common/hush.c

   1 /*
   2  * sh.c -- a prototype Bourne shell grammar parser
   3  *      Intended to follow the original Thompson and Ritchie
   4  *      "small and simple is beautiful" philosophy, which
   5  *      incidentally is a good match to today's BusyBox.
   6  *
   7  * Copyright (C) 2000,2001  Larry Doolittle  <larry@doolittle.boa.org>
   8  *
   9  * Credits:
  10  *      The parser routines proper are all original material, first
  11  *      written Dec 2000 and Jan 2001 by Larry Doolittle.
  12  *      The execution engine, the builtins, and much of the underlying
  13  *      support has been adapted from busybox-0.49pre's lash,
  14  *      which is Copyright (C) 2000 by Lineo, Inc., and
  15  *      written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
  16  *      That, in turn, is based in part on ladsh.c, by Michael K. Johnson and
  17  *      Erik W. Troan, which they placed in the public domain.  I don't know
  18  *      how much of the Johnson/Troan code has survived the repeated rewrites.
  19  * Other credits:
  20  *      simple_itoa() was lifted from boa-0.93.15
  21  *      b_addchr() derived from similar w_addchar function in glibc-2.2
  22  *      setup_redirect(), redirect_opt_num(), and big chunks of main()
  23  *        and many builtins derived from contributions by Erik Andersen
  24  *      miscellaneous bugfixes from Matt Kraai
  25  *
  26  * There are two big (and related) architecture differences between
  27  * this parser and the lash parser.  One is that this version is
  28  * actually designed from the ground up to understand nearly all
  29  * of the Bourne grammar.  The second, consequential change is that
  30  * the parser and input reader have been turned inside out.  Now,
  31  * the parser is in control, and asks for input as needed.  The old
  32  * way had the input reader in control, and it asked for parsing to
  33  * take place as needed.  The new way makes it much easier to properly
  34  * handle the recursion implicit in the various substitutions, especially
  35  * across continuation lines.
  36  *
  37  * Bash grammar not implemented: (how many of these were in original sh?)
  38  *      $@ (those sure look like weird quoting rules)
  39  *      $_
  40  *      ! negation operator for pipes
  41  *      &> and >& redirection of stdout+stderr
  42  *      Brace Expansion
  43  *      Tilde Expansion
  44  *      fancy forms of Parameter Expansion
  45  *      aliases
  46  *      Arithmetic Expansion
  47  *      <(list) and >(list) Process Substitution
  48  *      reserved words: case, esac, select, function
  49  *      Here Documents ( << word )
  50  *      Functions
  51  * Major bugs:
  52  *      job handling woefully incomplete and buggy
  53  *      reserved word execution woefully incomplete and buggy
  54  * to-do:
  55  *      port selected bugfixes from post-0.49 busybox lash - done?
  56  *      finish implementing reserved words: for, while, until, do, done
  57  *      change { and } from special chars to reserved words
  58  *      builtins: break, continue, eval, return, set, trap, ulimit
  59  *      test magic exec
  60  *      handle children going into background
  61  *      clean up recognition of null pipes
  62  *      check setting of global_argc and global_argv
  63  *      control-C handling, probably with longjmp
  64  *      follow IFS rules more precisely, including update semantics
  65  *      figure out what to do with backslash-newline
  66  *      explain why we use signal instead of sigaction
  67  *      propagate syntax errors, die on resource errors?
  68  *      continuation lines, both explicit and implicit - done?
  69  *      memory leak finding and plugging - done?
  70  *      more testing, especially quoting rules and redirection
  71  *      document how quoting rules not precisely followed for variable assignments
  72  *      maybe change map[] to use 2-bit entries
  73  *      (eventually) remove all the printf's
  74  *
  75  * This program is free software; you can redistribute it and/or modify
  76  * it under the terms of the GNU General Public License as published by
  77  * the Free Software Foundation; either version 2 of the License, or
  78  * (at your option) any later version.
  79  *
  80  * This program is distributed in the hope that it will be useful,
  81  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  82  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  83  * General Public License for more details.
  84  *
  85  * You should have received a copy of the GNU General Public License
  86  * along with this program; if not, write to the Free Software
  87  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  88  */
  89 #define __U_BOOT__
  90 #ifdef __U_BOOT__
  91 #include <malloc.h>         /* malloc, free, realloc*/
  92 #include <linux/ctype.h>    /* isalpha, isdigit */
  93 #include <common.h>        /* readline */
  94 #include <hush.h>
  95 #include <command.h>        /* find_cmd */
  96 #endif
  97 #ifndef __U_BOOT__
  98 #include <ctype.h>     /* isalpha, isdigit */
  99 #include <unistd.h>    /* getpid */
 100 #include <stdlib.h>    /* getenv, atoi */
 101 #include <string.h>    /* strchr */
 102 #include <stdio.h>     /* popen etc. */
 103 #include <glob.h>      /* glob, of course */
 104 #include <stdarg.h>    /* va_list */
 105 #include <errno.h>
 106 #include <fcntl.h>
 107 #include <getopt.h>    /* should be pretty obvious */
 108
 109 #include <sys/stat.h>  /* ulimit */
 110 #include <sys/types.h>
 111 #include <sys/wait.h>
 112 #include <signal.h>
 113
 114 /* #include <dmalloc.h> */
 115
 116 #if 1
 117 #include "busybox.h"
 118 #include "cmdedit.h"
 119 #else
 120 #define applet_name "hush"
 121 #include "standalone.h"
 122 #define hush_main main
 123 #undef CONFIG_FEATURE_SH_FANCY_PROMPT
 124 #define BB_BANNER
 125 #endif
 126 #endif
 127 #define SPECIAL_VAR_SYMBOL 03
 128 #ifndef __U_BOOT__
 129 #define FLAG_EXIT_FROM_LOOP 1
 130 #define FLAG_PARSE_SEMICOLON (1 << 1)           /* symbol ';' is special for parser */
 131 #define FLAG_REPARSING       (1 << 2)           /* >= 2nd pass */
 132
 133 #endif
 134
 135 #ifdef __U_BOOT__
 136 DECLARE_GLOBAL_DATA_PTR;
 137
 138 #define EXIT_SUCCESS 0
 139 #define EOF -1
 140 #define syntax() syntax_err()
 141 #define xstrdup strdup
 142 #define error_msg printf
 143 #else
 144 typedef enum {
 145         REDIRECT_INPUT     = 1,
 146         REDIRECT_OVERWRITE = 2,
 147         REDIRECT_APPEND    = 3,
 148         REDIRECT_HEREIS    = 4,
 149         REDIRECT_IO        = 5
 150 } redir_type;
 151
 152 /* The descrip member of this structure is only used to make debugging
 153  * output pretty */
 154 struct {int mode; int default_fd; char *descrip;} redir_table[] = {
 155         { 0,                         0, "()" },
 156         { O_RDONLY,                  0, "<"  },
 157         { O_CREAT|O_TRUNC|O_WRONLY,  1, ">"  },
 158         { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
 159         { O_RDONLY,                 -1, "<<" },
 160         { O_RDWR,                    1, "<>" }
 161 };
 162 #endif
 163
 164 typedef enum {
 165         PIPE_SEQ = 1,
 166         PIPE_AND = 2,
 167         PIPE_OR  = 3,
 168         PIPE_BG  = 4,
 169 } pipe_style;
 170
 171 /* might eventually control execution */
 172 typedef enum {
 173         RES_NONE  = 0,
 174         RES_IF    = 1,
 175         RES_THEN  = 2,
 176         RES_ELIF  = 3,
 177         RES_ELSE  = 4,
 178         RES_FI    = 5,
 179         RES_FOR   = 6,
 180         RES_WHILE = 7,
 181         RES_UNTIL = 8,
 182         RES_DO    = 9,
 183         RES_DONE  = 10,
 184         RES_XXXX  = 11,
 185         RES_IN    = 12,
 186         RES_SNTX  = 13
 187 } reserved_style;
 188 #define FLAG_END   (1<<RES_NONE)
 189 #define FLAG_IF    (1<<RES_IF)
 190 #define FLAG_THEN  (1<<RES_THEN)
 191 #define FLAG_ELIF  (1<<RES_ELIF)
 192 #define FLAG_ELSE  (1<<RES_ELSE)
 193 #define FLAG_FI    (1<<RES_FI)
 194 #define FLAG_FOR   (1<<RES_FOR)
 195 #define FLAG_WHILE (1<<RES_WHILE)
 196 #define FLAG_UNTIL (1<<RES_UNTIL)
 197 #define FLAG_DO    (1<<RES_DO)
 198 #define FLAG_DONE  (1<<RES_DONE)
 199 #define FLAG_IN    (1<<RES_IN)
 200 #define FLAG_START (1<<RES_XXXX)
 201
 202 /* This holds pointers to the various results of parsing */
 203 struct p_context {
 204         struct child_prog *child;
 205         struct pipe *list_head;
 206         struct pipe *pipe;
 207 #ifndef __U_BOOT__
 208         struct redir_struct *pending_redirect;
 209 #endif
 210         reserved_style w;
 211         int old_flag;                           /* for figuring out valid reserved words */
 212         struct p_context *stack;
 213         int type;                       /* define type of parser : ";$" common or special symbol */
 214         /* How about quoting status? */
 215 };
 216
 217 #ifndef __U_BOOT__
 218 struct redir_struct {
 219         redir_type type;                        /* type of redirection */
 220         int fd;                                         /* file descriptor being redirected */
 221         int dup;                                        /* -1, or file descriptor being duplicated */
 222         struct redir_struct *next;      /* pointer to the next redirect in the list */
 223         glob_t word;                            /* *word.gl_pathv is the filename */
 224 };
 225 #endif
 226
 227 struct child_prog {
 228 #ifndef __U_BOOT__
 229         pid_t pid;                                      /* 0 if exited */
 230 #endif
 231         char **argv;                            /* program name and arguments */
 232 #ifdef __U_BOOT__
 233         int    argc;                            /* number of program arguments */
 234 #endif
 235         struct pipe *group;                     /* if non-NULL, first in group or subshell */
 236 #ifndef __U_BOOT__
 237         int subshell;                           /* flag, non-zero if group must be forked */
 238         struct redir_struct *redirects; /* I/O redirections */
 239         glob_t glob_result;                     /* result of parameter globbing */
 240         int is_stopped;                         /* is the program currently running? */
 241         struct pipe *family;            /* pointer back to the child's parent pipe */
 242 #endif
 243         int sp;                         /* number of SPECIAL_VAR_SYMBOL */
 244         int type;
 245 };
 246
 247 struct pipe {
 248 #ifndef __U_BOOT__
 249         int jobid;                                      /* job number */
 250 #endif
 251         int num_progs;                          /* total number of programs in job */
 252 #ifndef __U_BOOT__
 253         int running_progs;                      /* number of programs running */
 254         char *text;                                     /* name of job */
 255         char *cmdbuf;                           /* buffer various argv's point into */
 256         pid_t pgrp;                                     /* process group ID for the job */
 257 #endif
 258         struct child_prog *progs;       /* array of commands in pipe */
 259         struct pipe *next;                      /* to track background commands */
 260 #ifndef __U_BOOT__
 261         int stopped_progs;                      /* number of programs alive, but stopped */
 262         int job_context;                        /* bitmask defining current context */
 263 #endif
 264         pipe_style followup;            /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
 265         reserved_style r_mode;          /* supports if, for, while, until */
 266 };
 267
 268 #ifndef __U_BOOT__
 269 struct close_me {
 270         int fd;
 271         struct close_me *next;
 272 };
 273 #endif
 274
 275 struct variables {
 276         char *name;
 277         char *value;
 278         int flg_export;
 279         int flg_read_only;
 280         struct variables *next;
 281 };
 282
 283 /* globals, connect us to the outside world
 284  * the first three support $?, $#, and $1 */
 285 #ifndef __U_BOOT__
 286 char **global_argv;
 287 unsigned int global_argc;
 288 #endif
 289 unsigned int last_return_code;
 290 int nesting_level;
 291 #ifndef __U_BOOT__
 292 extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */
 293 #endif
 294
 295 /* "globals" within this file */
 296 static uchar *ifs;
 297 static char map[256];
 298 #ifndef __U_BOOT__
 299 static int fake_mode;
 300 static int interactive;
 301 static struct close_me *close_me_head;
 302 static const char *cwd;
 303 static struct pipe *job_list;
 304 static unsigned int last_bg_pid;
 305 static unsigned int last_jobid;
 306 static unsigned int shell_terminal;
 307 static char *PS1;
 308 static char *PS2;
 309 struct variables shell_ver = { "HUSH_VERSION", "0.01", 1, 1, 0 };
 310 struct variables *top_vars = &shell_ver;
 311 #else
 312 static int flag_repeat = 0;
 313 static int do_repeat = 0;
 314 static struct variables *top_vars = NULL ;
 315 #endif /*__U_BOOT__ */
 316
 317 #define B_CHUNK (100)
 318 #define B_NOSPAC 1
 319
 320 typedef struct {
 321         char *data;
 322         int length;
 323         int maxlen;
 324         int quote;
 325         int nonnull;
 326 } o_string;
 327 #define NULL_O_STRING {NULL,0,0,0,0}
 328 /* used for initialization:
 329         o_string foo = NULL_O_STRING; */
 330
 331 /* I can almost use ordinary FILE *.  Is open_memstream() universally
 332  * available?  Where is it documented? */
 333 struct in_str {
 334         const char *p;
 335 #ifndef __U_BOOT__
 336         char peek_buf[2];
 337 #endif
 338         int __promptme;
 339         int promptmode;
 340 #ifndef __U_BOOT__
 341         FILE *file;
 342 #endif
 343         int (*get) (struct in_str *);
 344         int (*peek) (struct in_str *);
 345 };
 346 #define b_getch(input) ((input)->get(input))
 347 #define b_peek(input) ((input)->peek(input))
 348
 349 #ifndef __U_BOOT__
 350 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
 351
 352 struct built_in_command {
 353         char *cmd;                                      /* name */
 354         char *descr;                            /* description */
 355         int (*function) (struct child_prog *);  /* function ptr */
 356 };
 357 #endif
 358
 359 /* define DEBUG_SHELL for debugging output (obviously ;-)) */
 360 #if 0
 361 #define DEBUG_SHELL
 362 #endif
 363
 364 /* This should be in utility.c */
 365 #ifdef DEBUG_SHELL
 366 #ifndef __U_BOOT__
 367 static void debug_printf(const char *format, ...)
