipe_list(inner.list_head,0);
2747         debug_printf("pclosed, retcode=%d\n",retcode);
2748         /* XXX this process fails to trim a single trailing newline */
2749         return retcode;
2750 }
2751
2752 static int parse_group(o_string *dest, struct p_context *ctx,
2753         struct in_str *input, int ch)
2754 {
2755         int rcode, endch=0;
2756         struct p_context sub;
2757         struct child_prog *child = ctx->child;
2758         if (child->argv) {
2759                 syntax();
2760                 return 1;  /* syntax error, groups and arglists don't mix */
2761         }
2762         initialize_context(&sub);
2763         switch(ch) {
2764                 case '(': endch=')'; child->subshell=1; break;
2765                 case '{': endch='}'; break;
2766                 default: syntax();   /* really logic error */
2767         }
2768         rcode=parse_stream(dest,&sub,input,endch);
2769         done_word(dest,&sub); /* finish off the final word in the subcontext */
2770         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2771         child->group = sub.list_head;
2772         return rcode;
2773         /* child remains "open", available for possible redirects */
2774 }
2775 #endif
2776
2777 /* basically useful version until someone wants to get fancier,
2778  * see the bash man page under "Parameter Expansion" */
2779 static char *lookup_param(char *src)
2780 {
2781         char *p;
2782
2783         if (!src)
2784                 return NULL;
2785
2786                 p = getenv(src);
2787                 if (!p)
2788                         p = get_local_var(src);
2789
2790         return p;
2791 }
2792
2793 #ifdef __U_BOOT__
2794 static char *get_dollar_var(char ch)
2795 {
2796         static char buf[40];
2797
2798         buf[0] = '\0';
2799         switch (ch) {
2800                 case '?':
2801                         sprintf(buf, "%u", (unsigned int)last_return_code);
2802                         break;
2803                 default:
2804                         return NULL;
2805         }
2806         return buf;
2807 }
2808 #endif
2809
2810 /* return code: 0 for OK, 1 for syntax error */
2811 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2812 {
2813 #ifndef __U_BOOT__
2814         int i, advance=0;
2815 #else
2816         int advance=0;
2817 #endif
2818 #ifndef __U_BOOT__
2819         char sep[]=" ";
2820 #endif
2821         int ch = input->peek(input);  /* first character after the $ */
2822         debug_printf("handle_dollar: ch=%c\n",ch);
2823         if (isalpha(ch)) {
2824                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2825                 ctx->child->sp++;
2826                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2827                         b_getch(input);
2828                         b_addchr(dest,ch);
2829                 }
2830                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2831 #ifndef __U_BOOT__
2832         } else if (isdigit(ch)) {
2833                 i = ch-'0';  /* XXX is $0 special? */
2834                 if (i<global_argc) {
2835                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2836                 }
2837                 advance = 1;
2838 #endif
2839         } else switch (ch) {
2840 #ifndef __U_BOOT__
2841                 case '$':
2842                         b_adduint(dest,getpid());
2843                         advance = 1;
2844                         break;
2845                 case '!':
2846                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2847                         advance = 1;
2848                         break;
2849 #endif
2850                 case '?':
2851 #ifndef __U_BOOT__
2852                         b_adduint(dest,last_return_code);
2853 #else
2854                         ctx->child->sp++;
2855                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2856                         b_addchr(dest, '$');
2857                         b_addchr(dest, '?');
2858                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2859 #endif
2860                         advance = 1;
2861                         break;
2862 #ifndef __U_BOOT__
2863                 case '#':
2864                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2865                         advance = 1;
2866                         break;
2867 #endif
2868                 case '{':
2869                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2870                         ctx->child->sp++;
2871                         b_getch(input);
2872                         /* XXX maybe someone will try to escape the '}' */
2873                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2874                                 b_addchr(dest,ch);
2875                         }
2876                         if (ch != '}') {
2877                                 syntax();
2878                                 return 1;
2879                         }
2880                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2881                         break;
2882 #ifndef __U_BOOT__
2883                 case '(':
2884                         b_getch(input);
2885                         process_command_subs(dest, ctx, input, ')');
2886                         break;
2887                 case '*':
2888                         sep[0]=ifs[0];
2889                         for (i=1; i<global_argc; i++) {
2890                                 parse_string(dest, ctx, global_argv[i]);
2891                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2892                         }
2893                         break;
2894                 case '@':
2895                 case '-':
2896                 case '_':
2897                         /* still unhandled, but should be eventually */
2898                         error_msg("unhandled syntax: $%c",ch);
2899                         return 1;
2900                         break;
2901 #endif
2902                 default:
2903                         b_addqchr(dest,'$',dest->quote);
2904         }
2905         /* Eat the character if the flag was set.  If the compiler
2906          * is smart enough, we could substitute "b_getch(input);"
2907          * for all the "advance = 1;" above, and also end up with
2908          * a nice size-optimized program.  Hah!  That'll be the day.
