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 uchar *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 #ifdef CONFIG_BOOT_RETRY_TIME
1026 #  ifdef CONFIG_RESET_TO_RETRY
1027         extern int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1028 #  else
1029 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1030 #  endif
1031         reset_cmd_timeout();
1032 #endif
1033         i->__promptme = 1;
1034         if (i->promptmode == 1) {
1035                 n = readline(CFG_PROMPT);
1036         } else {
1037                 n = readline(CFG_PROMPT_HUSH_PS2);
1038         }
1039 #ifdef CONFIG_BOOT_RETRY_TIME
1040         if (n == -2) {
1041           puts("\nTimeout waiting for command\n");
1042 #  ifdef CONFIG_RESET_TO_RETRY
1043           do_reset(NULL, 0, 0, NULL);
1044 #  else
1045 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1046 #  endif
1047         }
1048 #endif
1049         if (n == -1 ) {
1050                 flag_repeat = 0;
1051                 i->__promptme = 0;
1052         }
1053         n = strlen(console_buffer);
1054         console_buffer[n] = '\n';
1055         console_buffer[n+1]= '\0';
1056         if (had_ctrlc()) flag_repeat = 0;
1057         clear_ctrlc();
1058         do_repeat = 0;
1059         if (i->promptmode == 1) {
1060                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1061                         strcpy(the_command,console_buffer);
1062                 }
1063                 else {
1064                         if (console_buffer[0] != '\n') {
1065                                 strcpy(the_command,console_buffer);
1066                                 flag_repeat = 1;
1067                         }
1068                         else {
1069                                 do_repeat = 1;
1070                         }
1071                 }
1072                 i->p = the_command;
1073         }
1074         else {
1075                 if (console_buffer[0] != '\n') {
1076                         if (strlen(the_command) + strlen(console_buffer)
1077                             < CFG_CBSIZE) {
1078                                 n = strlen(the_command);
1079                                 the_command[n-1] = ' ';
1080                                 strcpy(&the_command[n],console_buffer);
1081                         }
1082                         else {
1083                                 the_command[0] = '\n';
1084                                 the_command[1] = '\0';
1085                                 flag_repeat = 0;
1086                         }
1087                 }
1088                 if (i->__promptme == 0) {
1089                         the_command[0] = '\n';
1090                         the_command[1] = '\0';
1091                 }
1092                 i->p = console_buffer;
1093         }
1094 #endif
1095 }
1096
1097 /* This is the magic location that prints prompts
1098  * and gets data back from the user */
1099 static int file_get(struct in_str *i)
1100 {
1101         int ch;
1102
1103         ch = 0;
1104         /* If there is data waiting, eat it up */
1105         if (i->p && *i->p) {
1106                 ch=*i->p++;
1107         } else {
1108                 /* need to double check i->file because we might be doing something
1109                  * more complicated by now, like sourcing or substituting. */
1110 #ifndef __U_BOOT__
1111                 if (i->__promptme && interactive && i->file == stdin) {
1112                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1113 #else
1114                         while(! i->p  || strlen(i->p)==0 ) {
1115 #endif
1116                                 get_user_input(i);
1117                         }
1118                         i->promptmode=2;
1119 #ifndef __U_BOOT__
1120                         i->__promptme = 0;
1121 #endif
1122                         if (i->p && *i->p) {
1123                                 ch=*i->p++;
1124                         }
1125 #ifndef __U_BOOT__
1126                 } else {
1127                         ch = fgetc(i->file);
1128                 }
1129
1130 #endif
1131                 debug_printf("b_getch: got a %d\n", ch);
1132         }
1133 #ifndef __U_BOOT__
1134         if (ch == '\n') i->__promptme=1;
1135 #endif
1136         return ch;
1137 }
1138
1139 /* All the callers guarantee this routine will never be
1140  * used right after a newline, so prompting is not needed.
1141  */
1142 static int file_peek(struct in_str *i)
1143 {
1144 #ifndef __U_BOOT__
1145         if (i->p && *i->p) {
1146 #endif
1147                 return *i->p;
1148 #ifndef __U_BOOT__
1149         } else {
1150                 i->peek_buf[0] = fgetc(i->file);
1151                 i->peek_buf[1] = '\0';
1152                 i->p = i->peek_buf;
1153                 debug_printf("b_peek: got a %d\n", *i->p);
1154                 return *i->p;
1155         }
1156 #endif
1157 }
1158
1159 #ifndef __U_BOOT__
1160 static void setup_file_in_str(struct in_str *i, FILE *f)
1161 #else
1162 static void setup_file_in_str(struct in_str *i)
1163 #endif
1164 {
1165         i->peek = file_peek;
1166         i->get = file_get;
1167         i->__promptme=1;
1168         i->promptmode=1;
1169 #ifndef __U_BOOT__
1170         i->file = f;
1171 #endif
1172         i->p = NULL;
1173 }
1174
1175 static void setup_string_in_str(struct in_str *i, const char *s)
1176 {
1177         i->peek = static_peek;
1178         i->get = static_get;
1179         i->__promptme=1;
1180         i->promptmode=1;
1181         i->p = s;
1182 }
1183
1184 #ifndef __U_BOOT__
1185 static void mark_open(int fd)
1186 {
1187         struct close_me *new = xmalloc(sizeof(struct close_me));
1188         new->fd = fd;
1189         new->next = close_me_head;
1190         close_me_head = new;
1191 }
1192
1193 static void mark_closed(int fd)
1194 {
1195         struct close_me *tmp;
1196         if (close_me_head == NULL || close_me_head->fd != fd)
1197                 error_msg_and_die("corrupt close_me");
1198         tmp = close_me_head;
1199         close_me_head = close_me_head->next;
1200         free(tmp);
1201 }
1202
1203 static void close_all(void)
1204 {
1205         struct close_me *c;
1206         for (c=close_me_head; c; c=c->next) {
1207                 close(c->fd);
1208         }
1209         close_me_head = NULL;
1210 }
1211
1212 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1213  * and stderr if they are redirected. */
1214 static int setup_redirects(struct child_prog *prog, int squirrel[])
1215 {
1216         int openfd, mode;
1217         struct redir_struct *redir;
1218
1219         for (redir=prog->redirects; redir; redir=redir->next) {
1220                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1221                         /* something went wrong in the parse.  Pretend it didn't happen */
1222                         continue;
1223                 }
1224                 if (redir->dup == -1) {
1225                         mode=redir_table[redir->type].mode;
1226                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1227                         if (openfd < 0) {
1228                         /* this could get lost if stderr has been redirected, but
1229                            bash and ash both lose it as well (though zsh doesn't!) */
1230                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1231                                 return 1;
1232                         }
1233                 } else {
1234                         openfd = redir->dup;
1235                 }
1236
1237                 if (openfd != redir->fd) {
1238                         if (squirrel && redir->fd < 3) {
1239                                 squirrel[redir->fd] = dup(redir->fd);
1240                         }
1241                         if (openfd == -3) {
1242                                 close(openfd);
1243                         } else {
1244                                 dup2(openfd, redir->fd);
1245                                 if (redir->dup == -1)
1246                                         close (openfd);
1247                         }
1248                 }
1249         }
1250         return 0;
1251 }
1252
1253 static void restore_redirects(int squirrel[])
1254 {
1255         int i, fd;
1256         for (i=0; i<3; i++) {
1257                 fd = squirrel[i];
1258                 if (fd != -1) {
1259                         /* No error checking.  I sure wouldn't know what
1260                          * to do with an error if I found one! */
1261                         dup2(fd, i);
1262                         close(fd);
1263                 }
1264         }
1265 }
1266
1267 /* never returns */
1268 /* XXX no exit() here.  If you don't exec, use _exit instead.
1269  * The at_exit handlers apparently confuse the calling process,
1270  * in particular stdin handling.  Not sure why? */
1271 static void pseudo_exec(struct child_prog *child)
1272 {
1273         int i, rcode;
1274         char *p;
1275         struct built_in_command *x;
1276         if (child->argv) {
1277                 for (i=0; is_assignment(child->argv[i]); i++) {
1278                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1279                         p = insert_var_value(child->argv[i]);
1280                         putenv(strdup(p));
1281                         if (p != child->argv[i]) free(p);
1282                 }
1283                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1284                                         to exit, and therefore don't need to keep data
1285                                         structures consistent for free() use. */
1286                 /* If a variable is assigned in a forest, and nobody listens,
1287                  * was it ever really set?
1288                  */
1289                 if (child->argv[0] == NULL) {
1290                         _exit(EXIT_SUCCESS);
1291                 }
1292
1293                 /*
1294                  * Check if the command matches any of the builtins.
1295                  * Depending on context, this might be redundant.  But it's
1296                  * easier to waste a few CPU cycles than it is to figure out
1297                  * if this is one of those cases.
1298                  */
1299                 for (x = bltins; x->cmd; x++) {
1300                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1301                                 debug_printf("builtin exec %s\n", child->argv[0]);
1302                                 rcode = x->function(child);
1303                                 fflush(stdout);
1304                                 _exit(rcode);
1305                         }
1306                 }
1307
1308                 /* Check if the command matches any busybox internal commands
1309                  * ("applets") here.
1310                  * FIXME: This feature is not 100% safe, since
1311                  * BusyBox is not fully reentrant, so we have no guarantee the things
1312                  * from the .bss are still zeroed, or that things from .data are still
1313                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1314                  * really dislike relying on /proc for things.  We could exec ourself
1315                  * from global_argv[0], but if we are in a chroot, we may not be able
1316                  * to find ourself... */
1317 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1318                 {
1319                         int argc_l;
1320                         char** argv_l=child->argv;
1321                         char *name = child->argv[0];
1322
1323 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1324                         /* Following discussions from November 2000 on the busybox mailing
1325                          * list, the default configuration, (without
1326                          * get_last_path_component()) lets the user force use of an
1327                          * external command by specifying the full (with slashes) filename.