 368 {
 369         va_list args;
 370         va_start(args, format);
 371         vfprintf(stderr, format, args);
 372         va_end(args);
 373 }
 374 #else
 375 #define debug_printf(fmt,args...)       printf (fmt ,##args)
 376 #endif
 377 #else
 378 static inline void debug_printf(const char *format, ...) { }
 379 #endif
 380 #define final_printf debug_printf
 381
 382 #ifdef __U_BOOT__
 383 static void syntax_err(void) {
 384          printf("syntax error\n");
 385 }
 386 #else
 387 static void __syntax(char *file, int line) {
 388         error_msg("syntax error %s:%d", file, line);
 389 }
 390 #define syntax() __syntax(__FILE__, __LINE__)
 391 #endif
 392
 393 #ifdef __U_BOOT__
 394 static void *xmalloc(size_t size);
 395 static void *xrealloc(void *ptr, size_t size);
 396 #else
 397 /* Index of subroutines: */
 398 /*   function prototypes for builtins */
 399 static int builtin_cd(struct child_prog *child);
 400 static int builtin_env(struct child_prog *child);
 401 static int builtin_eval(struct child_prog *child);
 402 static int builtin_exec(struct child_prog *child);
 403 static int builtin_exit(struct child_prog *child);
 404 static int builtin_export(struct child_prog *child);
 405 static int builtin_fg_bg(struct child_prog *child);
 406 static int builtin_help(struct child_prog *child);
 407 static int builtin_jobs(struct child_prog *child);
 408 static int builtin_pwd(struct child_prog *child);
 409 static int builtin_read(struct child_prog *child);
 410 static int builtin_set(struct child_prog *child);
 411 static int builtin_shift(struct child_prog *child);
 412 static int builtin_source(struct child_prog *child);
 413 static int builtin_umask(struct child_prog *child);
 414 static int builtin_unset(struct child_prog *child);
 415 static int builtin_not_written(struct child_prog *child);
 416 #endif
 417 /*   o_string manipulation: */
 418 static int b_check_space(o_string *o, int len);
 419 static int b_addchr(o_string *o, int ch);
 420 static void b_reset(o_string *o);
 421 static int b_addqchr(o_string *o, int ch, int quote);
 422 #ifndef __U_BOOT__
 423 static int b_adduint(o_string *o, unsigned int i);
 424 #endif
 425 /*  in_str manipulations: */
 426 static int static_get(struct in_str *i);
 427 static int static_peek(struct in_str *i);
 428 static int file_get(struct in_str *i);
 429 static int file_peek(struct in_str *i);
 430 #ifndef __U_BOOT__
 431 static void setup_file_in_str(struct in_str *i, FILE *f);
 432 #else
 433 static void setup_file_in_str(struct in_str *i);
 434 #endif
 435 static void setup_string_in_str(struct in_str *i, const char *s);
 436 #ifndef __U_BOOT__
 437 /*  close_me manipulations: */
 438 static void mark_open(int fd);
 439 static void mark_closed(int fd);
 440 static void close_all(void);
 441 #endif
 442 /*  "run" the final data structures: */
 443 static char *indenter(int i);
 444 static int free_pipe_list(struct pipe *head, int indent);
 445 static int free_pipe(struct pipe *pi, int indent);
 446 /*  really run the final data structures: */
 447 #ifndef __U_BOOT__
 448 static int setup_redirects(struct child_prog *prog, int squirrel[]);
 449 #endif
 450 static int run_list_real(struct pipe *pi);
 451 #ifndef __U_BOOT__
 452 static void pseudo_exec(struct child_prog *child) __attribute__ ((noreturn));
 453 #endif
 454 static int run_pipe_real(struct pipe *pi);
 455 /*   extended glob support: */
 456 #ifndef __U_BOOT__
 457 static int globhack(const char *src, int flags, glob_t *pglob);
 458 static int glob_needed(const char *s);
 459 static int xglob(o_string *dest, int flags, glob_t *pglob);
 460 #endif
 461 /*   variable assignment: */
 462 static int is_assignment(const char *s);
 463 /*   data structure manipulation: */
 464 #ifndef __U_BOOT__
 465 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
 466 #endif
 467 static void initialize_context(struct p_context *ctx);
 468 static int done_word(o_string *dest, struct p_context *ctx);
 469 static int done_command(struct p_context *ctx);
 470 static int done_pipe(struct p_context *ctx, pipe_style type);
 471 /*   primary string parsing: */
 472 #ifndef __U_BOOT__
 473 static int redirect_dup_num(struct in_str *input);
 474 static int redirect_opt_num(o_string *o);
 475 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end);
 476 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
 477 #endif
 478 static char *lookup_param(char *src);
 479 static char *make_string(char **inp);
 480 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input);
 481 #ifndef __U_BOOT__
 482 static int parse_string(o_string *dest, struct p_context *ctx, const char *src);
 483 #endif
 484 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, int end_trigger);
 485 /*   setup: */
 486 static int parse_stream_outer(struct in_str *inp, int flag);
 487 #ifndef __U_BOOT__
 488 static int parse_string_outer(const char *s, int flag);
 489 static int parse_file_outer(FILE *f);
 490 #endif
 491 #ifndef __U_BOOT__
 492 /*   job management: */
 493 static int checkjobs(struct pipe* fg_pipe);
 494 static void insert_bg_job(struct pipe *pi);
 495 static void remove_bg_job(struct pipe *pi);
 496 #endif
 497 /*     local variable support */
 498 static char **make_list_in(char **inp, char *name);
 499 static char *insert_var_value(char *inp);
 500 static char *get_local_var(const char *var);
 501
 502 #ifndef __U_BOOT__
 503 /* Table of built-in functions.  They can be forked or not, depending on
 504  * context: within pipes, they fork.  As simple commands, they do not.
 505  * When used in non-forking context, they can change global variables
 506  * in the parent shell process.  If forked, of course they can not.
 507  * For example, 'unset foo | whatever' will parse and run, but foo will
 508  * still be set at the end. */
 509 static struct built_in_command bltins[] = {
 510         {"bg", "Resume a job in the background", builtin_fg_bg},
 511         {"break", "Exit for, while or until loop", builtin_not_written},
 512         {"cd", "Change working directory", builtin_cd},
 513         {"continue", "Continue for, while or until loop", builtin_not_written},
 514         {"env", "Print all environment variables", builtin_env},
 515         {"eval", "Construct and run shell command", builtin_eval},
 516         {"exec", "Exec command, replacing this shell with the exec'd process",
 517                 builtin_exec},
 518         {"exit", "Exit from shell()", builtin_exit},
 519         {"export", "Set environment variable", builtin_export},
 520         {"fg", "Bring job into the foreground", builtin_fg_bg},
 521         {"jobs", "Lists the active jobs", builtin_jobs},
 522         {"pwd", "Print current directory", builtin_pwd},
 523         {"read", "Input environment variable", builtin_read},
 524         {"return", "Return from a function", builtin_not_written},
 525         {"set", "Set/unset shell local variables", builtin_set},
 526         {"shift", "Shift positional parameters", builtin_shift},
 527         {"trap", "Trap signals", builtin_not_written},
 528         {"ulimit","Controls resource limits", builtin_not_written},
 529         {"umask","Sets file creation mask", builtin_umask},
 530         {"unset", "Unset environment variable", builtin_unset},
 531         {".", "Source-in and run commands in a file", builtin_source},
 532         {"help", "List shell built-in commands", builtin_help},
 533         {NULL, NULL, NULL}
 534 };
 535
 536 static const char *set_cwd(void)
 537 {
 538         if(cwd==unknown)
 539                 cwd = NULL;     /* xgetcwd(arg) called free(arg) */
 540         cwd = xgetcwd((char *)cwd);
 541         if (!cwd)
 542                 cwd = unknown;
 543         return cwd;
 544 }
 545
 546 /* built-in 'eval' handler */
 547 static int builtin_eval(struct child_prog *child)
 548 {
 549         char *str = NULL;
 550         int rcode = EXIT_SUCCESS;
 551
 552         if (child->argv[1]) {
 553                 str = make_string(child->argv + 1);
 554                 parse_string_outer(str, FLAG_EXIT_FROM_LOOP |
 555                                         FLAG_PARSE_SEMICOLON);
 556                 free(str);
 557                 rcode = last_return_code;
 558         }
 559         return rcode;
 560 }
 561
 562 /* built-in 'cd <path>' handler */
 563 static int builtin_cd(struct child_prog *child)
 564 {
 565         char *newdir;
 566         if (child->argv[1] == NULL)
 567                 newdir = getenv("HOME");
 568         else
 569                 newdir = child->argv[1];
 570         if (chdir(newdir)) {
 571                 printf("cd: %s: %s\n", newdir, strerror(errno));
 572                 return EXIT_FAILURE;
 573         }
 574         set_cwd();
 575         return EXIT_SUCCESS;
 576 }
 577
 578 /* built-in 'env' handler */
 579 static int builtin_env(struct child_prog *dummy)
 580 {
 581         char **e = environ;
 582         if (e == NULL) return EXIT_FAILURE;
 583         for (; *e; e++) {
 584                 puts(*e);
 585         }
 586         return EXIT_SUCCESS;
 587 }
 588
 589 /* built-in 'exec' handler */
 590 static int builtin_exec(struct child_prog *child)
 591 {
 592         if (child->argv[1] == NULL)
 593                 return EXIT_SUCCESS;   /* Really? */
 594         child->argv++;
 595         pseudo_exec(child);
 596         /* never returns */
 597 }
 598
 599 /* built-in 'exit' handler */
 600 static int builtin_exit(struct child_prog *child)
 601 {
 602         if (child->argv[1] == NULL)
 603                 exit(last_return_code);
 604         exit (atoi(child->argv[1]));
 605 }
 606
 607 /* built-in 'export VAR=value' handler */
 608 static int builtin_export(struct child_prog *child)
 609 {
 610         int res = 0;
 611         char *name = child->argv[1];
 612
 613         if (name == NULL) {
 614                 return (builtin_env(child));
 615         }
 616
 617         name = strdup(name);
 618
 619         if(name) {
 620                 char *value = strchr(name, '=');
 621
 622                 if (!value) {
 623                         char *tmp;
 624                         /* They are exporting something without an =VALUE */
 625
 626                         value = get_local_var(name);
 627                         if (value) {
 628                                 size_t ln = strlen(name);
 629
 630                                 tmp = realloc(name, ln+strlen(value)+2);
 631                                 if(tmp==NULL)
 632                                         res = -1;
 633                                 else {
 634                                         sprintf(tmp+ln, "=%s", value);
 635                                         name = tmp;
 636                                 }
 637                         } else {
 638                                 /* bash does not return an error when trying to export
 639                                  * an undefined variable.  Do likewise. */
 640                                 res = 1;
 641                         }
 642                 }
 643         }
 644         if (res<0)
 645                 perror_msg("export");
 646         else if(res==0)
 647                 res = set_local_var(name, 1);
 648         else
 649                 res = 0;
 650         free(name);
 651         return res;
 652 }
 653
 654 /* built-in 'fg' and 'bg' handler */
 655 static int builtin_fg_bg(struct child_prog *child)
 656 {
 657         int i, jobnum;
 658         struct pipe *pi=NULL;
 659
 660         if (!interactive)
 661                 return EXIT_FAILURE;
 662         /* If they gave us no args, assume they want the last backgrounded task */
 663         if (!child->argv[1]) {
 664                 for (pi = job_list; pi; pi = pi->next) {
 665                         if (pi->jobid == last_jobid) {
 666                                 break;
 667                         }
 668                 }
 669                 if (!pi) {
 670                         error_msg("%s: no current job", child->argv[0]);
 671                         return EXIT_FAILURE;
 672                 }
 673         } else {
 674                 if (sscanf(child->argv[1], "%%%d", &jobnum) != 1) {
 675                         error_msg("%s: bad argument '%s'", child->argv[0], child->argv[1]);
 676                         return EXIT_FAILURE;
 677                 }
 678                 for (pi = job_list; pi; pi = pi->next) {
 679                         if (pi->jobid == jobnum) {
 680                                 break;
 681                         }
 682                 }
 683                 if (!pi) {
 684                         error_msg("%s: %d: no such job", child->argv[0], jobnum);
 685                         return EXIT_FAILURE;
 686                 }
 687         }
 688
 689         if (*child->argv[0] == 'f') {
 690                 /* Put the job into the foreground.  */
 691                 tcsetpgrp(shell_terminal, pi->pgrp);
 692         }
 693
 694         /* Restart the processes in the job */
 695         for (i = 0; i < pi->num_progs; i++)
 696                 pi->progs[i].is_stopped = 0;
 697
 698         if ( (i=kill(- pi->pgrp, SIGCONT)) < 0) {
 699                 if (i == ESRCH) {
 700                         remove_bg_job(pi);
 701                 } else {
 702                         perror_msg("kill (SIGCONT)");
 703                 }
 704         }
 705
 706         pi->stopped_progs = 0;
 707         return EXIT_SUCCESS;
 708 }
 709
 710 /* built-in 'help' handler */
 711 static int builtin_help(struct child_prog *dummy)
 712 {
 713         struct built_in_command *x;
 714
 715         printf("\nBuilt-in commands:\n");
 716         printf("-------------------\n");
 717         for (x = bltins; x->cmd; x++) {
 718                 if (x->descr==NULL)
 719                         continue;
 720                 printf("%s\t%s\n", x->cmd, x->descr);
 721         }
 722         printf("\n\n");
 723         return EXIT_SUCCESS;
 724 }
 725
 726 /* built-in 'jobs' handler */
 727 static int builtin_jobs(struct child_prog *child)
 728 {
 729         struct pipe *job;
 730         char *status_string;
 731
 732         for (job = job_list; job; job = job->next) {
 733                 if (job->running_progs == job->stopped_progs)
 734                         status_string = "Stopped";
 735                 else
 736                         status_string = "Running";
 737
 738                 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->text);
 739         }
 740         return EXIT_SUCCESS;
 741 }
 742
 743
 744 /* built-in 'pwd' handler */
 745 static int builtin_pwd(struct child_prog *dummy)
 746 {
 747         puts(set_cwd());
 748         return EXIT_SUCCESS;
 749 }
 750
 751 /* built-in 'read VAR' handler */
 752 static int builtin_read(struct child_prog *child)
 753 {
 754         int res;
 755
 756         if (child->argv[1]) {
 757                 char string[BUFSIZ];
 758                 char *var = 0;
 759
 760                 string[0] = 0;  /* In case stdin has only EOF */
 761                 /* read string */
 762                 fgets(string, sizeof(string), stdin);
 763                 chomp(string);
 764                 var = malloc(strlen(child->argv[1])+strlen(string)+2);
 765                 if(var) {
 766                         sprintf(var, "%s=%s", child->argv[1], string);
 767                         res = set_local_var(var, 0);
 768                 } else
 769                         res = -1;
 770                 if (res)
 771                         fprintf(stderr, "read: %m\n");
 772                 free(var);      /* So not move up to avoid breaking errno */
 773                 return res;
 774         } else {
 775                 do res=getchar(); while(res!='\n' && res!=EOF);
 776                 return 0;
 777         }
 778 }
 779
 780 /* built-in 'set VAR=value' handler */
 781 static int builtin_set(struct child_prog *child)
 782 {
 783         char *temp = child->argv[1];
 784         struct variables *e;
 785
 786         if (temp == NULL)
 787                 for(e = top_vars; e; e=e->next)
 788                         printf("%s=%s\n", e->name, e->value);
 789         else
 790                 set_local_var(temp, 0);
 791
 792                 return EXIT_SUCCESS;
 793 }
 794
 795
 796 /* Built-in 'shift' handler */
 797 static int builtin_shift(struct child_prog *child)
 798 {
 799         int n=1;
 800         if (child->argv[1]) {
 801                 n=atoi(child->argv[1]);
 802         }
 803         if (n>=0 && n<global_argc) {
 804                 /* XXX This probably breaks $0 */
 805                 global_argc -= n;
 806                 global_argv += n;
 807                 return EXIT_SUCCESS;
 808         } else {
 809                 return EXIT_FAILURE;
 810         }
 811 }
 812
 813 /* Built-in '.' handler (read-in and execute commands from file) */
 814 static int builtin_source(struct child_prog *child)
 815 {
 816         FILE *input;
 817         int status;
 818
 819         if (child->argv[1] == NULL)
 820                 return EXIT_FAILURE;
 821
 822         /* XXX search through $PATH is missing */
 823         input = fopen(child->argv[1], "r");
 824         if (!input) {
 825                 error_msg("Couldn't open file '%s'", child->argv[1]);
 826                 return EXIT_FAILURE;
 827         }
 828
 829         /* Now run the file */
 830         /* XXX argv and argc are broken; need to save old global_argv
 831          * (pointer only is OK!) on this stack frame,
 832          * set global_argv=child->argv+1, recurse, and restore. */
 833         mark_open(fileno(input));
 834         status = parse_file_outer(input);
 835         mark_closed(fileno(input));
 836         fclose(input);
 837         return (status);
 838 }
 839
 840 static int builtin_umask(struct child_prog *child)
 841 {
 842         mode_t new_umask;
 843         const char *arg = child->argv[1];
 844         char *end;
 845         if (arg) {
 846                 new_umask=strtoul(arg, &end, 8);
 847                 if (*end!='\0' || end == arg) {
 848                         return EXIT_FAILURE;
 849                 }
 850         } else {
 851                 printf("%.3o\n", (unsigned int) (new_umask=umask(0)));
 852         }
 853         umask(new_umask);
 854         return EXIT_SUCCESS;
 855 }
 856
 857 /* built-in 'unset VAR' handler */
 858 static int builtin_unset(struct child_prog *child)
 859 {
 860         /* bash returned already true */
 861         unset_local_var(child->argv[1]);
 862         return EXIT_SUCCESS;
 863 }
 864
 865 static int builtin_not_written(struct child_prog *child)
 866 {
 867         printf("builtin_%s not written\n",child->argv[0]);
 868         return EXIT_FAILURE;
 869 }
 870 #endif
 871
 872 static int b_check_space(o_string *o, int len)
 873 {
 874         /* It would be easy to drop a more restrictive policy
 875          * in here, such as setting a maximum string length */
 876         if (o->length + len > o->maxlen) {
 877                 char *old_data = o->data;
 878                 /* assert (data == NULL || o->maxlen != 0); */
 879                 o->maxlen += max(2*len, B_CHUNK);
 880                 o->data = realloc(o->data, 1 + o->maxlen);
 881                 if (o->data == NULL) {
 882                         free(old_data);
 883                 }
 884         }
 885         return o->data == NULL;
 886 }
 887
 888 static int b_addchr(o_string *o, int ch)
 889 {
 890         debug_printf("b_addchr: %c %d %p\n", ch, o->length, o);
 891         if (b_check_space(o, 1)) return B_NOSPAC;
 892         o->data[o->length] = ch;
 893         o->length++;
 894         o->data[o->length] = '\0';
 895         return 0;
 896 }
 897
 898 static void b_reset(o_string *o)
 899 {
 900         o->length = 0;
 901         o->nonnull = 0;
 902         if (o->data != NULL) *o->data = '\0';
 903 }
 904
 905 static void b_free(o_string *o)
 906 {
 907         b_reset(o);
 908         free(o->data);
 909         o->data = NULL;
 910         o->maxlen = 0;
 911 }
 912
 913 /* My analysis of quoting semantics tells me that state information
 914  * is associated with a destination, not a source.