2909          */
2910         if (advance) b_getch(input);
2911         return 0;
2912 }
2913
2914 #ifndef __U_BOOT__
2915 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2916 {
2917         struct in_str foo;
2918         setup_string_in_str(&foo, src);
2919         return parse_stream(dest, ctx, &foo, '\0');
2920 }
2921 #endif
2922
2923 /* return code is 0 for normal exit, 1 for syntax error */
2924 int parse_stream(o_string *dest, struct p_context *ctx,
2925         struct in_str *input, int end_trigger)
2926 {
2927         unsigned int ch, m;
2928 #ifndef __U_BOOT__
2929         int redir_fd;
2930         redir_type redir_style;
2931 #endif
2932         int next;
2933
2934         /* Only double-quote state is handled in the state variable dest->quote.
2935          * A single-quote triggers a bypass of the main loop until its mate is
2936          * found.  When recursing, quote state is passed in via dest->quote. */
2937
2938         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2939         while ((ch=b_getch(input))!=EOF) {
2940                 m = map[ch];
2941 #ifdef __U_BOOT__
2942                 if (input->__promptme == 0) return 1;
2943 #endif
2944                 next = (ch == '\n') ? 0 : b_peek(input);
2945
2946                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2947                         ch >= ' ' ? ch : '.', ch, m,
2948                         dest->quote, ctx->stack == NULL ? '*' : '.');
2949
2950                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2951                         b_addqchr(dest, ch, dest->quote);
2952                 } else {
2953                         if (m==2) {  /* unquoted IFS */
2954                                 if (done_word(dest, ctx)) {
2955                                         return 1;
2956                                 }
2957                                 /* If we aren't performing a substitution, treat a newline as a
2958                                  * command separator.  */
2959                                 if (end_trigger != '\0' && ch=='\n')
2960                                         done_pipe(ctx,PIPE_SEQ);
2961                         }
2962                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2963                                 debug_printf("leaving parse_stream (triggered)\n");
2964                                 return 0;
2965                         }
2966 #if 0
2967                         if (ch=='\n') {
2968                                 /* Yahoo!  Time to run with it! */
2969                                 done_pipe(ctx,PIPE_SEQ);
2970                                 run_list(ctx->list_head);
2971                                 initialize_context(ctx);
2972                         }
2973 #endif
2974                         if (m!=2) switch (ch) {
2975                 case '#':
2976                         if (dest->length == 0 && !dest->quote) {
2977                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2978                         } else {
2979                                 b_addqchr(dest, ch, dest->quote);
2980                         }
2981                         break;
2982                 case '\\':
2983                         if (next == EOF) {
2984                                 syntax();
2985                                 return 1;
2986                         }
2987                         b_addqchr(dest, '\\', dest->quote);
2988                         b_addqchr(dest, b_getch(input), dest->quote);
2989                         break;
2990                 case '$':
2991                         if (handle_dollar(dest, ctx, input)!=0) return 1;
2992                         break;
2993                 case '\'':
2994                         dest->nonnull = 1;
2995                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
2996 #ifdef __U_BOOT__
2997                                 if(input->__promptme == 0) return 1;
2998 #endif
2999                                 b_addchr(dest,ch);
3000                         }
3001                         if (ch==EOF) {
3002                                 syntax();
3003                                 return 1;
3004                         }
3005                         break;
3006                 case '"':
3007                         dest->nonnull = 1;
3008                         dest->quote = !dest->quote;
3009                         break;
3010 #ifndef __U_BOOT__
3011                 case '`':
3012                         process_command_subs(dest, ctx, input, '`');
3013                         break;
3014                 case '>':
3015                         redir_fd = redirect_opt_num(dest);
3016                         done_word(dest, ctx);
3017                         redir_style=REDIRECT_OVERWRITE;