1328                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1329                          * _aways_ override external commands, so if you want to run
1330                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1331                          * filesystem and is _not_ busybox.  Some systems may want this,
1332                          * most do not.  */
1333                         name = get_last_path_component(name);
1334 #endif
1335                         /* Count argc for use in a second... */
1336                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1337                         optind = 1;
1338                         debug_printf("running applet %s\n", name);
1339                         run_applet_by_name(name, argc_l, child->argv);
1340                 }
1341 #endif
1342                 debug_printf("exec of %s\n",child->argv[0]);
1343                 execvp(child->argv[0],child->argv);
1344                 perror_msg("couldn't exec: %s",child->argv[0]);
1345                 _exit(1);
1346         } else if (child->group) {
1347                 debug_printf("runtime nesting to group\n");
1348                 interactive=0;    /* crucial!!!! */
1349                 rcode = run_list_real(child->group);
1350                 /* OK to leak memory by not calling free_pipe_list,
1351                  * since this process is about to exit */
1352                 _exit(rcode);
1353         } else {
1354                 /* Can happen.  See what bash does with ">foo" by itself. */
1355                 debug_printf("trying to pseudo_exec null command\n");
1356                 _exit(EXIT_SUCCESS);
1357         }
1358 }
1359
1360 static void insert_bg_job(struct pipe *pi)
1361 {
1362         struct pipe *thejob;
1363
1364         /* Linear search for the ID of the job to use */
1365         pi->jobid = 1;
1366         for (thejob = job_list; thejob; thejob = thejob->next)
1367                 if (thejob->jobid >= pi->jobid)
1368                         pi->jobid = thejob->jobid + 1;
1369
1370         /* add thejob to the list of running jobs */
1371         if (!job_list) {
1372                 thejob = job_list = xmalloc(sizeof(*thejob));
1373         } else {
1374                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1375                 thejob->next = xmalloc(sizeof(*thejob));
1376                 thejob = thejob->next;
1377         }
1378
1379         /* physically copy the struct job */
1380         memcpy(thejob, pi, sizeof(struct pipe));
1381         thejob->next = NULL;
1382         thejob->running_progs = thejob->num_progs;
1383         thejob->stopped_progs = 0;
1384         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1385
1386         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1387         {
1388                 char *bar=thejob->text;
1389                 char **foo=pi->progs[0].argv;
1390                 while(foo && *foo) {
1391                         bar += sprintf(bar, "%s ", *foo++);
1392                 }
1393         }
1394
1395         /* we don't wait for background thejobs to return -- append it
1396            to the list of backgrounded thejobs and leave it alone */
1397         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1398         last_bg_pid = thejob->progs[0].pid;
1399         last_jobid = thejob->jobid;
1400 }
1401
1402 /* remove a backgrounded job */
1403 static void remove_bg_job(struct pipe *pi)
1404 {
1405         struct pipe *prev_pipe;
1406
1407         if (pi == job_list) {
1408                 job_list = pi->next;
1409         } else {
1410                 prev_pipe = job_list;
1411                 while (prev_pipe->next != pi)
1412                         prev_pipe = prev_pipe->next;
1413                 prev_pipe->next = pi->next;
1414         }
1415         if (job_list)
1416                 last_jobid = job_list->jobid;
1417         else
1418                 last_jobid = 0;
1419
1420         pi->stopped_progs = 0;
1421         free_pipe(pi, 0);
1422         free(pi);
1423 }
1424
1425 /* Checks to see if any processes have exited -- if they
1426    have, figure out why and see if a job has completed */
1427 static int checkjobs(struct pipe* fg_pipe)
1428 {
1429         int attributes;
1430         int status;
1431         int prognum = 0;
1432         struct pipe *pi;
1433         pid_t childpid;
1434
1435         attributes = WUNTRACED;
1436         if (fg_pipe==NULL) {
1437                 attributes |= WNOHANG;
1438         }
1439
1440         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1441                 if (fg_pipe) {
1442                         int i, rcode = 0;
1443                         for (i=0; i < fg_pipe->num_progs; i++) {
1444                                 if (fg_pipe->progs[i].pid == childpid) {
1445                                         if (i==fg_pipe->num_progs-1)
1446                                                 rcode=WEXITSTATUS(status);
1447                                         (fg_pipe->num_progs)--;
1448                                         return(rcode);
1449                                 }
1450                         }
1451                 }
1452
1453                 for (pi = job_list; pi; pi = pi->next) {
1454                         prognum = 0;
1455                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1456                                 prognum++;
1457                         }
1458                         if (prognum < pi->num_progs)
1459                                 break;
1460                 }
1461
1462                 if(pi==NULL) {
1463                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1464                         continue;
1465                 }
1466
1467                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1468                         /* child exited */
1469                         pi->running_progs--;
1470                         pi->progs[prognum].pid = 0;
1471
1472                         if (!pi->running_progs) {
1473                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1474                                 remove_bg_job(pi);
1475                         }
1476                 } else {
1477                         /* child stopped */
1478                         pi->stopped_progs++;
1479                         pi->progs[prognum].is_stopped = 1;
1480
1481 #if 0
1482                         /* Printing this stuff is a pain, since it tends to
1483                          * overwrite the prompt an inconveinient moments.  So
1484                          * don't do that.  */
1485                         if (pi->stopped_progs == pi->num_progs) {
1486                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1487                         }
1488 #endif
1489                 }
1490         }
1491
1492         if (childpid == -1 && errno != ECHILD)
1493                 perror_msg("waitpid");
1494
1495         /* move the shell to the foreground */
1496         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1497         /*      perror_msg("tcsetpgrp-2"); */
1498         return -1;
1499 }
1500
1501 /* Figure out our controlling tty, checking in order stderr,
1502  * stdin, and stdout.  If check_pgrp is set, also check that
1503  * we belong to the foreground process group associated with
1504  * that tty.  The value of shell_terminal is needed in order to call
1505  * tcsetpgrp(shell_terminal, ...); */
1506 void controlling_tty(int check_pgrp)
1507 {
1508         pid_t curpgrp;
1509
1510         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1511                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1512                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1513                 goto shell_terminal_error;
1514
1515         if (check_pgrp && curpgrp != getpgid(0))
1516                 goto shell_terminal_error;
1517
1518         return;
1519
1520 shell_terminal_error:
1521                 shell_terminal = -1;
1522                 return;
1523 }
1524 #endif
1525
1526 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1527  * to finish.  See checkjobs().
1528  *
1529  * return code is normally -1, when the caller has to wait for children
1530  * to finish to determine the exit status of the pipe.  If the pipe
1531  * is a simple builtin command, however, the action is done by the
1532  * time run_pipe_real returns, and the exit code is provided as the
1533  * return value.
1534  *
1535  * The input of the pipe is always stdin, the output is always
1536  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1537  * because it tries to avoid running the command substitution in
1538  * subshell, when that is in fact necessary.  The subshell process
1539  * now has its stdout directed to the input of the appropriate pipe,
1540  * so this routine is noticeably simpler.
1541  */
1542 static int run_pipe_real(struct pipe *pi)
1543 {
1544         int i;
1545 #ifndef __U_BOOT__
1546         int nextin, nextout;
1547         int pipefds[2];                         /* pipefds[0] is for reading */
1548         struct child_prog *child;
1549         struct built_in_command *x;
1550         char *p;
1551 # if __GNUC__
1552         /* Avoid longjmp clobbering */
1553         (void) &i;
1554         (void) &nextin;
1555         (void) &nextout;
1556         (void) &child;
1557 # endif
1558 #else
1559         int nextin;
1560         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1561         struct child_prog *child;
1562         cmd_tbl_t *cmdtp;
1563         char *p;
1564 # if __GNUC__
1565         /* Avoid longjmp clobbering */
1566         (void) &i;
1567         (void) &nextin;
1568         (void) &child;
1569 # endif
1570 #endif  /* __U_BOOT__ */
1571
1572         nextin = 0;
1573 #ifndef __U_BOOT__
1574         pi->pgrp = -1;
1575 #endif
1576
1577         /* Check if this is a simple builtin (not part of a pipe).
1578          * Builtins within pipes have to fork anyway, and are handled in
1579          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1580          */
1581         if (pi->num_progs == 1) child = & (pi->progs[0]);
1582 #ifndef __U_BOOT__
1583         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1584                 int squirrel[] = {-1, -1, -1};
1585                 int rcode;
1586                 debug_printf("non-subshell grouping\n");
1587                 setup_redirects(child, squirrel);
1588                 /* XXX could we merge code with following builtin case,
1589                  * by creating a pseudo builtin that calls run_list_real? */
1590                 rcode = run_list_real(child->group);
1591                 restore_redirects(squirrel);
1592 #else
1593                 if (pi->num_progs == 1 && child->group) {
1594                 int rcode;
1595                 debug_printf("non-subshell grouping\n");
1596                 rcode = run_list_real(child->group);
1597 #endif
1598                 return rcode;
1599         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1600                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1601                 if (i!=0 && child->argv[i]==NULL) {
1602                         /* assignments, but no command: set the local environment */
1603                         for (i=0; child->argv[i]!=NULL; i++) {
1604
1605                                 /* Ok, this case is tricky.  We have to decide if this is a
1606                                  * local variable, or an already exported variable.  If it is
1607                                  * already exported, we have to export the new value.  If it is
1608                                  * not exported, we need only set this as a local variable.
1609                                  * This junk is all to decide whether or not to export this
1610                                  * variable. */
1611                                 int export_me=0;
1612                                 char *name, *value;
1613                                 name = xstrdup(child->argv[i]);
1614                                 debug_printf("Local environment set: %s\n", name);
1615                                 value = strchr(name, '=');
1616                                 if (value)
1617                                         *value=0;
1618 #ifndef __U_BOOT__
1619                                 if ( get_local_var(name)) {
1620                                         export_me=1;
1621                                 }
1622 #endif
1623                                 free(name);
1624                                 p = insert_var_value(child->argv[i]);
1625                                 set_local_var(p, export_me);
1626                                 if (p != child->argv[i]) free(p);
1627                         }
1628                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1629                 }
1630                 for (i = 0; is_assignment(child->argv[i]); i++) {
1631                         p = insert_var_value(child->argv[i]);
1632 #ifndef __U_BOOT__
1633                         putenv(strdup(p));
1634 #else
1635                         set_local_var(p, 0);
1636 #endif
1637                         if (p != child->argv[i]) {
1638                                 child->sp--;
1639                                 free(p);
1640                         }
1641                 }
1642                 if (child->sp) {
1643                         char * str = NULL;
1644
1645                         str = make_string((child->argv + i));
1646                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1647                         free(str);
1648                         return last_return_code;
1649                 }
1650 #ifndef __U_BOOT__
1651                 for (x = bltins; x->cmd; x++) {
1652                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1653                                 int squirrel[] = {-1, -1, -1};
1654                                 int rcode;
1655                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1656                                         debug_printf("magic exec\n");
1657                                         setup_redirects(child,NULL);
1658                                         return EXIT_SUCCESS;
1659                                 }
1660                                 debug_printf("builtin inline %s\n", child->argv[0]);
1661                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1662                                  * This is perfect for work that comes after exec().