 915  */
 916 static int b_addqchr(o_string *o, int ch, int quote)
 917 {
 918         if (quote && strchr("*?[\\",ch)) {
 919                 int rc;
 920                 rc = b_addchr(o, '\\');
 921                 if (rc) return rc;
 922         }
 923         return b_addchr(o, ch);
 924 }
 925
 926 /* belongs in utility.c */
 927 char *simple_itoa(unsigned int i)
 928 {
 929         /* 21 digits plus null terminator, good for 64-bit or smaller ints */
 930         static char local[22];
 931         char *p = &local[21];
 932         *p-- = '\0';
 933         do {
 934                 *p-- = '0' + i % 10;
 935                 i /= 10;
 936         } while (i > 0);
 937         return p + 1;
 938 }
 939
 940 #ifndef __U_BOOT__
 941 static int b_adduint(o_string *o, unsigned int i)
 942 {
 943         int r;
 944         char *p = simple_itoa(i);
 945         /* no escape checking necessary */
 946         do r=b_addchr(o, *p++); while (r==0 && *p);
 947         return r;
 948 }
 949 #endif
 950
 951 static int static_get(struct in_str *i)
 952 {
 953         int ch = *i->p++;
 954         if (ch=='\0') return EOF;
 955         return ch;
 956 }
 957
 958 static int static_peek(struct in_str *i)
 959 {
 960         return *i->p;
 961 }
 962
 963 #ifndef __U_BOOT__
 964 static inline void cmdedit_set_initial_prompt(void)
 965 {
 966 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 967         PS1 = NULL;
 968 #else
 969         PS1 = getenv("PS1");
 970         if(PS1==0)
 971                 PS1 = "\\w \\$ ";
 972 #endif
 973 }
 974
 975 static inline void setup_prompt_string(int promptmode, char **prompt_str)
 976 {
 977         debug_printf("setup_prompt_string %d ",promptmode);
 978 #ifndef CONFIG_FEATURE_SH_FANCY_PROMPT
 979         /* Set up the prompt */
 980         if (promptmode == 1) {
 981                 free(PS1);
 982                 PS1=xmalloc(strlen(cwd)+4);
 983                 sprintf(PS1, "%s %s", cwd, ( geteuid() != 0 ) ?  "$ ":"# ");
 984                 *prompt_str = PS1;
 985         } else {
 986                 *prompt_str = PS2;
 987         }
 988 #else
 989         *prompt_str = (promptmode==1)? PS1 : PS2;
 990 #endif
 991         debug_printf("result %s\n",*prompt_str);
 992 }
 993 #endif
 994
 995 static void get_user_input(struct in_str *i)
 996 {
 997 #ifndef __U_BOOT__
 998         char *prompt_str;
 999         static char the_command[BUFSIZ];
1000
1001         setup_prompt_string(i->promptmode, &prompt_str);
1002 #ifdef CONFIG_FEATURE_COMMAND_EDITING
1003         /*
1004          ** enable command line editing only while a command line
1005          ** is actually being read; otherwise, we'll end up bequeathing
1006          ** atexit() handlers and other unwanted stuff to our
1007          ** child processes (rob@sysgo.de)
1008          */
1009         cmdedit_read_input(prompt_str, the_command);
1010 #else
1011         fputs(prompt_str, stdout);
1012         fflush(stdout);
1013         the_command[0]=fgetc(i->file);
1014         the_command[1]='\0';
1015 #endif
1016         fflush(stdout);
1017         i->p = the_command;
1018 #else
1019         extern char console_buffer[];
1020         int n;
1021         static char the_command[CONFIG_SYS_CBSIZE];
1022
1023 #ifdef CONFIG_BOOT_RETRY_TIME
1024 #  ifndef CONFIG_RESET_TO_RETRY
1025 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1026 #  endif
1027         reset_cmd_timeout();
1028 #endif
1029         i->__promptme = 1;
1030         if (i->promptmode == 1) {
1031                 n = readline(CONFIG_SYS_PROMPT);
1032         } else {
1033                 n = readline(CONFIG_SYS_PROMPT_HUSH_PS2);
1034         }
1035 #ifdef CONFIG_BOOT_RETRY_TIME
1036         if (n == -2) {
1037           puts("\nTimeout waiting for command\n");
1038 #  ifdef CONFIG_RESET_TO_RETRY
1039           do_reset(NULL, 0, 0, NULL);
1040 #  else
1041 #       error "This currently only works with CONFIG_RESET_TO_RETRY enabled"
1042 #  endif
1043         }
1044 #endif
1045         if (n == -1 ) {
1046                 flag_repeat = 0;
1047                 i->__promptme = 0;
1048         }
1049         n = strlen(console_buffer);
1050         console_buffer[n] = '\n';
1051         console_buffer[n+1]= '\0';
1052         if (had_ctrlc()) flag_repeat = 0;
1053         clear_ctrlc();
1054         do_repeat = 0;
1055         if (i->promptmode == 1) {
1056                 if (console_buffer[0] == '\n'&& flag_repeat == 0) {
1057                         strcpy(the_command,console_buffer);
1058                 }
1059                 else {
1060                         if (console_buffer[0] != '\n') {
1061                                 strcpy(the_command,console_buffer);
1062                                 flag_repeat = 1;
1063                         }
1064                         else {
1065                                 do_repeat = 1;
1066                         }
1067                 }
1068                 i->p = the_command;
1069         }
1070         else {
1071                 if (console_buffer[0] != '\n') {
1072                         if (strlen(the_command) + strlen(console_buffer)
1073                             < CONFIG_SYS_CBSIZE) {
1074                                 n = strlen(the_command);
1075                                 the_command[n-1] = ' ';
1076                                 strcpy(&the_command[n],console_buffer);
1077                         }
1078                         else {
1079                                 the_command[0] = '\n';
1080                                 the_command[1] = '\0';
1081                                 flag_repeat = 0;
1082                         }
1083                 }
1084                 if (i->__promptme == 0) {
1085                         the_command[0] = '\n';
1086                         the_command[1] = '\0';
1087                 }
1088                 i->p = console_buffer;
1089         }
1090 #endif
1091 }
1092
1093 /* This is the magic location that prints prompts
1094  * and gets data back from the user */
1095 static int file_get(struct in_str *i)
1096 {
1097         int ch;
1098
1099         ch = 0;
1100         /* If there is data waiting, eat it up */
1101         if (i->p && *i->p) {
1102                 ch = *i->p++;
1103         } else {
1104                 /* need to double check i->file because we might be doing something
1105                  * more complicated by now, like sourcing or substituting. */
1106 #ifndef __U_BOOT__
1107                 if (i->__promptme && interactive && i->file == stdin) {
1108                         while(! i->p || (interactive && strlen(i->p)==0) ) {
1109 #else
1110                         while(! i->p  || strlen(i->p)==0 ) {
1111 #endif
1112                                 get_user_input(i);
1113                         }
1114                         i->promptmode=2;
1115 #ifndef __U_BOOT__
1116                         i->__promptme = 0;
1117 #endif
1118                         if (i->p && *i->p) {
1119                                 ch = *i->p++;
1120                         }
1121 #ifndef __U_BOOT__
1122                 } else {
1123                         ch = fgetc(i->file);
1124                 }
1125
1126 #endif
1127                 debug_printf("b_getch: got a %d\n", ch);
1128         }
1129 #ifndef __U_BOOT__
1130         if (ch == '\n') i->__promptme=1;
1131 #endif
1132         return ch;
1133 }
1134
1135 /* All the callers guarantee this routine will never be
1136  * used right after a newline, so prompting is not needed.
1137  */
1138 static int file_peek(struct in_str *i)
1139 {
1140 #ifndef __U_BOOT__
1141         if (i->p && *i->p) {
1142 #endif
1143                 return *i->p;
1144 #ifndef __U_BOOT__
1145         } else {
1146                 i->peek_buf[0] = fgetc(i->file);
1147                 i->peek_buf[1] = '\0';
1148                 i->p = i->peek_buf;
1149                 debug_printf("b_peek: got a %d\n", *i->p);
1150                 return *i->p;
1151         }
1152 #endif
1153 }
1154
1155 #ifndef __U_BOOT__
1156 static void setup_file_in_str(struct in_str *i, FILE *f)
1157 #else
1158 static void setup_file_in_str(struct in_str *i)
1159 #endif
1160 {
1161         i->peek = file_peek;
1162         i->get = file_get;
1163         i->__promptme=1;
1164         i->promptmode=1;
1165 #ifndef __U_BOOT__
1166         i->file = f;
1167 #endif
1168         i->p = NULL;
1169 }
1170
1171 static void setup_string_in_str(struct in_str *i, const char *s)
1172 {
1173         i->peek = static_peek;
1174         i->get = static_get;
1175         i->__promptme=1;
1176         i->promptmode=1;
1177         i->p = s;
1178 }
1179
1180 #ifndef __U_BOOT__
1181 static void mark_open(int fd)
1182 {
1183         struct close_me *new = xmalloc(sizeof(struct close_me));
1184         new->fd = fd;
1185         new->next = close_me_head;
1186         close_me_head = new;
1187 }
1188
1189 static void mark_closed(int fd)
1190 {
1191         struct close_me *tmp;
1192         if (close_me_head == NULL || close_me_head->fd != fd)
1193                 error_msg_and_die("corrupt close_me");
1194         tmp = close_me_head;
1195         close_me_head = close_me_head->next;
1196         free(tmp);
1197 }
1198
1199 static void close_all(void)
1200 {
1201         struct close_me *c;
1202         for (c=close_me_head; c; c=c->next) {
1203                 close(c->fd);
1204         }
1205         close_me_head = NULL;
1206 }
1207
1208 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1209  * and stderr if they are redirected. */
1210 static int setup_redirects(struct child_prog *prog, int squirrel[])
1211 {
1212         int openfd, mode;
1213         struct redir_struct *redir;
1214
1215         for (redir=prog->redirects; redir; redir=redir->next) {
1216                 if (redir->dup == -1 && redir->word.gl_pathv == NULL) {
1217                         /* something went wrong in the parse.  Pretend it didn't happen */
1218                         continue;
1219                 }
1220                 if (redir->dup == -1) {
1221                         mode=redir_table[redir->type].mode;
1222                         openfd = open(redir->word.gl_pathv[0], mode, 0666);
1223                         if (openfd < 0) {
1224                         /* this could get lost if stderr has been redirected, but
1225                            bash and ash both lose it as well (though zsh doesn't!) */
1226                                 perror_msg("error opening %s", redir->word.gl_pathv[0]);
1227                                 return 1;
1228                         }
1229                 } else {
1230                         openfd = redir->dup;
1231                 }
1232
1233                 if (openfd != redir->fd) {
1234                         if (squirrel && redir->fd < 3) {
1235                                 squirrel[redir->fd] = dup(redir->fd);
1236                         }
1237                         if (openfd == -3) {
1238                                 close(openfd);
1239                         } else {
1240                                 dup2(openfd, redir->fd);
1241                                 if (redir->dup == -1)
1242                                         close (openfd);
1243                         }
1244                 }
1245         }
1246         return 0;
1247 }
1248
1249 static void restore_redirects(int squirrel[])
1250 {
1251         int i, fd;
1252         for (i=0; i<3; i++) {
1253                 fd = squirrel[i];
1254                 if (fd != -1) {
1255                         /* No error checking.  I sure wouldn't know what
1256                          * to do with an error if I found one! */
1257                         dup2(fd, i);
1258                         close(fd);
1259                 }
1260         }
1261 }
1262
1263 /* never returns */
1264 /* XXX no exit() here.  If you don't exec, use _exit instead.
1265  * The at_exit handlers apparently confuse the calling process,
1266  * in particular stdin handling.  Not sure why? */
1267 static void pseudo_exec(struct child_prog *child)
1268 {
1269         int i, rcode;
1270         char *p;
1271         struct built_in_command *x;
1272         if (child->argv) {
1273                 for (i=0; is_assignment(child->argv[i]); i++) {
1274                         debug_printf("pid %d environment modification: %s\n",getpid(),child->argv[i]);
1275                         p = insert_var_value(child->argv[i]);
1276                         putenv(strdup(p));
1277                         if (p != child->argv[i]) free(p);
1278                 }
1279                 child->argv+=i;  /* XXX this hack isn't so horrible, since we are about
1280                                         to exit, and therefore don't need to keep data
1281                                         structures consistent for free() use. */
1282                 /* If a variable is assigned in a forest, and nobody listens,
1283                  * was it ever really set?
1284                  */
1285                 if (child->argv[0] == NULL) {
1286                         _exit(EXIT_SUCCESS);
1287                 }
1288
1289                 /*
1290                  * Check if the command matches any of the builtins.
1291                  * Depending on context, this might be redundant.  But it's
1292                  * easier to waste a few CPU cycles than it is to figure out
1293                  * if this is one of those cases.
1294                  */
1295                 for (x = bltins; x->cmd; x++) {
1296                         if (strcmp(child->argv[0], x->cmd) == 0 ) {
1297                                 debug_printf("builtin exec %s\n", child->argv[0]);
1298                                 rcode = x->function(child);
1299                                 fflush(stdout);
1300                                 _exit(rcode);
1301                         }
1302                 }
1303
1304                 /* Check if the command matches any busybox internal commands
1305                  * ("applets") here.
1306                  * FIXME: This feature is not 100% safe, since
1307                  * BusyBox is not fully reentrant, so we have no guarantee the things
1308                  * from the .bss are still zeroed, or that things from .data are still
1309                  * at their defaults.  We could exec ourself from /proc/self/exe, but I
1310                  * really dislike relying on /proc for things.  We could exec ourself
1311                  * from global_argv[0], but if we are in a chroot, we may not be able
1312                  * to find ourself... */
1313 #ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
1314                 {
1315                         int argc_l;
1316                         char** argv_l=child->argv;
1317                         char *name = child->argv[0];
1318
1319 #ifdef CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN
1320                         /* Following discussions from November 2000 on the busybox mailing
1321                          * list, the default configuration, (without
1322                          * get_last_path_component()) lets the user force use of an
1323                          * external command by specifying the full (with slashes) filename.