3018                         if (next == '>') {
3019                                 redir_style=REDIRECT_APPEND;
3020                                 b_getch(input);
3021                         } else if (next == '(') {
3022                                 syntax();   /* until we support >(list) Process Substitution */
3023                                 return 1;
3024                         }
3025                         setup_redirect(ctx, redir_fd, redir_style, input);
3026                         break;
3027                 case '<':
3028                         redir_fd = redirect_opt_num(dest);
3029                         done_word(dest, ctx);
3030                         redir_style=REDIRECT_INPUT;
3031                         if (next == '<') {
3032                                 redir_style=REDIRECT_HEREIS;
3033                                 b_getch(input);
3034                         } else if (next == '>') {
3035                                 redir_style=REDIRECT_IO;
3036                                 b_getch(input);
3037                         } else if (next == '(') {
3038                                 syntax();   /* until we support <(list) Process Substitution */
3039                                 return 1;
3040                         }
3041                         setup_redirect(ctx, redir_fd, redir_style, input);
3042                         break;
3043 #endif
3044                 case ';':
3045                         done_word(dest, ctx);
3046                         done_pipe(ctx,PIPE_SEQ);
3047                         break;
3048                 case '&':
3049                         done_word(dest, ctx);
3050                         if (next=='&') {
3051                                 b_getch(input);
3052                                 done_pipe(ctx,PIPE_AND);
3053                         } else {
3054 #ifndef __U_BOOT__
3055                                 done_pipe(ctx,PIPE_BG);
3056 #else
3057                                 syntax_err();
3058                                 return 1;
3059 #endif
3060                         }
3061                         break;
3062                 case '|':
3063                         done_word(dest, ctx);
3064                         if (next=='|') {
3065                                 b_getch(input);
3066                                 done_pipe(ctx,PIPE_OR);
3067                         } else {
3068                                 /* we could pick up a file descriptor choice here
3069                                  * with redirect_opt_num(), but bash doesn't do it.
3070                                  * "echo foo 2| cat" yields "foo 2". */
3071 #ifndef __U_BOOT__
3072                                 done_command(ctx);
3073 #else
3074                                 syntax_err();
3075                                 return 1;
3076 #endif
3077                         }
3078                         break;
3079 #ifndef __U_BOOT__
3080                 case '(':
3081                 case '{':
3082                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3083                         break;
3084                 case ')':
3085                 case '}':
3086                         syntax();   /* Proper use of this character caught by end_trigger */
3087                         return 1;
3088                         break;
3089 #endif
3090                 default:
3091                         syntax();   /* this is really an internal logic error */
3092                         return 1;
3093                         }
3094                 }
3095         }
3096         /* complain if quote?  No, maybe we just finished a command substitution
3097          * that was quoted.  Example:
3098          * $ echo "`cat foo` plus more"
3099          * and we just got the EOF generated by the subshell that ran "cat foo"
3100          * The only real complaint is if we got an EOF when end_trigger != '\0',
3101          * that is, we were really supposed to get end_trigger, and never got
3102          * one before the EOF.  Can't use the standard "syntax error" return code,
3103          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3104         debug_printf("leaving parse_stream (EOF)\n");
3105         if (end_trigger != '\0') return -1;
3106         return 0;
3107 }
3108
3109 void mapset(const unsigned char *set, int code)
3110 {
3111         const unsigned char *s;
3112         for (s=set; *s; s++) map[*s] = code;
3113 }
3114
3115 void update_ifs_map(void)
3116 {
3117         /* char *ifs and char map[256] are both globals. */
3118         ifs = getenv("IFS");
3119         if (ifs == NULL) ifs=" \t\n";
3120         /* Precompute a list of 'flow through' behavior so it can be treated
3121          * quickly up front.  Computation is necessary because of IFS.
