common/hush.c

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