1663                                  * Is it really safe for inline use?  Experimentally,
1664                                  * things seem to work with glibc. */
1665                                 setup_redirects(child, squirrel);
1666 #else
1667                         /* check ";", because ,example , argv consist from
1668                          * "help;flinfo" must not execute
1669                          */
1670                         if (strchr(child->argv[i], ';')) {
1671                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1672                                         child->argv[i]);
1673                                 return -1;
1674                         }
1675                         /* Look up command in command table */
1676
1677
1678                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1679                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1680                                 return -1;      /* give up after bad command */
1681                         } else {
1682                                 int rcode;
1683 #if (CONFIG_COMMANDS & CFG_CMD_BOOTD)
1684             extern int do_bootd (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
1685
1686                                 /* avoid "bootd" recursion */
1687                                 if (cmdtp->cmd == do_bootd) {
1688                                         if (flag & CMD_FLAG_BOOTD) {
1689                                                 printf ("'bootd' recursion detected\n");
1690                                                 return -1;
1691                                         }
1692                                 else
1693                                         flag |= CMD_FLAG_BOOTD;
1694                                 }
1695 #endif  /* CFG_CMD_BOOTD */
1696                                 /* found - check max args */
1697                                 if ((child->argc - i) > cmdtp->maxargs) {
1698                                         printf ("Usage:\n%s\n", cmdtp->usage);
1699                                         return -1;
1700                                 }
1701 #endif
1702                                 child->argv+=i;  /* XXX horrible hack */
1703 #ifndef __U_BOOT__
1704                                 rcode = x->function(child);
1705 #else
1706                                 /* OK - call function to do the command */
1707
1708                                 rcode = (cmdtp->cmd)
1709 (cmdtp, flag,child->argc-i,&child->argv[i]);
1710                                 if ( !cmdtp->repeatable )
1711                                         flag_repeat = 0;
1712
1713
1714 #endif
1715                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1716 #ifndef __U_BOOT__
1717
1718                                 restore_redirects(squirrel);
1719 #endif
1720
1721                                 return rcode;
1722                         }
1723                 }
1724 #ifndef __U_BOOT__
1725         }
1726
1727         for (i = 0; i < pi->num_progs; i++) {
1728                 child = & (pi->progs[i]);
1729
1730                 /* pipes are inserted between pairs of commands */
1731                 if ((i + 1) < pi->num_progs) {
1732                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1733                         nextout = pipefds[1];
1734                 } else {
1735                         nextout=1;
1736                         pipefds[0] = -1;
1737                 }
1738
1739                 /* XXX test for failed fork()? */
1740                 if (!(child->pid = fork())) {
1741                         /* Set the handling for job control signals back to the default.  */
1742                         signal(SIGINT, SIG_DFL);
1743                         signal(SIGQUIT, SIG_DFL);
1744                         signal(SIGTERM, SIG_DFL);
1745                         signal(SIGTSTP, SIG_DFL);
1746                         signal(SIGTTIN, SIG_DFL);
1747                         signal(SIGTTOU, SIG_DFL);
1748                         signal(SIGCHLD, SIG_DFL);
1749
1750                         close_all();
1751
1752                         if (nextin != 0) {
1753                                 dup2(nextin, 0);
1754                                 close(nextin);
1755                         }
1756                         if (nextout != 1) {
1757                                 dup2(nextout, 1);
1758                                 close(nextout);
1759                         }
1760                         if (pipefds[0]!=-1) {
1761                                 close(pipefds[0]);  /* opposite end of our output pipe */
1762                         }
1763
1764                         /* Like bash, explicit redirects override pipes,
1765                          * and the pipe fd is available for dup'ing. */
1766                         setup_redirects(child,NULL);
1767
1768                         if (interactive && pi->followup!=PIPE_BG) {
1769                                 /* If we (the child) win the race, put ourselves in the process
1770                                  * group whose leader is the first process in this pipe. */
1771                                 if (pi->pgrp < 0) {
1772                                         pi->pgrp = getpid();
1773                                 }
1774                                 if (setpgid(0, pi->pgrp) == 0) {
1775                                         tcsetpgrp(2, pi->pgrp);
1776                                 }
1777                         }
1778
1779                         pseudo_exec(child);
1780                 }
1781
1782
1783                 /* put our child in the process group whose leader is the
1784                    first process in this pipe */
1785                 if (pi->pgrp < 0) {
1786                         pi->pgrp = child->pid;
1787                 }
1788                 /* Don't check for errors.  The child may be dead already,
1789                  * in which case setpgid returns error code EACCES. */
1790                 setpgid(child->pid, pi->pgrp);
1791
1792                 if (nextin != 0)
1793                         close(nextin);
1794                 if (nextout != 1)
1795                         close(nextout);
1796
1797                 /* If there isn't another process, nextin is garbage
1798                    but it doesn't matter */
1799                 nextin = pipefds[0];
1800         }
1801 #endif
1802         return -1;
1803 }
1804
1805 static int run_list_real(struct pipe *pi)
1806 {
1807         char *save_name = NULL;
1808         char **list = NULL;
1809         char **save_list = NULL;
1810         struct pipe *rpipe;
1811         int flag_rep = 0;
1812 #ifndef __U_BOOT__
1813         int save_num_progs;
1814 #endif
1815         int rcode=0, flag_skip=1;
1816         int flag_restore = 0;
1817         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1818         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1819         /* check syntax for "for" */
1820         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1821                 if ((rpipe->r_mode == RES_IN ||
1822                     rpipe->r_mode == RES_FOR) &&
1823                     (rpipe->next == NULL)) {
1824                                 syntax();
1825 #ifdef __U_BOOT__
1826                                 flag_repeat = 0;
1827 #endif
1828                                 return 1;
1829                 }
1830                 if ((rpipe->r_mode == RES_IN &&
1831                         (rpipe->next->r_mode == RES_IN &&
1832                         rpipe->next->progs->argv != NULL))||
1833                         (rpipe->r_mode == RES_FOR &&
1834                         rpipe->next->r_mode != RES_IN)) {
1835                                 syntax();
1836 #ifdef __U_BOOT__
1837                                 flag_repeat = 0;
1838 #endif
1839                                 return 1;
1840                 }
1841         }
1842         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1843                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1844                         pi->r_mode == RES_FOR) {
1845 #ifdef __U_BOOT__
1846                                 /* check Ctrl-C */
1847                                 ctrlc();
1848                                 if ((had_ctrlc())) {
1849                                         return 1;
1850                                 }
1851 #endif
1852                                 flag_restore = 0;
1853                                 if (!rpipe) {
1854                                         flag_rep = 0;
1855                                         rpipe = pi;
1856                                 }
1857                 }
1858                 rmode = pi->r_mode;
1859                 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);
1860                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1861                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1862                         continue;
1863                 }
1864                 flag_skip = 1;
1865                 skip_more_in_this_rmode = RES_XXXX;
1866                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1867                 if (rmode == RES_THEN &&  if_code) continue;
1868                 if (rmode == RES_ELSE && !if_code) continue;
1869                 if (rmode == RES_ELIF && !if_code) break;
1870                 if (rmode == RES_FOR && pi->num_progs) {
1871                         if (!list) {
1872                                 /* if no variable values after "in" we skip "for" */
1873                                 if (!pi->next->progs->argv) continue;
1874                                 /* create list of variable values */
1875                                 list = make_list_in(pi->next->progs->argv,
1876                                         pi->progs->argv[0]);
1877                                 save_list = list;
1878                                 save_name = pi->progs->argv[0];
1879                                 pi->progs->argv[0] = NULL;
1880                                 flag_rep = 1;
1881                         }
1882                         if (!(*list)) {
1883                                 free(pi->progs->argv[0]);
1884                                 free(save_list);
1885                                 list = NULL;
1886                                 flag_rep = 0;
1887                                 pi->progs->argv[0] = save_name;
1888 #ifndef __U_BOOT__
1889                                 pi->progs->glob_result.gl_pathv[0] =
1890                                         pi->progs->argv[0];
1891 #endif
1892                                 continue;
1893                         } else {
1894                                 /* insert new value from list for variable */
1895                                 if (pi->progs->argv[0])
1896                                         free(pi->progs->argv[0]);
1897                                 pi->progs->argv[0] = *list++;
1898 #ifndef __U_BOOT__
1899                                 pi->progs->glob_result.gl_pathv[0] =
1900                                         pi->progs->argv[0];
1901 #endif
1902                         }
1903                 }
1904                 if (rmode == RES_IN) continue;
1905                 if (rmode == RES_DO) {
1906                         if (!flag_rep) continue;
1907                 }
1908                 if ((rmode == RES_DONE)) {
1909                         if (flag_rep) {
1910                                 flag_restore = 1;
1911                         } else {
1912                                 rpipe = NULL;
1913                         }
1914                 }
1915                 if (pi->num_progs == 0) continue;
1916 #ifndef __U_BOOT__
1917                 save_num_progs = pi->num_progs; /* save number of programs */
1918 #endif
1919                 rcode = run_pipe_real(pi);
1920                 debug_printf("run_pipe_real returned %d\n",rcode);
1921 #ifndef __U_BOOT__
1922                 if (rcode!=-1) {
1923                         /* We only ran a builtin: rcode was set by the return value
1924                          * of run_pipe_real(), and we don't need to wait for anything. */
1925                 } else if (pi->followup==PIPE_BG) {
1926                         /* XXX check bash's behavior with nontrivial pipes */
1927                         /* XXX compute jobid */
1928                         /* XXX what does bash do with attempts to background builtins? */
1929                         insert_bg_job(pi);
1930                         rcode = EXIT_SUCCESS;
1931                 } else {
1932                         if (interactive) {
1933                                 /* move the new process group into the foreground */
1934                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1935                                         perror_msg("tcsetpgrp-3");
1936                                 rcode = checkjobs(pi);
1937                                 /* move the shell to the foreground */
1938                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1939                                         perror_msg("tcsetpgrp-4");
1940                         } else {
1941                                 rcode = checkjobs(pi);
1942                         }
1943                         debug_printf("checkjobs returned %d\n",rcode);
1944                 }
1945                 last_return_code=rcode;
1946 #else
1947                 if (rcode < -1) {
1948                         last_return_code = -rcode - 2;
1949                         return -2;      /* exit */
1950                 }
1951                 last_return_code=(rcode == 0) ? 0 : 1;
1952 #endif
1953 #ifndef __U_BOOT__
1954                 pi->num_progs = save_num_progs; /* restore number of programs */
1955 #endif
1956                 if ( rmode == RES_IF || rmode == RES_ELIF )
1957                         next_if_code=rcode;  /* can be overwritten a number of times */
1958                 if (rmode == RES_WHILE)
1959                         flag_rep = !last_return_code;
1960                 if (rmode == RES_UNTIL)
1961                         flag_rep = last_return_code;