3122          * Special case handling of IFS == " \t\n" is not implemented.
3123          * The map[] array only really needs two bits each, and on most machines
3124          * that would be faster because of the reduced L1 cache footprint.
3125          */
3126         memset(map,0,sizeof(map)); /* most characters flow through always */
3127 #ifndef __U_BOOT__
3128         mapset("\\$'\"`", 3);      /* never flow through */
3129         mapset("<>;&|(){}#", 1);   /* flow through if quoted */
3130 #else
3131         mapset("\\$'\"", 3);       /* never flow through */
3132         mapset(";&|#", 1);         /* flow through if quoted */
3133 #endif
3134         mapset(ifs, 2);            /* also flow through if quoted */
3135 }
3136
3137 /* most recursion does not come through here, the exeception is
3138  * from builtin_source() */
3139 int parse_stream_outer(struct in_str *inp, int flag)
3140 {
3141
3142         struct p_context ctx;
3143         o_string temp=NULL_O_STRING;
3144         int rcode;
3145 #ifdef __U_BOOT__
3146         int code = 0;
3147 #endif
3148         do {
3149                 ctx.type = flag;
3150                 initialize_context(&ctx);
3151                 update_ifs_map();
3152                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset(";$&|", 0);
3153                 inp->promptmode=1;
3154                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3155 #ifdef __U_BOOT__
3156                 if (rcode == 1) flag_repeat = 0;
3157 #endif
3158                 if (rcode != 1 && ctx.old_flag != 0) {
3159                         syntax();
3160 #ifdef __U_BOOT__
3161                         flag_repeat = 0;
3162 #endif
3163                 }
3164                 if (rcode != 1 && ctx.old_flag == 0) {
3165                         done_word(&temp, &ctx);
3166                         done_pipe(&ctx,PIPE_SEQ);
3167 #ifndef __U_BOOT__
3168                         run_list(ctx.list_head);
3169 #else
3170                         code = run_list(ctx.list_head);
3171                         if (code == -2) {       /* exit */
3172                                 b_free(&temp);
3173                                 code = 0;
3174                                 /* XXX hackish way to not allow exit from main loop */
3175                                 if (inp->peek == file_peek) {
3176                                         printf("exit not allowed from main input shell.\n");
3177                                         continue;
3178                                 }
3179                                 break;
3180                         }
3181                         if (code == -1)
3182                             flag_repeat = 0;
3183 #endif
3184                 } else {
3185                         if (ctx.old_flag != 0) {
3186                                 free(ctx.stack);
3187                                 b_reset(&temp);
3188                         }
3189 #ifdef __U_BOOT__
3190                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3191                         inp->__promptme = 1;
3192 #endif
3193                         temp.nonnull = 0;
3194                         temp.quote = 0;
3195                         inp->p = NULL;
3196                         free_pipe_list(ctx.list_head,0);
3197                 }
3198                 b_free(&temp);
3199         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3200 #ifndef __U_BOOT__
3201         return 0;
3202 #else
3203         return (code != 0) ? 1 : 0;
3204 #endif /* __U_BOOT__ */
3205 }
3206
3207 #ifndef __U_BOOT__
3208 static int parse_string_outer(const char *s, int flag)
3209 #else
3210 int parse_string_outer(char *s, int flag)
3211 #endif  /* __U_BOOT__ */
3212 {
3213         struct in_str input;
3214 #ifdef __U_BOOT__
3215         char *p = NULL;
3216         int rcode;
3217         if ( !s || !*s)
3218                 return 1;
3219         if (!(p = strchr(s, '\n')) || *++p) {
3220                 p = xmalloc(strlen(s) + 2);
3221                 strcpy(p, s);
3222                 strcat(p, "\n");
3223                 setup_string_in_str(&input, p);
