1/* vi: set sw=4 ts=4: */ 2/* 3 * sh.c -- a prototype Bourne shell grammar parser 4 * Intended to follow the original Thompson and Ritchie 5 * "small and simple is beautiful" philosophy, which 6 * incidentally is a good match to today's BusyBox. 7 * 8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org> 9 * 10 * Credits: 11 * The parser routines proper are all original material, first 12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The 13 * execution engine, the builtins, and much of the underlying 14 * support has been adapted from busybox-0.49pre's lash, which is 15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> 16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn, 17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W. 18 * Troan, which they placed in the public domain. I don't know 19 * how much of the Johnson/Troan code has survived the repeated 20 * rewrites. 21 * 22 * Other credits: 23 * b_addchr() derived from similar w_addchar function in glibc-2.2 24 * setup_redirect(), redirect_opt_num(), and big chunks of main() 25 * and many builtins derived from contributions by Erik Andersen 26 * miscellaneous bugfixes from Matt Kraai 27 * 28 * There are two big (and related) architecture differences between 29 * this parser and the lash parser. One is that this version is 30 * actually designed from the ground up to understand nearly all 31 * of the Bourne grammar. The second, consequential change is that 32 * the parser and input reader have been turned inside out. Now, 33 * the parser is in control, and asks for input as needed. The old 34 * way had the input reader in control, and it asked for parsing to 35 * take place as needed. The new way makes it much easier to properly 36 * handle the recursion implicit in the various substitutions, especially 37 * across continuation lines. 38 * 39 * Bash grammar not implemented: (how many of these were in original sh?) 40 * $_ 41 * ! negation operator for pipes 42 * &> and >& redirection of stdout+stderr 43 * Brace Expansion 44 * Tilde Expansion 45 * fancy forms of Parameter Expansion 46 * aliases 47 * Arithmetic Expansion 48 * <(list) and >(list) Process Substitution 49 * reserved words: case, esac, select, function 50 * Here Documents ( << word ) 51 * Functions 52 * Major bugs: 53 * job handling woefully incomplete and buggy (improved --vda) 54 * reserved word execution woefully incomplete and buggy 55 * to-do: 56 * port selected bugfixes from post-0.49 busybox lash - done? 57 * finish implementing reserved words: for, while, until, do, done 58 * change { and } from special chars to reserved words 59 * builtins: break, continue, eval, return, set, trap, ulimit 60 * test magic exec 61 * handle children going into background 62 * clean up recognition of null pipes 63 * check setting of global_argc and global_argv 64 * control-C handling, probably with longjmp 65 * follow IFS rules more precisely, including update semantics 66 * figure out what to do with backslash-newline 67 * explain why we use signal instead of sigaction 68 * propagate syntax errors, die on resource errors? 69 * continuation lines, both explicit and implicit - done? 70 * memory leak finding and plugging - done? 71 * more testing, especially quoting rules and redirection 72 * document how quoting rules not precisely followed for variable assignments 73 * maybe change charmap[] to use 2-bit entries 74 * (eventually) remove all the printf's 75 * 76 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. 77 */ 78 79 80#include <glob.h> /* glob, of course */ 81#include <getopt.h> /* should be pretty obvious */ 82/* #include <dmalloc.h> */ 83 84extern char **environ; /* This is in <unistd.h>, but protected with __USE_GNU */ 85 86#include "busybox.h" /* for struct bb_applet */ 87 88 89/* If you comment out one of these below, it will be #defined later 90 * to perform debug printfs to stderr: */ 91#define debug_printf(...) do {} while (0) 92/* Finer-grained debug switches */ 93#define debug_printf_parse(...) do {} while (0) 94#define debug_print_tree(a, b) do {} while (0) 95#define debug_printf_exec(...) do {} while (0) 96#define debug_printf_jobs(...) do {} while (0) 97#define debug_printf_expand(...) do {} while (0) 98#define debug_printf_clean(...) do {} while (0) 99 100#ifndef debug_printf 101#define debug_printf(...) fprintf(stderr, __VA_ARGS__) 102#endif 103 104#ifndef debug_printf_parse 105#define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__) 106#endif 107 108#ifndef debug_printf_exec 109#define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__) 110#endif 111 112#ifndef debug_printf_jobs 113#define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__) 114#define DEBUG_SHELL_JOBS 1 115#endif 116 117#ifndef debug_printf_expand 118#define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__) 119#define DEBUG_EXPAND 1 120#endif 121 122/* Keep unconditionally on for now */ 123#define ENABLE_HUSH_DEBUG 1 124 125#ifndef debug_printf_clean 126/* broken, of course, but OK for testing */ 127static const char *indenter(int i) 128{ 129 static const char blanks[] ALIGN1 = 130 " "; 131 return &blanks[sizeof(blanks) - i - 1]; 132} 133#define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__) 134#define DEBUG_CLEAN 1 135#endif 136 137 138#if !ENABLE_HUSH_INTERACTIVE 139#undef ENABLE_FEATURE_EDITING 140#define ENABLE_FEATURE_EDITING 0 141#undef ENABLE_FEATURE_EDITING_FANCY_PROMPT 142#define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0 143#endif 144 145#define SPECIAL_VAR_SYMBOL 3 146 147#define PARSEFLAG_EXIT_FROM_LOOP 1 148#define PARSEFLAG_SEMICOLON (1 << 1) /* symbol ';' is special for parser */ 149#define PARSEFLAG_REPARSING (1 << 2) /* >= 2nd pass */ 150 151typedef enum { 152 REDIRECT_INPUT = 1, 153 REDIRECT_OVERWRITE = 2, 154 REDIRECT_APPEND = 3, 155 REDIRECT_HEREIS = 4, 156 REDIRECT_IO = 5 157} redir_type; 158 159/* The descrip member of this structure is only used to make debugging 160 * output pretty */ 161static const struct { 162 int mode; 163 signed char default_fd; 164 char descrip[3]; 165} redir_table[] = { 166 { 0, 0, "()" }, 167 { O_RDONLY, 0, "<" }, 168 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" }, 169 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" }, 170 { O_RDONLY, -1, "<<" }, 171 { O_RDWR, 1, "<>" } 172}; 173 174typedef enum { 175 PIPE_SEQ = 1, 176 PIPE_AND = 2, 177 PIPE_OR = 3, 178 PIPE_BG = 4, 179} pipe_style; 180 181/* might eventually control execution */ 182typedef enum { 183 RES_NONE = 0, 184#if ENABLE_HUSH_IF 185 RES_IF = 1, 186 RES_THEN = 2, 187 RES_ELIF = 3, 188 RES_ELSE = 4, 189 RES_FI = 5, 190#endif 191#if ENABLE_HUSH_LOOPS 192 RES_FOR = 6, 193 RES_WHILE = 7, 194 RES_UNTIL = 8, 195 RES_DO = 9, 196 RES_DONE = 10, 197 RES_IN = 11, 198#endif 199 RES_XXXX = 12, 200 RES_SNTX = 13 201} reserved_style; 202enum { 203 FLAG_END = (1 << RES_NONE ), 204#if ENABLE_HUSH_IF 205 FLAG_IF = (1 << RES_IF ), 206 FLAG_THEN = (1 << RES_THEN ), 207 FLAG_ELIF = (1 << RES_ELIF ), 208 FLAG_ELSE = (1 << RES_ELSE ), 209 FLAG_FI = (1 << RES_FI ), 210#endif 211#if ENABLE_HUSH_LOOPS 212 FLAG_FOR = (1 << RES_FOR ), 213 FLAG_WHILE = (1 << RES_WHILE), 214 FLAG_UNTIL = (1 << RES_UNTIL), 215 FLAG_DO = (1 << RES_DO ), 216 FLAG_DONE = (1 << RES_DONE ), 217 FLAG_IN = (1 << RES_IN ), 218#endif 219 FLAG_START = (1 << RES_XXXX ), 220}; 221 222/* This holds pointers to the various results of parsing */ 223struct p_context { 224 struct child_prog *child; 225 struct pipe *list_head; 226 struct pipe *pipe; 227 struct redir_struct *pending_redirect; 228 smallint res_w; 229 smallint parse_type; /* bitmask of PARSEFLAG_xxx, defines type of parser : ";$" common or special symbol */ 230 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */ 231 struct p_context *stack; 232 /* How about quoting status? */ 233}; 234 235struct redir_struct { 236 struct redir_struct *next; /* pointer to the next redirect in the list */ 237 redir_type type; /* type of redirection */ 238 int fd; /* file descriptor being redirected */ 239 int dup; /* -1, or file descriptor being duplicated */ 240 glob_t word; /* *word.gl_pathv is the filename */ 241}; 242 243struct child_prog { 244 pid_t pid; /* 0 if exited */ 245 char **argv; /* program name and arguments */ 246 struct pipe *group; /* if non-NULL, first in group or subshell */ 247 smallint subshell; /* flag, non-zero if group must be forked */ 248 smallint is_stopped; /* is the program currently running? */ 249 struct redir_struct *redirects; /* I/O redirections */ 250 glob_t glob_result; /* result of parameter globbing */ 251 struct pipe *family; /* pointer back to the child's parent pipe */ 252 //sp counting seems to be broken... so commented out, grep for '//sp:' 253 //sp: int sp; /* number of SPECIAL_VAR_SYMBOL */ 254 //seems to be unused, grep for '//pt:' 255 //pt: int parse_type; 256}; 257/* argv vector may contain variable references (^Cvar^C, ^C0^C etc) 258 * and on execution these are substituted with their values. 259 * Substitution can make _several_ words out of one argv[n]! 260 * Example: argv[0]=='.^C*^C.' here: echo .$*. 261 */ 262 263struct pipe { 264 struct pipe *next; 265 int num_progs; /* total number of programs in job */ 266 int running_progs; /* number of programs running (not exited) */ 267 int stopped_progs; /* number of programs alive, but stopped */ 268#if ENABLE_HUSH_JOB 269 int jobid; /* job number */ 270 pid_t pgrp; /* process group ID for the job */ 271 char *cmdtext; /* name of job */ 272#endif 273 char *cmdbuf; /* buffer various argv's point into */ 274 struct child_prog *progs; /* array of commands in pipe */ 275 int job_context; /* bitmask defining current context */ 276 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */ 277 smallint res_word; /* needed for if, for, while, until... */ 278}; 279 280struct close_me { 281 struct close_me *next; 282 int fd; 283}; 284 285/* On program start, environ points to initial environment. 286 * putenv adds new pointers into it, unsetenv removes them. 287 * Neither of these (de)allocates the strings. 288 * setenv allocates new strings in malloc space and does putenv, 289 * and thus setenv is unusable (leaky) for shell's purposes */ 290#define setenv(...) setenv_is_leaky_dont_use() 291struct variable { 292 struct variable *next; 293 char *varstr; /* points to "name=" portion */ 294 int max_len; /* if > 0, name is part of initial env; else name is malloced */ 295 smallint flg_export; /* putenv should be done on this var */ 296 smallint flg_read_only; 297}; 298 299typedef struct { 300 char *data; 301 int length; 302 int maxlen; 303 int quote; 304 int nonnull; 305} o_string; 306#define NULL_O_STRING {NULL,0,0,0,0} 307/* used for initialization: o_string foo = NULL_O_STRING; */ 308 309/* I can almost use ordinary FILE *. Is open_memstream() universally 310 * available? Where is it documented? */ 311struct in_str { 312 const char *p; 313 /* eof_flag=1: last char in ->p is really an EOF */ 314 char eof_flag; /* meaningless if ->p == NULL */ 315 char peek_buf[2]; 316#if ENABLE_HUSH_INTERACTIVE 317 smallint promptme; 318 smallint promptmode; /* 0: PS1, 1: PS2 */ 319#endif 320 FILE *file; 321 int (*get) (struct in_str *); 322 int (*peek) (struct in_str *); 323}; 324#define b_getch(input) ((input)->get(input)) 325#define b_peek(input) ((input)->peek(input)) 326 327enum { 328 CHAR_ORDINARY = 0, 329 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */ 330 CHAR_IFS = 2, /* treated as ordinary if quoted */ 331 CHAR_SPECIAL = 3, /* example: $ */ 332}; 333 334#define HUSH_VER_STR "0.02" 335 336/* "Globals" within this file */ 337 338/* Sorted roughly by size (smaller offsets == smaller code) */ 339struct globals { 340#if ENABLE_HUSH_INTERACTIVE 341 /* 'interactive_fd' is a fd# open to ctty, if we have one 342 * _AND_ if we decided to act interactively */ 343 int interactive_fd; 344 const char *PS1; 345 const char *PS2; 346#endif 347#if ENABLE_FEATURE_EDITING 348 line_input_t *line_input_state; 349#endif 350#if ENABLE_HUSH_JOB 351 int run_list_level; 352 pid_t saved_task_pgrp; 353 pid_t saved_tty_pgrp; 354 int last_jobid; 355 struct pipe *job_list; 356 struct pipe *toplevel_list; 357 smallint ctrl_z_flag; 358#endif 359 smallint fake_mode; 360 /* these three support $?, $#, and $1 */ 361 char **global_argv; 362 int global_argc; 363 int last_return_code; 364 const char *ifs; 365 struct close_me *close_me_head; 366 const char *cwd; 367 unsigned last_bg_pid; 368 struct variable *top_var; /* = &shell_ver (set in main()) */ 369 struct variable shell_ver; 370#if ENABLE_FEATURE_SH_STANDALONE 371 struct nofork_save_area nofork_save; 372#endif 373#if ENABLE_HUSH_JOB 374 sigjmp_buf toplevel_jb; 375#endif 376 unsigned char charmap[256]; 377 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2]; 378}; 379 380#define G (*ptr_to_globals) 381 382#if !ENABLE_HUSH_INTERACTIVE 383enum { interactive_fd = 0 }; 384#endif 385#if !ENABLE_HUSH_JOB 386enum { run_list_level = 0 }; 387#endif 388 389#if ENABLE_HUSH_INTERACTIVE 390#define interactive_fd (G.interactive_fd ) 391#define PS1 (G.PS1 ) 392#define PS2 (G.PS2 ) 393#endif 394#if ENABLE_FEATURE_EDITING 395#define line_input_state (G.line_input_state) 396#endif 397#if ENABLE_HUSH_JOB 398#define run_list_level (G.run_list_level ) 399#define saved_task_pgrp (G.saved_task_pgrp ) 400#define saved_tty_pgrp (G.saved_tty_pgrp ) 401#define last_jobid (G.last_jobid ) 402#define job_list (G.job_list ) 403#define toplevel_list (G.toplevel_list ) 404#define toplevel_jb (G.toplevel_jb ) 405#define ctrl_z_flag (G.ctrl_z_flag ) 406#endif /* JOB */ 407#define global_argv (G.global_argv ) 408#define global_argc (G.global_argc ) 409#define last_return_code (G.last_return_code) 410#define ifs (G.ifs ) 411#define fake_mode (G.fake_mode ) 412#define close_me_head (G.close_me_head ) 413#define cwd (G.cwd ) 414#define last_bg_pid (G.last_bg_pid ) 415#define top_var (G.top_var ) 416#define shell_ver (G.shell_ver ) 417#if ENABLE_FEATURE_SH_STANDALONE 418#define nofork_save (G.nofork_save ) 419#endif 420#if ENABLE_HUSH_JOB 421#define toplevel_jb (G.toplevel_jb ) 422#endif 423#define charmap (G.charmap ) 424#define user_input_buf (G.user_input_buf ) 425 426 427#define B_CHUNK 100 428#define B_NOSPAC 1 429#define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n" 430 431/* Normal */ 432static void syntax(const char *msg) 433{ 434 /* Was using fancy stuff: 435 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...) 