1324                          * If you enable CONFIG_FEATURE_SH_APPLETS_ALWAYS_WIN then applets
1325                          * _aways_ override external commands, so if you want to run
1326                          * /bin/cat, it will use BusyBox cat even if /bin/cat exists on the
1327                          * filesystem and is _not_ busybox.  Some systems may want this,
1328                          * most do not.  */
1329                         name = get_last_path_component(name);
1330 #endif
1331                         /* Count argc for use in a second... */
1332                         for(argc_l=0;*argv_l!=NULL; argv_l++, argc_l++);
1333                         optind = 1;
1334                         debug_printf("running applet %s\n", name);
1335                         run_applet_by_name(name, argc_l, child->argv);
1336                 }
1337 #endif
1338                 debug_printf("exec of %s\n",child->argv[0]);
1339                 execvp(child->argv[0],child->argv);
1340                 perror_msg("couldn't exec: %s",child->argv[0]);
1341                 _exit(1);
1342         } else if (child->group) {
1343                 debug_printf("runtime nesting to group\n");
1344                 interactive=0;    /* crucial!!!! */
1345                 rcode = run_list_real(child->group);
1346                 /* OK to leak memory by not calling free_pipe_list,
1347                  * since this process is about to exit */
1348                 _exit(rcode);
1349         } else {
1350                 /* Can happen.  See what bash does with ">foo" by itself. */
1351                 debug_printf("trying to pseudo_exec null command\n");
1352                 _exit(EXIT_SUCCESS);
1353         }
1354 }
1355
1356 static void insert_bg_job(struct pipe *pi)
1357 {
1358         struct pipe *thejob;
1359
1360         /* Linear search for the ID of the job to use */
1361         pi->jobid = 1;
1362         for (thejob = job_list; thejob; thejob = thejob->next)
1363                 if (thejob->jobid >= pi->jobid)
1364                         pi->jobid = thejob->jobid + 1;
1365
1366         /* add thejob to the list of running jobs */
1367         if (!job_list) {
1368                 thejob = job_list = xmalloc(sizeof(*thejob));
1369         } else {
1370                 for (thejob = job_list; thejob->next; thejob = thejob->next) /* nothing */;
1371                 thejob->next = xmalloc(sizeof(*thejob));
1372                 thejob = thejob->next;
1373         }
1374
1375         /* physically copy the struct job */
1376         memcpy(thejob, pi, sizeof(struct pipe));
1377         thejob->next = NULL;
1378         thejob->running_progs = thejob->num_progs;
1379         thejob->stopped_progs = 0;
1380         thejob->text = xmalloc(BUFSIZ); /* cmdedit buffer size */
1381
1382         /*if (pi->progs[0] && pi->progs[0].argv && pi->progs[0].argv[0]) */
1383         {
1384                 char *bar=thejob->text;
1385                 char **foo=pi->progs[0].argv;
1386                 while(foo && *foo) {
1387                         bar += sprintf(bar, "%s ", *foo++);
1388                 }
1389         }
1390
1391         /* we don't wait for background thejobs to return -- append it
1392            to the list of backgrounded thejobs and leave it alone */
1393         printf("[%d] %d\n", thejob->jobid, thejob->progs[0].pid);
1394         last_bg_pid = thejob->progs[0].pid;
1395         last_jobid = thejob->jobid;
1396 }
1397
1398 /* remove a backgrounded job */
1399 static void remove_bg_job(struct pipe *pi)
1400 {
1401         struct pipe *prev_pipe;
1402
1403         if (pi == job_list) {
1404                 job_list = pi->next;
1405         } else {
1406                 prev_pipe = job_list;
1407                 while (prev_pipe->next != pi)
1408                         prev_pipe = prev_pipe->next;
1409                 prev_pipe->next = pi->next;
1410         }
1411         if (job_list)
1412                 last_jobid = job_list->jobid;
1413         else
1414                 last_jobid = 0;
1415
1416         pi->stopped_progs = 0;
1417         free_pipe(pi, 0);
1418         free(pi);
1419 }
1420
1421 /* Checks to see if any processes have exited -- if they
1422    have, figure out why and see if a job has completed */
1423 static int checkjobs(struct pipe* fg_pipe)
1424 {
1425         int attributes;
1426         int status;
1427         int prognum = 0;
1428         struct pipe *pi;
1429         pid_t childpid;
1430
1431         attributes = WUNTRACED;
1432         if (fg_pipe==NULL) {
1433                 attributes |= WNOHANG;
1434         }
1435
1436         while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1437                 if (fg_pipe) {
1438                         int i, rcode = 0;
1439                         for (i=0; i < fg_pipe->num_progs; i++) {
1440                                 if (fg_pipe->progs[i].pid == childpid) {
1441                                         if (i==fg_pipe->num_progs-1)
1442                                                 rcode=WEXITSTATUS(status);
1443                                         (fg_pipe->num_progs)--;
1444                                         return(rcode);
1445                                 }
1446                         }
1447                 }
1448
1449                 for (pi = job_list; pi; pi = pi->next) {
1450                         prognum = 0;
1451                         while (prognum < pi->num_progs && pi->progs[prognum].pid != childpid) {
1452                                 prognum++;
1453                         }
1454                         if (prognum < pi->num_progs)
1455                                 break;
1456                 }
1457
1458                 if(pi==NULL) {
1459                         debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1460                         continue;
1461                 }
1462
1463                 if (WIFEXITED(status) || WIFSIGNALED(status)) {
1464                         /* child exited */
1465                         pi->running_progs--;
1466                         pi->progs[prognum].pid = 0;
1467
1468                         if (!pi->running_progs) {
1469                                 printf(JOB_STATUS_FORMAT, pi->jobid, "Done", pi->text);
1470                                 remove_bg_job(pi);
1471                         }
1472                 } else {
1473                         /* child stopped */
1474                         pi->stopped_progs++;
1475                         pi->progs[prognum].is_stopped = 1;
1476
1477 #if 0
1478                         /* Printing this stuff is a pain, since it tends to
1479                          * overwrite the prompt an inconveinient moments.  So
1480                          * don't do that.  */
1481                         if (pi->stopped_progs == pi->num_progs) {
1482                                 printf("\n"JOB_STATUS_FORMAT, pi->jobid, "Stopped", pi->text);
1483                         }
1484 #endif
1485                 }
1486         }
1487
1488         if (childpid == -1 && errno != ECHILD)
1489                 perror_msg("waitpid");
1490
1491         /* move the shell to the foreground */
1492         /*if (interactive && tcsetpgrp(shell_terminal, getpgid(0))) */
1493         /*      perror_msg("tcsetpgrp-2"); */
1494         return -1;
1495 }
1496
1497 /* Figure out our controlling tty, checking in order stderr,
1498  * stdin, and stdout.  If check_pgrp is set, also check that
1499  * we belong to the foreground process group associated with
1500  * that tty.  The value of shell_terminal is needed in order to call
1501  * tcsetpgrp(shell_terminal, ...); */
1502 void controlling_tty(int check_pgrp)
1503 {
1504         pid_t curpgrp;
1505
1506         if ((curpgrp = tcgetpgrp(shell_terminal = 2)) < 0
1507                         && (curpgrp = tcgetpgrp(shell_terminal = 0)) < 0
1508                         && (curpgrp = tcgetpgrp(shell_terminal = 1)) < 0)
1509                 goto shell_terminal_error;
1510
1511         if (check_pgrp && curpgrp != getpgid(0))
1512                 goto shell_terminal_error;
1513
1514         return;
1515
1516 shell_terminal_error:
1517                 shell_terminal = -1;
1518                 return;
1519 }
1520 #endif
1521
1522 /* run_pipe_real() starts all the jobs, but doesn't wait for anything
1523  * to finish.  See checkjobs().
1524  *
1525  * return code is normally -1, when the caller has to wait for children
1526  * to finish to determine the exit status of the pipe.  If the pipe
1527  * is a simple builtin command, however, the action is done by the
1528  * time run_pipe_real returns, and the exit code is provided as the
1529  * return value.
1530  *
1531  * The input of the pipe is always stdin, the output is always
1532  * stdout.  The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1533  * because it tries to avoid running the command substitution in
1534  * subshell, when that is in fact necessary.  The subshell process
1535  * now has its stdout directed to the input of the appropriate pipe,
1536  * so this routine is noticeably simpler.
1537  */
1538 static int run_pipe_real(struct pipe *pi)
1539 {
1540         int i;
1541 #ifndef __U_BOOT__
1542         int nextin, nextout;
1543         int pipefds[2];                         /* pipefds[0] is for reading */
1544         struct child_prog *child;
1545         struct built_in_command *x;
1546         char *p;
1547 # if __GNUC__
1548         /* Avoid longjmp clobbering */
1549         (void) &i;
1550         (void) &nextin;
1551         (void) &nextout;
1552         (void) &child;
1553 # endif
1554 #else
1555         int nextin;
1556         int flag = do_repeat ? CMD_FLAG_REPEAT : 0;
1557         struct child_prog *child;
1558         cmd_tbl_t *cmdtp;
1559         char *p;
1560 # if __GNUC__
1561         /* Avoid longjmp clobbering */
1562         (void) &i;
1563         (void) &nextin;
1564         (void) &child;
1565 # endif
1566 #endif  /* __U_BOOT__ */
1567
1568         nextin = 0;
1569 #ifndef __U_BOOT__
1570         pi->pgrp = -1;
1571 #endif
1572
1573         /* Check if this is a simple builtin (not part of a pipe).
1574          * Builtins within pipes have to fork anyway, and are handled in
1575          * pseudo_exec.  "echo foo | read bar" doesn't work on bash, either.
1576          */
1577         if (pi->num_progs == 1) child = & (pi->progs[0]);
1578 #ifndef __U_BOOT__
1579         if (pi->num_progs == 1 && child->group && child->subshell == 0) {
1580                 int squirrel[] = {-1, -1, -1};
1581                 int rcode;
1582                 debug_printf("non-subshell grouping\n");
1583                 setup_redirects(child, squirrel);
1584                 /* XXX could we merge code with following builtin case,
1585                  * by creating a pseudo builtin that calls run_list_real? */
1586                 rcode = run_list_real(child->group);
1587                 restore_redirects(squirrel);
1588 #else
1589                 if (pi->num_progs == 1 && child->group) {
1590                 int rcode;
1591                 debug_printf("non-subshell grouping\n");
1592                 rcode = run_list_real(child->group);
1593 #endif
1594                 return rcode;
1595         } else if (pi->num_progs == 1 && pi->progs[0].argv != NULL) {
1596                 for (i=0; is_assignment(child->argv[i]); i++) { /* nothing */ }
1597                 if (i!=0 && child->argv[i]==NULL) {
1598                         /* assignments, but no command: set the local environment */
1599                         for (i=0; child->argv[i]!=NULL; i++) {
1600
1601                                 /* Ok, this case is tricky.  We have to decide if this is a
1602                                  * local variable, or an already exported variable.  If it is
1603                                  * already exported, we have to export the new value.  If it is
1604                                  * not exported, we need only set this as a local variable.
1605                                  * This junk is all to decide whether or not to export this
1606                                  * variable. */
1607                                 int export_me=0;
1608                                 char *name, *value;
1609                                 name = xstrdup(child->argv[i]);
1610                                 debug_printf("Local environment set: %s\n", name);
1611                                 value = strchr(name, '=');
1612                                 if (value)
1613                                         *value=0;
1614 #ifndef __U_BOOT__
1615                                 if ( get_local_var(name)) {
1616                                         export_me=1;
1617                                 }
1618 #endif
1619                                 free(name);
1620                                 p = insert_var_value(child->argv[i]);
1621                                 set_local_var(p, export_me);
1622                                 if (p != child->argv[i]) free(p);
1623                         }
1624                         return EXIT_SUCCESS;   /* don't worry about errors in set_local_var() yet */
1625                 }
1626                 for (i = 0; is_assignment(child->argv[i]); i++) {
1627                         p = insert_var_value(child->argv[i]);
1628 #ifndef __U_BOOT__
1629                         putenv(strdup(p));
1630 #else
1631                         set_local_var(p, 0);
1632 #endif
1633                         if (p != child->argv[i]) {
1634                                 child->sp--;
1635                                 free(p);
1636                         }
1637                 }
1638                 if (child->sp) {
1639                         char * str = NULL;
1640
1641                         str = make_string((child->argv + i));
1642                         parse_string_outer(str, FLAG_EXIT_FROM_LOOP | FLAG_REPARSING);
1643                         free(str);
1644                         return last_return_code;
1645                 }
1646 #ifndef __U_BOOT__
1647                 for (x = bltins; x->cmd; x++) {
1648                         if (strcmp(child->argv[i], x->cmd) == 0 ) {
1649                                 int squirrel[] = {-1, -1, -1};
1650                                 int rcode;
1651                                 if (x->function == builtin_exec && child->argv[i+1]==NULL) {
1652                                         debug_printf("magic exec\n");
1653                                         setup_redirects(child,NULL);
1654                                         return EXIT_SUCCESS;
1655                                 }
1656                                 debug_printf("builtin inline %s\n", child->argv[0]);
1657                                 /* XXX setup_redirects acts on file descriptors, not FILEs.
1658                                  * This is perfect for work that comes after exec().
1659                                  * Is it really safe for inline use?  Experimentally,
1660                                  * things seem to work with glibc. */
1661                                 setup_redirects(child, squirrel);
1662 #else
1663                         /* check ";", because ,example , argv consist from
1664                          * "help;flinfo" must not execute
1665                          */
1666                         if (strchr(child->argv[i], ';')) {
1667                                 printf ("Unknown command '%s' - try 'help' or use 'run' command\n",
1668                                         child->argv[i]);
1669                                 return -1;
1670                         }
1671                         /* Look up command in command table */
1672
1673
1674                         if ((cmdtp = find_cmd(child->argv[i])) == NULL) {
1675                                 printf ("Unknown command '%s' - try 'help'\n", child->argv[i]);
1676                                 return -1;      /* give up after bad command */
1677                         } else {
1678                                 int rcode;
1679 #if defined(CONFIG_CMD_BOOTD)
1680                                 /* avoid "bootd" recursion */
1681                                 if (cmdtp->cmd == do_bootd) {
1682                                         if (flag & CMD_FLAG_BOOTD) {
1683                                                 printf ("'bootd' recursion detected\n");
1684                                                 return -1;
1685                                         }
1686                                 else
1687                                         flag |= CMD_FLAG_BOOTD;
1688                                 }
1689 #endif
1690                                 /* found - check max args */
1691                                 if ((child->argc - i) > cmdtp->maxargs)
1692                                         return cmd_usage(cmdtp);
1693 #endif
1694                                 child->argv+=i;  /* XXX horrible hack */
1695 #ifndef __U_BOOT__
1696                                 rcode = x->function(child);
1697 #else
1698                                 /* OK - call function to do the command */
1699
1700                                 rcode = (cmdtp->cmd)
1701 (cmdtp, flag,child->argc-i,&child->argv[i]);
1702                                 if ( !cmdtp->repeatable )
1703                                         flag_repeat = 0;
1704
1705
1706 #endif
1707                                 child->argv-=i;  /* XXX restore hack so free() can work right */
1708 #ifndef __U_BOOT__
1709
1710                                 restore_redirects(squirrel);
1711 #endif
1712
1713                                 return rcode;
1714                         }
1715                 }
1716 #ifndef __U_BOOT__
1717         }
1718
1719         for (i = 0; i < pi->num_progs; i++) {
1720                 child = & (pi->progs[i]);
1721
1722                 /* pipes are inserted between pairs of commands */
1723                 if ((i + 1) < pi->num_progs) {
1724                         if (pipe(pipefds)<0) perror_msg_and_die("pipe");
1725                         nextout = pipefds[1];
1726                 } else {
1727                         nextout=1;
1728                         pipefds[0] = -1;
1729                 }
1730
1731                 /* XXX test for failed fork()? */
1732                 if (!(child->pid = fork())) {
1733                         /* Set the handling for job control signals back to the default.  */
1734                         signal(SIGINT, SIG_DFL);
1735                         signal(SIGQUIT, SIG_DFL);
1736                         signal(SIGTERM, SIG_DFL);
1737                         signal(SIGTSTP, SIG_DFL);
1738                         signal(SIGTTIN, SIG_DFL);
1739                         signal(SIGTTOU, SIG_DFL);
1740                         signal(SIGCHLD, SIG_DFL);
1741
1742                         close_all();
1743
1744                         if (nextin != 0) {
1745                                 dup2(nextin, 0);
1746                                 close(nextin);
1747                         }
1748                         if (nextout != 1) {
1749                                 dup2(nextout, 1);
1750                                 close(nextout);
1751                         }
1752                         if (pipefds[0]!=-1) {
1753                                 close(pipefds[0]);  /* opposite end of our output pipe */
1754                         }
1755
1756                         /* Like bash, explicit redirects override pipes,
1757                          * and the pipe fd is available for dup'ing. */
1758                         setup_redirects(child,NULL);
1759
1760                         if (interactive && pi->followup!=PIPE_BG) {
1761                                 /* If we (the child) win the race, put ourselves in the process
1762                                  * group whose leader is the first process in this pipe. */
1763                                 if (pi->pgrp < 0) {
1764                                         pi->pgrp = getpid();
1765                                 }
1766                                 if (setpgid(0, pi->pgrp) == 0) {
1767                                         tcsetpgrp(2, pi->pgrp);
1768                                 }
1769                         }
1770
1771                         pseudo_exec(child);
1772                 }
1773
1774
1775                 /* put our child in the process group whose leader is the
1776                    first process in this pipe */
1777                 if (pi->pgrp < 0) {
1778                         pi->pgrp = child->pid;
1779                 }
1780                 /* Don't check for errors.  The child may be dead already,
1781                  * in which case setpgid returns error code EACCES. */
1782                 setpgid(child->pid, pi->pgrp);
1783
1784                 if (nextin != 0)
1785                         close(nextin);
1786                 if (nextout != 1)
1787                         close(nextout);
1788
1789                 /* If there isn't another process, nextin is garbage
1790                    but it doesn't matter */
1791                 nextin = pipefds[0];
1792         }
1793 #endif
1794         return -1;
1795 }
1796
1797 static int run_list_real(struct pipe *pi)
1798 {
1799         char *save_name = NULL;
1800         char **list = NULL;
1801         char **save_list = NULL;
1802         struct pipe *rpipe;
1803         int flag_rep = 0;
1804 #ifndef __U_BOOT__
1805         int save_num_progs;
1806 #endif
1807         int rcode=0, flag_skip=1;
1808         int flag_restore = 0;
1809         int if_code=0, next_if_code=0;  /* need double-buffer to handle elif */