1962                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1963                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1964                         skip_more_in_this_rmode=rmode;
1965 #ifndef __U_BOOT__
1966                 checkjobs(NULL);
1967 #endif
1968         }
1969         return rcode;
1970 }
1971
1972 /* broken, of course, but OK for testing */
1973 static char *indenter(int i)
1974 {
1975         static char blanks[]="                                    ";
1976         return &blanks[sizeof(blanks)-i-1];
1977 }
1978
1979 /* return code is the exit status of the pipe */
1980 static int free_pipe(struct pipe *pi, int indent)
1981 {
1982         char **p;
1983         struct child_prog *child;
1984 #ifndef __U_BOOT__
1985         struct redir_struct *r, *rnext;
1986 #endif
1987         int a, i, ret_code=0;
1988         char *ind = indenter(indent);
1989
1990 #ifndef __U_BOOT__
1991         if (pi->stopped_progs > 0)
1992                 return ret_code;
1993         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1994 #endif
1995         for (i=0; i<pi->num_progs; i++) {
1996                 child = &pi->progs[i];
1997                 final_printf("%s  command %d:\n",ind,i);
1998                 if (child->argv) {
1999                         for (a=0,p=child->argv; *p; a++,p++) {
2000                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
2001                         }
2002 #ifndef __U_BOOT__
2003                         globfree(&child->glob_result);
2004 #else
2005                         for (a = child->argc;a >= 0;a--) {
2006                                 free(child->argv[a]);
2007                         }
2008                                         free(child->argv);
2009                         child->argc = 0;
2010 #endif
2011                         child->argv=NULL;
2012                 } else if (child->group) {
2013 #ifndef __U_BOOT__
2014                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
2015 #endif
2016                         ret_code = free_pipe_list(child->group,indent+3);
2017                         final_printf("%s   end group\n",ind);
2018                 } else {
2019                         final_printf("%s   (nil)\n",ind);
2020                 }
2021 #ifndef __U_BOOT__
2022                 for (r=child->redirects; r; r=rnext) {
2023                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2024                         if (r->dup == -1) {
2025                                 /* guard against the case >$FOO, where foo is unset or blank */
2026                                 if (r->word.gl_pathv) {
2027                                         final_printf(" %s\n", *r->word.gl_pathv);
2028                                         globfree(&r->word);
2029                                 }
2030                         } else {
2031                                 final_printf("&%d\n", r->dup);
2032                         }
2033                         rnext=r->next;
2034                         free(r);
2035                 }
2036                 child->redirects=NULL;
2037 #endif
2038         }
2039         free(pi->progs);   /* children are an array, they get freed all at once */
2040         pi->progs=NULL;
2041         return ret_code;
2042 }
2043
2044 static int free_pipe_list(struct pipe *head, int indent)
2045 {
2046         int rcode=0;   /* if list has no members */
2047         struct pipe *pi, *next;
2048         char *ind = indenter(indent);
2049         for (pi=head; pi; pi=next) {
2050                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2051                 rcode = free_pipe(pi, indent);
2052                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2053                 next=pi->next;
2054                 pi->next=NULL;
2055                 free(pi);
2056         }
2057         return rcode;
2058 }
2059
2060 /* Select which version we will use */
2061 static int run_list(struct pipe *pi)
2062 {
2063         int rcode=0;
2064 #ifndef __U_BOOT__
2065         if (fake_mode==0) {
2066 #endif
2067                 rcode = run_list_real(pi);
2068 #ifndef __U_BOOT__
2069         }
2070 #endif
2071         /* free_pipe_list has the side effect of clearing memory
2072          * In the long run that function can be merged with run_list_real,
2073          * but doing that now would hobble the debugging effort. */
2074         free_pipe_list(pi,0);
2075         return rcode;
2076 }
2077
2078 /* The API for glob is arguably broken.  This routine pushes a non-matching
2079  * string into the output structure, removing non-backslashed backslashes.
2080  * If someone can prove me wrong, by performing this function within the
2081  * original glob(3) api, feel free to rewrite this routine into oblivion.
2082  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2083  * XXX broken if the last character is '\\', check that before calling.
2084  */
2085 #ifndef __U_BOOT__
2086 static int globhack(const char *src, int flags, glob_t *pglob)
2087 {
2088         int cnt=0, pathc;
2089         const char *s;
2090         char *dest;
2091         for (cnt=1, s=src; s && *s; s++) {
2092                 if (*s == '\\') s++;
2093                 cnt++;
2094         }
2095         dest = malloc(cnt);
2096         if (!dest) return GLOB_NOSPACE;
2097         if (!(flags & GLOB_APPEND)) {
2098                 pglob->gl_pathv=NULL;
2099                 pglob->gl_pathc=0;
2100                 pglob->gl_offs=0;
2101                 pglob->gl_offs=0;
2102         }
2103         pathc = ++pglob->gl_pathc;
2104         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2105         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2106         pglob->gl_pathv[pathc-1]=dest;
2107         pglob->gl_pathv[pathc]=NULL;
2108         for (s=src; s && *s; s++, dest++) {
2109                 if (*s == '\\') s++;
2110                 *dest = *s;
2111         }
2112         *dest='\0';
2113         return 0;
2114 }
2115
2116 /* XXX broken if the last character is '\\', check that before calling */
2117 static int glob_needed(const char *s)
2118 {
2119         for (; *s; s++) {
2120                 if (*s == '\\') s++;
2121                 if (strchr("*[?",*s)) return 1;
2122         }
2123         return 0;
2124 }
2125
2126 #if 0
2127 static void globprint(glob_t *pglob)
2128 {
2129         int i;
2130         debug_printf("glob_t at %p:\n", pglob);
2131         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2132                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2133         for (i=0; i<pglob->gl_pathc; i++)
2134                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2135                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2136 }
2137 #endif
2138
2139 static int xglob(o_string *dest, int flags, glob_t *pglob)
2140 {
2141         int gr;
2142
2143         /* short-circuit for null word */
2144         /* we can code this better when the debug_printf's are gone */
2145         if (dest->length == 0) {
2146                 if (dest->nonnull) {
2147                         /* bash man page calls this an "explicit" null */
2148                         gr = globhack(dest->data, flags, pglob);
2149                         debug_printf("globhack returned %d\n",gr);
2150                 } else {
2151                         return 0;
2152                 }
2153         } else if (glob_needed(dest->data)) {
2154                 gr = glob(dest->data, flags, NULL, pglob);
2155                 debug_printf("glob returned %d\n",gr);
2156                 if (gr == GLOB_NOMATCH) {
2157                         /* quote removal, or more accurately, backslash removal */
2158                         gr = globhack(dest->data, flags, pglob);
2159                         debug_printf("globhack returned %d\n",gr);
2160                 }
2161         } else {
2162                 gr = globhack(dest->data, flags, pglob);
2163                 debug_printf("globhack returned %d\n",gr);
2164         }
2165         if (gr == GLOB_NOSPACE)
2166                 error_msg_and_die("out of memory during glob");
2167         if (gr != 0) { /* GLOB_ABORTED ? */
2168                 error_msg("glob(3) error %d",gr);
2169         }
2170         /* globprint(glob_target); */
2171         return gr;
2172 }
2173 #endif
2174
2175 #ifdef __U_BOOT__
2176 static char *get_dollar_var(char ch);
2177 #endif
2178
2179 /* This is used to get/check local shell variables */
2180 static char *get_local_var(const char *s)
2181 {
2182         struct variables *cur;
2183
2184         if (!s)
2185                 return NULL;
2186
2187 #ifdef __U_BOOT__
2188         if (*s == '$')
2189                 return get_dollar_var(s[1]);
2190 #endif
2191
2192         for (cur = top_vars; cur; cur=cur->next)
2193                 if(strcmp(cur->name, s)==0)
2194                         return cur->value;
2195         return NULL;
2196 }
2197
2198 /* This is used to set local shell variables
2199    flg_export==0 if only local (not exporting) variable
2200    flg_export==1 if "new" exporting environ
2201    flg_export>1  if current startup environ (not call putenv()) */
2202 static int set_local_var(const char *s, int flg_export)
2203 {
2204         char *name, *value;
2205         int result=0;
2206         struct variables *cur;
2207
2208 #ifdef __U_BOOT__
2209         /* might be possible! */
2210         if (!isalpha(*s))
2211                 return -1;
2212 #endif
2213
2214         name=strdup(s);
2215
2216 #ifdef __U_BOOT__
2217         if (getenv(name) != NULL) {
2218                 printf ("ERROR: "
2219                                 "There is a global environment variable with the same name.\n");
2220                 free(name);
2221                 return -1;
2222         }
2223 #endif
2224         /* Assume when we enter this function that we are already in
2225          * NAME=VALUE format.  So the first order of business is to
2226          * split 's' on the '=' into 'name' and 'value' */
2227         value = strchr(name, '=');
2228         if (value==0 && ++value==0) {
2229                 free(name);
2230                 return -1;
2231         }
2232         *value++ = 0;
2233
2234         for(cur = top_vars; cur; cur = cur->next) {
2235                 if(strcmp(cur->name, name)==0)
2236                         break;
2237         }
2238
2239         if(cur) {
2240                 if(strcmp(cur->value, value)==0) {
2241                         if(flg_export>0 && cur->flg_export==0)
2242                                 cur->flg_export=flg_export;
2243                         else
2244                                 result++;
2245                 } else {
2246                         if(cur->flg_read_only) {
2247                                 error_msg("%s: readonly variable", name);
2248                                 result = -1;
2249                         } else {
2250                                 if(flg_export>0 || cur->flg_export>1)
2251                                         cur->flg_export=1;
2252                                 free(cur->value);
2253
2254                                 cur->value = strdup(value);
2255                         }
2256                 }
2257         } else {
2258                 cur = malloc(sizeof(struct variables));
2259                 if(!cur) {
2260                         result = -1;
2261                 } else {
2262                         cur->name = strdup(name);
2263                         if(cur->name == 0) {
2264                                 free(cur);
2265                                 result = -1;
2266                         } else {
2267                                 struct variables *bottom = top_vars;
2268                                 cur->value = strdup(value);
2269                                 cur->next = 0;
2270                                 cur->flg_export = flg_export;
2271                                 cur->flg_read_only = 0;
2272                                 while(bottom->next) bottom=bottom->next;
2273                                 bottom->next = cur;
2274                         }
2275                 }
2276         }
2277
2278 #ifndef __U_BOOT__
2279         if(result==0 && cur->flg_export==1) {
2280                 *(value-1) = '=';
2281                 result = putenv(name);
2282         } else {
2283 #endif
2284                 free(name);
2285 #ifndef __U_BOOT__
2286                 if(result>0)            /* equivalent to previous set */
2287                         result = 0;
2288         }
2289 #endif
2290         return result;
2291 }
2292
2293 #ifndef __U_BOOT__
2294 static void unset_local_var(const char *name)
2295 {
2296         struct variables *cur;
2297
2298         if (name) {
2299                 for (cur = top_vars; cur; cur=cur->next) {
2300                         if(strcmp(cur->name, name)==0)
2301                                 break;
2302                 }
2303                 if(cur!=0) {
2304                         struct variables *next = top_vars;
2305                         if(cur->flg_read_only) {
2306                                 error_msg("%s: readonly variable", name);
2307                                 return;
2308                         } else {
2309                                 if(cur->flg_export)
2310                                         unsetenv(cur->name);
2311                                 free(cur->name);
2312                                 free(cur->value);
2313                                 while (next->next != cur)
2314                                         next = next->next;
2315                                 next->next = cur->next;
2316                         }
2317                         free(cur);
2318                 }
2319         }
2320 }
2321 #endif
2322
2323 static int is_assignment(const char *s)
2324 {
2325         if (s == NULL)
2326                 return 0;
2327
2328         if (!isalpha(*s)) return 0;
2329         ++s;
2330         while(isalnum(*s) || *s=='_') ++s;
2331         return *s=='=';
2332 }
2333
2334 #ifndef __U_BOOT__
2335 /* the src parameter allows us to peek forward to a possible &n syntax
2336  * for file descriptor duplication, e.g., "2>&1".