436 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */ 437 void (*fp)(const char *s, ...); 438 439 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die); 440 fp(msg ? "%s: %s" : "syntax error", "syntax error", msg); 441} 442 443/* Index of subroutines: */ 444/* function prototypes for builtins */ 445static int builtin_cd(char **argv); 446static int builtin_eval(char **argv); 447static int builtin_exec(char **argv); 448static int builtin_exit(char **argv); 449static int builtin_export(char **argv); 450#if ENABLE_HUSH_JOB 451static int builtin_fg_bg(char **argv); 452static int builtin_jobs(char **argv); 453#endif 454#if ENABLE_HUSH_HELP 455static int builtin_help(char **argv); 456#endif 457static int builtin_pwd(char **argv); 458static int builtin_read(char **argv); 459static int builtin_set(char **argv); 460static int builtin_shift(char **argv); 461static int builtin_source(char **argv); 462static int builtin_umask(char **argv); 463static int builtin_unset(char **argv); 464//static int builtin_not_written(char **argv); 465/* o_string manipulation: */ 466static int b_check_space(o_string *o, int len); 467static int b_addchr(o_string *o, int ch); 468static void b_reset(o_string *o); 469static int b_addqchr(o_string *o, int ch, int quote); 470/* in_str manipulations: */ 471static int static_get(struct in_str *i); 472static int static_peek(struct in_str *i); 473static int file_get(struct in_str *i); 474static int file_peek(struct in_str *i); 475static void setup_file_in_str(struct in_str *i, FILE *f); 476static void setup_string_in_str(struct in_str *i, const char *s); 477/* close_me manipulations: */ 478static void mark_open(int fd); 479static void mark_closed(int fd); 480static void close_all(void); 481/* "run" the final data structures: */ 482#if !defined(DEBUG_CLEAN) 483#define free_pipe_list(head, indent) free_pipe_list(head) 484#define free_pipe(pi, indent) free_pipe(pi) 485#endif 486static int free_pipe_list(struct pipe *head, int indent); 487static int free_pipe(struct pipe *pi, int indent); 488/* really run the final data structures: */ 489static int setup_redirects(struct child_prog *prog, int squirrel[]); 490static int run_list_real(struct pipe *pi); 491static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN; 492static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN; 493static int run_pipe_real(struct pipe *pi); 494/* extended glob support: */ 495static int globhack(const char *src, int flags, glob_t *pglob); 496static int glob_needed(const char *s); 497static int xglob(o_string *dest, int flags, glob_t *pglob); 498/* variable assignment: */ 499static int is_assignment(const char *s); 500/* data structure manipulation: */ 501static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input); 502static void initialize_context(struct p_context *ctx); 503static int done_word(o_string *dest, struct p_context *ctx); 504static int done_command(struct p_context *ctx); 505static int done_pipe(struct p_context *ctx, pipe_style type); 506/* primary string parsing: */ 507static int redirect_dup_num(struct in_str *input); 508static int redirect_opt_num(o_string *o); 509#if ENABLE_HUSH_TICK 510static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end); 511#endif 512static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch); 513static const char *lookup_param(const char *src); 514static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input); 515static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger); 516/* setup: */ 517static int parse_and_run_stream(struct in_str *inp, int parse_flag); 518static int parse_and_run_string(const char *s, int parse_flag); 519static int parse_and_run_file(FILE *f); 520/* job management: */ 521static int checkjobs(struct pipe* fg_pipe); 522#if ENABLE_HUSH_JOB 523static int checkjobs_and_fg_shell(struct pipe* fg_pipe); 524static void insert_bg_job(struct pipe *pi); 525static void remove_bg_job(struct pipe *pi); 526static void delete_finished_bg_job(struct pipe *pi); 527#else 528int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */ 529#endif 530/* local variable support */ 531static char **expand_strvec_to_strvec(char **argv); 532/* used for eval */ 533static char *expand_strvec_to_string(char **argv); 534/* used for expansion of right hand of assignments */ 535static char *expand_string_to_string(const char *str); 536static struct variable *get_local_var(const char *name); 537static int set_local_var(char *str, int flg_export); 538static void unset_local_var(const char *name); 539 540/* Table of built-in functions. They can be forked or not, depending on 541 * context: within pipes, they fork. As simple commands, they do not. 542 * When used in non-forking context, they can change global variables 543 * in the parent shell process. If forked, of course they cannot. 544 * For example, 'unset foo | whatever' will parse and run, but foo will 545 * still be set at the end. */ 546struct built_in_command { 547 const char *cmd; /* name */ 548 int (*function) (char **argv); /* function ptr */ 549#if ENABLE_HUSH_HELP 550 const char *descr; /* description */ 551#define BLTIN(cmd, func, help) { cmd, func, help } 552#else 553#define BLTIN(cmd, func, help) { cmd, func } 554#endif 555}; 556 557static const struct built_in_command bltins[] = { 558#if ENABLE_HUSH_JOB 559 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"), 560#endif 561// BLTIN("break" , builtin_not_written, "Exit for, while or until loop"), 562 BLTIN("cd" , builtin_cd, "Change working directory"), 563// BLTIN("continue", builtin_not_written, "Continue for, while or until loop"), 564 BLTIN("eval" , builtin_eval, "Construct and run shell command"), 565 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"), 566 BLTIN("exit" , builtin_exit, "Exit from shell"), 567 BLTIN("export", builtin_export, "Set environment variable"), 568#if ENABLE_HUSH_JOB 569 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"), 570 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"), 571#endif 572// TODO: remove pwd? we have it as an applet... 573 BLTIN("pwd" , builtin_pwd, "Print current directory"), 574 BLTIN("read" , builtin_read, "Input environment variable"), 575// BLTIN("return", builtin_not_written, "Return from a function"), 576 BLTIN("set" , builtin_set, "Set/unset shell local variables"), 577 BLTIN("shift" , builtin_shift, "Shift positional parameters"), 578// BLTIN("trap" , builtin_not_written, "Trap signals"), 579// BLTIN("ulimit", builtin_not_written, "Controls resource limits"), 580 BLTIN("umask" , builtin_umask, "Sets file creation mask"), 581 BLTIN("unset" , builtin_unset, "Unset environment variable"), 582 BLTIN("." , builtin_source, "Source-in and run commands in a file"), 583#if ENABLE_HUSH_HELP 584 BLTIN("help" , builtin_help, "List shell built-in commands"), 585#endif 586 BLTIN(NULL, NULL, NULL) 587}; 588 589#if ENABLE_HUSH_JOB 590 591/* move to libbb? */ 592static void signal_SA_RESTART(int sig, void (*handler)(int)) 593{ 594 struct sigaction sa; 595 sa.sa_handler = handler; 596 sa.sa_flags = SA_RESTART; 597 sigemptyset(&sa.sa_mask); 598 sigaction(sig, &sa, NULL); 599} 600 601/* Signals are grouped, we handle them in batches */ 602static void set_fatal_sighandler(void (*handler)(int)) 603{ 604 signal(SIGILL , handler); 605 signal(SIGTRAP, handler); 606 signal(SIGABRT, handler); 607 signal(SIGFPE , handler); 608 signal(SIGBUS , handler); 609 signal(SIGSEGV, handler); 610 /* bash 3.2 seems to handle these just like 'fatal' ones */ 611 signal(SIGHUP , handler); 612 signal(SIGPIPE, handler); 613 signal(SIGALRM, handler); 614} 615static void set_jobctrl_sighandler(void (*handler)(int)) 616{ 617 signal(SIGTSTP, handler); 618 signal(SIGTTIN, handler); 619 signal(SIGTTOU, handler); 620} 621static void set_misc_sighandler(void (*handler)(int)) 622{ 623 signal(SIGINT , handler); 624 signal(SIGQUIT, handler); 625 signal(SIGTERM, handler); 626} 627/* SIGCHLD is special and handled separately */ 628 629static void set_every_sighandler(void (*handler)(int)) 630{ 631 set_fatal_sighandler(handler); 632 set_jobctrl_sighandler(handler); 633 set_misc_sighandler(handler); 634 signal(SIGCHLD, handler); 635} 636 637static void handler_ctrl_c(int sig) 638{ 639 debug_printf_jobs("got sig %d\n", sig); 640// as usual we can have all kinds of nasty problems with leaked malloc data here 641 siglongjmp(toplevel_jb, 1); 642} 643 644static void handler_ctrl_z(int sig) 645{ 646 pid_t pid; 647 648 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid()); 649 pid = fork(); 650 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */ 651 return; 652 ctrl_z_flag = 1; 653 if (!pid) { /* child */ 654 setpgrp(); 655 debug_printf_jobs("set pgrp for child %d ok\n", getpid()); 656 set_every_sighandler(SIG_DFL); 657 raise(SIGTSTP); /* resend TSTP so that child will be stopped */ 658 debug_printf_jobs("returning in child\n"); 659 /* return to nofork, it will eventually exit now, 660 * not return back to shell */ 661 return; 662 } 663 /* parent */ 664 /* finish filling up pipe info */ 665 toplevel_list->pgrp = pid; /* child is in its own pgrp */ 666 toplevel_list->progs[0].pid = pid; 667 /* parent needs to longjmp out of running nofork. 668 * we will "return" exitcode 0, with child put in background */ 669// as usual we can have all kinds of nasty problems with leaked malloc data here 670 debug_printf_jobs("siglongjmp in parent\n"); 671 siglongjmp(toplevel_jb, 1); 672} 673 674/* Restores tty foreground process group, and exits. 675 * May be called as signal handler for fatal signal 676 * (will faithfully resend signal to itself, producing correct exit state) 677 * or called directly with -EXITCODE. 678 * We also call it if xfunc is exiting. */ 679static void sigexit(int sig) ATTRIBUTE_NORETURN; 680static void sigexit(int sig) 681{ 682 sigset_t block_all; 683 684 /* Disable all signals: job control, SIGPIPE, etc. */ 685 sigfillset(&block_all); 686 sigprocmask(SIG_SETMASK, &block_all, NULL); 687 688 if (interactive_fd) 689 tcsetpgrp(interactive_fd, saved_tty_pgrp); 690 691 /* Not a signal, just exit */ 692 if (sig <= 0) 693 _exit(- sig); 694 695 /* Enable only this sig and kill ourself with it */ 696 signal(sig, SIG_DFL); 697 sigdelset(&block_all, sig); 698 sigprocmask(SIG_SETMASK, &block_all, NULL); 699 raise(sig); 700 _exit(1); /* Should not reach it */ 701} 702 703/* Restores tty foreground process group, and exits. */ 704static void hush_exit(int exitcode) ATTRIBUTE_NORETURN; 705static void hush_exit(int exitcode) 706{ 707 fflush(NULL); /* flush all streams */ 708 sigexit(- (exitcode & 0xff)); 709} 710 711#else /* !JOB */ 712 713#define set_fatal_sighandler(handler) ((void)0) 714#define set_jobctrl_sighandler(handler) ((void)0) 715#define set_misc_sighandler(handler) ((void)0) 716#define hush_exit(e) exit(e) 717 718#endif /* JOB */ 719 720 721static const char *set_cwd(void) 722{ 723 if (cwd == bb_msg_unknown) 724 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */ 725 cwd = xrealloc_getcwd_or_warn((char *)cwd); 726 if (!cwd) 727 cwd = bb_msg_unknown; 728 return cwd; 729} 730 731/* built-in 'eval' handler */ 732static int builtin_eval(char **argv) 733{ 734 int rcode = EXIT_SUCCESS; 735 736 if (argv[1]) { 737 char *str = expand_strvec_to_string(argv + 1); 738 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP | 739 PARSEFLAG_SEMICOLON); 740 free(str); 741 rcode = last_return_code; 742 } 743 return rcode; 744} 745 746/* built-in 'cd <path>' handler */ 747static int builtin_cd(char **argv) 748{ 749 const char *newdir; 750 if (argv[1] == NULL) 751 newdir = getenv("HOME") ? : "/"; 752 else 753 newdir = argv[1]; 754 if (chdir(newdir)) { 755 printf("cd: %s: %s\n", newdir, strerror(errno)); 756 return EXIT_FAILURE; 757 } 758 set_cwd(); 759 return EXIT_SUCCESS; 760} 761 762/* built-in 'exec' handler */ 763static int builtin_exec(char **argv) 764{ 765 if (argv[1] == NULL) 766 return EXIT_SUCCESS; /* Really? */ 767 pseudo_exec_argv(argv + 1); 768 /* never returns */ 769} 770 771/* built-in 'exit' handler */ 772static int builtin_exit(char **argv) 773{ 774// TODO: bash does it ONLY on top-level sh exit (+interacive only?) 775 //puts("exit"); /* bash does it */ 776// TODO: warn if we have background jobs: "There are stopped jobs" 777// On second consecutive 'exit', exit anyway. 