1810         reserved_style rmode, skip_more_in_this_rmode=RES_XXXX;
1811         /* check syntax for "for" */
1812         for (rpipe = pi; rpipe; rpipe = rpipe->next) {
1813                 if ((rpipe->r_mode == RES_IN ||
1814                     rpipe->r_mode == RES_FOR) &&
1815                     (rpipe->next == NULL)) {
1816                                 syntax();
1817 #ifdef __U_BOOT__
1818                                 flag_repeat = 0;
1819 #endif
1820                                 return 1;
1821                 }
1822                 if ((rpipe->r_mode == RES_IN &&
1823                         (rpipe->next->r_mode == RES_IN &&
1824                         rpipe->next->progs->argv != NULL))||
1825                         (rpipe->r_mode == RES_FOR &&
1826                         rpipe->next->r_mode != RES_IN)) {
1827                                 syntax();
1828 #ifdef __U_BOOT__
1829                                 flag_repeat = 0;
1830 #endif
1831                                 return 1;
1832                 }
1833         }
1834         for (; pi; pi = (flag_restore != 0) ? rpipe : pi->next) {
1835                 if (pi->r_mode == RES_WHILE || pi->r_mode == RES_UNTIL ||
1836                         pi->r_mode == RES_FOR) {
1837 #ifdef __U_BOOT__
1838                                 /* check Ctrl-C */
1839                                 ctrlc();
1840                                 if ((had_ctrlc())) {
1841                                         return 1;
1842                                 }
1843 #endif
1844                                 flag_restore = 0;
1845                                 if (!rpipe) {
1846                                         flag_rep = 0;
1847                                         rpipe = pi;
1848                                 }
1849                 }
1850                 rmode = pi->r_mode;
1851                 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);
1852                 if (rmode == skip_more_in_this_rmode && flag_skip) {
1853                         if (pi->followup == PIPE_SEQ) flag_skip=0;
1854                         continue;
1855                 }
1856                 flag_skip = 1;
1857                 skip_more_in_this_rmode = RES_XXXX;
1858                 if (rmode == RES_THEN || rmode == RES_ELSE) if_code = next_if_code;
1859                 if (rmode == RES_THEN &&  if_code) continue;
1860                 if (rmode == RES_ELSE && !if_code) continue;
1861                 if (rmode == RES_ELIF && !if_code) break;
1862                 if (rmode == RES_FOR && pi->num_progs) {
1863                         if (!list) {
1864                                 /* if no variable values after "in" we skip "for" */
1865                                 if (!pi->next->progs->argv) continue;
1866                                 /* create list of variable values */
1867                                 list = make_list_in(pi->next->progs->argv,
1868                                         pi->progs->argv[0]);
1869                                 save_list = list;
1870                                 save_name = pi->progs->argv[0];
1871                                 pi->progs->argv[0] = NULL;
1872                                 flag_rep = 1;
1873                         }
1874                         if (!(*list)) {
1875                                 free(pi->progs->argv[0]);
1876                                 free(save_list);
1877                                 list = NULL;
1878                                 flag_rep = 0;
1879                                 pi->progs->argv[0] = save_name;
1880 #ifndef __U_BOOT__
1881                                 pi->progs->glob_result.gl_pathv[0] =
1882                                         pi->progs->argv[0];
1883 #endif
1884                                 continue;
1885                         } else {
1886                                 /* insert new value from list for variable */
1887                                 if (pi->progs->argv[0])
1888                                         free(pi->progs->argv[0]);
1889                                 pi->progs->argv[0] = *list++;
1890 #ifndef __U_BOOT__
1891                                 pi->progs->glob_result.gl_pathv[0] =
1892                                         pi->progs->argv[0];
1893 #endif
1894                         }
1895                 }
1896                 if (rmode == RES_IN) continue;
1897                 if (rmode == RES_DO) {
1898                         if (!flag_rep) continue;
1899                 }
1900                 if ((rmode == RES_DONE)) {
1901                         if (flag_rep) {
1902                                 flag_restore = 1;
1903                         } else {
1904                                 rpipe = NULL;
1905                         }
1906                 }
1907                 if (pi->num_progs == 0) continue;
1908 #ifndef __U_BOOT__
1909                 save_num_progs = pi->num_progs; /* save number of programs */
1910 #endif
1911                 rcode = run_pipe_real(pi);
1912                 debug_printf("run_pipe_real returned %d\n",rcode);
1913 #ifndef __U_BOOT__
1914                 if (rcode!=-1) {
1915                         /* We only ran a builtin: rcode was set by the return value
1916                          * of run_pipe_real(), and we don't need to wait for anything. */
1917                 } else if (pi->followup==PIPE_BG) {
1918                         /* XXX check bash's behavior with nontrivial pipes */
1919                         /* XXX compute jobid */
1920                         /* XXX what does bash do with attempts to background builtins? */
1921                         insert_bg_job(pi);
1922                         rcode = EXIT_SUCCESS;
1923                 } else {
1924                         if (interactive) {
1925                                 /* move the new process group into the foreground */
1926                                 if (tcsetpgrp(shell_terminal, pi->pgrp) && errno != ENOTTY)
1927                                         perror_msg("tcsetpgrp-3");
1928                                 rcode = checkjobs(pi);
1929                                 /* move the shell to the foreground */
1930                                 if (tcsetpgrp(shell_terminal, getpgid(0)) && errno != ENOTTY)
1931                                         perror_msg("tcsetpgrp-4");
1932                         } else {
1933                                 rcode = checkjobs(pi);
1934                         }
1935                         debug_printf("checkjobs returned %d\n",rcode);
1936                 }
1937                 last_return_code=rcode;
1938 #else
1939                 if (rcode < -1) {
1940                         last_return_code = -rcode - 2;
1941                         return -2;      /* exit */
1942                 }
1943                 last_return_code=(rcode == 0) ? 0 : 1;
1944 #endif
1945 #ifndef __U_BOOT__
1946                 pi->num_progs = save_num_progs; /* restore number of programs */
1947 #endif
1948                 if ( rmode == RES_IF || rmode == RES_ELIF )
1949                         next_if_code=rcode;  /* can be overwritten a number of times */
1950                 if (rmode == RES_WHILE)
1951                         flag_rep = !last_return_code;
1952                 if (rmode == RES_UNTIL)
1953                         flag_rep = last_return_code;
1954                 if ( (rcode==EXIT_SUCCESS && pi->followup==PIPE_OR) ||
1955                      (rcode!=EXIT_SUCCESS && pi->followup==PIPE_AND) )
1956                         skip_more_in_this_rmode=rmode;
1957 #ifndef __U_BOOT__
1958                 checkjobs(NULL);
1959 #endif
1960         }
1961         return rcode;
1962 }
1963
1964 /* broken, of course, but OK for testing */
1965 static char *indenter(int i)
1966 {
1967         static char blanks[]="                                    ";
1968         return &blanks[sizeof(blanks)-i-1];
1969 }
1970
1971 /* return code is the exit status of the pipe */
1972 static int free_pipe(struct pipe *pi, int indent)
1973 {
1974         char **p;
1975         struct child_prog *child;
1976 #ifndef __U_BOOT__
1977         struct redir_struct *r, *rnext;
1978 #endif
1979         int a, i, ret_code=0;
1980         char *ind = indenter(indent);
1981
1982 #ifndef __U_BOOT__
1983         if (pi->stopped_progs > 0)
1984                 return ret_code;
1985         final_printf("%s run pipe: (pid %d)\n",ind,getpid());
1986 #endif
1987         for (i=0; i<pi->num_progs; i++) {
1988                 child = &pi->progs[i];
1989                 final_printf("%s  command %d:\n",ind,i);
1990                 if (child->argv) {
1991                         for (a=0,p=child->argv; *p; a++,p++) {
1992                                 final_printf("%s   argv[%d] = %s\n",ind,a,*p);
1993                         }
1994 #ifndef __U_BOOT__
1995                         globfree(&child->glob_result);
1996 #else
1997                         for (a = 0; a < child->argc; a++) {
1998                                 free(child->argv[a]);
1999                         }
2000                                         free(child->argv);
2001                         child->argc = 0;
2002 #endif
2003                         child->argv=NULL;
2004                 } else if (child->group) {
2005 #ifndef __U_BOOT__
2006                         final_printf("%s   begin group (subshell:%d)\n",ind, child->subshell);
2007 #endif
2008                         ret_code = free_pipe_list(child->group,indent+3);
2009                         final_printf("%s   end group\n",ind);
2010                 } else {
2011                         final_printf("%s   (nil)\n",ind);
2012                 }
2013 #ifndef __U_BOOT__
2014                 for (r=child->redirects; r; r=rnext) {
2015                         final_printf("%s   redirect %d%s", ind, r->fd, redir_table[r->type].descrip);
2016                         if (r->dup == -1) {
2017                                 /* guard against the case >$FOO, where foo is unset or blank */
2018                                 if (r->word.gl_pathv) {
2019                                         final_printf(" %s\n", *r->word.gl_pathv);
2020                                         globfree(&r->word);
2021                                 }
2022                         } else {
2023                                 final_printf("&%d\n", r->dup);
2024                         }
2025                         rnext=r->next;
2026                         free(r);
2027                 }
2028                 child->redirects=NULL;
2029 #endif
2030         }
2031         free(pi->progs);   /* children are an array, they get freed all at once */
2032         pi->progs=NULL;
2033         return ret_code;
2034 }
2035
2036 static int free_pipe_list(struct pipe *head, int indent)
2037 {
2038         int rcode=0;   /* if list has no members */
2039         struct pipe *pi, *next;
2040         char *ind = indenter(indent);
2041         for (pi=head; pi; pi=next) {
2042                 final_printf("%s pipe reserved mode %d\n", ind, pi->r_mode);
2043                 rcode = free_pipe(pi, indent);
2044                 final_printf("%s pipe followup code %d\n", ind, pi->followup);
2045                 next=pi->next;
2046                 pi->next=NULL;
2047                 free(pi);
2048         }
2049         return rcode;
2050 }
2051
2052 /* Select which version we will use */
2053 static int run_list(struct pipe *pi)
2054 {
2055         int rcode=0;
2056 #ifndef __U_BOOT__
2057         if (fake_mode==0) {
2058 #endif
2059                 rcode = run_list_real(pi);
2060 #ifndef __U_BOOT__
2061         }
2062 #endif
2063         /* free_pipe_list has the side effect of clearing memory
2064          * In the long run that function can be merged with run_list_real,
2065          * but doing that now would hobble the debugging effort. */
2066         free_pipe_list(pi,0);
2067         return rcode;
2068 }
2069
2070 /* The API for glob is arguably broken.  This routine pushes a non-matching
2071  * string into the output structure, removing non-backslashed backslashes.
2072  * If someone can prove me wrong, by performing this function within the
2073  * original glob(3) api, feel free to rewrite this routine into oblivion.
2074  * Return code (0 vs. GLOB_NOSPACE) matches glob(3).
2075  * XXX broken if the last character is '\\', check that before calling.
2076  */
2077 #ifndef __U_BOOT__
2078 static int globhack(const char *src, int flags, glob_t *pglob)
2079 {
2080         int cnt=0, pathc;
2081         const char *s;
2082         char *dest;
2083         for (cnt=1, s=src; s && *s; s++) {
2084                 if (*s == '\\') s++;
2085                 cnt++;
2086         }
2087         dest = malloc(cnt);
2088         if (!dest) return GLOB_NOSPACE;
2089         if (!(flags & GLOB_APPEND)) {
2090                 pglob->gl_pathv=NULL;
2091                 pglob->gl_pathc=0;
2092                 pglob->gl_offs=0;
2093                 pglob->gl_offs=0;
2094         }
2095         pathc = ++pglob->gl_pathc;
2096         pglob->gl_pathv = realloc(pglob->gl_pathv, (pathc+1)*sizeof(*pglob->gl_pathv));
2097         if (pglob->gl_pathv == NULL) return GLOB_NOSPACE;
2098         pglob->gl_pathv[pathc-1]=dest;
2099         pglob->gl_pathv[pathc]=NULL;
2100         for (s=src; s && *s; s++, dest++) {
2101                 if (*s == '\\') s++;
2102                 *dest = *s;
2103         }
2104         *dest='\0';
2105         return 0;
2106 }
2107
2108 /* XXX broken if the last character is '\\', check that before calling */
2109 static int glob_needed(const char *s)
2110 {
2111         for (; *s; s++) {
2112                 if (*s == '\\') s++;
2113                 if (strchr("*[?",*s)) return 1;
2114         }
2115         return 0;
2116 }
2117
2118 #if 0
2119 static void globprint(glob_t *pglob)
2120 {
2121         int i;
2122         debug_printf("glob_t at %p:\n", pglob);
2123         debug_printf("  gl_pathc=%d  gl_pathv=%p  gl_offs=%d  gl_flags=%d\n",
2124                 pglob->gl_pathc, pglob->gl_pathv, pglob->gl_offs, pglob->gl_flags);
2125         for (i=0; i<pglob->gl_pathc; i++)
2126                 debug_printf("pglob->gl_pathv[%d] = %p = %s\n", i,
2127                         pglob->gl_pathv[i], pglob->gl_pathv[i]);
2128 }
2129 #endif
2130
2131 static int xglob(o_string *dest, int flags, glob_t *pglob)
2132 {
2133         int gr;
2134
2135         /* short-circuit for null word */
2136         /* we can code this better when the debug_printf's are gone */
2137         if (dest->length == 0) {
2138                 if (dest->nonnull) {
2139                         /* bash man page calls this an "explicit" null */
2140                         gr = globhack(dest->data, flags, pglob);
2141                         debug_printf("globhack returned %d\n",gr);
2142                 } else {
2143                         return 0;
2144                 }
2145         } else if (glob_needed(dest->data)) {
2146                 gr = glob(dest->data, flags, NULL, pglob);
2147                 debug_printf("glob returned %d\n",gr);
2148                 if (gr == GLOB_NOMATCH) {
2149                         /* quote removal, or more accurately, backslash removal */
2150                         gr = globhack(dest->data, flags, pglob);
2151                         debug_printf("globhack returned %d\n",gr);
2152                 }
2153         } else {
2154                 gr = globhack(dest->data, flags, pglob);
2155                 debug_printf("globhack returned %d\n",gr);
2156         }
2157         if (gr == GLOB_NOSPACE)
2158                 error_msg_and_die("out of memory during glob");
2159         if (gr != 0) { /* GLOB_ABORTED ? */
2160                 error_msg("glob(3) error %d",gr);
2161         }
2162         /* globprint(glob_target); */
2163         return gr;
2164 }
2165 #endif
2166
2167 #ifdef __U_BOOT__
2168 static char *get_dollar_var(char ch);
2169 #endif
2170
2171 /* This is used to get/check local shell variables */
2172 static char *get_local_var(const char *s)
2173 {
2174         struct variables *cur;
2175
2176         if (!s)
2177                 return NULL;
2178
2179 #ifdef __U_BOOT__
2180         if (*s == '$')
2181                 return get_dollar_var(s[1]);
2182 #endif
2183
2184         for (cur = top_vars; cur; cur=cur->next)
2185                 if(strcmp(cur->name, s)==0)
2186                         return cur->value;
2187         return NULL;
2188 }
2189
2190 /* This is used to set local shell variables
2191    flg_export==0 if only local (not exporting) variable
2192    flg_export==1 if "new" exporting environ
2193    flg_export>1  if current startup environ (not call putenv()) */
2194 int set_local_var(const char *s, int flg_export)
2195 {
2196         char *name, *value;
2197         int result=0;
2198         struct variables *cur;
2199
2200 #ifdef __U_BOOT__
2201         /* might be possible! */
2202         if (!isalpha(*s))
2203                 return -1;
2204 #endif
2205
2206         name=strdup(s);
2207
2208 #ifdef __U_BOOT__
2209         if (getenv(name) != NULL) {
2210                 printf ("ERROR: "
2211                                 "There is a global environment variable with the same name.\n");
2212                 free(name);
2213                 return -1;
2214         }
2215 #endif
2216         /* Assume when we enter this function that we are already in
2217          * NAME=VALUE format.  So the first order of business is to
2218          * split 's' on the '=' into 'name' and 'value' */
2219         value = strchr(name, '=');
2220         if (value==0 && ++value==0) {
2221                 free(name);
2222                 return -1;
2223         }
2224         *value++ = 0;
2225
2226         for(cur = top_vars; cur; cur = cur->next) {
2227                 if(strcmp(cur->name, name)==0)
2228                         break;
2229         }
2230
2231         if(cur) {
2232                 if(strcmp(cur->value, value)==0) {
2233                         if(flg_export>0 && cur->flg_export==0)
2234                                 cur->flg_export=flg_export;
2235                         else
2236                                 result++;
2237                 } else {
2238                         if(cur->flg_read_only) {
2239                                 error_msg("%s: readonly variable", name);
2240                                 result = -1;
2241                         } else {
2242                                 if(flg_export>0 || cur->flg_export>1)
2243                                         cur->flg_export=1;
2244                                 free(cur->value);
2245
2246                                 cur->value = strdup(value);
2247                         }
2248                 }
2249         } else {
2250                 cur = malloc(sizeof(struct variables));
2251                 if(!cur) {
2252                         result = -1;
2253                 } else {
2254                         cur->name = strdup(name);
2255                         if(cur->name == 0) {
2256                                 free(cur);
2257                                 result = -1;
2258                         } else {
2259                                 struct variables *bottom = top_vars;
2260                                 cur->value = strdup(value);
2261                                 cur->next = 0;
2262                                 cur->flg_export = flg_export;
2263                                 cur->flg_read_only = 0;
2264                                 while(bottom->next) bottom=bottom->next;
2265                                 bottom->next = cur;
2266                         }
2267                 }
2268         }
2269
2270 #ifndef __U_BOOT__
2271         if(result==0 && cur->flg_export==1) {
2272                 *(value-1) = '=';
2273                 result = putenv(name);
2274         } else {
2275 #endif
2276                 free(name);
2277 #ifndef __U_BOOT__
2278                 if(result>0)            /* equivalent to previous set */
2279                         result = 0;
2280         }
2281 #endif
2282         return result;
2283 }
2284
2285 void unset_local_var(const char *name)
2286 {
2287         struct variables *cur;
2288
2289         if (name) {
2290                 for (cur = top_vars; cur; cur=cur->next) {
2291                         if(strcmp(cur->name, name)==0)
2292                                 break;
2293                 }
2294                 if(cur!=0) {
2295                         struct variables *next = top_vars;
2296                         if(cur->flg_read_only) {
2297                                 error_msg("%s: readonly variable", name);
2298                                 return;
2299                         } else {
2300 #ifndef __U_BOOT__
2301                                 if(cur->flg_export)
2302                                         unsetenv(cur->name);
2303 #endif
2304                                 free(cur->name);
2305                                 free(cur->value);
2306                                 while (next->next != cur)
2307                                         next = next->next;
2308                                 next->next = cur->next;
2309                         }
2310                         free(cur);
2311                 }
2312         }
2313 }
2314
2315 static int is_assignment(const char *s)
2316 {
2317         if (s == NULL)
2318                 return 0;
2319
2320         if (!isalpha(*s)) return 0;
2321         ++s;
2322         while(isalnum(*s) || *s=='_') ++s;
2323         return *s=='=';
2324 }
2325
2326 #ifndef __U_BOOT__
2327 /* the src parameter allows us to peek forward to a possible &n syntax
2328  * for file descriptor duplication, e.g., "2>&1".
