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} 442 443 444/* Index of subroutines: */ 445/* function prototypes for builtins */ 446static int builtin_cd(char **argv); 447static int builtin_eval(char **argv); 448static int builtin_exec(char **argv); 449static int builtin_exit(char **argv); 450static int builtin_export(char **argv); 451#if ENABLE_HUSH_JOB 452static int builtin_fg_bg(char **argv); 453static int builtin_jobs(char **argv); 454#endif 455#if ENABLE_HUSH_HELP 456static int builtin_help(char **argv); 457#endif 458static int builtin_pwd(char **argv); 459static int builtin_read(char **argv); 460static int builtin_set(char **argv); 461static int builtin_shift(char **argv); 462static int builtin_source(char **argv); 463static int builtin_umask(char **argv); 464static int builtin_unset(char **argv); 465//static int builtin_not_written(char **argv); 466/* o_string manipulation: */ 467static int b_check_space(o_string *o, int len); 468static int b_addchr(o_string *o, int ch); 469static void b_reset(o_string *o); 470static int b_addqchr(o_string *o, int ch, int quote); 471/* in_str manipulations: */ 472static int static_get(struct in_str *i); 473static int static_peek(struct in_str *i); 474static int file_get(struct in_str *i); 475static int file_peek(struct in_str *i); 476static void setup_file_in_str(struct in_str *i, FILE *f); 477static void setup_string_in_str(struct in_str *i, const char *s); 478/* close_me manipulations: */ 479static void mark_open(int fd); 480static void mark_closed(int fd); 481static void close_all(void); 482/* "run" the final data structures: */ 483#if !defined(DEBUG_CLEAN) 484#define free_pipe_list(head, indent) free_pipe_list(head) 485#define free_pipe(pi, indent) free_pipe(pi) 486#endif 487static int free_pipe_list(struct pipe *head, int indent); 488static int free_pipe(struct pipe *pi, int indent); 489/* really run the final data structures: */ 490static int setup_redirects(struct child_prog *prog, int squirrel[]); 491static int run_list_real(struct pipe *pi); 492static void pseudo_exec_argv(char **argv) ATTRIBUTE_NORETURN; 493static void pseudo_exec(struct child_prog *child) ATTRIBUTE_NORETURN; 494static int run_pipe_real(struct pipe *pi); 495/* extended glob support: */ 496static int globhack(const char *src, int flags, glob_t *pglob); 497static int glob_needed(const char *s); 498static int xglob(o_string *dest, int flags, glob_t *pglob); 499/* variable assignment: */ 500static int is_assignment(const char *s); 501/* data structure manipulation: */ 502static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input); 503static void initialize_context(struct p_context *ctx); 504static int done_word(o_string *dest, struct p_context *ctx); 505static int done_command(struct p_context *ctx); 506static int done_pipe(struct p_context *ctx, pipe_style type); 507/* primary string parsing: */ 508static int redirect_dup_num(struct in_str *input); 509static int redirect_opt_num(o_string *o); 510#if ENABLE_HUSH_TICK 511static int process_command_subs(o_string *dest, struct p_context *ctx, struct in_str *input, const char *subst_end); 512#endif 513static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch); 514static const char *lookup_param(const char *src); 515static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input); 516static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger); 517/* setup: */ 518static int parse_and_run_stream(struct in_str *inp, int parse_flag); 519static int parse_and_run_string(const char *s, int parse_flag); 520static int parse_and_run_file(FILE *f); 521/* job management: */ 522static int checkjobs(struct pipe* fg_pipe); 523#if ENABLE_HUSH_JOB 524static int checkjobs_and_fg_shell(struct pipe* fg_pipe); 525static void insert_bg_job(struct pipe *pi); 526static void remove_bg_job(struct pipe *pi); 527static void delete_finished_bg_job(struct pipe *pi); 528#else 529int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */ 530#endif 531/* local variable support */ 532static char **expand_strvec_to_strvec(char **argv); 533/* used for eval */ 534static char *expand_strvec_to_string(char **argv); 535/* used for expansion of right hand of assignments */ 536static char *expand_string_to_string(const char *str); 537static struct variable *get_local_var(const char *name); 538static int set_local_var(char *str, int flg_export); 539static void unset_local_var(const char *name); 540 541/* Table of built-in functions. They can be forked or not, depending on 542 * context: within pipes, they fork. As simple commands, they do not. 543 * When used in non-forking context, they can change global variables 544 * in the parent shell process. If forked, of course they cannot. 