778 779 if (argv[1] == NULL) 780 hush_exit(last_return_code); 781 /* mimic bash: exit 123abc == exit 255 + error msg */ 782 xfunc_error_retval = 255; 783 /* bash: exit -2 == exit 254, no error msg */ 784 hush_exit(xatoi(argv[1]) & 0xff); 785} 786 787/* built-in 'export VAR=value' handler */ 788static int builtin_export(char **argv) 789{ 790 const char *value; 791 char *name = argv[1]; 792 793 if (name == NULL) { 794 // TODO: 795 // ash emits: export VAR='VAL' 796 // bash: declare -x VAR="VAL" 797 // (both also escape as needed (quotes, $, etc)) 798 char **e = environ; 799 if (e) 800 while (*e) 801 puts(*e++); 802 return EXIT_SUCCESS; 803 } 804 805 value = strchr(name, '='); 806 if (!value) { 807 /* They are exporting something without a =VALUE */ 808 struct variable *var; 809 810 var = get_local_var(name); 811 if (var) { 812 var->flg_export = 1; 813 putenv(var->varstr); 814 } 815 /* bash does not return an error when trying to export 816 * an undefined variable. Do likewise. */ 817 return EXIT_SUCCESS; 818 } 819 820 set_local_var(xstrdup(name), 1); 821 return EXIT_SUCCESS; 822} 823 824#if ENABLE_HUSH_JOB 825/* built-in 'fg' and 'bg' handler */ 826static int builtin_fg_bg(char **argv) 827{ 828 int i, jobnum; 829 struct pipe *pi; 830 831 if (!interactive_fd) 832 return EXIT_FAILURE; 833 /* If they gave us no args, assume they want the last backgrounded task */ 834 if (!argv[1]) { 835 for (pi = job_list; pi; pi = pi->next) { 836 if (pi->jobid == last_jobid) { 837 goto found; 838 } 839 } 840 bb_error_msg("%s: no current job", argv[0]); 841 return EXIT_FAILURE; 842 } 843 if (sscanf(argv[1], "%%%d", &jobnum) != 1) { 844 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]); 845 return EXIT_FAILURE; 846 } 847 for (pi = job_list; pi; pi = pi->next) { 848 if (pi->jobid == jobnum) { 849 goto found; 850 } 851 } 852 bb_error_msg("%s: %d: no such job", argv[0], jobnum); 853 return EXIT_FAILURE; 854 found: 855 // TODO: bash prints a string representation 856 // of job being foregrounded (like "sleep 1 | cat") 857 if (*argv[0] == 'f') { 858 /* Put the job into the foreground. */ 859 tcsetpgrp(interactive_fd, pi->pgrp); 860 } 861 862 /* Restart the processes in the job */ 863 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp); 864 for (i = 0; i < pi->num_progs; i++) { 865 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid); 866 pi->progs[i].is_stopped = 0; 867 } 868 pi->stopped_progs = 0; 869 870 i = kill(- pi->pgrp, SIGCONT); 871 if (i < 0) { 872 if (errno == ESRCH) { 873 delete_finished_bg_job(pi); 874 return EXIT_SUCCESS; 875 } else { 876 bb_perror_msg("kill (SIGCONT)"); 877 } 878 } 879 880 if (*argv[0] == 'f') { 881 remove_bg_job(pi); 882 return checkjobs_and_fg_shell(pi); 883 } 884 return EXIT_SUCCESS; 885} 886#endif 887 888/* built-in 'help' handler */ 889#if ENABLE_HUSH_HELP 890static int builtin_help(char **argv ATTRIBUTE_UNUSED) 891{ 892 const struct built_in_command *x; 893 894 printf("\nBuilt-in commands:\n"); 895 printf("-------------------\n"); 896 for (x = bltins; x->cmd; x++) { 897 printf("%s\t%s\n", x->cmd, x->descr); 898 } 899 printf("\n\n"); 900 return EXIT_SUCCESS; 901} 902#endif 903 904#if ENABLE_HUSH_JOB 905/* built-in 'jobs' handler */ 906static int builtin_jobs(char **argv ATTRIBUTE_UNUSED) 907{ 908 struct pipe *job; 909 const char *status_string; 910 911 for (job = job_list; job; job = job->next) { 912 if (job->running_progs == job->stopped_progs) 913 status_string = "Stopped"; 914 else 915 status_string = "Running"; 916 917 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext); 918 } 919 return EXIT_SUCCESS; 920} 921#endif 922 923/* built-in 'pwd' handler */ 924static int builtin_pwd(char **argv ATTRIBUTE_UNUSED) 925{ 926 puts(set_cwd()); 927 return EXIT_SUCCESS; 928} 929 930/* built-in 'read VAR' handler */ 931static int builtin_read(char **argv) 932{ 933 char *string; 934 const char *name = argv[1] ? argv[1] : "REPLY"; 935 936 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name)); 937 return set_local_var(string, 0); 938} 939 940/* built-in 'set [VAR=value]' handler */ 941static int builtin_set(char **argv) 942{ 943 char *temp = argv[1]; 944 struct variable *e; 945 946 if (temp == NULL) 947 for (e = top_var; e; e = e->next) 948 puts(e->varstr); 949 else 950 set_local_var(xstrdup(temp), 0); 951 952 return EXIT_SUCCESS; 953} 954 955 956/* Built-in 'shift' handler */ 957static int builtin_shift(char **argv) 958{ 959 int n = 1; 960 if (argv[1]) { 961 n = atoi(argv[1]); 962 } 963 if (n >= 0 && n < global_argc) { 964 global_argv[n] = global_argv[0]; 965 global_argc -= n; 966 global_argv += n; 967 return EXIT_SUCCESS; 968 } 969 return EXIT_FAILURE; 970} 971 972/* Built-in '.' handler (read-in and execute commands from file) */ 973static int builtin_source(char **argv) 974{ 975 FILE *input; 976 int status; 977 978 if (argv[1] == NULL) 979 return EXIT_FAILURE; 980 981 input = fopen(argv[1], "r"); 982 if (!input) { 983 bb_error_msg("cannot open '%s'", argv[1]); 984 return EXIT_FAILURE; 985 } 986 987 /* Now run the file */ 988 mark_open(fileno(input)); 989 status = parse_and_run_file(input); 990 mark_closed(fileno(input)); 991 fclose(input); 992 return status; 993} 994 995static int builtin_umask(char **argv) 996{ 997 mode_t new_umask; 998 const char *arg = argv[1]; 999 char *end; 1000 if (arg) { 1001 new_umask = strtoul(arg, &end, 8); 1002 if (*end != '\0' || end == arg) { 1003 return EXIT_FAILURE; 1004 } 1005 } else { 1006 new_umask = umask(0); 1007 printf("%.3o\n", (unsigned) new_umask); 1008 } 1009 umask(new_umask); 1010 return EXIT_SUCCESS; 1011} 1012 1013/* built-in 'unset VAR' handler */ 1014static int builtin_unset(char **argv) 1015{ 1016 /* bash always returns true */ 1017 unset_local_var(argv[1]); 1018 return EXIT_SUCCESS; 1019} 1020 1021//static int builtin_not_written(char **argv) 1022//{ 1023// printf("builtin_%s not written\n", argv[0]); 1024// return EXIT_FAILURE; 1025//} 1026 1027static int b_check_space(o_string *o, int len) 1028{ 1029 /* It would be easy to drop a more restrictive policy 1030 * in here, such as setting a maximum string length */ 1031 if (o->length + len > o->maxlen) { 1032 /* assert(data == NULL || o->maxlen != 0); */ 1033 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK); 1034 o->data = xrealloc(o->data, 1 + o->maxlen); 1035 } 1036 return o->data == NULL; 1037} 1038 1039static int b_addchr(o_string *o, int ch) 1040{ 1041 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); 1042 if (b_check_space(o, 1)) 1043 return B_NOSPAC; 1044 o->data[o->length] = ch; 1045 o->length++; 1046 o->data[o->length] = '\0'; 1047 return 0; 1048} 1049 1050static void b_reset(o_string *o) 1051{ 1052 o->length = 0; 1053 o->nonnull = 0; 1054 if (o->data != NULL) 1055 *o->data = '\0'; 1056} 1057 1058static void b_free(o_string *o) 1059{ 1060 b_reset(o); 1061 free(o->data); 1062 o->data = NULL; 1063 o->maxlen = 0; 1064} 1065 1066/* My analysis of quoting semantics tells me that state information 1067 * is associated with a destination, not a source. 1068 */ 1069static int b_addqchr(o_string *o, int ch, int quote) 1070{ 1071 if (quote && strchr("*?[\\", ch)) { 1072 int rc; 1073 rc = b_addchr(o, '\\'); 1074 if (rc) 1075 return rc; 1076 } 1077 return b_addchr(o, ch); 1078} 1079 1080static int static_get(struct in_str *i) 1081{ 1082 int ch = *i->p++; 1083 if (ch == '\0') return EOF; 1084 return ch; 1085} 1086 1087static int static_peek(struct in_str *i) 1088{ 1089 return *i->p; 1090} 1091 1092#if ENABLE_HUSH_INTERACTIVE 1093#if ENABLE_FEATURE_EDITING 1094static void cmdedit_set_initial_prompt(void) 1095{ 1096#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT 1097 PS1 = NULL; 1098#else 1099 PS1 = getenv("PS1"); 1100 if (PS1 == NULL) 1101 PS1 = "\\w \\$ "; 1102#endif 1103} 1104#endif /* EDITING */ 1105 1106static const char* setup_prompt_string(int promptmode) 1107{ 1108 const char *prompt_str; 1109 debug_printf("setup_prompt_string %d ", promptmode); 1110#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT 1111 /* Set up the prompt */ 1112 if (promptmode == 0) { /* PS1 */ 1113 free((char*)PS1); 1114 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#'); 1115 prompt_str = PS1; 1116 } else { 1117 prompt_str = PS2; 1118 } 1119#else 1120 prompt_str = (promptmode == 0) ? PS1 : PS2; 1121#endif 1122 debug_printf("result '%s'\n", prompt_str); 1123 return prompt_str; 1124} 1125 1126static void get_user_input(struct in_str *i) 1127{ 1128 int r; 1129 const char *prompt_str; 1130 1131 prompt_str = setup_prompt_string(i->promptmode); 1132#if ENABLE_FEATURE_EDITING 1133 /* Enable command line editing only while a command line 1134 * is actually being read; otherwise, we'll end up bequeathing 1135 * atexit() handlers and other unwanted stuff to our 1136 * child processes (rob@sysgo.de) */ 1137 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state); 1138 i->eof_flag = (r < 0); 1139 if (i->eof_flag) { /* EOF/error detected */ 1140 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ 1141 user_input_buf[1] = '\0'; 1142 } 1143#else 1144 fputs(prompt_str, stdout); 1145 fflush(stdout); 1146 user_input_buf[0] = r = fgetc(i->file); 1147 /*user_input_buf[1] = '\0'; - already is and never changed */ 1148 i->eof_flag = (r == EOF); 1149#endif 1150 i->p = user_input_buf; 1151} 1152#endif /* INTERACTIVE */ 1153 1154/* This is the magic location that prints prompts 1155 * and gets data back from the user */ 1156static int file_get(struct in_str *i) 1157{ 1158 int ch; 1159 1160 /* If there is data waiting, eat it up */ 1161 if (i->p && *i->p) { 1162#if ENABLE_HUSH_INTERACTIVE 1163 take_cached: 1164#endif 1165 ch = *i->p++; 1166 if (i->eof_flag && !*i->p) 1167 ch = EOF; 1168 } else { 1169 /* need to double check i->file because we might be doing something 1170 * more complicated by now, like sourcing or substituting. */ 1171#if ENABLE_HUSH_INTERACTIVE 1172 if (interactive_fd && i->promptme && i->file == stdin) { 1173 do { 1174 get_user_input(i); 1175 } while (!*i->p); /* need non-empty line */ 1176 i->promptmode = 1; /* PS2 */ 1177 i->promptme = 0; 1178 goto take_cached; 1179 } 1180#endif 1181 ch = fgetc(i->file); 1182 } 1183 debug_printf("file_get: got a '%c' %d\n", ch, ch); 1184#if ENABLE_HUSH_INTERACTIVE 1185 if (ch == '\n') 1186 i->promptme = 1; 1187#endif 1188 return ch; 1189} 1190 1191/* All the callers guarantee this routine will never be 1192 * used right after a newline, so prompting is not needed. 1193 */ 1194static int file_peek(struct in_str *i) 1195{ 1196 int ch; 1197 if (i->p && *i->p) { 1198 if (i->eof_flag && !i->p[1]) 1199 return EOF; 1200 return *i->p; 1201 } 1202 ch = fgetc(i->file); 1203 i->eof_flag = (ch == EOF); 1204 i->peek_buf[0] = ch; 1205 i->peek_buf[1] = '\0'; 1206 i->p = i->peek_buf; 1207 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p); 1208 return ch; 1209} 1210 1211static void setup_file_in_str(struct in_str *i, FILE *f) 1212{ 1213 i->peek = file_peek; 1214 i->get = file_get; 1215#if ENABLE_HUSH_INTERACTIVE 1216 i->promptme = 1; 1217 i->promptmode = 0; /* PS1 */ 1218#endif 1219 i->file = f; 1220 i->p = NULL; 1221} 1222 1223static void setup_string_in_str(struct in_str *i, const char *s) 1224{ 1225 i->peek = static_peek; 1226 i->get = static_get; 1227#if ENABLE_HUSH_INTERACTIVE 1228 i->promptme = 1; 1229 i->promptmode = 0; /* PS1 */ 1230#endif 1231 i->p = s; 1232 i->eof_flag = 0; 1233} 1234 1235static void mark_open(int fd) 1236{ 1237 struct close_me *new = xmalloc(sizeof(struct close_me)); 1238 new->fd = fd; 1239 new->next = close_me_head; 1240 close_me_head = new; 1241} 1242 1243static void mark_closed(int fd) 1244{ 1245 struct close_me *tmp; 1246 if (close_me_head == NULL || close_me_head->fd != fd) 1247 bb_error_msg_and_die("corrupt close_me"); 1248 tmp = close_me_head; 1249 close_me_head = close_me_head->next; 1250 free(tmp); 1251} 1252 1253static void close_all(void) 1254{ 1255 struct close_me *c; 1256 for (c = close_me_head; c; c = c->next) { 1257 close(c->fd); 1258 } 1259 close_me_head = NULL; 1260} 1261 1262/* squirrel != NULL means we squirrel away copies of stdin, stdout, 1263 * and stderr if they are redirected. */ 1264static int setup_redirects(struct child_prog *prog, int squirrel[]) 1265{ 1266 int openfd, mode; 1267 struct redir_struct *redir; 1268 1269 for (redir = prog->redirects; redir; redir = redir->next) { 1270 if (redir->dup == -1 && redir->word.gl_pathv == NULL) { 1271 /* something went wrong in the parse. Pretend it didn't happen */ 1272 continue; 1273 } 1274 if (redir->dup == -1) { 1275 mode = redir_table[redir->type].mode; 1276 openfd = open_or_warn(redir->word.gl_pathv[0], mode); 1277 if (openfd < 0) { 1278 /* this could get lost if stderr has been redirected, but 1279 bash and ash both lose it as well (though zsh doesn't!) */ 1280 return 1; 1281 } 1282 } else { 1283 openfd = redir->dup; 1284 } 1285 1286 if (openfd != redir->fd) { 1287 if (squirrel && redir->fd < 3) { 1288 squirrel[redir->fd] = dup(redir->fd); 1289 } 1290 if (openfd == -3) { 1291 close(openfd); 1292 } else { 1293 dup2(openfd, redir->fd); 1294 if (redir->dup == -1) 1295 close(openfd); 1296 } 1297 } 1298 } 1299 return 0; 1300} 1301 1302static void restore_redirects(int squirrel[]) 1303{ 1304 int i, fd; 1305 for (i = 0; i < 3; i++) { 1306 fd = squirrel[i]; 1307 if (fd != -1) { 1308 /* We simply die on error */ 1309 xmove_fd(fd, i); 1310 } 1311 } 1312} 1313 1314/* never returns */ 1315static void pseudo_exec_argv(char **argv) 1316{ 1317 int i, rcode; 1318 char *p; 1319 const struct built_in_command *x; 1320 1321 for (i = 0; is_assignment(argv[i]); i++) { 1322 debug_printf_exec("pid %d environment modification: %s\n", 1323 getpid(), argv[i]); 1324 p = expand_string_to_string(argv[i]); 1325 putenv(p); 1326 } 1327 argv += i; 1328 /* If a variable is assigned in a forest, and nobody listens, 1329 * was it ever really set? 1330 */ 1331 if (argv[0] == NULL) { 1332 _exit(EXIT_SUCCESS); 1333 } 1334 1335 argv = expand_strvec_to_strvec(argv); 1336 1337 /* 1338 * Check if the command matches any of the builtins. 1339 * Depending on context, this might be redundant. But it's 1340 * easier to waste a few CPU cycles than it is to figure out 1341 * if this is one of those cases. 1342 */ 1343 for (x = bltins; x->cmd; x++) { 1344 if (strcmp(argv[0], x->cmd) == 0) { 1345 debug_printf_exec("running builtin '%s'\n", argv[0]); 1346 rcode = x->function(argv); 1347 fflush(stdout); 1348 _exit(rcode); 1349 } 1350 } 1351 1352 /* Check if the command matches any busybox applets */ 1353#if ENABLE_FEATURE_SH_STANDALONE 1354 if (strchr(argv[0], '/') == NULL) { 1355 const struct bb_applet *a = find_applet_by_name(argv[0]); 1356 if (a) { 1357 if (a->noexec) { 1358 current_applet = a; 1359 debug_printf_exec("running applet '%s'\n", argv[0]); 1360// is it ok that run_current_applet_and_exit() does exit(), not _exit()? 1361 run_current_applet_and_exit(argv); 1362 } 1363 /* re-exec ourselves with the new arguments */ 1364 debug_printf_exec("re-execing applet '%s'\n", argv[0]); 1365 execvp(bb_busybox_exec_path, argv); 1366 /* If they called chroot or otherwise made the binary no longer 1367 * executable, fall through */ 1368 } 1369 } 1370#endif 1371 1372 debug_printf_exec("execing '%s'\n", argv[0]); 1373 execvp(argv[0], argv); 1374 bb_perror_msg("cannot exec '%s'", argv[0]); 1375 _exit(1); 1376} 1377 1378static void pseudo_exec(struct child_prog *child) 1379{ 1380// until it does exec/_exit, but currently it does. 1381 int rcode; 1382 1383 if (child->argv) { 1384 pseudo_exec_argv(child->argv); 1385 } 1386 1387 if (child->group) { 1388#if ENABLE_HUSH_INTERACTIVE 1389 debug_printf_exec("pseudo_exec: setting interactive_fd=0\n"); 1390 interactive_fd = 0; /* crucial!!!! */ 1391#endif 1392 debug_printf_exec("pseudo_exec: run_list_real\n"); 1393 rcode = run_list_real(child->group); 1394 /* OK to leak memory by not calling free_pipe_list, 1395 * since this process is about to exit */ 1396 _exit(rcode); 1397 } 1398 1399 /* Can happen. See what bash does with ">foo" by itself. */ 1400 debug_printf("trying to pseudo_exec null command\n"); 1401 _exit(EXIT_SUCCESS); 1402} 1403 1404#if ENABLE_HUSH_JOB 1405static const char *get_cmdtext(struct pipe *pi) 1406{ 1407 char **argv; 1408 char *p; 1409 int len; 1410 1411 /* This is subtle. ->cmdtext is created only on first backgrounding. 