2329  * Return code is 0 normally, 1 if a syntax error is detected in src.
2330  * Resource errors (in xmalloc) cause the process to exit */
2331 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2332         struct in_str *input)
2333 {
2334         struct child_prog *child=ctx->child;
2335         struct redir_struct *redir = child->redirects;
2336         struct redir_struct *last_redir=NULL;
2337
2338         /* Create a new redir_struct and drop it onto the end of the linked list */
2339         while(redir) {
2340                 last_redir=redir;
2341                 redir=redir->next;
2342         }
2343         redir = xmalloc(sizeof(struct redir_struct));
2344         redir->next=NULL;
2345         redir->word.gl_pathv=NULL;
2346         if (last_redir) {
2347                 last_redir->next=redir;
2348         } else {
2349                 child->redirects=redir;
2350         }
2351
2352         redir->type=style;
2353         redir->fd= (fd==-1) ? redir_table[style].default_fd : fd ;
2354
2355         debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2356
2357         /* Check for a '2>&1' type redirect */
2358         redir->dup = redirect_dup_num(input);
2359         if (redir->dup == -2) return 1;  /* syntax error */
2360         if (redir->dup != -1) {
2361                 /* Erik had a check here that the file descriptor in question
2362                  * is legit; I postpone that to "run time"
2363                  * A "-" representation of "close me" shows up as a -3 here */
2364                 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2365         } else {
2366                 /* We do _not_ try to open the file that src points to,
2367                  * since we need to return and let src be expanded first.
2368                  * Set ctx->pending_redirect, so we know what to do at the
2369                  * end of the next parsed word.
2370                  */
2371                 ctx->pending_redirect = redir;
2372         }
2373         return 0;
2374 }
2375 #endif
2376
2377 struct pipe *new_pipe(void) {
2378         struct pipe *pi;
2379         pi = xmalloc(sizeof(struct pipe));
2380         pi->num_progs = 0;
2381         pi->progs = NULL;
2382         pi->next = NULL;
2383         pi->followup = 0;  /* invalid */
2384         pi->r_mode = RES_NONE;
2385         return pi;
2386 }
2387
2388 static void initialize_context(struct p_context *ctx)
2389 {
2390         ctx->pipe=NULL;
2391 #ifndef __U_BOOT__
2392         ctx->pending_redirect=NULL;
2393 #endif
2394         ctx->child=NULL;
2395         ctx->list_head=new_pipe();
2396         ctx->pipe=ctx->list_head;
2397         ctx->w=RES_NONE;
2398         ctx->stack=NULL;
2399 #ifdef __U_BOOT__
2400         ctx->old_flag=0;
2401 #endif
2402         done_command(ctx);   /* creates the memory for working child */
2403 }
2404
2405 /* normal return is 0
2406  * if a reserved word is found, and processed, return 1
2407  * should handle if, then, elif, else, fi, for, while, until, do, done.
2408  * case, function, and select are obnoxious, save those for later.
2409  */
2410 struct reserved_combo {
2411         char *literal;
2412         int code;
2413         long flag;
2414 };
2415 /* Mostly a list of accepted follow-up reserved words.
2416  * FLAG_END means we are done with the sequence, and are ready
2417  * to turn the compound list into a command.
2418  * FLAG_START means the word must start a new compound list.
2419  */
2420 static struct reserved_combo reserved_list[] = {
2421         { "if",    RES_IF,    FLAG_THEN | FLAG_START },
2422         { "then",  RES_THEN,  FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2423         { "elif",  RES_ELIF,  FLAG_THEN },
2424         { "else",  RES_ELSE,  FLAG_FI   },
2425         { "fi",    RES_FI,    FLAG_END  },
2426         { "for",   RES_FOR,   FLAG_IN   | FLAG_START },
2427         { "while", RES_WHILE, FLAG_DO   | FLAG_START },
2428         { "until", RES_UNTIL, FLAG_DO   | FLAG_START },
2429         { "in",    RES_IN,    FLAG_DO   },
2430         { "do",    RES_DO,    FLAG_DONE },
2431         { "done",  RES_DONE,  FLAG_END  }
2432 };
2433 #define NRES (sizeof(reserved_list)/sizeof(struct reserved_combo))
2434
2435 int reserved_word(o_string *dest, struct p_context *ctx)
2436 {
2437         struct reserved_combo *r;
2438         for (r=reserved_list;
2439                 r<reserved_list+NRES; r++) {
2440                 if (strcmp(dest->data, r->literal) == 0) {
2441                         debug_printf("found reserved word %s, code %d\n",r->literal,r->code);
2442                         if (r->flag & FLAG_START) {
2443                                 struct p_context *new = xmalloc(sizeof(struct p_context));
2444                                 debug_printf("push stack\n");
2445                                 if (ctx->w == RES_IN || ctx->w == RES_FOR) {
2446                                         syntax();
2447                                         free(new);
2448                                         ctx->w = RES_SNTX;
2449                                         b_reset(dest);
2450                                         return 1;
2451                                 }
2452                                 *new = *ctx;   /* physical copy */
2453                                 initialize_context(ctx);
2454                                 ctx->stack=new;
2455                         } else if ( ctx->w == RES_NONE || ! (ctx->old_flag & (1<<r->code))) {
2456                                 syntax();
2457                                 ctx->w = RES_SNTX;
2458                                 b_reset(dest);
2459                                 return 1;
2460                         }
2461                         ctx->w=r->code;
2462                         ctx->old_flag = r->flag;
2463                         if (ctx->old_flag & FLAG_END) {
2464                                 struct p_context *old;
2465                                 debug_printf("pop stack\n");
2466                                 done_pipe(ctx,PIPE_SEQ);
2467                                 old = ctx->stack;
2468                                 old->child->group = ctx->list_head;
2469 #ifndef __U_BOOT__
2470                                 old->child->subshell = 0;
2471 #endif
2472                                 *ctx = *old;   /* physical copy */
2473                                 free(old);
2474                         }
2475                         b_reset (dest);
2476                         return 1;
2477                 }
2478         }
2479         return 0;
2480 }
2481
2482 /* normal return is 0.
2483  * Syntax or xglob errors return 1. */
2484 static int done_word(o_string *dest, struct p_context *ctx)
2485 {
2486         struct child_prog *child=ctx->child;
2487 #ifndef __U_BOOT__
2488         glob_t *glob_target;
2489         int gr, flags = 0;
2490 #else
2491         char *str, *s;
2492         int argc, cnt;
2493 #endif
2494
2495         debug_printf("done_word: %s %p\n", dest->data, child);
2496         if (dest->length == 0 && !dest->nonnull) {
2497                 debug_printf("  true null, ignored\n");
2498                 return 0;
2499         }
2500 #ifndef __U_BOOT__
2501         if (ctx->pending_redirect) {
2502                 glob_target = &ctx->pending_redirect->word;
2503         } else {
2504 #endif
2505                 if (child->group) {
2506                         syntax();
2507                         return 1;  /* syntax error, groups and arglists don't mix */
2508                 }
2509                 if (!child->argv && (ctx->type & FLAG_PARSE_SEMICOLON)) {
2510                         debug_printf("checking %s for reserved-ness\n",dest->data);
2511                         if (reserved_word(dest,ctx)) return ctx->w==RES_SNTX;
2512                 }
2513 #ifndef __U_BOOT__
2514                 glob_target = &child->glob_result;
2515                 if (child->argv) flags |= GLOB_APPEND;
2516 #else
2517                 for (cnt = 1, s = dest->data; s && *s; s++) {
2518                         if (*s == '\\') s++;
2519                         cnt++;
2520                 }
2521                 str = malloc(cnt);
2522                 if (!str) return 1;
2523                 if ( child->argv == NULL) {
2524                         child->argc=0;
2525                 }
2526                 argc = ++child->argc;
2527                 child->argv = realloc(child->argv, (argc+1)*sizeof(*child->argv));
2528                 if (child->argv == NULL) return 1;
2529                 child->argv[argc-1]=str;
2530                 child->argv[argc]=NULL;
2531                 for (s = dest->data; s && *s; s++,str++) {
2532                         if (*s == '\\') s++;
2533                         *str = *s;
2534                 }
2535                 *str = '\0';
2536 #endif
2537 #ifndef __U_BOOT__
2538         }
2539         gr = xglob(dest, flags, glob_target);
2540         if (gr != 0) return 1;
2541 #endif
2542
2543         b_reset(dest);
2544 #ifndef __U_BOOT__
2545         if (ctx->pending_redirect) {
2546                 ctx->pending_redirect=NULL;
2547                 if (glob_target->gl_pathc != 1) {
2548                         error_msg("ambiguous redirect");
2549                         return 1;
2550                 }
2551         } else {
2552                 child->argv = glob_target->gl_pathv;
2553         }
2554 #endif
2555         if (ctx->w == RES_FOR) {
2556                 done_word(dest,ctx);
2557                 done_pipe(ctx,PIPE_SEQ);
2558         }
2559         return 0;
2560 }
2561
2562 /* The only possible error here is out of memory, in which case
2563  * xmalloc exits. */
2564 static int done_command(struct p_context *ctx)
2565 {
2566         /* The child is really already in the pipe structure, so
2567          * advance the pipe counter and make a new, null child.
2568          * Only real trickiness here is that the uncommitted
2569          * child structure, to which ctx->child points, is not
2570          * counted in pi->num_progs. */
2571         struct pipe *pi=ctx->pipe;
2572         struct child_prog *prog=ctx->child;
2573
2574         if (prog && prog->group == NULL
2575                  && prog->argv == NULL
2576 #ifndef __U_BOOT__
2577                  && prog->redirects == NULL) {
2578 #else
2579                                                                                 ) {
2580 #endif
2581                 debug_printf("done_command: skipping null command\n");
2582                 return 0;
2583         } else if (prog) {
2584                 pi->num_progs++;
2585                 debug_printf("done_command: num_progs incremented to %d\n",pi->num_progs);
2586         } else {
2587                 debug_printf("done_command: initializing\n");
2588         }
2589         pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2590
2591         prog = pi->progs + pi->num_progs;
2592 #ifndef __U_BOOT__
2593         prog->redirects = NULL;
2594 #endif
2595         prog->argv = NULL;
2596 #ifndef __U_BOOT__
2597         prog->is_stopped = 0;
2598 #endif
2599         prog->group = NULL;
2600 #ifndef __U_BOOT__
2601         prog->glob_result.gl_pathv = NULL;
2602         prog->family = pi;
2603 #endif
2604         prog->sp = 0;
2605         ctx->child = prog;
2606         prog->type = ctx->type;
2607
2608         /* but ctx->pipe and ctx->list_head remain unchanged */
2609         return 0;
2610 }
2611
2612 static int done_pipe(struct p_context *ctx, pipe_style type)
2613 {
2614         struct pipe *new_p;
2615         done_command(ctx);  /* implicit closure of previous command */
2616         debug_printf("done_pipe, type %d\n", type);
2617         ctx->pipe->followup = type;
2618         ctx->pipe->r_mode = ctx->w;
2619         new_p=new_pipe();
2620         ctx->pipe->next = new_p;
2621         ctx->pipe = new_p;
2622         ctx->child = NULL;
2623         done_command(ctx);  /* set up new pipe to accept commands */
2624         return 0;
2625 }
2626
2627 #ifndef __U_BOOT__
2628 /* peek ahead in the in_str to find out if we have a "&n" construct,
2629  * as in "2>&1", that represents duplicating a file descriptor.
2630  * returns either -2 (syntax error), -1 (no &), or the number found.
2631  */
2632 static int redirect_dup_num(struct in_str *input)
2633 {
2634         int ch, d=0, ok=0;
2635         ch = b_peek(input);
2636         if (ch != '&') return -1;
2637
2638         b_getch(input);  /* get the & */
2639         ch=b_peek(input);
2640         if (ch == '-') {
2641                 b_getch(input);
2642                 return -3;  /* "-" represents "close me" */
2643         }
2644         while (isdigit(ch)) {
2645                 d = d*10+(ch-'0');
2646                 ok=1;
2647                 b_getch(input);
2648                 ch = b_peek(input);
2649         }
2650         if (ok) return d;
2651
2652         error_msg("ambiguous redirect");
2653         return -2;
2654 }
2655
2656 /* If a redirect is immediately preceded by a number, that number is
2657  * supposed to tell which file descriptor to redirect.  This routine
2658  * looks for such preceding numbers.  In an ideal world this routine
2659  * needs to handle all the following classes of redirects...
2660  *     echo 2>foo     # redirects fd  2 to file "foo", nothing passed to echo
2661  *     echo 49>foo    # redirects fd 49 to file "foo", nothing passed to echo
2662  *     echo -2>foo    # redirects fd  1 to file "foo",    "-2" passed to echo
2663  *     echo 49x>foo   # redirects fd  1 to file "foo",   "49x" passed to echo
2664  * A -1 output from this program means no valid number was found, so the
2665  * caller should use the appropriate default for this redirection.