2337  * Return code is 0 normally, 1 if a syntax error is detected in src.
2338  * Resource errors (in xmalloc) cause the process to exit */
2339 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2340         struct in_str *input)
2341 {
2342         struct child_prog *child=ctx->child;
2343         struct redir_struct *redir = child->redirects;
2344         struct redir_struct *last_redir=NULL;
2345
2346         /* Create a new redir_struct and drop it onto the end of the linked list */
2347         while(redir) {
2348                 last_redir=redir;
2349                 redir=redir->next;
2350         }
2351         redir = xmalloc(sizeof(struct redir_struct));
2352         redir->next=NULL;
2353         redir->word.gl_pathv=NULL;
2354         if (last_redir) {
2355                 last_redir->next=redir;
2356         } else {
2357                 child->redirects=redir;
2358         }
2359
2360         redir->type=style;
2361         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2362
2363         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2364
2365         /* Check for a '2>&1' type redirect */
2366         redir->dup = redirect_dup_num(input);
2367         if (redir->dup == -2) return 1;  /* syntax error */
2368         if (redir->dup != -1) {
2369                 /* Erik had a check here that the file descriptor in question
2370                  * is legit; I postpone that to "run time"
2371                  * A "-" representation of "close me" shows up as a -3 here */
2372                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2373         } else {
2374                 /* We do _not_ try to open the file that src points to,
2375                  * since we need to return and let src be expanded first.
2376                  * Set ctx->pending_redirect, so we know what to do at the
2377                  * end of the next parsed word.
2378                  */
2379                 ctx->pending_redirect = redir;
2380         }
2381         return 0;
2382 }
2383 #endif
2384
2385 struct pipe *new_pipe(void) {
2386         struct pipe *pi;
2387         pi = xmalloc(sizeof(struct pipe));
2388         pi->num_progs = 0;
2389         pi->progs = NULL;
2390         pi->next = NULL;
2391         pi->followup = 0;  /* invalid */
2392         pi->r_mode = RES_NONE;
2393         return pi;
2394 }
2395
2396 static void initialize_context(struct p_context *ctx)
2397 {
2398         ctx->pipe=NULL;
2399 #ifndef __U_BOOT__
2400         ctx->pending_redirect=NULL;
2401 #endif
2402         ctx->child=NULL;
2403         ctx->list_head=new_pipe();
2404         ctx->pipe=ctx->list_head;
2405         ctx->w=RES_NONE;
2406         ctx->stack=NULL;
2407 #ifdef __U_BOOT__
2408         ctx->old_flag=0;
2409 #endif
2410         done_command(ctx);   /* creates the memory for working child */
2411 }
2412
2413 /* normal return is 0
2414  * if a reserved word is found, and processed, return 1
2415  * should handle if, then, elif, else, fi, for, while, until, do, done.
2416  * case, function, and select are obnoxious, save those for later.
2417  */
2418 struct reserved_combo {
2419         char *literal;
2420         int code;
2421         long flag;
2422 };
2423 /* Mostly a list of accepted follow-up reserved words.
2424  * FLAG_END means we are done with the sequence, and are ready
2425  * to turn the compound list into a command.
2426  * FLAG_START means the word must start a new compound list.
2427  */
2428 static struct reserved_combo reserved_list[] = {
2429         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2430         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2431         { "elif",  RES_ELIF,  FLAG_THEN },
2432         { "else",  RES_ELSE,  FLAG_FI   },
2433         { "fi",    RES_FI,    FLAG_END  },
2434         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2435         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2436         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2437         { "in",    RES_IN,    FLAG_DO   },
2438         { "do",    RES_DO,    FLAG_DONE },
2439         { "done",  RES_DONE,  FLAG_END  }
2440 };
2441 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2442
2443 int reserved_word(o_string *dest, struct p_context *ctx)
2444 {
2445         struct reserved_combo *r;
2446         for (r=reserved_list;
2447                 r<reserved_list+NRES; r++) {
2448                 if (strcmp(dest->data, r->literal) == 0) {
2449                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2450                         if (r->flag & FLAG_START) {
2451                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2452                                 debug_printf("push stack\n");
2453                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2454                                         syntax();
2455                                         free(new);
2456                                         ctx->w = RES_SNTX;
2457                                         b_reset(dest);
2458                                         return 1;
2459                                 }
2460                                 *new = *ctx;   /* physical copy */
2461                                 initialize_context(ctx);
2462                                 ctx->stack=new;
2463                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2464                                 syntax();
2465                                 ctx->w = RES_SNTX;
2466                                 b_reset(dest);
2467                                 return 1;
2468                         }
2469                         ctx->w=r->code;
2470                         ctx->old_flag = r->flag;
2471                         if (ctx->old_flag & FLAG_END) {
2472                                 struct p_context *old;
2473                                 debug_printf("pop stack\n");
2474                                 done_pipe(ctx,PIPE_SEQ);
2475                                 old = ctx->stack;
2476                                 old->child->group = ctx->list_head;
2477 #ifndef __U_BOOT__
2478                                 old->child->subshell = 0;
2479 #endif
2480                                 *ctx = *old;   /* physical copy */
2481                                 free(old);
2482                         }
2483                         b_reset (dest);
2484                         return 1;
2485                 }
2486         }
2487         return 0;
2488 }
2489
2490 /* normal return is 0.
2491  * Syntax or xglob errors return 1. */
2492 static int done_word(o_string *dest, struct p_context *ctx)
2493 {
2494         struct child_prog *child=ctx->child;
2495 #ifndef __U_BOOT__
2496         glob_t *glob_target;
2497         int gr, flags = 0;
2498 #else
2499         char *str, *s;
2500         int argc, cnt;
2501 #endif
2502
2503         debug_printf("done_word: %s %p\n", dest->data, child);
2504         if (dest->length == 0 && !dest->nonnull) {
2505                 debug_printf("  true null, ignored\n");
2506                 return 0;
2507         }
2508 #ifndef __U_BOOT__
2509         if (ctx->pending_redirect) {
2510                 glob_target = &ctx->pending_redirect->word;
2511         } else {
2512 #endif
2513                 if (child->group) {
2514                         syntax();
2515                         return 1;  /* syntax error, groups and arglists don't mix */
2516                 }
2517                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2518                         debug_printf("checking %s for reserved-ness\n",dest->data);
2519                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2520                 }
2521 #ifndef __U_BOOT__
2522                 glob_target = &child->glob_result;
2523                 if (child->argv) flags |= GLOB_APPEND;
2524 #else
2525                 for (cnt = 1, s = dest->data; s && *s; s++) {
2526                         if (*s == '\\') s++;
2527                         cnt++;
2528                 }
2529                 str = malloc(cnt);
2530                 if (!str) return 1;
2531                 if ( child->argv == NULL) {
2532                         child->argc=0;
2533                 }
2534                 argc = ++child->argc;
2535                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2536                 if (child->argv == NULL) return 1;
2537                 child->argv[argc-1]=str;
2538                 child->argv[argc]=NULL;
2539                 for (s = dest->data; s && *s; s++,str++) {
2540                         if (*s == '\\') s++;
2541                         *str = *s;
2542                 }
2543                 *str = '\0';
2544 #endif
2545 #ifndef __U_BOOT__
2546         }
2547         gr = xglob(dest, flags, glob_target);
2548         if (gr != 0) return 1;
2549 #endif
2550
2551         b_reset(dest);
2552 #ifndef __U_BOOT__
2553         if (ctx->pending_redirect) {
2554                 ctx->pending_redirect=NULL;
2555                 if (glob_target->gl_pathc != 1) {
2556                         error_msg("ambiguous redirect");
2557                         return 1;
2558                 }
2559         } else {
2560                 child->argv = glob_target->gl_pathv;
2561         }
2562 #endif
2563         if (ctx->w == RES_FOR) {
2564                 done_word(dest,ctx);
2565                 done_pipe(ctx,PIPE_SEQ);
2566         }
2567         return 0;
2568 }
2569
2570 /* The only possible error here is out of memory, in which case
2571  * xmalloc exits. */
2572 static int done_command(struct p_context *ctx)
2573 {
2574         /* The child is really already in the pipe structure, so
2575          * advance the pipe counter and make a new, null child.