1412 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...) 1413 * On subsequent bg argv is trashed, but we won't use it */ 1414 if (pi->cmdtext) 1415 return pi->cmdtext; 1416 argv = pi->progs[0].argv; 1417 if (!argv || !argv[0]) 1418 return (pi->cmdtext = xzalloc(1)); 1419 1420 len = 0; 1421 do len += strlen(*argv) + 1; while (*++argv); 1422 pi->cmdtext = p = xmalloc(len); 1423 argv = pi->progs[0].argv; 1424 do { 1425 len = strlen(*argv); 1426 memcpy(p, *argv, len); 1427 p += len; 1428 *p++ = ' '; 1429 } while (*++argv); 1430 p[-1] = '\0'; 1431 return pi->cmdtext; 1432} 1433 1434static void insert_bg_job(struct pipe *pi) 1435{ 1436 struct pipe *thejob; 1437 int i; 1438 1439 /* Linear search for the ID of the job to use */ 1440 pi->jobid = 1; 1441 for (thejob = job_list; thejob; thejob = thejob->next) 1442 if (thejob->jobid >= pi->jobid) 1443 pi->jobid = thejob->jobid + 1; 1444 1445 /* Add thejob to the list of running jobs */ 1446 if (!job_list) { 1447 thejob = job_list = xmalloc(sizeof(*thejob)); 1448 } else { 1449 for (thejob = job_list; thejob->next; thejob = thejob->next) 1450 continue; 1451 thejob->next = xmalloc(sizeof(*thejob)); 1452 thejob = thejob->next; 1453 } 1454 1455 /* Physically copy the struct job */ 1456 memcpy(thejob, pi, sizeof(struct pipe)); 1457 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs); 1458 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */ 1459 for (i = 0; i < pi->num_progs; i++) { 1460// TODO: do we really need to have so many fields which are just dead weight 1461// at execution stage? 1462 thejob->progs[i].pid = pi->progs[i].pid; 1463 /* all other fields are not used and stay zero */ 1464 } 1465 thejob->next = NULL; 1466 thejob->cmdtext = xstrdup(get_cmdtext(pi)); 1467 1468 /* We don't wait for background thejobs to return -- append it 1469 to the list of backgrounded thejobs and leave it alone */ 1470 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext); 1471 last_bg_pid = thejob->progs[0].pid; 1472 last_jobid = thejob->jobid; 1473} 1474 1475static void remove_bg_job(struct pipe *pi) 1476{ 1477 struct pipe *prev_pipe; 1478 1479 if (pi == job_list) { 1480 job_list = pi->next; 1481 } else { 1482 prev_pipe = job_list; 1483 while (prev_pipe->next != pi) 1484 prev_pipe = prev_pipe->next; 1485 prev_pipe->next = pi->next; 1486 } 1487 if (job_list) 1488 last_jobid = job_list->jobid; 1489 else 1490 last_jobid = 0; 1491} 1492 1493/* remove a backgrounded job */ 1494static void delete_finished_bg_job(struct pipe *pi) 1495{ 1496 remove_bg_job(pi); 1497 pi->stopped_progs = 0; 1498 free_pipe(pi, 0); 1499 free(pi); 1500} 1501#endif /* JOB */ 1502 1503/* Checks to see if any processes have exited -- if they 1504 have, figure out why and see if a job has completed */ 1505static int checkjobs(struct pipe* fg_pipe) 1506{ 1507 int attributes; 1508 int status; 1509#if ENABLE_HUSH_JOB 1510 int prognum = 0; 1511 struct pipe *pi; 1512#endif 1513 pid_t childpid; 1514 int rcode = 0; 1515 1516 attributes = WUNTRACED; 1517 if (fg_pipe == NULL) { 1518 attributes |= WNOHANG; 1519 } 1520 1521/* Do we do this right? 1522 * bash-3.00# sleep 20 | false 1523 * <ctrl-Z pressed> 1524 * [3]+ Stopped sleep 20 | false 1525 * bash-3.00# echo $? 1526 * 1 <========== bg pipe is not fully done, but exitcode is already known! 1527 */ 1528 1529//are stopped. Testcase: "cat | cat" in a script (not on command line) 1530// + killall -STOP cat 1531 1532 wait_more: 1533 while ((childpid = waitpid(-1, &status, attributes)) > 0) { 1534 const int dead = WIFEXITED(status) || WIFSIGNALED(status); 1535 1536#ifdef DEBUG_SHELL_JOBS 1537 if (WIFSTOPPED(status)) 1538 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", 1539 childpid, WSTOPSIG(status), WEXITSTATUS(status)); 1540 if (WIFSIGNALED(status)) 1541 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", 1542 childpid, WTERMSIG(status), WEXITSTATUS(status)); 1543 if (WIFEXITED(status)) 1544 debug_printf_jobs("pid %d exited, exitcode %d\n", 1545 childpid, WEXITSTATUS(status)); 1546#endif 1547 /* Were we asked to wait for fg pipe? */ 1548 if (fg_pipe) { 1549 int i; 1550 for (i = 0; i < fg_pipe->num_progs; i++) { 1551 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid); 1552 if (fg_pipe->progs[i].pid == childpid) { 1553 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */ 1554 if (dead) { 1555 fg_pipe->progs[i].pid = 0; 1556 fg_pipe->running_progs--; 1557 if (i == fg_pipe->num_progs-1) 1558 /* last process gives overall exitstatus */ 1559 rcode = WEXITSTATUS(status); 1560 } else { 1561 fg_pipe->progs[i].is_stopped = 1; 1562 fg_pipe->stopped_progs++; 1563 } 1564 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n", 1565 fg_pipe->running_progs, fg_pipe->stopped_progs); 1566 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) { 1567 /* All processes in fg pipe have exited/stopped */ 1568#if ENABLE_HUSH_JOB 1569 if (fg_pipe->running_progs) 1570 insert_bg_job(fg_pipe); 1571#endif 1572 return rcode; 1573 } 1574 /* There are still running processes in the fg pipe */ 1575 goto wait_more; 1576 } 1577 } 1578 /* fall through to searching process in bg pipes */ 1579 } 1580 1581#if ENABLE_HUSH_JOB 1582 /* We asked to wait for bg or orphaned children */ 1583 /* No need to remember exitcode in this case */ 1584 for (pi = job_list; pi; pi = pi->next) { 1585 prognum = 0; 1586 while (prognum < pi->num_progs) { 1587 if (pi->progs[prognum].pid == childpid) 1588 goto found_pi_and_prognum; 1589 prognum++; 1590 } 1591 } 1592#endif 1593 1594 /* Happens when shell is used as init process (init=/bin/sh) */ 1595 debug_printf("checkjobs: pid %d was not in our list!\n", childpid); 1596 goto wait_more; 1597 1598#if ENABLE_HUSH_JOB 1599 found_pi_and_prognum: 1600 if (dead) { 1601 /* child exited */ 1602 pi->progs[prognum].pid = 0; 1603 pi->running_progs--; 1604 if (!pi->running_progs) { 1605 printf(JOB_STATUS_FORMAT, pi->jobid, 1606 "Done", pi->cmdtext); 1607 delete_finished_bg_job(pi); 1608 } 1609 } else { 1610 /* child stopped */ 1611 pi->stopped_progs++; 1612 pi->progs[prognum].is_stopped = 1; 1613 } 1614#endif 1615 } 1616 1617 /* wait found no children or failed */ 1618 1619 if (childpid && errno != ECHILD) 1620 bb_perror_msg("waitpid"); 1621 return rcode; 1622} 1623 1624#if ENABLE_HUSH_JOB 1625static int checkjobs_and_fg_shell(struct pipe* fg_pipe) 1626{ 1627 pid_t p; 1628 int rcode = checkjobs(fg_pipe); 1629 /* Job finished, move the shell to the foreground */ 1630 p = getpgid(0); /* pgid of our process */ 1631 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p); 1632 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY) 1633 bb_perror_msg("tcsetpgrp-4a"); 1634 return rcode; 1635} 1636#endif 1637 1638/* run_pipe_real() starts all the jobs, but doesn't wait for anything 1639 * to finish. See checkjobs(). 1640 * 1641 * return code is normally -1, when the caller has to wait for children 1642 * to finish to determine the exit status of the pipe. If the pipe 1643 * is a simple builtin command, however, the action is done by the 1644 * time run_pipe_real returns, and the exit code is provided as the 1645 * return value. 1646 * 1647 * The input of the pipe is always stdin, the output is always 1648 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus, 1649 * because it tries to avoid running the command substitution in 1650 * subshell, when that is in fact necessary. The subshell process 1651 * now has its stdout directed to the input of the appropriate pipe, 1652 * so this routine is noticeably simpler. 1653 * 1654 * Returns -1 only if started some children. IOW: we have to 1655 * mask out retvals of builtins etc with 0xff! 1656 */ 1657static int run_pipe_real(struct pipe *pi) 1658{ 1659 int i; 1660 int nextin, nextout; 1661 int pipefds[2]; /* pipefds[0] is for reading */ 1662 struct child_prog *child; 1663 const struct built_in_command *x; 1664 char *p; 1665 /* it is not always needed, but we aim to smaller code */ 1666 int squirrel[] = { -1, -1, -1 }; 1667 int rcode; 1668 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG); 1669 1670 debug_printf_exec("run_pipe_real start: single_fg=%d\n", single_fg); 1671 1672 nextin = 0; 1673#if ENABLE_HUSH_JOB 1674 pi->pgrp = -1; 1675#endif 1676 pi->running_progs = 1; 1677 pi->stopped_progs = 0; 1678 1679 /* Check if this is a simple builtin (not part of a pipe). 1680 * Builtins within pipes have to fork anyway, and are handled in 1681 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. 1682 */ 1683 child = &(pi->progs[0]); 1684 if (single_fg && child->group && child->subshell == 0) { 1685 debug_printf("non-subshell grouping\n"); 1686 setup_redirects(child, squirrel); 1687 debug_printf_exec(": run_list_real\n"); 1688 rcode = run_list_real(child->group); 1689 restore_redirects(squirrel); 1690 debug_printf_exec("run_pipe_real return %d\n", rcode); 1691 return rcode; // do we need to add '... & 0xff' ? 1692 } 1693 1694 if (single_fg && child->argv != NULL) { 1695 char **argv_expanded; 1696 char **argv = child->argv; 1697 1698 for (i = 0; is_assignment(argv[i]); i++) 1699 continue; 1700 if (i != 0 && argv[i] == NULL) { 1701 /* assignments, but no command: set the local environment */ 1702 for (i = 0; argv[i] != NULL; i++) { 1703 debug_printf("local environment set: %s\n", argv[i]); 1704 p = expand_string_to_string(argv[i]); 1705 set_local_var(p, 0); 1706 } 1707 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */ 1708 } 1709 for (i = 0; is_assignment(argv[i]); i++) { 1710 p = expand_string_to_string(argv[i]); 1711 //sp: child->sp--; 1712 putenv(p); 1713 } 1714 for (x = bltins; x->cmd; x++) { 1715 if (strcmp(argv[i], x->cmd) == 0) { 1716 if (x->function == builtin_exec && argv[i+1] == NULL) { 1717 debug_printf("magic exec\n"); 1718 setup_redirects(child, NULL); 1719 return EXIT_SUCCESS; 1720 } 1721 debug_printf("builtin inline %s\n", argv[0]); 1722 setup_redirects(child, squirrel); 1723 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]); 1724 //sp: if (child->sp) /* btw we can do it unconditionally... */ 1725 argv_expanded = expand_strvec_to_strvec(argv + i); 1726 rcode = x->function(argv_expanded) & 0xff; 1727 free(argv_expanded); 1728 restore_redirects(squirrel); 1729 debug_printf_exec("run_pipe_real return %d\n", rcode); 1730 return rcode; 1731 } 1732 } 1733#if ENABLE_FEATURE_SH_STANDALONE 1734 { 1735 const struct bb_applet *a = find_applet_by_name(argv[i]); 1736 if (a && a->nofork) { 1737 setup_redirects(child, squirrel); 1738 save_nofork_data(&nofork_save); 1739 argv_expanded = argv + i; 1740 //sp: if (child->sp) 1741 argv_expanded = expand_strvec_to_strvec(argv + i); 1742 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]); 1743 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff; 1744 free(argv_expanded); 1745 restore_redirects(squirrel); 1746 debug_printf_exec("run_pipe_real return %d\n", rcode); 1747 return rcode; 1748 } 1749 } 1750#endif 1751 } 1752 1753 /* Going to fork a child per each pipe member */ 1754 pi->running_progs = 0; 1755 1756 /* Disable job control signals for shell (parent) and 1757 * for initial child code after fork */ 1758 set_jobctrl_sighandler(SIG_IGN); 1759 1760 for (i = 0; i < pi->num_progs; i++) { 1761 child = &(pi->progs[i]); 1762 if (child->argv) 1763 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]); 1764 else 1765 debug_printf_exec(": pipe member with no argv\n"); 1766 1767 /* pipes are inserted between pairs of commands */ 1768 if ((i + 1) < pi->num_progs) { 1769 pipe(pipefds); 1770 nextout = pipefds[1]; 1771 } else { 1772 nextout = 1; 1773 pipefds[0] = -1; 1774 } 1775 1776#if BB_MMU 1777 child->pid = fork(); 1778#else 1779 child->pid = vfork(); 1780#endif 1781 if (!child->pid) { /* child */ 1782 /* Every child adds itself to new process group 1783 * with pgid == pid of first child in pipe */ 1784#if ENABLE_HUSH_JOB 1785 if (run_list_level == 1 && interactive_fd) { 1786 /* Don't do pgrp restore anymore on fatal signals */ 1787 set_fatal_sighandler(SIG_DFL); 1788 if (pi->pgrp < 0) /* true for 1st process only */ 1789 pi->pgrp = getpid(); 1790 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) { 1791 /* We do it in *every* child, not just first, 1792 * to avoid races */ 1793 tcsetpgrp(interactive_fd, pi->pgrp); 1794 } 1795 } 1796#endif 1797 /* in non-interactive case fatal sigs are already SIG_DFL */ 1798 close_all(); 1799 if (nextin != 0) { 1800 dup2(nextin, 0); 1801 close(nextin); 1802 } 1803 if (nextout != 1) { 1804 dup2(nextout, 1); 1805 close(nextout); 1806 } 1807 if (pipefds[0] != -1) { 1808 close(pipefds[0]); /* opposite end of our output pipe */ 1809 } 1810 /* Like bash, explicit redirects override pipes, 1811 * and the pipe fd is available for dup'ing. */ 1812 setup_redirects(child, NULL); 1813 1814 /* Restore default handlers just prior to exec */ 1815 set_jobctrl_sighandler(SIG_DFL); 1816 set_misc_sighandler(SIG_DFL); 1817 signal(SIGCHLD, SIG_DFL); 1818 pseudo_exec(child); 1819 } 1820 1821 pi->running_progs++; 1822 1823#if ENABLE_HUSH_JOB 1824 /* Second and next children need to know pid of first one */ 1825 if (pi->pgrp < 0) 1826 pi->pgrp = child->pid; 1827#endif 1828 if (nextin != 0) 1829 close(nextin); 1830 if (nextout != 1) 1831 close(nextout); 1832 1833 /* If there isn't another process, nextin is garbage 1834 but it doesn't matter */ 1835 nextin = pipefds[0]; 1836 } 1837 debug_printf_exec("run_pipe_real return -1\n"); 1838 return -1; 1839} 1840 1841#ifndef debug_print_tree 1842static void debug_print_tree(struct pipe *pi, int lvl) 1843{ 1844 static const char *PIPE[] = { 1845 [PIPE_SEQ] = "SEQ", 1846 [PIPE_AND] = "AND", 1847 [PIPE_OR ] = "OR" , 1848 [PIPE_BG ] = "BG" , 1849 }; 1850 static const char *RES[] = { 1851 [RES_NONE ] = "NONE" , 1852#if ENABLE_HUSH_IF 1853 [RES_IF ] = "IF" , 1854 [RES_THEN ] = "THEN" , 1855 [RES_ELIF ] = "ELIF" , 1856 [RES_ELSE ] = "ELSE" , 1857 [RES_FI ] = "FI" , 1858#endif 1859#if ENABLE_HUSH_LOOPS 1860 [RES_FOR ] = "FOR" , 1861 [RES_WHILE] = "WHILE", 1862 [RES_UNTIL] = "UNTIL", 1863 [RES_DO ] = "DO" , 1864 [RES_DONE ] = "DONE" , 1865 [RES_IN ] = "IN" , 1866#endif 1867 [RES_XXXX ] = "XXXX" , 1868 [RES_SNTX ] = "SNTX" , 1869 }; 1870 1871 int pin, prn; 1872 1873 pin = 0; 1874 while (pi) { 1875 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "", 1876 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]); 1877 prn = 0; 1878 while (prn < pi->num_progs) { 1879 struct child_prog *child = &pi->progs[prn]; 