3224                 rcode = parse_stream_outer(&input, flag);
3225                 free(p);
3226                 return rcode;
3227         } else {
3228 #endif
3229         setup_string_in_str(&input, s);
3230         return parse_stream_outer(&input, flag);
3231 #ifdef __U_BOOT__
3232         }
3233 #endif
3234 }
3235
3236 #ifndef __U_BOOT__
3237 static int parse_file_outer(FILE *f)
3238 #else
3239 int parse_file_outer(void)
3240 #endif
3241 {
3242         int rcode;
3243         struct in_str input;
3244 #ifndef __U_BOOT__
3245         setup_file_in_str(&input, f);
3246 #else
3247         setup_file_in_str(&input);
3248 #endif
3249         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3250         return rcode;
3251 }
3252
3253 #ifdef __U_BOOT__
3254 static void u_boot_hush_reloc(void)
3255 {
3256         DECLARE_GLOBAL_DATA_PTR;
3257         unsigned long addr;
3258         struct reserved_combo *r;
3259
3260         for (r=reserved_list; r<reserved_list+NRES; r++) {
3261                 addr = (ulong) (r->literal) + gd->reloc_off;
3262                 r->literal = (char *)addr;
3263         }
3264 }
3265
3266 int u_boot_hush_start(void)
3267 {
3268         if (top_vars == NULL) {
3269                 top_vars = malloc(sizeof(struct variables));
3270                 top_vars->name = "HUSH_VERSION";
3271                 top_vars->value = "0.01";
3272                 top_vars->next = 0;
3273                 top_vars->flg_export = 0;
3274                 top_vars->flg_read_only = 1;
3275                 u_boot_hush_reloc();
3276         }
3277         return 0;
3278 }
3279
3280 static void *xmalloc(size_t size)
3281 {
3282         void *p = NULL;
3283
3284         if (!(p = malloc(size))) {
3285             printf("ERROR : memory not allocated\n");
3286             for(;;);
3287         }
3288         return p;
3289 }
3290
3291 static void *xrealloc(void *ptr, size_t size)
3292 {
3293         void *p = NULL;
3294
3295         if (!(p = realloc(ptr, size))) {
3296             printf("ERROR : memory not allocated\n");
3297             for(;;);
3298         }
3299         return p;
3300 }
3301 #endif /* __U_BOOT__ */
3302
3303 #ifndef __U_BOOT__
3304 /* Make sure we have a controlling tty.  If we get started under a job
3305  * aware app (like bash for example), make sure we are now in charge so
3306  * we don't fight over who gets the foreground */
3307 static void setup_job_control(void)
3308 {
3309         static pid_t shell_pgrp;
3310         /* Loop until we are in the foreground.  */
3311         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3312                 kill (- shell_pgrp, SIGTTIN);
3313
3314         /* Ignore interactive and job-control signals.  */
3315         signal(SIGINT, SIG_IGN);
3316         signal(SIGQUIT, SIG_IGN);
3317         signal(SIGTERM, SIG_IGN);
3318         signal(SIGTSTP, SIG_IGN);
3319         signal(SIGTTIN, SIG_IGN);
3320         signal(SIGTTOU, SIG_IGN);
3321         signal(SIGCHLD, SIG_IGN);
3322
3323         /* Put ourselves in our own process group.  */
3324         setsid();
3325         shell_pgrp = getpid ();
3326         setpgid (shell_pgrp, shell_pgrp);
3327
3328         /* Grab control of the terminal.  */
3329         tcsetpgrp(shell_terminal, shell_pgrp);
3330 }
3331
3332 int hush_main(int argc, char **argv)
3333 {
3334         int opt;
3335         FILE *input;
3336         char **e = environ;
3337
3338         /* XXX what should these be while sourcing /etc/profile? */
3339         global_argc = argc;
3340         global_argv = argv;
3341
3342         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3343          * hush_main(), therefore we cannot rely on the BSS to zero out this
3344          * stuff.  Reset these to 0 every time. */
3345         ifs = NULL;
3346         /* map[] is taken care of with call to update_ifs_map() */
3347         fake_mode = 0;
3348         interactive = 0;
3349         close_me_head = NULL;
3350         last_bg_pid = 0;
3351         job_list = NULL;
3352         last_jobid = 0;
3353
3354         /* Initialize some more globals to non-zero values */
3355         set_cwd();