2576          * Only real trickiness here is that the uncommitted
2577          * child structure, to which ctx->child points, is not
2578          * counted in pi->num_progs. */
2579         struct pipe *pi=ctx->pipe;
2580         struct child_prog *prog=ctx->child;
2581
2582         if (prog && prog->group == NULL
2583                  && prog->argv == NULL
2584 #ifndef __U_BOOT__
2585                  && prog->redirects == NULL) {
2586 #else
2587                                                                                 ) {
2588 #endif
2589                 debug_printf("done_command: skipping null command\n");
2590                 return 0;
2591         } else if (prog) {
2592                 pi->num_progs++;
2593                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2594         } else {
2595                 debug_printf("done_command: initializing\n");
2596         }
2597         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2598
2599         prog = pi->progs + pi->num_progs;
2600 #ifndef __U_BOOT__
2601         prog->redirects = NULL;
2602 #endif
2603         prog->argv = NULL;
2604 #ifndef __U_BOOT__
2605         prog->is_stopped = 0;
2606 #endif
2607         prog->group = NULL;
2608 #ifndef __U_BOOT__
2609         prog->glob_result.gl_pathv = NULL;
2610         prog->family = pi;
2611 #endif
2612         prog->sp = 0;
2613         ctx->child = prog;
2614         prog->type = ctx->type;
2615
2616         /* but ctx->pipe and ctx->list_head remain unchanged */
2617         return 0;
2618 }
2619
2620 static int done_pipe(struct p_context *ctx, pipe_style type)
2621 {
2622         struct pipe *new_p;
2623         done_command(ctx);  /* implicit closure of previous command */
2624         debug_printf("done_pipe, type %d\n", type);
2625         ctx->pipe->followup = type;
2626         ctx->pipe->r_mode = ctx->w;
2627         new_p=new_pipe();
2628         ctx->pipe->next = new_p;
2629         ctx->pipe = new_p;
2630         ctx->child = NULL;
2631         done_command(ctx);  /* set up new pipe to accept commands */
2632         return 0;
2633 }
2634
2635 #ifndef __U_BOOT__
2636 /* peek ahead in the in_str to find out if we have a "&n" construct,
2637  * as in "2>&1", that represents duplicating a file descriptor.
2638  * returns either -2 (syntax error), -1 (no &), or the number found.
2639  */
2640 static int redirect_dup_num(struct in_str *input)
2641 {
2642         int ch, d=0, ok=0;
2643         ch = b_peek(input);
2644         if (ch != '&') return -1;
2645
2646         b_getch(input);  /* get the & */
2647         ch=b_peek(input);
2648         if (ch == '-') {
2649                 b_getch(input);
2650                 return -3;  /* "-" represents "close me" */
2651         }
2652         while (isdigit(ch)) {
2653                 d = d*10+(ch-'0');
2654                 ok=1;
2655                 b_getch(input);
2656                 ch = b_peek(input);
2657         }
2658         if (ok) return d;
2659
2660         error_msg("ambiguous redirect");
2661         return -2;
2662 }
2663
2664 /* If a redirect is immediately preceded by a number, that number is
2665  * supposed to tell which file descriptor to redirect.  This routine
2666  * looks for such preceding numbers.  In an ideal world this routine
2667  * needs to handle all the following classes of redirects...
2668  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2669  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2670  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2671  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2672  * A -1 output from this program means no valid number was found, so the
2673  * caller should use the appropriate default for this redirection.
2674  */
2675 static int redirect_opt_num(o_string *o)
2676 {
2677         int num;
2678
2679         if (o->length==0) return -1;
2680         for(num=0; num<o->length; num++) {
2681                 if (!isdigit(*(o->data+num))) {
2682                         return -1;
2683                 }
2684         }
2685         /* reuse num (and save an int) */
2686         num=atoi(o->data);
2687         b_reset(o);
2688         return num;
2689 }
2690
2691 FILE *generate_stream_from_list(struct pipe *head)
2692 {
2693         FILE *pf;
2694 #if 1
2695         int pid, channel[2];
2696         if (pipe(channel)<0) perror_msg_and_die("pipe");
2697         pid=fork();
2698         if (pid<0) {
2699                 perror_msg_and_die("fork");
2700         } else if (pid==0) {
2701                 close(channel[0]);
2702                 if (channel[1] != 1) {
2703                         dup2(channel[1],1);
2704                         close(channel[1]);
2705                 }
2706 #if 0
2707 #define SURROGATE "surrogate response"
2708                 write(1,SURROGATE,sizeof(SURROGATE));
2709                 _exit(run_list(head));
2710 #else
2711                 _exit(run_list_real(head));   /* leaks memory */
2712 #endif
2713         }
2714         debug_printf("forked child %d\n",pid);
2715         close(channel[1]);
2716         pf = fdopen(channel[0],"r");
2717         debug_printf("pipe on FILE *%p\n",pf);
2718 #else
2719         free_pipe_list(head,0);
2720         pf=popen("echo surrogate response","r");
2721         debug_printf("started fake pipe on FILE *%p\n",pf);
2722 #endif
2723         return pf;
2724 }
2725
2726 /* this version hacked for testing purposes */
2727 /* return code is exit status of the process that is run. */
2728 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2729 {
2730         int retcode;
2731         o_string result=NULL_O_STRING;
2732         struct p_context inner;
2733         FILE *p;
2734         struct in_str pipe_str;
2735         initialize_context(&inner);
2736
2737         /* recursion to generate command */
2738         retcode = parse_stream(&result, &inner, input, subst_end);
2739         if (retcode != 0) return retcode;  /* syntax error or EOF */
2740         done_word(&result, &inner);
2741         done_pipe(&inner, PIPE_SEQ);
2742         b_free(&result);
2743
2744         p=generate_stream_from_list(inner.list_head);
2745         if (p==NULL) return 1;
2746         mark_open(fileno(p));
2747         setup_file_in_str(&pipe_str, p);
2748
2749         /* now send results of command back into original context */
2750         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2751         /* XXX In case of a syntax error, should we try to kill the child?
2752          * That would be tough to do right, so just read until EOF. */
2753         if (retcode == 1) {
2754                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2755         }
2756
2757         debug_printf("done reading from pipe, pclose()ing\n");
2758         /* This is the step that wait()s for the child.  Should be pretty
2759          * safe, since we just read an EOF from its stdout.  We could try
2760          * to better, by using wait(), and keeping track of background jobs
2761          * at the same time.  That would be a lot of work, and contrary
2762          * to the KISS philosophy of this program. */
2763         mark_closed(fileno(p));
2764         retcode=pclose(p);
2765         free_pipe_list(inner.list_head,0);
2766         debug_printf("pclosed, retcode=%d\n",retcode);
2767         /* XXX this process fails to trim a single trailing newline */
2768         return retcode;
2769 }
2770
2771 static int parse_group(o_string *dest, struct p_context *ctx,
2772         struct in_str *input, int ch)
2773 {
2774         int rcode, endch=0;
2775         struct p_context sub;
2776         struct child_prog *child = ctx->child;
2777         if (child->argv) {
2778                 syntax();
2779                 return 1;  /* syntax error, groups and arglists don't mix */
2780         }
2781         initialize_context(&sub);
2782         switch(ch) {
2783                 case '(': endch=')'; child->subshell=1; break;
2784                 case '{': endch='}'; break;
2785                 default: syntax();   /* really logic error */
2786         }
2787         rcode=parse_stream(dest,&sub,input,endch);
2788         done_word(dest,&sub); /* finish off the final word in the subcontext */
2789         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2790         child->group = sub.list_head;
2791         return rcode;
2792         /* child remains "open", available for possible redirects */
2793 }
2794 #endif
2795
2796 /* basically useful version until someone wants to get fancier,
2797  * see the bash man page under "Parameter Expansion" */
2798 static char *lookup_param(char *src)
2799 {
2800         char *p;
2801
2802         if (!src)
2803                 return NULL;
2804
2805                 p = getenv(src);
2806                 if (!p)
2807                         p = get_local_var(src);
2808
2809         return p;
2810 }
2811
2812 #ifdef __U_BOOT__
2813 static char *get_dollar_var(char ch)
2814 {
2815         static char buf[40];
2816
2817         buf[0] = '\0';
2818         switch (ch) {
2819                 case '?':
2820                         sprintf(buf, "%u", (unsigned int)last_return_code);
2821                         break;
2822                 default:
2823                         return NULL;
2824         }
2825         return buf;
2826 }
2827 #endif
2828
2829 /* return code: 0 for OK, 1 for syntax error */
2830 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2831 {
2832 #ifndef __U_BOOT__
2833         int i, advance=0;
2834 #else
2835         int advance=0;
2836 #endif
2837 #ifndef __U_BOOT__
2838         char sep[]=" ";
2839 #endif
2840         int ch = input->peek(input);  /* first character after the $ */
2841         debug_printf("handle_dollar: ch=%c\n",ch);
2842         if (isalpha(ch)) {
2843                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2844                 ctx->child->sp++;
2845                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2846                         b_getch(input);
2847                         b_addchr(dest,ch);
2848                 }
2849                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2850 #ifndef __U_BOOT__
2851         } else if (isdigit(ch)) {
2852                 i = ch-'0';  /* XXX is $0 special? */
2853                 if (i<global_argc) {
2854                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2855                 }
2856                 advance = 1;
2857 #endif
2858         } else switch (ch) {
2859 #ifndef __U_BOOT__
2860                 case '$':
2861                         b_adduint(dest,getpid());
2862                         advance = 1;
2863                         break;
2864                 case '!':
2865                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2866                         advance = 1;
2867                         break;
2868 #endif
2869                 case '?':
2870 #ifndef __U_BOOT__
2871                         b_adduint(dest,last_return_code);
2872 #else
2873                         ctx->child->sp++;
2874                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2875                         b_addchr(dest, '$');
2876                         b_addchr(dest, '?');
2877                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2878 #endif
2879                         advance = 1;
2880                         break;
2881 #ifndef __U_BOOT__
2882                 case '#':
2883                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2884                         advance = 1;
2885                         break;
2886 #endif
2887                 case '{':
2888                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2889                         ctx->child->sp++;
2890                         b_getch(input);
2891                         /* XXX maybe someone will try to escape the '}' */
2892                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2893                                 b_addchr(dest,ch);
2894                         }
2895                         if (ch != '}') {
2896                                 syntax();
2897                                 return 1;
2898                         }
2899                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2900                         break;
2901 #ifndef __U_BOOT__
2902                 case '(':
2903                         b_getch(input);
2904                         process_command_subs(dest, ctx, input, ')');
2905                         break;
2906                 case '*':
2907                         sep[0]=ifs[0];
2908                         for (i=1; i<global_argc; i++) {
2909                                 parse_string(dest, ctx, global_argv[i]);
2910                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2911                         }
2912                         break;
2913                 case '@':
2914                 case '-':
2915                 case '_':
2916                         /* still unhandled, but should be eventually */
2917                         error_msg("unhandled syntax: $%c",ch);
2918                         return 1;
2919                         break;
2920 #endif
2921                 default:
2922                         b_addqchr(dest,'$',dest->quote);
2923         }
2924         /* Eat the character if the flag was set.  If the compiler
2925          * is smart enough, we could substitute "b_getch(input);"
2926          * for all the "advance = 1;" above, and also end up with
2927          * a nice size-optimized program.  Hah!  That'll be the day.