1880 char **argv = child->argv; 1881 1882 fprintf(stderr, "%*s prog %d", lvl*2, "", prn); 1883 if (child->group) { 1884 fprintf(stderr, " group %s: (argv=%p)\n", 1885 (child->subshell ? "()" : "{}"), 1886 argv); 1887 debug_print_tree(child->group, lvl+1); 1888 prn++; 1889 continue; 1890 } 1891 if (argv) while (*argv) { 1892 fprintf(stderr, " '%s'", *argv); 1893 argv++; 1894 } 1895 fprintf(stderr, "\n"); 1896 prn++; 1897 } 1898 pi = pi->next; 1899 pin++; 1900 } 1901} 1902#endif 1903 1904/* NB: called by pseudo_exec, and therefore must not modify any 1905 * global data until exec/_exit (we can be a child after vfork!) */ 1906static int run_list_real(struct pipe *pi) 1907{ 1908 struct pipe *rpipe; 1909#if ENABLE_HUSH_LOOPS 1910 char *for_varname = NULL; 1911 char **for_lcur = NULL; 1912 char **for_list = NULL; 1913 int flag_rep = 0; 1914#endif 1915 int save_num_progs; 1916 int flag_skip = 1; 1917 int rcode = 0; /* probably for gcc only */ 1918 int flag_restore = 0; 1919#if ENABLE_HUSH_IF 1920 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */ 1921#else 1922 enum { if_code = 0, next_if_code = 0 }; 1923#endif 1924 reserved_style rword; 1925 reserved_style skip_more_for_this_rword = RES_XXXX; 1926 1927 debug_printf_exec("run_list_real start lvl %d\n", run_list_level + 1); 1928 1929#if ENABLE_HUSH_LOOPS 1930 /* check syntax for "for" */ 1931 for (rpipe = pi; rpipe; rpipe = rpipe->next) { 1932 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR) 1933 && (rpipe->next == NULL) 1934 ) { 1935 syntax("malformed for"); /* no IN or no commands after IN */ 1936 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level); 1937 return 1; 1938 } 1939 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL) 1940 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN) 1941 ) { 1942 /* TODO: what is tested in the first condition? */ 1943 syntax("malformed for"); /* 2nd condition: not followed by IN */ 1944 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level); 1945 return 1; 1946 } 1947 } 1948#else 1949 rpipe = NULL; 1950#endif 1951 1952#if ENABLE_HUSH_JOB 1953 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done". 1954 * We are saving state before entering outermost list ("while...done") 1955 * so that ctrl-Z will correctly background _entire_ outermost list, 1956 * not just a part of it (like "sleep 1 | exit 2") */ 1957 if (++run_list_level == 1 && interactive_fd) { 1958 if (sigsetjmp(toplevel_jb, 1)) { 1959 /* ctrl-Z forked and we are parent; or ctrl-C. 1960 * Sighandler has longjmped us here */ 1961 signal(SIGINT, SIG_IGN); 1962 signal(SIGTSTP, SIG_IGN); 1963 /* Restore level (we can be coming from deep inside 1964 * nested levels) */ 1965 run_list_level = 1; 1966#if ENABLE_FEATURE_SH_STANDALONE 1967 if (nofork_save.saved) { /* if save area is valid */ 1968 debug_printf_jobs("exiting nofork early\n"); 1969 restore_nofork_data(&nofork_save); 1970 } 1971#endif 1972 if (ctrl_z_flag) { 1973 /* ctrl-Z has forked and stored pid of the child in pi->pid. 1974 * Remember this child as background job */ 1975 insert_bg_job(pi); 1976 } else { 1977 /* ctrl-C. We just stop doing whatever we were doing */ 1978 putchar('\n'); 1979 } 1980 rcode = 0; 1981 goto ret; 1982 } 1983 /* ctrl-Z handler will store pid etc in pi */ 1984 toplevel_list = pi; 1985 ctrl_z_flag = 0; 1986#if ENABLE_FEATURE_SH_STANDALONE 1987 nofork_save.saved = 0; /* in case we will run a nofork later */ 1988#endif 1989 signal_SA_RESTART(SIGTSTP, handler_ctrl_z); 1990 signal(SIGINT, handler_ctrl_c); 1991 } 1992#endif 1993 1994 for (; pi; pi = flag_restore ? rpipe : pi->next) { 1995 rword = pi->res_word; 1996#if ENABLE_HUSH_LOOPS 1997 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) { 1998 flag_restore = 0; 1999 if (!rpipe) { 2000 flag_rep = 0; 2001 rpipe = pi; 2002 } 2003 } 2004#endif 2005 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n", 2006 rword, if_code, next_if_code, skip_more_for_this_rword); 2007 if (rword == skip_more_for_this_rword && flag_skip) { 2008 if (pi->followup == PIPE_SEQ) 2009 flag_skip = 0; 2010 continue; 2011 } 2012 flag_skip = 1; 2013 skip_more_for_this_rword = RES_XXXX; 2014#if ENABLE_HUSH_IF 2015 if (rword == RES_THEN || rword == RES_ELSE) 2016 if_code = next_if_code; 2017 if (rword == RES_THEN && if_code) 2018 continue; 2019 if (rword == RES_ELSE && !if_code) 2020 continue; 2021 if (rword == RES_ELIF && !if_code) 2022 break; 2023#endif 2024#if ENABLE_HUSH_LOOPS 2025 if (rword == RES_FOR && pi->num_progs) { 2026 if (!for_lcur) { 2027 /* if no variable values after "in" we skip "for" */ 2028 if (!pi->next->progs->argv) 2029 continue; 2030 /* create list of variable values */ 2031 for_list = expand_strvec_to_strvec(pi->next->progs->argv); 2032 for_lcur = for_list; 2033 for_varname = pi->progs->argv[0]; 2034 pi->progs->argv[0] = NULL; 2035 flag_rep = 1; 2036 } 2037 free(pi->progs->argv[0]); 2038 if (!*for_lcur) { 2039 free(for_list); 2040 for_lcur = NULL; 2041 flag_rep = 0; 2042 pi->progs->argv[0] = for_varname; 2043 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0]; 2044 continue; 2045 } 2046 /* insert next value from for_lcur */ 2047 /* vda: does it need escaping? */ 2048 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++); 2049 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0]; 2050 } 2051 if (rword == RES_IN) 2052 continue; 2053 if (rword == RES_DO) { 2054 if (!flag_rep) 2055 continue; 2056 } 2057 if (rword == RES_DONE) { 2058 if (flag_rep) { 2059 flag_restore = 1; 2060 } else { 2061 rpipe = NULL; 2062 } 2063 } 2064#endif 2065 if (pi->num_progs == 0) 2066 continue; 2067 save_num_progs = pi->num_progs; /* save number of programs */ 2068 debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs); 2069 rcode = run_pipe_real(pi); 2070 if (rcode != -1) { 2071 /* We only ran a builtin: rcode was set by the return value 2072 * of run_pipe_real(), and we don't need to wait for anything. */ 2073 } else if (pi->followup == PIPE_BG) { 2074 /* What does bash do with attempts to background builtins? */ 2075 /* Even bash 3.2 doesn't do that well with nested bg: 2076 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". 2077 * I'm NOT treating inner &'s as jobs */ 2078#if ENABLE_HUSH_JOB 2079 if (run_list_level == 1) 2080 insert_bg_job(pi); 2081#endif 2082 rcode = EXIT_SUCCESS; 2083 } else { 2084#if ENABLE_HUSH_JOB 2085 /* Paranoia, just "interactive_fd" should be enough? */ 2086 if (run_list_level == 1 && interactive_fd) { 2087 /* waits for completion, then fg's main shell */ 2088 rcode = checkjobs_and_fg_shell(pi); 2089 } else 2090#endif 2091 { 2092 /* this one just waits for completion */ 2093 rcode = checkjobs(pi); 2094 } 2095 debug_printf_exec(": checkjobs returned %d\n", rcode); 2096 } 2097 debug_printf_exec(": setting last_return_code=%d\n", rcode); 2098 last_return_code = rcode; 2099 pi->num_progs = save_num_progs; /* restore number of programs */ 2100#if ENABLE_HUSH_IF 2101 if (rword == RES_IF || rword == RES_ELIF) 2102 next_if_code = rcode; /* can be overwritten a number of times */ 2103#endif 2104#if ENABLE_HUSH_LOOPS 2105 if (rword == RES_WHILE) 2106 flag_rep = !last_return_code; 2107 if (rword == RES_UNTIL) 2108 flag_rep = last_return_code; 2109#endif 2110 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR) 2111 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND) 2112 ) { 2113 skip_more_for_this_rword = rword; 2114 } 2115 checkjobs(NULL); 2116 } 2117 2118#if ENABLE_HUSH_JOB 2119 if (ctrl_z_flag) { 2120 /* ctrl-Z forked somewhere in the past, we are the child, 2121 * and now we completed running the list. Exit. */ 2122 exit(rcode); 2123 } 2124 ret: 2125 if (!--run_list_level && interactive_fd) { 2126 signal(SIGTSTP, SIG_IGN); 2127 signal(SIGINT, SIG_IGN); 2128 } 2129#endif 2130 debug_printf_exec("run_list_real lvl %d return %d\n", run_list_level + 1, rcode); 2131 return rcode; 2132} 2133 2134/* return code is the exit status of the pipe */ 2135static int free_pipe(struct pipe *pi, int indent) 2136{ 2137 char **p; 2138 struct child_prog *child; 2139 struct redir_struct *r, *rnext; 2140 int a, i, ret_code = 0; 2141 2142 if (pi->stopped_progs > 0) 2143 return ret_code; 2144 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid()); 2145 for (i = 0; i < pi->num_progs; i++) { 2146 child = &pi->progs[i]; 2147 debug_printf_clean("%s command %d:\n", indenter(indent), i); 2148 if (child->argv) { 2149 for (a = 0, p = child->argv; *p; a++, p++) { 2150 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); 2151 } 2152 globfree(&child->glob_result); 2153 child->argv = NULL; 2154 } else if (child->group) { 2155 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell); 2156 ret_code = free_pipe_list(child->group, indent+3); 2157 debug_printf_clean("%s end group\n", indenter(indent)); 2158 } else { 2159 debug_printf_clean("%s (nil)\n", indenter(indent)); 2160 } 2161 for (r = child->redirects; r; r = rnext) { 2162 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip); 2163 if (r->dup == -1) { 2164 /* guard against the case >$FOO, where foo is unset or blank */ 2165 if (r->word.gl_pathv) { 2166 debug_printf_clean(" %s\n", *r->word.gl_pathv); 2167 globfree(&r->word); 2168 } 2169 } else { 2170 debug_printf_clean("&%d\n", r->dup); 2171 } 2172 rnext = r->next; 2173 free(r); 2174 } 2175 child->redirects = NULL; 2176 } 2177 free(pi->progs); /* children are an array, they get freed all at once */ 2178 pi->progs = NULL; 2179#if ENABLE_HUSH_JOB 2180 free(pi->cmdtext); 2181 pi->cmdtext = NULL; 2182#endif 2183 return ret_code; 2184} 2185 2186static int free_pipe_list(struct pipe *head, int indent) 2187{ 2188 int rcode = 0; /* if list has no members */ 2189 struct pipe *pi, *next; 2190 2191 for (pi = head; pi; pi = next) { 2192 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word); 2193 rcode = free_pipe(pi, indent); 2194 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup); 2195 next = pi->next; 2196 /*pi->next = NULL;*/ 2197 free(pi); 2198 } 2199 return rcode; 2200} 2201 2202/* Select which version we will use */ 2203static int run_list(struct pipe *pi) 2204{ 2205 int rcode = 0; 2206 debug_printf_exec("run_list entered\n"); 2207 if (fake_mode == 0) { 2208 debug_printf_exec(": run_list_real with %d members\n", pi->num_progs); 2209 rcode = run_list_real(pi); 2210 } 2211 /* free_pipe_list has the side effect of clearing memory. 2212 * In the long run that function can be merged with run_list_real, 2213 * but doing that now would hobble the debugging effort. */ 2214 free_pipe_list(pi, 0); 2215 debug_printf_exec("run_list return %d\n", rcode); 2216 return rcode; 2217} 2218 2219static int globhack(const char *src, int flags, glob_t *pglob) 2220{ 2221 int cnt = 0, pathc; 2222 const char *s; 2223 char *dest; 2224 for (cnt = 1, s = src; s && *s; s++) { 2225 if (*s == '\\') s++; 2226 cnt++; 2227 } 2228 dest = xmalloc(cnt); 2229 if (!(flags & GLOB_APPEND)) { 2230 pglob->gl_pathv = NULL; 2231 pglob->gl_pathc = 0; 2232 pglob->gl_offs = 0; 2233 pglob->gl_offs = 0; 2234 } 2235 pathc = ++pglob->gl_pathc; 2236 pglob->gl_pathv = xrealloc(pglob->gl_pathv, (pathc+1) * sizeof(*pglob->gl_pathv)); 2237 pglob->gl_pathv[pathc-1] = dest; 2238 pglob->gl_pathv[pathc] = NULL; 2239 for (s = src; s && *s; s++, dest++) { 2240 if (*s == '\\') s++; 2241 *dest = *s; 2242 } 2243 *dest = '\0'; 2244 return 0; 2245} 2246 2247static int glob_needed(const char *s) 2248{ 2249 for (; *s; s++) { 2250 if (*s == '\\') s++; 2251 if (strchr("*[?", *s)) return 1; 2252 } 2253 return 0; 2254} 2255 2256static int xglob(o_string *dest, int flags, glob_t *pglob) 2257{ 2258 int gr; 2259 2260 /* short-circuit for null word */ 2261 /* we can code this better when the debug_printf's are gone */ 2262 if (dest->length == 0) { 2263 if (dest->nonnull) { 2264 /* bash man page calls this an "explicit" null */ 2265 gr = globhack(dest->data, flags, pglob); 2266 debug_printf("globhack returned %d\n", gr); 2267 } else { 2268 return 0; 2269 } 2270 } else if (glob_needed(dest->data)) { 2271 gr = glob(dest->data, flags, NULL, pglob); 2272 debug_printf("glob returned %d\n", gr); 2273 if (gr == GLOB_NOMATCH) { 2274 /* quote removal, or more accurately, backslash removal */ 2275 gr = globhack(dest->data, flags, pglob); 2276 debug_printf("globhack returned %d\n", gr); 2277 } 2278 } else { 2279 gr = globhack(dest->data, flags, pglob); 2280 debug_printf("globhack returned %d\n", gr); 2281 } 2282 if (gr == GLOB_NOSPACE) 2283 bb_error_msg_and_die("out of memory during glob"); 2284 if (gr != 0) { /* GLOB_ABORTED ? */ 2285 bb_error_msg("glob(3) error %d", gr); 2286 } 2287 /* globprint(glob_target); */ 2288 return gr; 2289} 2290 2291/* expand_strvec_to_strvec() takes a list of strings, expands 2292 * all variable references within and returns a pointer to 2293 * a list of expanded strings, possibly with larger number 2294 * of strings. (Think VAR="a b"; echo $VAR). 2295 * This new list is allocated as a single malloc block. 2296 * NULL-terminated list of char* pointers is at the beginning of it, 2297 * followed by strings themself. 2298 * Caller can deallocate entire list by single free(list). */ 2299 2300/* Helpers first: 2301 * count_XXX estimates size of the block we need. It's okay 2302 * to over-estimate sizes a bit, if it makes code simpler */ 2303static int count_ifs(const char *str) 2304{ 2305 int cnt = 0; 2306 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs); 2307 while (1) { 2308 str += strcspn(str, ifs); 2309 if (!*str) break; 2310 str++; /* str += strspn(str, ifs); */ 2311 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */ 2312 } 2313 debug_printf_expand(" return %d\n", cnt); 2314 return cnt; 2315} 2316 2317static void count_var_expansion_space(int *countp, int *lenp, char *arg) 2318{ 2319 char first_ch; 2320 int i; 2321 int len = *lenp; 2322 int count = *countp; 2323 const char *val; 2324 char *p; 2325 2326 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { 2327 len += p - arg; 2328 arg = ++p; 2329 p = strchr(p, SPECIAL_VAR_SYMBOL); 2330 first_ch = arg[0]; 2331 2332 switch (first_ch & 0x7f) { 2333 /* high bit in 1st_ch indicates that var is double-quoted */ 2334 case '$': /* pid */ 2335 case '!': /* bg pid */ 2336 case '?': /* exitcode */ 2337 case '#': /* argc */ 2338 len += sizeof(int)*3 + 1; /* enough for int */ 2339 break; 2340 case '*': 2341 case '@': 2342 for (i = 1; i < global_argc; i++) { 2343 len += strlen(global_argv[i]) + 1; 2344 count++; 2345 if (!