545 * For example, 'unset foo | whatever' will parse and run, but foo will 546 * still be set at the end. */ 547struct built_in_command { 548 const char *cmd; /* name */ 549 int (*function) (char **argv); /* function ptr */ 550#if ENABLE_HUSH_HELP 551 const char *descr; /* description */ 552#define BLTIN(cmd, func, help) { cmd, func, help } 553#else 554#define BLTIN(cmd, func, help) { cmd, func } 555#endif 556}; 557 558static const struct built_in_command bltins[] = { 559#if ENABLE_HUSH_JOB 560 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"), 561#endif 562// BLTIN("break" , builtin_not_written, "Exit for, while or until loop"), 563 BLTIN("cd" , builtin_cd, "Change working directory"), 564// BLTIN("continue", builtin_not_written, "Continue for, while or until loop"), 565 BLTIN("eval" , builtin_eval, "Construct and run shell command"), 566 BLTIN("exec" , builtin_exec, "Exec command, replacing this shell with the exec'd process"), 567 BLTIN("exit" , builtin_exit, "Exit from shell"), 568 BLTIN("export", builtin_export, "Set environment variable"), 569#if ENABLE_HUSH_JOB 570 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"), 571 BLTIN("jobs" , builtin_jobs, "Lists the active jobs"), 572#endif 573// TODO: remove pwd? we have it as an applet... 574 BLTIN("pwd" , builtin_pwd, "Print current directory"), 575 BLTIN("read" , builtin_read, "Input environment variable"), 576// BLTIN("return", builtin_not_written, "Return from a function"), 577 BLTIN("set" , builtin_set, "Set/unset shell local variables"), 578 BLTIN("shift" , builtin_shift, "Shift positional parameters"), 579// BLTIN("trap" , builtin_not_written, "Trap signals"), 580// BLTIN("ulimit", builtin_not_written, "Controls resource limits"), 581 BLTIN("umask" , builtin_umask, "Sets file creation mask"), 582 BLTIN("unset" , builtin_unset, "Unset environment variable"), 583 BLTIN("." , builtin_source, "Source-in and run commands in a file"), 584#if ENABLE_HUSH_HELP 585 BLTIN("help" , builtin_help, "List shell built-in commands"), 586#endif 587 BLTIN(NULL, NULL, NULL) 588}; 589 590#if ENABLE_HUSH_JOB 591 592/* move to libbb? */ 593static void signal_SA_RESTART(int sig, void (*handler)(int)) 594{ 595 struct sigaction sa; 596 sa.sa_handler = handler; 597 sa.sa_flags = SA_RESTART; 598 sigemptyset(&sa.sa_mask); 599 sigaction(sig, &sa, NULL); 600} 601 602/* Signals are grouped, we handle them in batches */ 603static void set_fatal_sighandler(void (*handler)(int)) 604{ 605 signal(SIGILL , handler); 606 signal(SIGTRAP, handler); 607 signal(SIGABRT, handler); 608 signal(SIGFPE , handler); 609 signal(SIGBUS , handler); 610 signal(SIGSEGV, handler); 611 /* bash 3.2 seems to handle these just like 'fatal' ones */ 612 signal(SIGHUP , handler); 613 signal(SIGPIPE, handler); 614 signal(SIGALRM, handler); 615} 616static void set_jobctrl_sighandler(void (*handler)(int)) 617{ 618 signal(SIGTSTP, handler); 619 signal(SIGTTIN, handler); 620 signal(SIGTTOU, handler); 621} 622static void set_misc_sighandler(void (*handler)(int)) 623{ 624 signal(SIGINT , handler); 625 signal(SIGQUIT, handler); 626 signal(SIGTERM, handler); 627} 628/* SIGCHLD is special and handled separately */ 629 630static void set_every_sighandler(void (*handler)(int)) 631{ 632 set_fatal_sighandler(handler); 633 set_jobctrl_sighandler(handler); 634 set_misc_sighandler(handler); 635 signal(SIGCHLD, handler); 636} 637 638static void handler_ctrl_c(int sig) 639{ 640 debug_printf_jobs("got sig %d\n", sig); 641// as usual we can have all kinds of nasty problems with leaked malloc data here 642 siglongjmp(toplevel_jb, 1); 643} 644 645static void handler_ctrl_z(int sig) 646{ 647 