2666  */
2667 static int redirect_opt_num(o_string *o)
2668 {
2669         int num;
2670
2671         if (o->length==0) return -1;
2672         for(num=0; num<o->length; num++) {
2673                 if (!isdigit(*(o->data+num))) {
2674                         return -1;
2675                 }
2676         }
2677         /* reuse num (and save an int) */
2678         num=atoi(o->data);
2679         b_reset(o);
2680         return num;
2681 }
2682
2683 FILE *generate_stream_from_list(struct pipe *head)
2684 {
2685         FILE *pf;
2686 #if 1
2687         int pid, channel[2];
2688         if (pipe(channel)<0) perror_msg_and_die("pipe");
2689         pid=fork();
2690         if (pid<0) {
2691                 perror_msg_and_die("fork");
2692         } else if (pid==0) {
2693                 close(channel[0]);
2694                 if (channel[1] != 1) {
2695                         dup2(channel[1],1);
2696                         close(channel[1]);
2697                 }
2698 #if 0
2699 #define SURROGATE "surrogate response"
2700                 write(1,SURROGATE,sizeof(SURROGATE));
2701                 _exit(run_list(head));
2702 #else
2703                 _exit(run_list_real(head));   /* leaks memory */
2704 #endif
2705         }
2706         debug_printf("forked child %d\n",pid);
2707         close(channel[1]);
2708         pf = fdopen(channel[0],"r");
2709         debug_printf("pipe on FILE *%p\n",pf);
2710 #else
2711         free_pipe_list(head,0);
2712         pf=popen("echo surrogate response","r");
2713         debug_printf("started fake pipe on FILE *%p\n",pf);
2714 #endif
2715         return pf;
2716 }
2717
2718 /* this version hacked for testing purposes */
2719 /* return code is exit status of the process that is run. */
2720 static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, int subst_end)
2721 {
2722         int retcode;
2723         o_string result=NULL_O_STRING;
2724         struct p_context inner;
2725         FILE *p;
2726         struct in_str pipe_str;
2727         initialize_context(&inner);
2728
2729         /* recursion to generate command */
2730         retcode = parse_stream(&result, &inner, input, subst_end);
2731         if (retcode != 0) return retcode;  /* syntax error or EOF */
2732         done_word(&result, &inner);
2733         done_pipe(&inner, PIPE_SEQ);
2734         b_free(&result);
2735
2736         p=generate_stream_from_list(inner.list_head);
2737         if (p==NULL) return 1;
2738         mark_open(fileno(p));
2739         setup_file_in_str(&pipe_str, p);
2740
2741         /* now send results of command back into original context */
2742         retcode = parse_stream(dest, ctx, &pipe_str, '\0');
2743         /* XXX In case of a syntax error, should we try to kill the child?
2744          * That would be tough to do right, so just read until EOF. */
2745         if (retcode == 1) {
2746                 while (b_getch(&pipe_str)!=EOF) { /* discard */ };
2747         }
2748
2749         debug_printf("done reading from pipe, pclose()ing\n");
2750         /* This is the step that wait()s for the child.  Should be pretty
2751          * safe, since we just read an EOF from its stdout.  We could try
2752          * to better, by using wait(), and keeping track of background jobs
2753          * at the same time.  That would be a lot of work, and contrary
2754          * to the KISS philosophy of this program. */
2755         mark_closed(fileno(p));
2756         retcode=pclose(p);
2757         free_pipe_list(inner.list_head,0);
2758         debug_printf("pclosed, retcode=%d\n",retcode);
2759         /* XXX this process fails to trim a single trailing newline */
2760         return retcode;
2761 }
2762
2763 static int parse_group(o_string *dest, struct p_context *ctx,
2764         struct in_str *input, int ch)
2765 {
2766         int rcode, endch=0;
2767         struct p_context sub;
2768         struct child_prog *child = ctx->child;
2769         if (child->argv) {
2770                 syntax();
2771                 return 1;  /* syntax error, groups and arglists don't mix */
2772         }
2773         initialize_context(&sub);
2774         switch(ch) {
2775                 case '(': endch=')'; child->subshell=1; break;
2776                 case '{': endch='}'; break;
2777                 default: syntax();   /* really logic error */
2778         }
2779         rcode=parse_stream(dest,&sub,input,endch);
2780         done_word(dest,&sub); /* finish off the final word in the subcontext */
2781         done_pipe(&sub, PIPE_SEQ);  /* and the final command there, too */
2782         child->group = sub.list_head;
2783         return rcode;
2784         /* child remains "open", available for possible redirects */
2785 }
2786 #endif
2787
2788 /* basically useful version until someone wants to get fancier,
2789  * see the bash man page under "Parameter Expansion" */
2790 static char *lookup_param(char *src)
2791 {
2792         char *p;
2793
2794         if (!src)
2795                 return NULL;
2796
2797                 p = getenv(src);
2798                 if (!p)
2799                         p = get_local_var(src);
2800
2801         return p;
2802 }
2803
2804 #ifdef __U_BOOT__
2805 static char *get_dollar_var(char ch)
2806 {
2807         static char buf[40];
2808
2809         buf[0] = '\0';
2810         switch (ch) {
2811                 case '?':
2812                         sprintf(buf, "%u", (unsigned int)last_return_code);
2813                         break;
2814                 default:
2815                         return NULL;
2816         }
2817         return buf;
2818 }
2819 #endif
2820
2821 /* return code: 0 for OK, 1 for syntax error */
2822 static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input)
2823 {
2824 #ifndef __U_BOOT__
2825         int i, advance=0;
2826 #else
2827         int advance=0;
2828 #endif
2829 #ifndef __U_BOOT__
2830         char sep[]=" ";
2831 #endif
2832         int ch = input->peek(input);  /* first character after the $ */
2833         debug_printf("handle_dollar: ch=%c\n",ch);
2834         if (isalpha(ch)) {
2835                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2836                 ctx->child->sp++;
2837                 while(ch=b_peek(input),isalnum(ch) || ch=='_') {
2838                         b_getch(input);
2839                         b_addchr(dest,ch);
2840                 }
2841                 b_addchr(dest, SPECIAL_VAR_SYMBOL);
2842 #ifndef __U_BOOT__
2843         } else if (isdigit(ch)) {
2844                 i = ch-'0';  /* XXX is $0 special? */
2845                 if (i<global_argc) {
2846                         parse_string(dest, ctx, global_argv[i]); /* recursion */
2847                 }
2848                 advance = 1;
2849 #endif
2850         } else switch (ch) {
2851 #ifndef __U_BOOT__
2852                 case '$':
2853                         b_adduint(dest,getpid());
2854                         advance = 1;
2855                         break;
2856                 case '!':
2857                         if (last_bg_pid > 0) b_adduint(dest, last_bg_pid);
2858                         advance = 1;
2859                         break;
2860 #endif
2861                 case '?':
2862 #ifndef __U_BOOT__
2863                         b_adduint(dest,last_return_code);
2864 #else
2865                         ctx->child->sp++;
2866                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2867                         b_addchr(dest, '$');
2868                         b_addchr(dest, '?');
2869                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2870 #endif
2871                         advance = 1;
2872                         break;
2873 #ifndef __U_BOOT__
2874                 case '#':
2875                         b_adduint(dest,global_argc ? global_argc-1 : 0);
2876                         advance = 1;
2877                         break;
2878 #endif
2879                 case '{':
2880                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2881                         ctx->child->sp++;
2882                         b_getch(input);
2883                         /* XXX maybe someone will try to escape the '}' */
2884                         while(ch=b_getch(input),ch!=EOF && ch!='}') {
2885                                 b_addchr(dest,ch);
2886                         }
2887                         if (ch != '}') {
2888                                 syntax();
2889                                 return 1;
2890                         }
2891                         b_addchr(dest, SPECIAL_VAR_SYMBOL);
2892                         break;
2893 #ifndef __U_BOOT__
2894                 case '(':
2895                         b_getch(input);
2896                         process_command_subs(dest, ctx, input, ')');
2897                         break;
2898                 case '*':
2899                         sep[0]=ifs[0];
2900                         for (i=1; i<global_argc; i++) {
2901                                 parse_string(dest, ctx, global_argv[i]);
2902                                 if (i+1 < global_argc) parse_string(dest, ctx, sep);
2903                         }
2904                         break;
2905                 case '@':
2906                 case '-':
2907                 case '_':
2908                         /* still unhandled, but should be eventually */
2909                         error_msg("unhandled syntax: $%c",ch);
2910                         return 1;
2911                         break;
2912 #endif
2913                 default:
2914                         b_addqchr(dest,'$',dest->quote);
2915         }
2916         /* Eat the character if the flag was set.  If the compiler
2917          * is smart enough, we could substitute "b_getch(input);"
2918          * for all the "advance = 1;" above, and also end up with
2919          * a nice size-optimized program.  Hah!  That'll be the day.
2920          */
2921         if (advance) b_getch(input);
2922         return 0;
2923 }
2924
2925 #ifndef __U_BOOT__
2926 int parse_string(o_string *dest, struct p_context *ctx, const char *src)
2927 {
2928         struct in_str foo;
2929         setup_string_in_str(&foo, src);
2930         return parse_stream(dest, ctx, &foo, '\0');
2931 }
2932 #endif
2933
2934 /* return code is 0 for normal exit, 1 for syntax error */
2935 int parse_stream(o_string *dest, struct p_context *ctx,
2936         struct in_str *input, int end_trigger)
2937 {
2938         unsigned int ch, m;
2939 #ifndef __U_BOOT__
2940         int redir_fd;
2941         redir_type redir_style;
2942 #endif
2943         int next;
2944
2945         /* Only double-quote state is handled in the state variable dest->quote.
2946          * A single-quote triggers a bypass of the main loop until its mate is
2947          * found.  When recursing, quote state is passed in via dest->quote. */
2948
2949         debug_printf("parse_stream, end_trigger=%d\n",end_trigger);
2950         while ((ch=b_getch(input))!=EOF) {
2951                 m = map[ch];
2952 #ifdef __U_BOOT__
2953                 if (input->__promptme == 0) return 1;
2954 #endif
2955                 next = (ch == '\n') ? 0 : b_peek(input);
2956
2957                 debug_printf("parse_stream: ch=%c (%d) m=%d quote=%d - %c\n",
2958                         ch >= ' ' ? ch : '.', ch, m,
2959                         dest->quote, ctx->stack == NULL ? '*' : '.');
2960
2961                 if (m==0 || ((m==1 || m==2) && dest->quote)) {
2962                         b_addqchr(dest, ch, dest->quote);
2963                 } else {
2964                         if (m==2) {  /* unquoted IFS */
2965                                 if (done_word(dest, ctx)) {
2966                                         return 1;
2967                                 }
2968                                 /* If we aren't performing a substitution, treat a newline as a
2969                                  * command separator.  */
2970                                 if (end_trigger != '\0' && ch=='\n')
2971                                         done_pipe(ctx,PIPE_SEQ);
2972                         }
2973                         if (ch == end_trigger && !dest->quote && ctx->w==RES_NONE) {
2974                                 debug_printf("leaving parse_stream (triggered)\n");
2975                                 return 0;
2976                         }
2977 #if 0
2978                         if (ch=='\n') {
2979                                 /* Yahoo!  Time to run with it! */
2980                                 done_pipe(ctx,PIPE_SEQ);
2981                                 run_list(ctx->list_head);
2982                                 initialize_context(ctx);
2983                         }
2984 #endif
2985                         if (m!=2) switch (ch) {
2986                 case '#':
2987                         if (dest->length == 0 && !dest->quote) {
2988                                 while(ch=b_peek(input),ch!=EOF && ch!='\n') { b_getch(input); }
2989                         } else {
2990                                 b_addqchr(dest, ch, dest->quote);
2991                         }
2992                         break;
2993                 case '\\':
2994                         if (next == EOF) {
2995                                 syntax();
2996                                 return 1;
2997                         }
2998                         b_addqchr(dest, '\\', dest->quote);
2999                         b_addqchr(dest, b_getch(input), dest->quote);
3000                         break;
3001                 case '$':
3002                         if (handle_dollar(dest, ctx, input)!=0) return 1;
3003                         break;
3004                 case '\'':
3005                         dest->nonnull = 1;
3006                         while(ch=b_getch(input),ch!=EOF && ch!='\'') {
3007 #ifdef __U_BOOT__
3008                                 if(input->__promptme == 0) return 1;
3009 #endif
3010                                 b_addchr(dest,ch);
3011                         }
3012                         if (ch==EOF) {
3013                                 syntax();
3014                                 return 1;
3015                         }
3016                         break;
3017                 case '"':
3018                         dest->nonnull = 1;
3019                         dest->quote = !dest->quote;
3020                         break;
3021 #ifndef __U_BOOT__
3022                 case '`':
3023                         process_command_subs(dest, ctx, input, '`');
3024                         break;
3025                 case '>':
3026                         redir_fd = redirect_opt_num(dest);
3027                         done_word(dest, ctx);
3028                         redir_style=REDIRECT_OVERWRITE;
3029                         if (next == '>') {
3030                                 redir_style=REDIRECT_APPEND;
3031                                 b_getch(input);
3032                         } else if (next == '(') {
3033                                 syntax();   /* until we support >(list) Process Substitution */
3034                                 return 1;
3035                         }
3036                         setup_redirect(ctx, redir_fd, redir_style, input);
3037                         break;
3038                 case '<':
3039                         redir_fd = redirect_opt_num(dest);
3040                         done_word(dest, ctx);
3041                         redir_style=REDIRECT_INPUT;
3042                         if (next == '<') {
3043                                 redir_style=REDIRECT_HEREIS;
3044                                 b_getch(input);
3045                         } else if (next == '>') {
3046                                 redir_style=REDIRECT_IO;
3047                                 b_getch(input);
3048                         } else if (next == '(') {
3049                                 syntax();   /* until we support <(list) Process Substitution */
3050                                 return 1;
3051                         }
3052                         setup_redirect(ctx, redir_fd, redir_style, input);
3053                         break;
3054 #endif
3055                 case ';':
3056                         done_word(dest, ctx);
3057                         done_pipe(ctx,PIPE_SEQ);
3058                         break;
3059                 case '&':
3060                         done_word(dest, ctx);
3061                         if (next=='&') {
3062                                 b_getch(input);
3063                                 done_pipe(ctx,PIPE_AND);
3064                         } else {
3065 #ifndef __U_BOOT__
3066                                 done_pipe(ctx,PIPE_BG);
3067 #else
3068                                 syntax_err();
3069                                 return 1;
3070 #endif
3071                         }
3072                         break;
3073                 case '|':
3074                         done_word(dest, ctx);
3075                         if (next=='|') {
3076                                 b_getch(input);
3077                                 done_pipe(ctx,PIPE_OR);
3078                         } else {
3079                                 /* we could pick up a file descriptor choice here
3080                                  * with redirect_opt_num(), but bash doesn't do it.
3081                                  * "echo foo 2| cat" yields "foo 2". */
3082 #ifndef __U_BOOT__
3083                                 done_command(ctx);
3084 #else
3085                                 syntax_err();
3086                                 return 1;
3087 #endif
3088                         }
3089                         break;
3090 #ifndef __U_BOOT__
3091                 case '(':
3092                 case '{':
3093                         if (parse_group(dest, ctx, input, ch)!=0) return 1;
3094                         break;
3095                 case ')':
3096                 case '}':
3097                         syntax();   /* Proper use of this character caught by end_trigger */
3098                         return 1;
3099                         break;
3100 #endif
3101                 default:
3102                         syntax();   /* this is really an internal logic error */
3103                         return 1;
3104                         }
3105                 }
3106         }
3107         /* complain if quote?  No, maybe we just finished a command substitution
3108          * that was quoted.  Example:
3109          * $ echo "`cat foo` plus more"
3110          * and we just got the EOF generated by the subshell that ran "cat foo"
3111          * The only real complaint is if we got an EOF when end_trigger != '\0',
3112          * that is, we were really supposed to get end_trigger, and never got
3113          * one before the EOF.  Can't use the standard "syntax error" return code,
3114          * so that parse_stream_outer can distinguish the EOF and exit smoothly. */
3115         debug_printf("leaving parse_stream (EOF)\n");
3116         if (end_trigger != '\0') return -1;
3117         return 0;
3118 }
3119
3120 void mapset(const unsigned char *set, int code)
3121 {
3122         const unsigned char *s;
3123         for (s=set; *s; s++) map[*s] = code;
3124 }
3125
3126 void update_ifs_map(void)
3127 {
3128         /* char *ifs and char map[256] are both globals. */
3129         ifs = (uchar *)getenv("IFS");
3130         if (ifs == NULL) ifs=(uchar *)" \t\n";
3131         /* Precompute a list of 'flow through' behavior so it can be treated
3132          * quickly up front.  Computation is necessary because of IFS.
3133          * Special case handling of IFS == " \t\n" is not implemented.
3134          * The map[] array only really needs two bits each, and on most machines
3135          * that would be faster because of the reduced L1 cache footprint.