(first_ch & 0x80)) 2346 count += count_ifs(global_argv[i]); 2347 } 2348 break; 2349 default: 2350 *p = '\0'; 2351 arg[0] = first_ch & 0x7f; 2352 if (isdigit(arg[0])) { 2353 i = xatoi_u(arg); 2354 val = NULL; 2355 if (i < global_argc) 2356 val = global_argv[i]; 2357 } else 2358 val = lookup_param(arg); 2359 arg[0] = first_ch; 2360 *p = SPECIAL_VAR_SYMBOL; 2361 2362 if (val) { 2363 len += strlen(val) + 1; 2364 if (!(first_ch & 0x80)) 2365 count += count_ifs(val); 2366 } 2367 } 2368 arg = ++p; 2369 } 2370 2371 len += strlen(arg) + 1; 2372 count++; 2373 *lenp = len; 2374 *countp = count; 2375} 2376 2377/* Store given string, finalizing the word and starting new one whenever 2378 * we encounter ifs char(s). This is used for expanding variable values. 2379 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ 2380static int expand_on_ifs(char **list, int n, char **posp, const char *str) 2381{ 2382 char *pos = *posp; 2383 while (1) { 2384 int word_len = strcspn(str, ifs); 2385 if (word_len) { 2386 memcpy(pos, str, word_len); /* store non-ifs chars */ 2387 pos += word_len; 2388 str += word_len; 2389 } 2390 if (!*str) /* EOL - do not finalize word */ 2391 break; 2392 *pos++ = '\0'; 2393 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' " 2394 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2395 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2396 list[n++] = pos; 2397 str += strspn(str, ifs); /* skip ifs chars */ 2398 } 2399 *posp = pos; 2400 return n; 2401} 2402 2403/* Expand all variable references in given string, adding words to list[] 2404 * at n, n+1,... positions. Return updated n (so that list[n] is next one 2405 * to be filled). This routine is extremely tricky: has to deal with 2406 * variables/parameters with whitespace, $* and $@, and constructs like 2407 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ 2408/* NB: another bug is that we cannot detect empty strings yet: 2409 * "" or $empty"" expands to zero words, has to expand to empty word */ 2410static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask) 2411{ 2412 /* or_mask is either 0 (normal case) or 0x80 2413 * (expansion of right-hand side of assignment == 1-element expand) */ 2414 2415 char first_ch, ored_ch; 2416 int i; 2417 const char *val; 2418 char *p; 2419 char *pos = *posp; 2420 2421 ored_ch = 0; 2422 2423 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' " 2424 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2425 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2426 list[n++] = pos; 2427 2428 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { 2429 memcpy(pos, arg, p - arg); 2430 pos += (p - arg); 2431 arg = ++p; 2432 p = strchr(p, SPECIAL_VAR_SYMBOL); 2433 2434 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ 2435 ored_ch |= first_ch; 2436 val = NULL; 2437 switch (first_ch & 0x7f) { 2438 /* Highest bit in first_ch indicates that var is double-quoted */ 2439 case '$': /* pid */ 2440 val = utoa(getpid()); 2441 break; 2442 case '!': /* bg pid */ 2443 val = last_bg_pid ? utoa(last_bg_pid) : (char*)""; 2444 break; 2445 case '?': /* exitcode */ 2446 val = utoa(last_return_code); 2447 break; 2448 case '#': /* argc */ 2449 val = utoa(global_argc ? global_argc-1 : 0); 2450 break; 2451 case '*': 2452 case '@': 2453 i = 1; 2454 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ 2455 while (i < global_argc) { 2456 n = expand_on_ifs(list, n, &pos, global_argv[i]); 2457 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1); 2458 if (global_argv[i++][0] && i < global_argc) { 2459 /* this argv[] is not empty and not last: 2460 * put terminating NUL, start new word */ 2461 *pos++ = '\0'; 2462 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' " 2463 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2464 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2465 list[n++] = pos; 2466 } 2467 } 2468 } else 2469 /* If or_mask is nonzero, we handle assignment 'a=....$@.....' 2470 * and in this case should theat it like '$*' */ 2471 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ 2472 while (1) { 2473 strcpy(pos, global_argv[i]); 2474 pos += strlen(global_argv[i]); 2475 if (++i >= global_argc) 2476 break; 2477 *pos++ = '\0'; 2478 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' " 2479 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2480 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2481 list[n++] = pos; 2482 } 2483 } else { /* quoted $*: add as one word */ 2484 while (1) { 2485 strcpy(pos, global_argv[i]); 2486 pos += strlen(global_argv[i]); 2487 if (++i >= global_argc) 2488 break; 2489 if (ifs[0]) 2490 *pos++ = ifs[0]; 2491 } 2492 } 2493 break; 2494 default: 2495 *p = '\0'; 2496 arg[0] = first_ch & 0x7f; 2497 if (isdigit(arg[0])) { 2498 i = xatoi_u(arg); 2499 val = NULL; 2500 if (i < global_argc) 2501 val = global_argv[i]; 2502 } else 2503 val = lookup_param(arg); 2504 arg[0] = first_ch; 2505 *p = SPECIAL_VAR_SYMBOL; 2506 if (!(first_ch & 0x80)) { /* unquoted $VAR */ 2507 if (val) { 2508 n = expand_on_ifs(list, n, &pos, val); 2509 val = NULL; 2510 } 2511 } /* else: quoted $VAR, val will be appended at pos */ 2512 } 2513 if (val) { 2514 strcpy(pos, val); 2515 pos += strlen(val); 2516 } 2517 arg = ++p; 2518 } 2519 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos); 2520 strcpy(pos, arg); 2521 pos += strlen(arg) + 1; 2522 if (pos == list[n-1] + 1) { /* expansion is empty */ 2523 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */ 2524 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n); 2525 pos--; 2526 n--; 2527 } 2528 } 2529 2530 *posp = pos; 2531 return n; 2532} 2533 2534static char **expand_variables(char **argv, char or_mask) 2535{ 2536 int n; 2537 int count = 1; 2538 int len = 0; 2539 char *pos, **v, **list; 2540 2541 v = argv; 2542 if (!*v) debug_printf_expand("count_var_expansion_space: " 2543 "argv[0]=NULL count=%d len=%d alloc_space=%d\n", 2544 count, len, sizeof(char*) * count + len); 2545 while (*v) { 2546 count_var_expansion_space(&count, &len, *v); 2547 debug_printf_expand("count_var_expansion_space: " 2548 "'%s' count=%d len=%d alloc_space=%d\n", 2549 *v, count, len, sizeof(char*) * count + len); 2550 v++; 2551 } 2552 len += sizeof(char*) * count; /* total to alloc */ 2553 list = xmalloc(len); 2554 pos = (char*)(list + count); 2555 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos); 2556 n = 0; 2557 v = argv; 2558 while (*v) 2559 n = expand_vars_to_list(list, n, &pos, *v++, or_mask); 2560 2561 if (n) debug_printf_expand("finalized list[%d]=%p '%s' " 2562 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2563 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2564 list[n] = NULL; 2565 2566#ifdef DEBUG_EXPAND 2567 { 2568 int m = 0; 2569 while (m <= n) { 2570 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]); 2571 m++; 2572 } 2573 debug_printf_expand("used_space=%d\n", pos - (char*)list); 2574 } 2575#endif 2576 if (ENABLE_HUSH_DEBUG) 2577 if (pos - (char*)list > len) 2578 bb_error_msg_and_die("BUG in varexp"); 2579 return list; 2580} 2581 2582static char **expand_strvec_to_strvec(char **argv) 2583{ 2584 return expand_variables(argv, 0); 2585} 2586 2587static char *expand_string_to_string(const char *str) 2588{ 2589 char *argv[2], **list; 2590 2591 argv[0] = (char*)str; 2592 argv[1] = NULL; 2593 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ 2594 if (ENABLE_HUSH_DEBUG) 2595 if (!list[0] || list[1]) 2596 bb_error_msg_and_die("BUG in varexp2"); 2597 /* actually, just move string 2*sizeof(char*) bytes back */ 2598 strcpy((char*)list, list[0]); 2599 debug_printf_expand("string_to_string='%s'\n", (char*)list); 2600 return (char*)list; 2601} 2602 2603static char* expand_strvec_to_string(char **argv) 2604{ 2605 char **list; 2606 2607 list = expand_variables(argv, 0x80); 2608 /* Convert all NULs to spaces */ 2609 if (list[0]) { 2610 int n = 1; 2611 while (list[n]) { 2612 if (ENABLE_HUSH_DEBUG) 2613 if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) 2614 bb_error_msg_and_die("BUG in varexp3"); 2615 list[n][-1] = ' '; /* TODO: or to ifs[0]? */ 2616 n++; 2617 } 2618 } 2619 strcpy((char*)list, list[0]); 2620 debug_printf_expand("strvec_to_string='%s'\n", (char*)list); 2621 return (char*)list; 2622} 2623 2624/* This is used to get/check local shell variables */ 2625static struct variable *get_local_var(const char *name) 2626{ 2627 struct variable *cur; 2628 int len; 2629 2630 if (!name) 2631 return NULL; 2632 len = strlen(name); 2633 for (cur = top_var; cur; cur = cur->next) { 2634 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') 2635 return cur; 2636 } 2637 return NULL; 2638} 2639 2640/* str holds "NAME=VAL" and is expected to be malloced. 2641 * We take ownership of it. */ 2642static int set_local_var(char *str, int flg_export) 2643{ 2644 struct variable *cur; 2645 char *value; 2646 int name_len; 2647 2648 value = strchr(str, '='); 2649 if (!value) { /* not expected to ever happen? */ 2650 free(str); 2651 return -1; 2652 } 2653 2654 name_len = value - str + 1; /* including '=' */ 2655 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ 2656 while (1) { 2657 if (strncmp(cur->varstr, str, name_len) != 0) { 2658 if (!cur->next) { 2659 /* Bail out. Note that now cur points 2660 * to last var in linked list */ 2661 break; 2662 } 2663 cur = cur->next; 2664 continue; 2665 } 2666 /* We found an existing var with this name */ 2667 *value = '\0'; 2668 if (cur->flg_read_only) { 2669 bb_error_msg("%s: readonly variable", str); 2670 free(str); 2671 return -1; 2672 } 2673 unsetenv(str); /* just in case */ 2674 *value = '='; 2675 if (strcmp(cur->varstr, str) == 0) { 2676 free_and_exp: 2677 free(str); 2678 goto exp; 2679 } 2680 if (cur->max_len >= strlen(str)) { 2681 /* This one is from startup env, reuse space */ 2682 strcpy(cur->varstr, str); 2683 goto free_and_exp; 2684 } 2685 /* max_len == 0 signifies "malloced" var, which we can 2686 * (and has to) free */ 2687 if (!cur->max_len) 2688 free(cur->varstr); 2689 cur->max_len = 0; 2690 goto set_str_and_exp; 2691 } 2692 2693 /* Not found - create next variable struct */ 2694 cur->next = xzalloc(sizeof(*cur)); 2695 cur = cur->next; 2696 2697 set_str_and_exp: 2698 cur->varstr = str; 2699 exp: 2700 if (flg_export) 2701 cur->flg_export = 1; 2702 if (cur->flg_export) 2703 return putenv(cur->varstr); 2704 return 0; 2705} 2706 2707static void unset_local_var(const char *name) 2708{ 2709 struct variable *cur; 2710 struct variable *prev = prev; /* for gcc */ 2711 int name_len; 2712 2713 if (!name) 2714 return; 2715 name_len = strlen(name); 2716 cur = top_var; 2717 while (cur) { 2718 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { 2719 if (cur->flg_read_only) { 2720 bb_error_msg("%s: readonly variable", name); 2721 return; 2722 } 2723 /* prev is ok to use here because 1st variable, HUSH_VERSION, 2724 * is ro, and we cannot reach this code on the 1st pass */ 2725 prev->next = cur->next; 2726 unsetenv(cur->varstr); 2727 if (!cur->max_len) 2728 free(cur->varstr); 2729 free(cur); 2730 return; 2731 } 2732 prev = cur; 2733 cur = cur->next; 2734 } 2735} 2736 2737static int is_assignment(const char *s) 2738{ 2739 if (!s || !isalpha(*s)) 2740 return 0; 2741 s++; 2742 while (isalnum(*s) || *s == '_') 2743 s++; 2744 return *s == '='; 2745} 2746 2747/* the src parameter allows us to peek forward to a possible &n syntax 2748 * for file descriptor duplication, e.g., "2>&1". 2749 * Return code is 0 normally, 1 if a syntax error is detected in src. 2750 * Resource errors (in xmalloc) cause the process to exit */ 2751static int setup_redirect(struct p_context *ctx, int fd, redir_type style, 2752 struct in_str *input) 2753{ 2754 struct child_prog *child = ctx->child; 2755 struct redir_struct *redir = child->redirects; 2756 struct redir_struct *last_redir = NULL; 2757 2758 /* Create a new redir_struct and drop it onto the end of the linked list */ 2759 while (redir) { 2760 last_redir = redir; 2761 redir = redir->next; 2762 } 2763 redir = xmalloc(sizeof(struct redir_struct)); 2764 redir->next = NULL; 2765 redir->word.gl_pathv = NULL; 2766 if (last_redir) { 2767 last_redir->next = redir; 2768 } else { 2769 child->redirects = redir; 2770 } 2771 2772 redir->type = style; 2773 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd; 2774 2775 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); 2776 2777 /* Check for a '2>&1' type redirect */ 2778 redir->dup = redirect_dup_num(input); 2779 if (redir->dup == -2) return 1; /* syntax error */ 2780 if (redir->dup != -1) { 2781 /* Erik had a check here that the file descriptor in question 2782 * is legit; I postpone that to "run time" 2783 * A "-" representation of "close me" shows up as a -3 here */ 2784 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup); 2785 } else { 2786 /* We do _not_ try to open the file that src points to, 2787 * since we need to return and let src be expanded first. 2788 * Set ctx->pending_redirect, so we know what to do at the 2789 * end of the next parsed word. */ 2790 ctx->pending_redirect = redir; 2791 } 2792 return 0; 2793} 2794 2795static struct pipe *new_pipe(void) 2796{ 2797 struct pipe *pi; 2798 pi = xzalloc(sizeof(struct pipe)); 2799 /*pi->num_progs = 0;*/ 2800 /*pi->progs = NULL;*/ 2801 /*pi->next = NULL;*/ 2802 /*pi->followup = 0; invalid */ 2803 if (RES_NONE) 2804 pi->res_word = RES_NONE; 2805 return pi; 2806} 2807 2808static void initialize_context(struct p_context *ctx) 2809{ 2810 ctx->child = NULL; 2811 ctx->pipe = ctx->list_head = new_pipe(); 2812 ctx->pending_redirect = NULL; 2813 ctx->res_w = RES_NONE; 2814 //only ctx->parse_type is not touched... is this intentional? 2815 ctx->old_flag = 0; 2816 ctx->stack = NULL; 2817 done_command(ctx); /* creates the memory for working child */ 2818} 2819 2820/* normal return is 0 2821 * if a reserved word is found, and processed, return 1 2822 * should handle if, then, elif, else, fi, for, while, until, do, done. 2823 * case, function, and select are obnoxious, save those for later. 2824 */ 2825#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS 2826static int reserved_word(o_string *dest, struct p_context *ctx) 2827{ 2828 struct reserved_combo { 2829 char literal[7]; 2830 unsigned char code; 2831 int flag; 2832 }; 2833 /* Mostly a list of accepted follow-up reserved words. 