2928          */
2929         if (advance) b_getch(input);
2930         return 0;
2931 }
2932
2933 #ifndef __U_BOOT__
2934 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2935 {
2936         struct in_str foo;
2937         setup_string_in_str(&foo, src);
2938         return parse_stream(dest, ctx, &foo, '\0');
2939 }
2940 #endif
2941
2942 /* return code is 0 for normal exit, 1 for syntax error */
2943 int parse_stream(o_string *dest, struct p_context *ctx,
2944         struct in_str *input, int end_trigger)
2945 {
2946         unsigned int ch, m;
2947 #ifndef __U_BOOT__
2948         int redir_fd;
2949         redir_type redir_style;
2950 #endif
2951         int next;
2952
2953         /* Only double-quote state is handled in the state variable dest->quote.
2954          * A single-quote triggers a bypass of the main loop until its mate is
2955          * found.  When recursing, quote state is passed in via dest->quote. */
2956
2957         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2958         while ((ch=b_getch(input))!=EOF) {
2959                 m = map[ch];
2960 #ifdef __U_BOOT__
2961                 if (input->__promptme == 0) return 1;
2962 #endif
2963                 next = (ch == '\n') ? 0 : b_peek(input);
2964
2965                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2966                         ch >= ' ' ? ch : '.', ch, m,
2967                         dest->quote, ctx->stack == NULL ? '*' : '.');
2968
2969                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2970                         b_addqchr(dest, ch, dest->quote);
2971                 } else {
2972                         if (m==2) {  /* unquoted IFS */
2973                                 if (done_word(dest, ctx)) {
2974                                         return 1;
2975                                 }
2976                                 /* If we aren't performing a substitution, treat a newline as a
2977                                  * command separator.  */
2978                                 if (end_trigger != '\0' && ch=='\n')
2979                                         done_pipe(ctx,PIPE_SEQ);
2980                         }
2981                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2982                                 debug_printf("leaving parse_stream (triggered)\n");
2983                                 return 0;
2984                         }
2985 #if 0
2986                         if (ch=='\n') {
2987                                 /* Yahoo!  Time to run with it! */
2988                                 done_pipe(ctx,PIPE_SEQ);
2989                                 run_list(ctx->list_head);
2990                                 initialize_context(ctx);
2991                         }
2992 #endif
2993                         if (m!=2) switch (ch) {
2994                 case '#':
2995                         if (dest->length == 0 && !dest->quote) {
2996                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2997                         } else {
2998                                 b_addqchr(dest, ch, dest->quote);
2999                         }
3000                         break;
3001                 case '\\':
3002                         if (next == EOF) {
3003                                 syntax();
3004                                 return 1;
3005                         }
3006                         b_addqchr(dest, '\\', dest->quote);
3007                         b_addqchr(dest, b_getch(input), dest->quote);
3008                         break;
3009                 case '$':
3010                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3011                         break;
3012                 case '\'':
3013                         dest->nonnull = 1;
3014                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3015 #ifdef __U_BOOT__
3016                                 if(input->__promptme == 0) return 1;
3017 #endif
3018                                 b_addchr(dest,ch);
3019                         }
3020                         if (ch==EOF) {
3021                                 syntax();
3022                                 return 1;
3023                         }
3024                         break;
3025                 case '"':
3026                         dest->nonnull = 1;
3027                         dest->quote = !dest->quote;
3028                         break;
3029 #ifndef __U_BOOT__
3030                 case '`':
3031                         process_command_subs(dest, ctx, input, '`');
3032                         break;
3033                 case '>':
3034                         redir_fd = redirect_opt_num(dest);
3035                         done_word(dest, ctx);
3036                         redir_style=REDIRECT_OVERWRITE;
3037                         if (next == '>') {
3038                                 redir_style=REDIRECT_APPEND;
3039                                 b_getch(input);
3040                         } else if (next == '(') {
3041                                 syntax();   /* until we support >(list) Process Substitution */
3042                                 return 1;
3043                         }
3044                         setup_redirect(ctx, redir_fd, redir_style, input);
3045                         break;
3046                 case '<':
3047                         redir_fd = redirect_opt_num(dest);
3048                         done_word(dest, ctx);
3049                         redir_style=REDIRECT_INPUT;
3050                         if (next == '<') {
3051                                 redir_style=REDIRECT_HEREIS;
3052                                 b_getch(input);
3053                         } else if (next == '>') {
3054                                 redir_style=REDIRECT_IO;
3055                                 b_getch(input);
3056                         } else if (next == '(') {
3057                                 syntax();   /* until we support <(list) Process Substitution */
3058                                 return 1;
3059                         }
3060                         setup_redirect(ctx, redir_fd, redir_style, input);
3061                         break;
3062 #endif
3063                 case ';':
3064                         done_word(dest, ctx);
3065                         done_pipe(ctx,PIPE_SEQ);
3066                         break;
3067                 case '&':
3068                         done_word(dest, ctx);
3069                         if (next=='&') {
3070                                 b_getch(input);
3071                                 done_pipe(ctx,PIPE_AND);
3072                         } else {
3073 #ifndef __U_BOOT__
3074                                 done_pipe(ctx,PIPE_BG);
3075 #else
3076                                 syntax_err();
3077                                 return 1;
3078 #endif
3079                         }
3080                         break;
3081                 case '|':
3082                         done_word(dest, ctx);
3083                         if (next=='|') {
3084                                 b_getch(input);
3085                                 done_pipe(ctx,PIPE_OR);
3086                         } else {
3087                                 /* we could pick up a file descriptor choice here
3088                                  * with redirect_opt_num(), but bash doesn't do it.
3089                                  * "echo foo 2| cat" yields "foo 2". */
3090 #ifndef __U_BOOT__
3091                                 done_command(ctx);
3092 #else
3093                                 syntax_err();
3094                                 return 1;
3095 #endif
3096                         }
3097                         break;
3098 #ifndef __U_BOOT__
3099                 case '(':
3100                 case '{':
3101                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3102                         break;
3103                 case ')':
3104                 case '}':
3105                         syntax();   /* Proper use of this character caught by end_trigger */
3106                         return 1;
3107                         break;
3108 #endif
3109                 default:
3110                         syntax();   /* this is really an internal logic error */
3111                         return 1;
3112                         }
3113                 }
3114         }
3115         /* complain if quote?  No, maybe we just finished a command substitution
3116          * that was quoted.  Example:
3117          * $ echo "`cat foo` plus more"
3118          * and we just got the EOF generated by the subshell that ran "cat foo"
3119          * The only real complaint is if we got an EOF when end_trigger != '\0',
3120          * that is, we were really supposed to get end_trigger, and never got
3121          * one before the EOF.  Can't use the standard "syntax error" return code,
3122          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3123         debug_printf("leaving parse_stream (EOF)\n");
3124         if (end_trigger != '\0') return -1;
3125         return 0;
3126 }
3127
3128 void mapset(const unsigned char *set, int code)
3129 {
3130         const unsigned char *s;
3131         for (s=set; *s; s++) map[*s] = code;
3132 }
3133
3134 void update_ifs_map(void)
3135 {
3136         /* char *ifs and char map[256] are both globals. */
3137         ifs = (uchar *)getenv("IFS");
3138         if (ifs == NULL) ifs=(uchar *)" \t\n";
3139         /* Precompute a list of 'flow through' behavior so it can be treated
3140          * quickly up front.  Computation is necessary because of IFS.
3141          * Special case handling of IFS == " \t\n" is not implemented.
3142          * The map[] array only really needs two bits each, and on most machines
3143          * that would be faster because of the reduced L1 cache footprint.
3144          */
3145         memset(map,0,sizeof(map)); /* most characters flow through always */
3146 #ifndef __U_BOOT__
3147         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3148         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3149 #else
3150         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3151         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3152 #endif
3153         mapset(ifs, 2);            /* also flow through if quoted */
3154 }
3155
3156 /* most recursion does not come through here, the exeception is
3157  * from builtin_source() */
3158 int parse_stream_outer(struct in_str *inp, int flag)
3159 {
3160
3161         struct p_context ctx;
3162         o_string temp=NULL_O_STRING;
3163         int rcode;
3164 #ifdef __U_BOOT__
3165         int code = 0;
3166 #endif
3167         do {
3168                 ctx.type = flag;
3169                 initialize_context(&ctx);
3170                 update_ifs_map();
3171                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3172                 inp->promptmode=1;
3173                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3174 #ifdef __U_BOOT__
3175                 if (rcode == 1) flag_repeat = 0;
3176 #endif
3177                 if (rcode != 1 && ctx.old_flag != 0) {
3178                         syntax();
3179 #ifdef __U_BOOT__
3180                         flag_repeat = 0;
3181 #endif
3182                 }
3183                 if (rcode != 1 && ctx.old_flag == 0) {
3184                         done_word(&temp, &ctx);
3185                         done_pipe(&ctx,PIPE_SEQ);
3186 #ifndef __U_BOOT__
3187                         run_list(ctx.list_head);
3188 #else
3189                         code = run_list(ctx.list_head);
3190                         if (code == -2) {       /* exit */
3191                                 b_free(&temp);
3192                                 code = 0;
3193                                 /* XXX hackish way to not allow exit from main loop */
3194                                 if (inp->peek == file_peek) {
3195                                         printf("exit not allowed from main input shell.\n");
3196                                         continue;
3197                                 }
3198                                 break;
3199                         }
3200                         if (code == -1)
3201                             flag_repeat = 0;
3202 #endif
3203                 } else {
3204                         if (ctx.old_flag != 0) {
3205                                 free(ctx.stack);
3206                                 b_reset(&temp);
3207                         }
3208 #ifdef __U_BOOT__
3209                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3210                         inp->__promptme = 1;
3211 #endif
3212                         temp.nonnull = 0;
3213                         temp.quote = 0;
3214                         inp->p = NULL;
3215                         free_pipe_list(ctx.list_head,0);
3216                 }
3217                 b_free(&temp);
3218         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3219 #ifndef __U_BOOT__
3220         return 0;
3221 #else
3222         return (code != 0) ? 1 : 0;