3136          */
3137         memset(map,0,sizeof(map)); /* most characters flow through always */
3138 #ifndef __U_BOOT__
3139         mapset((uchar *)"\\$'\"`", 3);      /* never flow through */
3140         mapset((uchar *)"<>;&|(){}#", 1);   /* flow through if quoted */
3141 #else
3142         mapset((uchar *)"\\$'\"", 3);       /* never flow through */
3143         mapset((uchar *)";&|#", 1);         /* flow through if quoted */
3144 #endif
3145         mapset(ifs, 2);            /* also flow through if quoted */
3146 }
3147
3148 /* most recursion does not come through here, the exeception is
3149  * from builtin_source() */
3150 int parse_stream_outer(struct in_str *inp, int flag)
3151 {
3152
3153         struct p_context ctx;
3154         o_string temp=NULL_O_STRING;
3155         int rcode;
3156 #ifdef __U_BOOT__
3157         int code = 0;
3158 #endif
3159         do {
3160                 ctx.type = flag;
3161                 initialize_context(&ctx);
3162                 update_ifs_map();
3163                 if (!(flag & FLAG_PARSE_SEMICOLON) || (flag & FLAG_REPARSING)) mapset((uchar *)";$&|", 0);
3164                 inp->promptmode=1;
3165                 rcode = parse_stream(&temp, &ctx, inp, '\n');
3166 #ifdef __U_BOOT__
3167                 if (rcode == 1) flag_repeat = 0;
3168 #endif
3169                 if (rcode != 1 && ctx.old_flag != 0) {
3170                         syntax();
3171 #ifdef __U_BOOT__
3172                         flag_repeat = 0;
3173 #endif
3174                 }
3175                 if (rcode != 1 && ctx.old_flag == 0) {
3176                         done_word(&temp, &ctx);
3177                         done_pipe(&ctx,PIPE_SEQ);
3178 #ifndef __U_BOOT__
3179                         run_list(ctx.list_head);
3180 #else
3181                         code = run_list(ctx.list_head);
3182                         if (code == -2) {       /* exit */
3183                                 b_free(&temp);
3184                                 code = 0;
3185                                 /* XXX hackish way to not allow exit from main loop */
3186                                 if (inp->peek == file_peek) {
3187                                         printf("exit not allowed from main input shell.\n");
3188                                         continue;
3189                                 }
3190                                 break;
3191                         }
3192                         if (code == -1)
3193                             flag_repeat = 0;
3194 #endif
3195                 } else {
3196                         if (ctx.old_flag != 0) {
3197                                 free(ctx.stack);
3198                                 b_reset(&temp);
3199                         }
3200 #ifdef __U_BOOT__
3201                         if (inp->__promptme == 0) printf("<INTERRUPT>\n");
3202                         inp->__promptme = 1;
3203 #endif
3204                         temp.nonnull = 0;
3205                         temp.quote = 0;
3206                         inp->p = NULL;
3207                         free_pipe_list(ctx.list_head,0);
3208                 }
3209                 b_free(&temp);
3210         } while (rcode != -1 && !(flag & FLAG_EXIT_FROM_LOOP));   /* loop on syntax errors, return on EOF */
3211 #ifndef __U_BOOT__
3212         return 0;
3213 #else
3214         return (code != 0) ? 1 : 0;
3215 #endif /* __U_BOOT__ */
3216 }
3217
3218 #ifndef __U_BOOT__
3219 static int parse_string_outer(const char *s, int flag)
3220 #else
3221 int parse_string_outer(char *s, int flag)
3222 #endif  /* __U_BOOT__ */
3223 {
3224         struct in_str input;
3225 #ifdef __U_BOOT__
3226         char *p = NULL;
3227         int rcode;
3228         if ( !s || !*s)
3229                 return 1;
3230         if (!(p = strchr(s, '\n')) || *++p) {
3231                 p = xmalloc(strlen(s) + 2);
3232                 strcpy(p, s);
3233                 strcat(p, "\n");
3234                 setup_string_in_str(&input, p);
3235                 rcode = parse_stream_outer(&input, flag);
3236                 free(p);
3237                 return rcode;
3238         } else {
3239 #endif
3240         setup_string_in_str(&input, s);
3241         return parse_stream_outer(&input, flag);
3242 #ifdef __U_BOOT__
3243         }
3244 #endif
3245 }
3246
3247 #ifndef __U_BOOT__
3248 static int parse_file_outer(FILE *f)
3249 #else
3250 int parse_file_outer(void)
3251 #endif
3252 {
3253         int rcode;
3254         struct in_str input;
3255 #ifndef __U_BOOT__
3256         setup_file_in_str(&input, f);
3257 #else
3258         setup_file_in_str(&input);
3259 #endif
3260         rcode = parse_stream_outer(&input, FLAG_PARSE_SEMICOLON);
3261         return rcode;
3262 }
3263
3264 #ifdef __U_BOOT__
3265 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3266 static void u_boot_hush_reloc(void)
3267 {
3268         unsigned long addr;
3269         struct reserved_combo *r;
3270
3271         for (r=reserved_list; r<reserved_list+NRES; r++) {
3272                 addr = (ulong) (r->literal) + gd->reloc_off;
3273                 r->literal = (char *)addr;
3274         }
3275 }
3276 #endif
3277
3278 int u_boot_hush_start(void)
3279 {
3280         if (top_vars == NULL) {
3281                 top_vars = malloc(sizeof(struct variables));
3282                 top_vars->name = "HUSH_VERSION";
3283                 top_vars->value = "0.01";
3284                 top_vars->next = 0;
3285                 top_vars->flg_export = 0;
3286                 top_vars->flg_read_only = 1;
3287 #ifdef CONFIG_NEEDS_MANUAL_RELOC
3288                 u_boot_hush_reloc();
3289 #endif
3290         }
3291         return 0;
3292 }
3293
3294 static void *xmalloc(size_t size)
3295 {
3296         void *p = NULL;
3297
3298         if (!(p = malloc(size))) {
3299             printf("ERROR : memory not allocated\n");
3300             for(;;);
3301         }
3302         return p;
3303 }
3304
3305 static void *xrealloc(void *ptr, size_t size)
3306 {
3307         void *p = NULL;
3308
3309         if (!(p = realloc(ptr, size))) {
3310             printf("ERROR : memory not allocated\n");
3311             for(;;);
3312         }
3313         return p;
3314 }
3315 #endif /* __U_BOOT__ */
3316
3317 #ifndef __U_BOOT__
3318 /* Make sure we have a controlling tty.  If we get started under a job
3319  * aware app (like bash for example), make sure we are now in charge so
3320  * we don't fight over who gets the foreground */
3321 static void setup_job_control(void)
3322 {
3323         static pid_t shell_pgrp;
3324         /* Loop until we are in the foreground.  */
3325         while (tcgetpgrp (shell_terminal) != (shell_pgrp = getpgrp ()))
3326                 kill (- shell_pgrp, SIGTTIN);
3327
3328         /* Ignore interactive and job-control signals.  */
3329         signal(SIGINT, SIG_IGN);
3330         signal(SIGQUIT, SIG_IGN);
3331         signal(SIGTERM, SIG_IGN);
3332         signal(SIGTSTP, SIG_IGN);
3333         signal(SIGTTIN, SIG_IGN);
3334         signal(SIGTTOU, SIG_IGN);
3335         signal(SIGCHLD, SIG_IGN);
3336
3337         /* Put ourselves in our own process group.  */
3338         setsid();
3339         shell_pgrp = getpid ();
3340         setpgid (shell_pgrp, shell_pgrp);
3341
3342         /* Grab control of the terminal.  */
3343         tcsetpgrp(shell_terminal, shell_pgrp);
3344 }
3345
3346 int hush_main(int argc, char * const *argv)
3347 {
3348         int opt;
3349         FILE *input;
3350         char **e = environ;
3351
3352         /* XXX what should these be while sourcing /etc/profile? */
3353         global_argc = argc;
3354         global_argv = argv;
3355
3356         /* (re?) initialize globals.  Sometimes hush_main() ends up calling
3357          * hush_main(), therefore we cannot rely on the BSS to zero out this
3358          * stuff.  Reset these to 0 every time. */
3359         ifs = NULL;
3360         /* map[] is taken care of with call to update_ifs_map() */
3361         fake_mode = 0;
3362         interactive = 0;
3363         close_me_head = NULL;
3364         last_bg_pid = 0;
3365         job_list = NULL;
3366         last_jobid = 0;
3367
3368         /* Initialize some more globals to non-zero values */
3369         set_cwd();
3370 #ifdef CONFIG_FEATURE_COMMAND_EDITING
3371         cmdedit_set_initial_prompt();
3372 #else
3373         PS1 = NULL;
3374 #endif
3375         PS2 = "> ";
3376
3377         /* initialize our shell local variables with the values
3378          * currently living in the environment */
3379         if (e) {
3380                 for (; *e; e++)
3381                         set_local_var(*e, 2);   /* without call putenv() */
3382         }
3383
3384         last_return_code=EXIT_SUCCESS;
3385
3386
3387         if (argv[0] && argv[0][0] == '-') {
3388                 debug_printf("\nsourcing /etc/profile\n");
3389                 if ((input = fopen("/etc/profile", "r")) != NULL) {
3390                         mark_open(fileno(input));
3391                         parse_file_outer(input);
3392                         mark_closed(fileno(input));
3393                         fclose(input);
3394                 }
3395         }
3396         input=stdin;
3397
3398         while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3399                 switch (opt) {
3400                         case 'c':
3401                                 {
3402                                         global_argv = argv+optind;
3403                                         global_argc = argc-optind;
3404                                         opt = parse_string_outer(optarg, FLAG_PARSE_SEMICOLON);
3405                                         goto final_return;
3406                                 }
3407                                 break;
3408                         case 'i':
3409                                 interactive++;
3410                                 break;
3411                         case 'f':
3412                                 fake_mode++;
3413                                 break;
3414                         default:
3415 #ifndef BB_VER
3416                                 fprintf(stderr, "Usage: sh [FILE]...\n"
3417                                                 "   or: sh -c command [args]...\n\n");
3418                                 exit(EXIT_FAILURE);
3419 #else
3420                                 show_usage();
3421 #endif
3422                 }
3423         }
3424         /* A shell is interactive if the `-i' flag was given, or if all of
3425          * the following conditions are met:
3426          *        no -c command
3427          *    no arguments remaining or the -s flag given
3428          *    standard input is a terminal
3429          *    standard output is a terminal
3430          *    Refer to Posix.2, the description of the `sh' utility. */
3431         if (argv[optind]==NULL && input==stdin &&
3432                         isatty(fileno(stdin)) && isatty(fileno(stdout))) {
3433                 interactive++;
3434         }
3435
3436         debug_printf("\ninteractive=%d\n", interactive);
3437         if (interactive) {
3438                 /* Looks like they want an interactive shell */
3439 #ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
3440                 printf( "\n\n" BB_BANNER " hush - the humble shell v0.01 (testing)\n");
3441                 printf( "Enter 'help' for a list of built-in commands.\n\n");
3442 #endif
3443                 setup_job_control();
3444         }
3445
3446         if (argv[optind]==NULL) {
3447                 opt=parse_file_outer(stdin);
3448                 goto final_return;
3449         }
3450
3451         debug_printf("\nrunning script '%s'\n", argv[optind]);
3452         global_argv = argv+optind;
3453         global_argc = argc-optind;
3454         input = xfopen(argv[optind], "r");
3455         opt = parse_file_outer(input);
3456
3457 #ifdef CONFIG_FEATURE_CLEAN_UP
3458         fclose(input);
3459         if (cwd && cwd != unknown)
3460                 free((char*)cwd);
3461         {
3462                 struct variables *cur, *tmp;
3463                 for(cur = top_vars; cur; cur = tmp) {
3464                         tmp = cur->next;
3465                         if (!cur->flg_read_only) {
3466                                 free(cur->name);
3467                                 free(cur->value);
3468                                 free(cur);
3469                         }
3470                 }
3471         }
3472 #endif
3473
3474 final_return:
3475         return(opt?opt:last_return_code);
3476 }
3477 #endif
3478
3479 static char *insert_var_value(char *inp)
3480 {
3481         int res_str_len = 0;
3482         int len;
3483         int done = 0;
3484         char *p, *p1, *res_str = NULL;
3485
3486         while ((p = strchr(inp, SPECIAL_VAR_SYMBOL))) {
3487                 if (p != inp) {
3488                         len = p - inp;
3489                         res_str = xrealloc(res_str, (res_str_len + len));
3490                         strncpy((res_str + res_str_len), inp, len);
3491                         res_str_len += len;
3492                 }
3493                 inp = ++p;
3494                 p = strchr(inp, SPECIAL_VAR_SYMBOL);
3495                 *p = '\0';
3496                 if ((p1 = lookup_param(inp))) {
3497                         len = res_str_len + strlen(p1);
3498                         res_str = xrealloc(res_str, (1 + len));
3499                         strcpy((res_str + res_str_len), p1);
3500                         res_str_len = len;
3501                 }
3502                 *p = SPECIAL_VAR_SYMBOL;
3503                 inp = ++p;
3504                 done = 1;
3505         }
3506         if (done) {
3507                 res_str = xrealloc(res_str, (1 + res_str_len + strlen(inp)));
3508                 strcpy((res_str + res_str_len), inp);
3509                 while ((p = strchr(res_str, '\n'))) {
3510                         *p = ' ';
3511                 }
3512         }
3513         return (res_str == NULL) ? inp : res_str;
3514 }
3515
3516 static char **make_list_in(char **inp, char *name)
3517 {
3518         int len, i;
3519         int name_len = strlen(name);
3520         int n = 0;
3521         char **list;
3522         char *p1, *p2, *p3;
3523
3524         /* create list of variable values */
3525         list = xmalloc(sizeof(*list));
3526         for (i = 0; inp[i]; i++) {
3527                 p3 = insert_var_value(inp[i]);
3528                 p1 = p3;
3529                 while (*p1) {
3530                         if ((*p1 == ' ')) {
3531                                 p1++;
3532                                 continue;
3533                         }
3534                         if ((p2 = strchr(p1, ' '))) {
3535                                 len = p2 - p1;
3536                         } else {
3537                                 len = strlen(p1);
3538                                 p2 = p1 + len;
3539                         }
3540                         /* we use n + 2 in realloc for list,because we add
3541                          * new element and then we will add NULL element */
3542                         list = xrealloc(list, sizeof(*list) * (n + 2));
3543                         list[n] = xmalloc(2 + name_len + len);
3544                         strcpy(list[n], name);
3545                         strcat(list[n], "=");
3546                         strncat(list[n], p1, len);
3547                         list[n++][name_len + len + 1] = '\0';
3548                         p1 = p2;
3549                 }
3550                 if (p3 != inp[i]) free(p3);
3551         }
3552         list[n] = NULL;
3553         return list;
3554 }
3555
3556 /* Make new string for parser */
3557 static char * make_string(char ** inp)
3558 {
3559         char *p;
3560         char *str = NULL;
3561         int n;
3562         int len = 2;
3563
3564         for (n = 0; inp[n]; n++) {
3565                 p = insert_var_value(inp[n]);
3566                 str = xrealloc(str, (len + strlen(p)));
3567                 if (n) {
3568                         strcat(str, " ");
3569                 } else {
3570                         *str = '\0';
3571                 }
3572                 strcat(str, p);
3573                 len = strlen(str) + 3;
3574                 if (p != inp[n]) free(p);
3575         }
3576         len = strlen(str);
3577         *(str + len) = '\n';
3578         *(str + len + 1) = '\0';
3579         return str;
3580 }
3581
3582 #ifdef __U_BOOT__
3583 int do_showvar (cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
3584 {
3585         int i, k;
3586         int rcode = 0;
3587         struct variables *cur;
3588
3589         if (argc == 1) {                /* Print all env variables      */
3590                 for (cur = top_vars; cur; cur = cur->next) {
3591                         printf ("%s=%s\n", cur->name, cur->value);
3592                         if (ctrlc ()) {
3593                                 puts ("\n ** Abort\n");
3594                                 return 1;
3595                         }
3596                 }
3597                 return 0;
3598         }
3599         for (i = 1; i < argc; ++i) {    /* print single env variables   */
3600                 char *name = argv[i];
3601
3602                 k = -1;
3603                 for (cur = top_vars; cur; cur = cur->next) {
3604                         if(strcmp (cur->name, name) == 0) {
3605                                 k = 0;
3606                                 printf ("%s=%s\n", cur->name, cur->value);
3607                         }
3608                         if (ctrlc ()) {
3609                                 puts ("\n ** Abort\n");
3610                                 return 1;
3611                         }
3612                 }
3613                 if (k < 0) {
3614                         printf ("## Error: \"%s\" not defined\n", name);
3615                         rcode ++;
3616                 }
3617         }
3618         return rcode;
3619 }
3620
3621 U_BOOT_CMD(
3622         showvar, CONFIG_SYS_MAXARGS, 1, do_showvar,
3623         "print local hushshell variables",
3624         "\n    - print values of all hushshell variables\n"
3625         "showvar name ...\n"
3626         "    - print value of hushshell variable 'name'"
3627 );
3628
3629 #endif
3630 /****************************************************************************/