2834 * FLAG_END means we are done with the sequence, and are ready 2835 * to turn the compound list into a command. 2836 * FLAG_START means the word must start a new compound list. 2837 */ 2838 static const struct reserved_combo reserved_list[] = { 2839#if ENABLE_HUSH_IF 2840 { "if", RES_IF, FLAG_THEN | FLAG_START }, 2841 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, 2842 { "elif", RES_ELIF, FLAG_THEN }, 2843 { "else", RES_ELSE, FLAG_FI }, 2844 { "fi", RES_FI, FLAG_END }, 2845#endif 2846#if ENABLE_HUSH_LOOPS 2847 { "for", RES_FOR, FLAG_IN | FLAG_START }, 2848 { "while", RES_WHILE, FLAG_DO | FLAG_START }, 2849 { "until", RES_UNTIL, FLAG_DO | FLAG_START }, 2850 { "in", RES_IN, FLAG_DO }, 2851 { "do", RES_DO, FLAG_DONE }, 2852 { "done", RES_DONE, FLAG_END } 2853#endif 2854 }; 2855 2856 const struct reserved_combo *r; 2857 2858 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { 2859 if (strcmp(dest->data, r->literal) != 0) 2860 continue; 2861 debug_printf("found reserved word %s, code %d\n", r->literal, r->code); 2862 if (r->flag & FLAG_START) { 2863 struct p_context *new; 2864 debug_printf("push stack\n"); 2865#if ENABLE_HUSH_LOOPS 2866 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) { 2867 syntax("malformed for"); /* example: 'for if' */ 2868 ctx->res_w = RES_SNTX; 2869 b_reset(dest); 2870 return 1; 2871 } 2872#endif 2873 new = xmalloc(sizeof(*new)); 2874 *new = *ctx; /* physical copy */ 2875 initialize_context(ctx); 2876 ctx->stack = new; 2877 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) { 2878 syntax(NULL); 2879 ctx->res_w = RES_SNTX; 2880 b_reset(dest); 2881 return 1; 2882 } 2883 ctx->res_w = r->code; 2884 ctx->old_flag = r->flag; 2885 if (ctx->old_flag & FLAG_END) { 2886 struct p_context *old; 2887 debug_printf("pop stack\n"); 2888 done_pipe(ctx, PIPE_SEQ); 2889 old = ctx->stack; 2890 old->child->group = ctx->list_head; 2891 old->child->subshell = 0; 2892 *ctx = *old; /* physical copy */ 2893 free(old); 2894 } 2895 b_reset(dest); 2896 return 1; 2897 } 2898 return 0; 2899} 2900#else 2901#define reserved_word(dest, ctx) ((int)0) 2902#endif 2903 2904/* Normal return is 0. 2905 * Syntax or xglob errors return 1. */ 2906static int done_word(o_string *dest, struct p_context *ctx) 2907{ 2908 struct child_prog *child = ctx->child; 2909 glob_t *glob_target; 2910 int gr, flags = 0; 2911 2912 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child); 2913 if (dest->length == 0 && !dest->nonnull) { 2914 debug_printf_parse("done_word return 0: true null, ignored\n"); 2915 return 0; 2916 } 2917 if (ctx->pending_redirect) { 2918 glob_target = &ctx->pending_redirect->word; 2919 } else { 2920 if (child->group) { 2921 syntax(NULL); 2922 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); 2923 return 1; 2924 } 2925 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) { 2926 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data); 2927 if (reserved_word(dest, ctx)) { 2928 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX)); 2929 return (ctx->res_w == RES_SNTX); 2930 } 2931 } 2932 glob_target = &child->glob_result; 2933 if (child->argv) 2934 flags |= GLOB_APPEND; 2935 } 2936 gr = xglob(dest, flags, glob_target); 2937 if (gr != 0) { 2938 debug_printf_parse("done_word return 1: xglob returned %d\n", gr); 2939 return 1; 2940 } 2941 2942 b_reset(dest); 2943 if (ctx->pending_redirect) { 2944 ctx->pending_redirect = NULL; 2945 if (glob_target->gl_pathc != 1) { 2946 bb_error_msg("ambiguous redirect"); 2947 debug_printf_parse("done_word return 1: ambiguous redirect\n"); 2948 return 1; 2949 } 2950 } else { 2951 child->argv = glob_target->gl_pathv; 2952 } 2953#if ENABLE_HUSH_LOOPS 2954 if (ctx->res_w == RES_FOR) { 2955 done_word(dest, ctx); 2956 done_pipe(ctx, PIPE_SEQ); 2957 } 2958#endif 2959 debug_printf_parse("done_word return 0\n"); 2960 return 0; 2961} 2962 2963/* The only possible error here is out of memory, in which case 2964 * xmalloc exits. */ 2965static int done_command(struct p_context *ctx) 2966{ 2967 /* The child is really already in the pipe structure, so 2968 * advance the pipe counter and make a new, null child. */ 2969 struct pipe *pi = ctx->pipe; 2970 struct child_prog *child = ctx->child; 2971 2972 if (child) { 2973 if (child->group == NULL 2974 && child->argv == NULL 2975 && child->redirects == NULL 2976 ) { 2977 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs); 2978 return pi->num_progs; 2979 } 2980 pi->num_progs++; 2981 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs); 2982 } else { 2983 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs); 2984 } 2985 2986 /* Only real trickiness here is that the uncommitted 2987 * child structure is not counted in pi->num_progs. */ 2988 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); 2989 child = &pi->progs[pi->num_progs]; 2990 2991 memset(child, 0, sizeof(*child)); 2992 /*child->redirects = NULL;*/ 2993 /*child->argv = NULL;*/ 2994 /*child->is_stopped = 0;*/ 2995 /*child->group = NULL;*/ 2996 /*child->glob_result.gl_pathv = NULL;*/ 2997 child->family = pi; 2998 //sp: /*child->sp = 0;*/ 2999 //pt: child->parse_type = ctx->parse_type; 3000 3001 ctx->child = child; 3002 /* but ctx->pipe and ctx->list_head remain unchanged */ 3003 3004 return pi->num_progs; /* used only for 0/nonzero check */ 3005} 3006 3007static int done_pipe(struct p_context *ctx, pipe_style type) 3008{ 3009 struct pipe *new_p; 3010 int not_null; 3011 3012 debug_printf_parse("done_pipe entered, followup %d\n", type); 3013 not_null = done_command(ctx); /* implicit closure of previous command */ 3014 ctx->pipe->followup = type; 3015 ctx->pipe->res_word = ctx->res_w; 3016 /* Without this check, even just <enter> on command line generates 3017 * tree of three NOPs (!). Which is harmless but annoying. 3018 * IOW: it is safe to do it unconditionally. */ 3019 if (not_null) { 3020 new_p = new_pipe(); 3021 ctx->pipe->next = new_p; 3022 ctx->pipe = new_p; 3023 ctx->child = NULL; 3024 done_command(ctx); /* set up new pipe to accept commands */ 3025 } 3026 debug_printf_parse("done_pipe return 0\n"); 3027 return 0; 3028} 3029 3030/* peek ahead in the in_str to find out if we have a "&n" construct, 3031 * as in "2>&1", that represents duplicating a file descriptor. 3032 * returns either -2 (syntax error), -1 (no &), or the number found. 3033 */ 3034static int redirect_dup_num(struct in_str *input) 3035{ 3036 int ch, d = 0, ok = 0; 3037 ch = b_peek(input); 3038 if (ch != '&') return -1; 3039 3040 b_getch(input); /* get the & */ 3041 ch = b_peek(input); 3042 if (ch == '-') { 3043 b_getch(input); 3044 return -3; /* "-" represents "close me" */ 3045 } 3046 while (isdigit(ch)) { 3047 d = d*10 + (ch-'0'); 3048 ok = 1; 3049 b_getch(input); 3050 ch = b_peek(input); 3051 } 3052 if (ok) return d; 3053 3054 bb_error_msg("ambiguous redirect"); 3055 return -2; 3056} 3057 3058/* If a redirect is immediately preceded by a number, that number is 3059 * supposed to tell which file descriptor to redirect. This routine 3060 * looks for such preceding numbers. In an ideal world this routine 3061 * needs to handle all the following classes of redirects... 3062 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo 3063 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo 3064 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo 3065 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo 3066 * A -1 output from this program means no valid number was found, so the 3067 * caller should use the appropriate default for this redirection. 3068 */ 3069static int redirect_opt_num(o_string *o) 3070{ 3071 int num; 3072 3073 if (o->length == 0) 3074 return -1; 3075 for (num = 0; num < o->length; num++) { 3076 if (!isdigit(*(o->data + num))) { 3077 return -1; 3078 } 3079 } 3080 /* reuse num (and save an int) */ 3081 num = atoi(o->data); 3082 b_reset(o); 3083 return num; 3084} 3085 3086#if ENABLE_HUSH_TICK 3087static FILE *generate_stream_from_list(struct pipe *head) 3088{ 3089 FILE *pf; 3090 int pid, channel[2]; 3091 3092 xpipe(channel); 3093#if BB_MMU 3094 pid = fork(); 3095#else 3096 pid = vfork(); 3097#endif 3098 if (pid < 0) { 3099 bb_perror_msg_and_die("fork"); 3100 } else if (pid == 0) { 3101 close(channel[0]); 3102 if (channel[1] != 1) { 3103 dup2(channel[1], 1); 3104 close(channel[1]); 3105 } 3106 /* Prevent it from trying to handle ctrl-z etc */ 3107#if ENABLE_HUSH_JOB 3108 run_list_level = 1; 3109#endif 3110 /* Process substitution is not considered to be usual 3111 * 'command execution'. 3112 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */ 3113 /* Not needed, we are relying on it being disabled 3114 * everywhere outside actual command execution. */ 3115 /*set_jobctrl_sighandler(SIG_IGN);*/ 3116 set_misc_sighandler(SIG_DFL); 3117 _exit(run_list_real(head)); /* leaks memory */ 3118 } 3119 close(channel[1]); 3120 pf = fdopen(channel[0], "r"); 3121 return pf; 3122} 3123 3124/* Return code is exit status of the process that is run. */ 3125static int process_command_subs(o_string *dest, struct p_context *ctx, 3126 struct in_str *input, const char *subst_end) 3127{ 3128 int retcode, ch, eol_cnt; 3129 o_string result = NULL_O_STRING; 3130 struct p_context inner; 3131 FILE *p; 3132 struct in_str pipe_str; 3133 3134 initialize_context(&inner); 3135 3136 /* recursion to generate command */ 3137 retcode = parse_stream(&result, &inner, input, subst_end); 3138 if (retcode != 0) 3139 return retcode; /* syntax error or EOF */ 3140 done_word(&result, &inner); 3141 done_pipe(&inner, PIPE_SEQ); 3142 b_free(&result); 3143 3144 p = generate_stream_from_list(inner.list_head); 3145 if (p == NULL) return 1; 3146 mark_open(fileno(p)); 3147 setup_file_in_str(&pipe_str, p); 3148 3149 /* now send results of command back into original context */ 3150 eol_cnt = 0; 3151 while ((ch = b_getch(&pipe_str)) != EOF) { 3152 if (ch == '\n') { 3153 eol_cnt++; 3154 continue; 3155 } 3156 while (eol_cnt) { 3157 b_addqchr(dest, '\n', dest->quote); 3158 eol_cnt--; 3159 } 3160 b_addqchr(dest, ch, dest->quote); 3161 } 3162 3163 debug_printf("done reading from pipe, pclose()ing\n"); 3164 /* This is the step that wait()s for the child. Should be pretty 3165 * safe, since we just read an EOF from its stdout. We could try 3166 * to do better, by using wait(), and keeping track of background jobs 3167 * at the same time. That would be a lot of work, and contrary 3168 * to the KISS philosophy of this program. */ 3169 mark_closed(fileno(p)); 3170 retcode = fclose(p); 3171 free_pipe_list(inner.list_head, 0); 3172 debug_printf("closed FILE from child, retcode=%d\n", retcode); 3173 return retcode; 3174} 3175#endif 3176 3177static int parse_group(o_string *dest, struct p_context *ctx, 3178 struct in_str *input, int ch) 3179{ 3180 int rcode; 3181 const char *endch = NULL; 3182 struct p_context sub; 3183 struct child_prog *child = ctx->child; 3184 3185 debug_printf_parse("parse_group entered\n"); 3186 if (child->argv) { 3187 syntax(NULL); 3188 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n"); 3189 return 1; 3190 } 3191 initialize_context(&sub); 3192 endch = "}"; 3193 if (ch == '(') { 3194 endch = ")"; 3195 child->subshell = 1; 3196 } 3197 rcode = parse_stream(dest, &sub, input, endch); 3198//vda: err chk? 3199 done_word(dest, &sub); /* finish off the final word in the subcontext */ 3200 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */ 3201 child->group = sub.list_head; 3202 3203 debug_printf_parse("parse_group return %d\n", rcode); 3204 return rcode; 3205 /* child remains "open", available for possible redirects */ 3206} 3207 3208/* Basically useful version until someone wants to get fancier, 3209 * see the bash man page under "Parameter Expansion" */ 3210static const char *lookup_param(const char *src) 3211{ 3212 struct variable *var = get_local_var(src); 3213 if (var) 3214 return strchr(var->varstr, '=') + 1; 3215 return NULL; 3216} 3217 3218/* return code: 0 for OK, 1 for syntax error */ 3219static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input) 3220{ 3221 int ch = b_peek(input); /* first character after the $ */ 3222 unsigned char quote_mask = dest->quote ? 0x80 : 0; 3223 3224 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch); 3225 if (isalpha(ch)) { 3226 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3227 //sp: ctx->child->sp++; 3228 while (1) { 3229 debug_printf_parse(": '%c'\n", ch); 3230 b_getch(input); 3231 b_addchr(dest, ch | quote_mask); 3232 quote_mask = 0; 3233 ch = b_peek(input); 3234 if (!isalnum(ch) && ch != '_') 3235 break; 3236 } 3237 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3238 } else if (isdigit(ch)) { 3239 make_one_char_var: 3240 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3241 //sp: ctx->child->sp++; 3242 debug_printf_parse(": '%c'\n", ch); 3243 b_getch(input); 3244 b_addchr(dest, ch | quote_mask); 3245 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3246 } else switch (ch) { 3247 case '$': /* pid */ 3248 case '!': /* last bg pid */ 3249 case '?': /* last exit code */ 3250 case '#': /* number of args */ 3251 case '*': /* args */ 3252 case '@': /* args */ 3253 goto make_one_char_var; 3254 case '{': 3255 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3256 //sp: ctx->child->sp++; 3257 b_getch(input); 3258 while (1) { 3259 ch = b_getch(input); 3260 if (ch == '}') 3261 break; 3262 if (!isalnum(ch) && ch != '_') { 3263 syntax("unterminated ${name}"); 3264 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n"); 3265 return 1; 3266 } 3267 debug_printf_parse(": '%c'\n", ch); 3268 b_addchr(dest, ch | quote_mask); 3269 quote_mask = 0; 3270 } 3271 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3272 break; 3273#if ENABLE_HUSH_TICK 3274 case '(': 3275 b_getch(input); 3276 process_command_subs(dest, ctx, input, ")"); 3277 break; 3278#endif 3279 case '-': 3280 case '_': 3281 /* still unhandled, but should be eventually */ 3282 bb_error_msg("unhandled syntax: $%c", ch); 3283 return 1; 3284 break; 3285 default: 3286 b_addqchr(dest, '$', dest->quote); 3287 } 3288 debug_printf_parse("handle_dollar return 0\n"); 3289 return 0; 3290} 3291 3292/* return code is 0 for normal exit, 1 for syntax error */ 3293static int parse_stream(o_string *dest, struct p_context *ctx, 3294 struct in_str *input, const char *end_trigger) 3295{ 3296 int ch, m; 3297 int redir_fd; 3298 redir_type redir_style; 3299 int next; 3300 3301 /* Only double-quote state is handled in the state variable dest->quote. 