3223 #endif /* __U_BOOT__ */
3224 }
3225
3226 #ifndef __U_BOOT__
3227 static int parse_string_outer(const char *s, int flag)
3228 #else
3229 int parse_string_outer(char *s, int flag)
3230 #endif  /* __U_BOOT__ */
3231 {
3232         struct in_str input;
3233 #ifdef __U_BOOT__
3234         char *p = NULL;
3235         int rcode;
3236         if ( !s || !*s)
3237                 return 1;
3238         if (!(p = strchr(s, '\n')) || *++p) {
3239                 p = xmalloc(strlen(s) + 2);
3240                 strcpy(p, s);
3241                 strcat(p, "\n");
3242                 setup_string_in_str(&input, p);
3243                 rcode = parse_stream_outer(&input, flag);
3244                 free(p);
3245                 return rcode;
3246         } else {
3247 #endif
3248         setup_string_in_str(&input, s);
3249         return parse_stream_outer(&input, flag);
3250 #ifdef __U_BOOT__
3251         }
3252 #endif
3253 }
3254
3255 #ifndef __U_BOOT__
3256 static int parse_file_outer(FILE *f)
3257 #else
3258 int parse_file_outer(void)
3259 #endif
3260 {
3261         int rcode;
3262         struct in_str input;
3263 #ifndef __U_BOOT__
3264         setup_file_in_str(&input, f);
3265 #else
3266         setup_file_in_str(&input);
3267 #endif
3268         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3269         return rcode;
3270 }
3271
3272 #ifdef __U_BOOT__
3273 static void u_boot_hush_reloc(void)
3274 {
3275         DECLARE_GLOBAL_DATA_PTR;
3276         unsigned long addr;
3277         struct reserved_combo *r;
3278
3279         for (r=reserved_list; r<reserved_list+NRES; r++) {
3280                 addr = (ulong) (r->literal) + gd->reloc_off;
3281                 r->literal = (char *)addr;
3282         }
3283 }
3284
3285 int u_boot_hush_start(void)
3286 {
3287         if (top_vars == NULL) {
3288                 top_vars = malloc(sizeof(struct variables));
3289                 top_vars->name = "HUSH_VERSION";
3290                 top_vars->value = "0.01";
3291                 top_vars->next = 0;
3292                 top_vars->flg_export = 0;
3293                 top_vars->flg_read_only = 1;
3294                 u_boot_hush_reloc();
3295         }
3296         return 0;
3297 }
3298
3299 static void *xmalloc(size_t size)
3300 {
3301         void *p = NULL;
3302
3303         if (!(p = malloc(size))) {
3304             printf("ERROR : memory not allocated\n");
3305             for(;;);
3306         }
3307         return p;
3308 }
3309
3310 static void *xrealloc(void *ptr, size_t size)
3311 {
3312         void *p = NULL;
3313
3314         if (!(p = realloc(ptr, size))) {
3315             printf("ERROR : memory not allocated\n");
3316             for(;;);
3317         }
3318         return p;
3319 }
3320 #endif /* __U_BOOT__ */
3321
3322 #ifndef __U_BOOT__
3323 /* Make sure we have a controlling tty.  If we get started under a job
3324  * aware app (like bash for example), make sure we are now in charge so
3325  * we don't fight over who gets the foreground */
3326 static void setup_job_control(void)
3327 {
3328         static pid_t shell_pgrp;
3329         /* Loop until we are in the foreground.  */
3330         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3331                 kill (- shell_pgrp, SIGTTIN);
3332
3333         /* Ignore interactive and job-control signals.  */
3334         signal(SIGINT, SIG_IGN);
3335         signal(SIGQUIT, SIG_IGN);
3336         signal(SIGTERM, SIG_IGN);
3337         signal(SIGTSTP, SIG_IGN);
3338         signal(SIGTTIN, SIG_IGN);
3339         signal(SIGTTOU, SIG_IGN);
3340         signal(SIGCHLD, SIG_IGN);
3341
3342         /* Put ourselves in our own process group.  */
3343         setsid();
3344         shell_pgrp = getpid ();
3345         setpgid (shell_pgrp, shell_pgrp);
3346
3347         /* Grab control of the terminal.  */
3348         tcsetpgrp(shell_terminal, shell_pgrp);
3349 }
3350
3351 int hush_main(int argc, char **argv)
3352 {
3353         int opt;
3354         FILE *input;
3355         char **e = environ;
3356
3357         /* XXX what should these be while sourcing /etc/profile? */
3358         global_argc = argc;
3359         global_argv = argv;
3360
3361         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3362          * hush_main(), therefore we cannot rely on the BSS to zero out this
3363          * stuff.  Reset these to 0 every time. */
3364         ifs = NULL;
3365         /* map[] is taken care of with call to update_ifs_map() */
3366         fake_mode = 0;
3367         interactive = 0;
3368         close_me_head = NULL;
3369         last_bg_pid = 0;
3370         job_list = NULL;
3371         last_jobid = 0;
3372
3373         /* Initialize some more globals to non-zero values */
3374         set_cwd();
3375 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3376         cmdedit_set_initial_prompt();
3377 #else
3378         PS1 = NULL;
3379 #endif
3380         PS2 = "> ";
3381
3382         /* initialize our shell local variables with the values
3383          * currently living in the environment */
3384         if (e) {
3385                 for (; *e; e++)
3386                         set_local_var(*e, 2);   /* without call putenv() */
3387         }
3388
3389         last_return_code=EXIT_SUCCESS;
3390
3391
3392         if (argv[0] && argv[0][0] == '-') {
3393                 debug_printf("\nsourcing /etc/profile\n");
3394                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3395                         mark_open(fileno(input));
3396                         parse_file_outer(input);
3397                         mark_closed(fileno(input));
3398                         fclose(input);
3399                 }
3400         }
3401         input=stdin;
3402
3403         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3404                 switch (opt) {
3405                         case 'c':
3406                                 {
3407                                         global_argv = argv+optind;
3408                                         global_argc = argc-optind;
3409                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3410                                         goto final_return;
3411                                 }
3412                                 break;
3413                         case 'i':
3414                                 interactive++;
3415                                 break;
3416                         case 'f':
3417                                 fake_mode++;
3418                                 break;
3419                         default:
3420 #ifndef BB_VER
3421                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3422                                                 "   or: sh -c command [args]...\n\n");
3423                                 exit(EXIT_FAILURE);
3424 #else
3425                                 show_usage();
3426 #endif
3427                 }
3428         }
3429         /* A shell is interactive if the `-i' flag was given, or if all of
3430          * the following conditions are met:
3431          *        no -c command
3432          *    no arguments remaining or the -s flag given
3433          *    standard input is a terminal
3434          *    standard output is a terminal
3435          *    Refer to Posix.2, the description of the `sh' utility. */
3436         if (argv[optind]==NULL && input==stdin &&
3437                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3438                 interactive++;
3439         }
3440
3441         debug_printf("\ninteractive=%d\n", interactive);
3442         if (interactive) {
3443                 /* Looks like they want an interactive shell */
3444 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3445                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3446                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3447 #endif
3448                 setup_job_control();
3449         }
3450
3451         if (argv[optind]==NULL) {
3452                 opt=parse_file_outer(stdin);
3453                 goto final_return;
3454         }
3455
3456         debug_printf("\nrunning script '%s'\n", argv[optind]);
3457         global_argv = argv+optind;
3458         global_argc = argc-optind;
3459         input = xfopen(argv[optind], "r");
3460         opt = parse_file_outer(input);
3461
3462 #ifdef CONFIG_FEATURE_CLEAN_UP
3463         fclose(input);
3464         if (cwd && cwd != unknown)
3465                 free((char*)cwd);
3466         {
3467                 struct variables *cur, *tmp;
3468                 for(cur = top_vars; cur; cur = tmp) {
3469                         tmp = cur->next;
3470                         if (!cur->flg_read_only) {
3471                                 free(cur->name);
3472                                 free(cur->value);
3473                                 free(cur);
3474                         }
3475                 }
3476         }
3477 #endif
3478
3479 final_return:
3480         return(opt?opt:last_return_code);
3481 }
3482 #endif
3483
3484 static char *insert_var_value(char *inp)
3485 {
3486         int res_str_len = 0;
3487         int len;
3488         int done = 0;
3489         char *p, *p1, *res_str = NULL;
3490
3491         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3492                 if (p != inp) {
3493                         len = p - inp;
3494                         res_str = xrealloc(res_str, (res_str_len + len));
3495                         strncpy((res_str + res_str_len), inp, len);
3496                         res_str_len += len;
3497                 }
3498                 inp = ++p;
3499                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3500                 *p = '\0';
3501                 if ((p1 = lookup_param(inp))) {
3502                         len = res_str_len + strlen(p1);
3503                         res_str = xrealloc(res_str, (1 + len));
3504                         strcpy((res_str + res_str_len), p1);
3505                         res_str_len = len;
3506                 }
3507                 *p = SPECIAL_VAR_SYMBOL;
3508                 inp = ++p;
3509                 done = 1;
3510         }
3511         if (done) {
3512                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3513                 strcpy((res_str + res_str_len), inp);
3514                 while ((p = strchr(res_str, '\n'))) {
3515                         *p = ' ';
3516                 }
3517         }
3518         return (res_str == NULL) ? inp : res_str;
3519 }
3520
3521 static char **make_list_in(char **inp, char *name)
3522 {
3523         int len, i;
3524         int name_len = strlen(name);
3525         int n = 0;
3526         char **list;
3527         char *p1, *p2, *p3;
3528
3529         /* create list of variable values */
3530         list = xmalloc(sizeof(*list));
3531         for (i = 0; inp[i]; i++) {
3532                 p3 = insert_var_value(inp[i]);
3533                 p1 = p3;
3534                 while (*p1) {
3535                         if ((*p1 == ' ')) {
3536                                 p1++;
3537                                 continue;
3538                         }
3539                         if ((p2 = strchr(p1, ' '))) {
3540                                 len = p2 - p1;
3541                         } else {
3542                                 len = strlen(p1);
3543                                 p2 = p1 + len;
3544                         }
3545                         /* we use n + 2 in realloc for list,because we add
3546                          * new element and then we will add NULL element */
3547                         list = xrealloc(list, sizeof(*list) * (n + 2));
3548                         list[n] = xmalloc(2 + name_len + len);
3549                         strcpy(list[n], name);
3550                         strcat(list[n], "=");
3551                         strncat(list[n], p1, len);
3552                         list[n++][name_len + len + 1] = '\0';
3553                         p1 = p2;
3554                 }
3555                 if (p3 != inp[i]) free(p3);
3556         }
3557         list[n] = NULL;
3558         return list;
3559 }
3560
3561 /* Make new string for parser */
3562 static char * make_string(char ** inp)
3563 {
3564         char *p;
3565         char *str = NULL;
3566         int n;
3567         int len = 2;
3568
3569         for (n = 0; inp[n]; n++) {
3570                 p = insert_var_value(inp[n]);
3571                 str = xrealloc(str, (len + strlen(p)));
3572                 if (n) {
3573                         strcat(str, " ");
3574                 } else {
3575                         *str = '\0';
3576                 }
3577                 strcat(str, p);
3578                 len = strlen(str) + 3;
3579                 if (p != inp[n]) free(p);
3580         }
3581         len = strlen(str);
3582         *(str + len) = '\n';
3583         *(str + len + 1) = '\0';
3584         return str;
3585 }
3586
3587 #endif /* CFG_HUSH_PARSER */
3588 /****************************************************************************/