3356 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3357         cmdedit_set_initial_prompt();
3358 #else
3359         PS1 = NULL;
3360 #endif
3361         PS2 = "> ";
3362
3363         /* initialize our shell local variables with the values
3364          * currently living in the environment */
3365         if (e) {
3366                 for (; *e; e++)
3367                         set_local_var(*e, 2);   /* without call putenv() */
3368         }
3369
3370         last_return_code=EXIT_SUCCESS;
3371
3372
3373         if (argv[0] && argv[0][0] == '-') {
3374                 debug_printf("\nsourcing /etc/profile\n");
3375                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3376                         mark_open(fileno(input));
3377                         parse_file_outer(input);
3378                         mark_closed(fileno(input));
3379                         fclose(input);
3380                 }
3381         }
3382         input=stdin;
3383
3384         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3385                 switch (opt) {
3386                         case 'c':
3387                                 {
3388                                         global_argv = argv+optind;
3389                                         global_argc = argc-optind;
3390                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3391                                         goto final_return;
3392                                 }
3393                                 break;
3394                         case 'i':
3395                                 interactive++;
3396                                 break;
3397                         case 'f':
3398                                 fake_mode++;
3399                                 break;
3400                         default:
3401 #ifndef BB_VER
3402                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3403                                                 "   or: sh -c command [args]...\n\n");
3404                                 exit(EXIT_FAILURE);
3405 #else
3406                                 show_usage();
3407 #endif
3408                 }
3409         }
3410         /* A shell is interactive if the `-i' flag was given, or if all of
3411          * the following conditions are met:
3412          *        no -c command
3413          *    no arguments remaining or the -s flag given
3414          *    standard input is a terminal
3415          *    standard output is a terminal
3416          *    Refer to Posix.2, the description of the `sh' utility. */
3417         if (argv[optind]==NULL && input==stdin &&
3418                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3419                 interactive++;
3420         }
3421
3422         debug_printf("\ninteractive=%d\n", interactive);
3423         if (interactive) {
3424                 /* Looks like they want an interactive shell */
3425 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3426                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3427                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3428 #endif
3429                 setup_job_control();
3430         }
3431
3432         if (argv[optind]==NULL) {
3433                 opt=parse_file_outer(stdin);
3434                 goto final_return;
3435         }
3436
3437         debug_printf("\nrunning script '%s'\n", argv[optind]);
3438         global_argv = argv+optind;
3439         global_argc = argc-optind;
3440         input = xfopen(argv[optind], "r");
3441         opt = parse_file_outer(input);
3442
3443 #ifdef CONFIG_FEATURE_CLEAN_UP
3444         fclose(input);
3445         if (cwd && cwd != unknown)
3446                 free((char*)cwd);
3447         {
3448                 struct variables *cur, *tmp;
3449                 for(cur = top_vars; cur; cur = tmp) {
3450                         tmp = cur->next;
3451                         if (!cur->flg_read_only) {
3452                                 free(cur->name);
3453                                 free(cur->value);
3454                                 free(cur);
3455                         }
3456                 }
3457         }