3302 * A single-quote triggers a bypass of the main loop until its mate is 3303 * found. When recursing, quote state is passed in via dest->quote. */ 3304 3305 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger); 3306 3307 while (1) { 3308 m = CHAR_IFS; 3309 next = '\0'; 3310 ch = b_getch(input); 3311 if (ch != EOF) { 3312 m = charmap[ch]; 3313 if (ch != '\n') 3314 next = b_peek(input); 3315 } 3316 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n", 3317 ch, ch, m, dest->quote); 3318 if (m == CHAR_ORDINARY 3319 || (m != CHAR_SPECIAL && dest->quote) 3320 ) { 3321 if (ch == EOF) { 3322 syntax("unterminated \""); 3323 debug_printf_parse("parse_stream return 1: unterminated \"\n"); 3324 return 1; 3325 } 3326 b_addqchr(dest, ch, dest->quote); 3327 continue; 3328 } 3329 if (m == CHAR_IFS) { 3330 if (done_word(dest, ctx)) { 3331 debug_printf_parse("parse_stream return 1: done_word!=0\n"); 3332 return 1; 3333 } 3334 if (ch == EOF) 3335 break; 3336 /* If we aren't performing a substitution, treat 3337 * a newline as a command separator. 3338 * [why we don't handle it exactly like ';'? --vda] */ 3339 if (end_trigger && ch == '\n') { 3340 done_pipe(ctx, PIPE_SEQ); 3341 } 3342 } 3343 if ((end_trigger && strchr(end_trigger, ch)) 3344 && !dest->quote && ctx->res_w == RES_NONE 3345 ) { 3346 debug_printf_parse("parse_stream return 0: end_trigger char found\n"); 3347 return 0; 3348 } 3349 if (m == CHAR_IFS) 3350 continue; 3351 switch (ch) { 3352 case '#': 3353 if (dest->length == 0 && !dest->quote) { 3354 while (1) { 3355 ch = b_peek(input); 3356 if (ch == EOF || ch == '\n') 3357 break; 3358 b_getch(input); 3359 } 3360 } else { 3361 b_addqchr(dest, ch, dest->quote); 3362 } 3363 break; 3364 case '\\': 3365 if (next == EOF) { 3366 syntax("\\<eof>"); 3367 debug_printf_parse("parse_stream return 1: \\<eof>\n"); 3368 return 1; 3369 } 3370 b_addqchr(dest, '\\', dest->quote); 3371 b_addqchr(dest, b_getch(input), dest->quote); 3372 break; 3373 case '$': 3374 if (handle_dollar(dest, ctx, input) != 0) { 3375 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n"); 3376 return 1; 3377 } 3378 break; 3379 case '\'': 3380 dest->nonnull = 1; 3381 while (1) { 3382 ch = b_getch(input); 3383 if (ch == EOF || ch == '\'') 3384 break; 3385 b_addchr(dest, ch); 3386 } 3387 if (ch == EOF) { 3388 syntax("unterminated '"); 3389 debug_printf_parse("parse_stream return 1: unterminated '\n"); 3390 return 1; 3391 } 3392 break; 3393 case '"': 3394 dest->nonnull = 1; 3395 dest->quote = !dest->quote; 3396 break; 3397#if ENABLE_HUSH_TICK 3398 case '`': 3399 process_command_subs(dest, ctx, input, "`"); 3400 break; 3401#endif 3402 case '>': 3403 redir_fd = redirect_opt_num(dest); 3404 done_word(dest, ctx); 3405 redir_style = REDIRECT_OVERWRITE; 3406 if (next == '>') { 3407 redir_style = REDIRECT_APPEND; 3408 b_getch(input); 3409 } 3410 setup_redirect(ctx, redir_fd, redir_style, input); 3411 break; 3412 case '<': 3413 redir_fd = redirect_opt_num(dest); 3414 done_word(dest, ctx); 3415 redir_style = REDIRECT_INPUT; 3416 if (next == '<') { 3417 redir_style = REDIRECT_HEREIS; 3418 b_getch(input); 3419 } else if (next == '>') { 3420 redir_style = REDIRECT_IO; 3421 b_getch(input); 3422 } 3423 setup_redirect(ctx, redir_fd, redir_style, input); 3424 break; 3425 case ';': 3426 done_word(dest, ctx); 3427 done_pipe(ctx, PIPE_SEQ); 3428 break; 3429 case '&': 3430 done_word(dest, ctx); 3431 if (next == '&') { 3432 b_getch(input); 3433 done_pipe(ctx, PIPE_AND); 3434 } else { 3435 done_pipe(ctx, PIPE_BG); 3436 } 3437 break; 3438 case '|': 3439 done_word(dest, ctx); 3440 if (next == '|') { 3441 b_getch(input); 3442 done_pipe(ctx, PIPE_OR); 3443 } else { 3444 /* we could pick up a file descriptor choice here 3445 * with redirect_opt_num(), but bash doesn't do it. 3446 * "echo foo 2| cat" yields "foo 2". */ 3447 done_command(ctx); 3448 } 3449 break; 3450 case '(': 3451 case '{': 3452 if (parse_group(dest, ctx, input, ch) != 0) { 3453 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n"); 3454 return 1; 3455 } 3456 break; 3457 case ')': 3458 case '}': 3459 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */ 3460 debug_printf_parse("parse_stream return 1: unexpected '}'\n"); 3461 return 1; 3462 default: 3463 if (ENABLE_HUSH_DEBUG) 3464 bb_error_msg_and_die("BUG: unexpected %c\n", ch); 3465 } 3466 } 3467 /* Complain if quote? No, maybe we just finished a command substitution 3468 * that was quoted. Example: 3469 * $ echo "`cat foo` plus more" 3470 * and we just got the EOF generated by the subshell that ran "cat foo" 3471 * The only real complaint is if we got an EOF when end_trigger != NULL, 3472 * that is, we were really supposed to get end_trigger, and never got 3473 * one before the EOF. Can't use the standard "syntax error" return code, 3474 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ 3475 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL)); 3476 if (end_trigger) 3477 return -1; 3478 return 0; 3479} 3480 3481static void set_in_charmap(const char *set, int code) 3482{ 3483 while (*set) 3484 charmap[(unsigned char)*set++] = code; 3485} 3486 3487static void update_charmap(void) 3488{ 3489 /* char *ifs and char charmap[256] are both globals. */ 3490 ifs = getenv("IFS"); 3491 if (ifs == NULL) 3492 ifs = " \t\n"; 3493 /* Precompute a list of 'flow through' behavior so it can be treated 3494 * quickly up front. Computation is necessary because of IFS. 3495 * Special case handling of IFS == " \t\n" is not implemented. 3496 * The charmap[] array only really needs two bits each, 3497 * and on most machines that would be faster (reduced L1 cache use). 3498 */ 3499 memset(charmap, CHAR_ORDINARY, sizeof(charmap)); 3500#if ENABLE_HUSH_TICK 3501 set_in_charmap("\\$\"`", CHAR_SPECIAL); 3502#else 3503 set_in_charmap("\\$\"", CHAR_SPECIAL); 3504#endif 3505 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED); 3506 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */ 3507} 3508 3509/* most recursion does not come through here, the exception is 3510 * from builtin_source() and builtin_eval() */ 3511static int parse_and_run_stream(struct in_str *inp, int parse_flag) 3512{ 3513 struct p_context ctx; 3514 o_string temp = NULL_O_STRING; 3515 int rcode; 3516 do { 3517 ctx.parse_type = parse_flag; 3518 initialize_context(&ctx); 3519 update_charmap(); 3520 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING)) 3521 set_in_charmap(";$&|", CHAR_ORDINARY); 3522#if ENABLE_HUSH_INTERACTIVE 3523 inp->promptmode = 0; /* PS1 */ 3524#endif 3525 /* We will stop & execute after each ';' or '\n'. 3526 * Example: "sleep 9999; echo TEST" + ctrl-C: 3527 * TEST should be printed */ 3528 rcode = parse_stream(&temp, &ctx, inp, ";\n"); 3529 if (rcode != 1 && ctx.old_flag != 0) { 3530 syntax(NULL); 3531 } 3532 if (rcode != 1 && ctx.old_flag == 0) { 3533 done_word(&temp, &ctx); 3534 done_pipe(&ctx, PIPE_SEQ); 3535 debug_print_tree(ctx.list_head, 0); 3536 debug_printf_exec("parse_stream_outer: run_list\n"); 3537 run_list(ctx.list_head); 3538 } else { 3539 if (ctx.old_flag != 0) { 3540 free(ctx.stack); 3541 b_reset(&temp); 3542 } 3543 temp.nonnull = 0; 3544 temp.quote = 0; 3545 inp->p = NULL; 3546 free_pipe_list(ctx.list_head, 0); 3547 } 3548 b_free(&temp); 3549 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ 3550 return 0; 3551} 3552 3553static int parse_and_run_string(const char *s, int parse_flag) 3554{ 3555 struct in_str input; 3556 setup_string_in_str(&input, s); 3557 return parse_and_run_stream(&input, parse_flag); 3558} 3559 3560static int parse_and_run_file(FILE *f) 3561{ 3562 int rcode; 3563 struct in_str input; 3564 setup_file_in_str(&input, f); 3565 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON); 3566 return rcode; 3567} 3568 3569#if ENABLE_HUSH_JOB 3570/* Make sure we have a controlling tty. If we get started under a job 3571 * aware app (like bash for example), make sure we are now in charge so 3572 * we don't fight over who gets the foreground */ 3573static void setup_job_control(void) 3574{ 3575 pid_t shell_pgrp; 3576 3577 saved_task_pgrp = shell_pgrp = getpgrp(); 3578 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp); 3579 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC); 3580 3581 /* If we were ran as 'hush &', 3582 * sleep until we are in the foreground. */ 3583 while (tcgetpgrp(interactive_fd) != shell_pgrp) { 3584 /* Send TTIN to ourself (should stop us) */ 3585 kill(- shell_pgrp, SIGTTIN); 3586 shell_pgrp = getpgrp(); 3587 } 3588 3589 /* Ignore job-control and misc signals. */ 3590 set_jobctrl_sighandler(SIG_IGN); 3591 set_misc_sighandler(SIG_IGN); 3592//huh? signal(SIGCHLD, SIG_IGN); 3593 3594 /* We _must_ restore tty pgrp on fatal signals */ 3595 set_fatal_sighandler(sigexit); 3596 3597 /* Put ourselves in our own process group. */ 3598 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */ 3599 /* Grab control of the terminal. */ 3600 tcsetpgrp(interactive_fd, getpid()); 3601} 3602#endif 3603 3604int hush_main(int argc, char **argv); 3605int hush_main(int argc, char **argv) 3606{ 3607 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR; 3608 static const struct variable const_shell_ver = { 3609 .next = NULL, 3610 .varstr = (char*)version_str, 3611 .max_len = 1, /* 0 can provoke free(name) */ 3612 .flg_export = 1, 3613 .flg_read_only = 1, 3614 }; 3615 3616 int opt; 3617 FILE *input; 3618 char **e; 3619 struct variable *cur_var; 3620 3621 PTR_TO_GLOBALS = xzalloc(sizeof(G)); 3622 3623 /* Deal with HUSH_VERSION */ 3624 shell_ver = const_shell_ver; /* copying struct here */ 3625 top_var = &shell_ver; 3626 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */ 3627 /* Initialize our shell local variables with the values 3628 * currently living in the environment */ 3629 cur_var = top_var; 3630 e = environ; 3631 if (e) while (*e) { 3632 char *value = strchr(*e, '='); 3633 if (value) { /* paranoia */ 3634 cur_var->next = xzalloc(sizeof(*cur_var)); 3635 cur_var = cur_var->next; 3636 cur_var->varstr = *e; 3637 cur_var->max_len = strlen(*e); 3638 cur_var->flg_export = 1; 3639 } 3640 e++; 3641 } 3642 putenv((char *)version_str); /* reinstate HUSH_VERSION */ 3643 3644#if ENABLE_FEATURE_EDITING 3645 line_input_state = new_line_input_t(FOR_SHELL); 3646#endif 3647 global_argc = argc; 3648 global_argv = argv; 3649 /* Initialize some more globals to non-zero values */ 3650 set_cwd(); 3651#if ENABLE_HUSH_INTERACTIVE 3652#if ENABLE_FEATURE_EDITING 3653 cmdedit_set_initial_prompt(); 3654#endif 3655 PS2 = "> "; 3656#endif 3657 3658 if (EXIT_SUCCESS) /* otherwise is already done */ 3659 last_return_code = EXIT_SUCCESS; 3660 3661 if (argv[0] && argv[0][0] == '-') { 3662 debug_printf("sourcing /etc/profile\n"); 3663 input = fopen("/etc/profile", "r"); 3664 if (input != NULL) { 3665 mark_open(fileno(input)); 3666 parse_and_run_file(input); 3667 mark_closed(fileno(input)); 3668 fclose(input); 3669 } 3670 } 3671 input = stdin; 3672 3673 while ((opt = getopt(argc, argv, "c:xif")) > 0) { 3674 switch (opt) { 3675 case 'c': 3676 global_argv = argv + optind; 3677 global_argc = argc - optind; 3678 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON); 3679 goto final_return; 3680 case 'i': 3681 /* Well, we cannot just declare interactiveness, 3682 * we have to have some stuff (ctty, etc) */ 3683 /* interactive_fd++; */ 3684 break; 3685 case 'f': 3686 fake_mode = 1; 3687 break; 3688 default: 3689#ifndef BB_VER 3690 fprintf(stderr, "Usage: sh [FILE]...\n" 3691 " or: sh -c command [args]...\n\n"); 3692 exit(EXIT_FAILURE); 3693#else 3694 bb_show_usage(); 3695#endif 3696 } 3697 } 3698#if ENABLE_HUSH_JOB 3699 /* A shell is interactive if the '-i' flag was given, or if all of 3700 * the following conditions are met: 3701 * no -c command 3702 * no arguments remaining or the -s flag given 3703 * standard input is a terminal 3704 * standard output is a terminal 3705 * Refer to Posix.2, the description of the 'sh' utility. */ 3706 if (argv[optind] == NULL && input == stdin 3707 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) 3708 ) { 3709 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); 3710 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp); 3711 if (saved_tty_pgrp >= 0) { 3712 /* try to dup to high fd#, >= 255 */ 3713 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); 3714 if (interactive_fd < 0) { 3715 /* try to dup to any fd */ 3716 interactive_fd = dup(STDIN_FILENO); 3717 if (interactive_fd < 0) 3718 /* give up */ 3719 interactive_fd = 0; 3720 } 3721 // TODO: track & disallow any attempts of user 3722 // to (inadvertently) close/redirect it 3723 } 3724 } 3725 debug_printf("interactive_fd=%d\n", interactive_fd); 3726 if (interactive_fd) { 3727 /* Looks like they want an interactive shell */ 3728 setup_job_control(); 3729 /* Make xfuncs do cleanup on exit */ 3730 die_sleep = -1; /* flag */ 3731 if (setjmp(die_jmp)) { 3732 /* xfunc has failed! die die die */ 3733 hush_exit(xfunc_error_retval); 3734 } 3735#if !ENABLE_FEATURE_SH_EXTRA_QUIET 3736 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner); 3737 printf("Enter 'help' for a list of built-in commands.\n\n"); 3738#endif 3739 } 3740#elif ENABLE_HUSH_INTERACTIVE 3741/* no job control compiled, only prompt/line editing */ 3742 if (argv[optind] == NULL && input == stdin 3743 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) 3744 ) { 3745 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); 3746 if (interactive_fd < 0) { 3747 /* try to dup to any fd */ 3748 interactive_fd = dup(STDIN_FILENO); 3749 if (interactive_fd < 0) 3750 /* give up */ 3751 interactive_fd = 0; 3752 } 3753 } 3754 3755#endif 3756 3757 if (argv[optind] == NULL) { 3758 opt = parse_and_run_file(stdin); 3759 goto final_return; 3760 } 3761 3762 debug_printf("\nrunning script '%s'\n", argv[optind]); 3763 global_argv = argv + optind; 3764 global_argc = argc - optind; 3765 input = xfopen(argv[optind], "r"); 3766 opt = parse_and_run_file(input); 3767 3768 final_return: 3769 3770#if ENABLE_FEATURE_CLEAN_UP 3771 fclose(input); 3772 if (cwd != bb_msg_unknown) 3773 free((char*)cwd); 3774 cur_var = top_var->next; 3775 while (cur_var) { 3776 struct variable *tmp = cur_var; 3777 if (!cur_var->max_len) 3778 free(cur_var->varstr); 3779 cur_var = cur_var->next; 3780 free(tmp); 3781 } 3782#endif 3783 hush_exit(opt ? opt : last_return_code); 3784} 3785