3458 #endif
3459
3460 final_return:
3461         return(opt?opt:last_return_code);
3462 }
3463 #endif
3464
3465 static char *insert_var_value(char *inp)
3466 {
3467         int res_str_len = 0;
3468         int len;
3469         int done = 0;
3470         char *p, *p1, *res_str = NULL;
3471
3472         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3473                 if (p != inp) {
3474                         len = p - inp;
3475                         res_str = xrealloc(res_str, (res_str_len + len));
3476                         strncpy((res_str + res_str_len), inp, len);
3477                         res_str_len += len;
3478                 }
3479                 inp = ++p;
3480                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3481                 *p = '\0';
3482                 if ((p1 = lookup_param(inp))) {
3483                         len = res_str_len + strlen(p1);
3484                         res_str = xrealloc(res_str, (1 + len));
3485                         strcpy((res_str + res_str_len), p1);
3486                         res_str_len = len;
3487                 }
3488                 *p = SPECIAL_VAR_SYMBOL;
3489                 inp = ++p;
3490                 done = 1;
3491         }
3492         if (done) {
3493                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3494                 strcpy((res_str + res_str_len), inp);
3495                 while ((p = strchr(res_str, '\n'))) {
3496                         *p = ' ';
3497                 }
3498         }
3499         return (res_str == NULL) ? inp : res_str;
3500 }
3501
3502 static char **make_list_in(char **inp, char *name)
3503 {
3504         int len, i;
3505         int name_len = strlen(name);
3506         int n = 0;
3507         char **list;
3508         char *p1, *p2, *p3;
3509
3510         /* create list of variable values */
3511         list = xmalloc(sizeof(*list));
3512         for (i = 0; inp[i]; i++) {
3513                 p3 = insert_var_value(inp[i]);
3514                 p1 = p3;
3515                 while (*p1) {
3516                         if ((*p1 == ' ')) {
3517                                 p1++;
3518                                 continue;
3519                         }
3520                         if ((p2 = strchr(p1, ' '))) {
3521                                 len = p2 - p1;
3522                         } else {
3523                                 len = strlen(p1);
3524                                 p2 = p1 + len;
3525                         }
3526                         /* we use n + 2 in realloc for list,because we add
3527                          * new element and then we will add NULL element */
3528                         list = xrealloc(list, sizeof(*list) * (n + 2));
3529                         list[n] = xmalloc(2 + name_len + len);
3530                         strcpy(list[n], name);
3531                         strcat(list[n], "=");
3532                         strncat(list[n], p1, len);
3533                         list[n++][name_len + len + 1] = '\0';
3534                         p1 = p2;
3535                 }
3536                 if (p3 != inp[i]) free(p3);
3537         }
3538         list[n] = NULL;
3539         return list;
3540 }
3541
3542 /* Make new string for parser */
3543 static char * make_string(char ** inp)
3544 {
3545         char *p;
3546         char *str = NULL;
3547         int n;
3548         int len = 2;
3549
3550         for (n = 0; inp[n]; n++) {
3551                 p = insert_var_value(inp[n]);
3552                 str = xrealloc(str, (len + strlen(p)));
3553                 if (n) {
3554                         strcat(str, " ");
3555                 } else {
3556                         *str = '\0';
3557                 }
3558                 strcat(str, p);
3559                 len = strlen(str) + 3;
3560                 if (p != inp[n]) free(p);
3561         }
3562         len = strlen(str);
3563         *(str + len) = '\n';
3564         *(str + len + 1) = '\0';
3565         return str;
3566 }
3567
3568 #endif /* CFG_HUSH_PARSER */
3569 /****************************************************************************/