pid_t pid; 648 649 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid()); 650 pid = fork(); 651 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */ 652 return; 653 ctrl_z_flag = 1; 654 if (!pid) { /* child */ 655 setpgrp(); 656 debug_printf_jobs("set pgrp for child %d ok\n", getpid()); 657 set_every_sighandler(SIG_DFL); 658 raise(SIGTSTP); /* resend TSTP so that child will be stopped */ 659 debug_printf_jobs("returning in child\n"); 660 /* return to nofork, it will eventually exit now, 661 * not return back to shell */ 662 return; 663 } 664 /* parent */ 665 /* finish filling up pipe info */ 666 toplevel_list->pgrp = pid; /* child is in its own pgrp */ 667 toplevel_list->progs[0].pid = pid; 668 /* parent needs to longjmp out of running nofork. 669 * we will "return" exitcode 0, with child put in background */ 670// as usual we can have all kinds of nasty problems with leaked malloc data here 671 debug_printf_jobs("siglongjmp in parent\n"); 672 siglongjmp(toplevel_jb, 1); 673} 674 675/* Restores tty foreground process group, and exits. 676 * May be called as signal handler for fatal signal 677 * (will faithfully resend signal to itself, producing correct exit state) 678 * or called directly with -EXITCODE. 679 * We also call it if xfunc is exiting. */ 680static void sigexit(int sig) ATTRIBUTE_NORETURN; 681static void sigexit(int sig) 682{ 683 sigset_t block_all; 684 685 /* Disable all signals: job control, SIGPIPE, etc. */ 686 sigfillset(&block_all); 687 sigprocmask(SIG_SETMASK, &block_all, NULL); 688 689 if (interactive_fd) 690 tcsetpgrp(interactive_fd, saved_tty_pgrp); 691 692 /* Not a signal, just exit */ 693 if (sig <= 0) 694 _exit(- sig); 695 696 /* Enable only this sig and kill ourself with it */ 697 signal(sig, SIG_DFL); 698 sigdelset(&block_all, sig); 699 sigprocmask(SIG_SETMASK, &block_all, NULL); 700 raise(sig); 701 _exit(1); /* Should not reach it */ 702} 703 704/* Restores tty foreground process group, and exits. */ 705static void hush_exit(int exitcode) ATTRIBUTE_NORETURN; 706static void hush_exit(int exitcode) 707{ 708 fflush(NULL); /* flush all streams */ 709 sigexit(- (exitcode & 0xff)); 710} 711 712#else /* !JOB */ 713 714#define set_fatal_sighandler(handler) ((void)0) 715#define set_jobctrl_sighandler(handler) ((void)0) 716#define set_misc_sighandler(handler) ((void)0) 717#define hush_exit(e) exit(e) 718 719#endif /* JOB */ 720 721 722static const char *set_cwd(void) 723{ 724 if (cwd == bb_msg_unknown) 725 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */ 726 cwd = xrealloc_getcwd_or_warn((char *)cwd); 727 if (!cwd) 728 cwd = bb_msg_unknown; 729 return cwd; 730} 731 732/* built-in 'eval' handler */ 733static int builtin_eval(char **argv) 734{ 735 int rcode = EXIT_SUCCESS; 736 737 if (argv[1]) { 738 char *str = expand_strvec_to_string(argv + 1); 739 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP | 740 PARSEFLAG_SEMICOLON); 741 free(str); 742 rcode = last_return_code; 743 } 744 return rcode; 745} 746 747/* built-in 'cd <path>' handler */ 748static int builtin_cd(char **argv) 749{ 750 const char *newdir; 751 if (argv[1] == NULL) 752 newdir = getenv("HOME") ? : "/"; 753 else 754 newdir = argv[1]; 755 if (chdir(newdir)) { 756 printf("cd: %s: %s\n", newdir, strerror(errno)); 757 return EXIT_FAILURE; 758 } 759 set_cwd(); 760 return EXIT_SUCCESS; 761} 762 763/* built-in 'exec' handler */ 764static int builtin_exec(char **argv) 765{ 766 if (argv[1] == NULL) 767 return EXIT_SUCCESS; /* Really? */ 768 pseudo_exec_argv(argv + 1); 769 /* never returns */ 770} 771 772/* built-in 'exit' handler */ 773static int builtin_exit(char **argv) 774{ 775// TODO: bash does it ONLY on top-level sh exit (+interacive only?) 776 //puts("exit"); /* bash does it */ 777// TODO: warn if we have background jobs: "There are stopped jobs" 778// On second consecutive 'exit', exit anyway. 779 780 if (argv[1] == NULL) 781 hush_exit(last_return_code); 782 /* mimic bash: exit 123abc == exit 255 + error msg */ 783 xfunc_error_retval = 255; 784 /* bash: exit -2 == exit 254, no error msg */ 785 hush_exit(xatoi(argv[1]) & 0xff); 786} 787 788/* built-in 'export VAR=value' handler */ 789static int builtin_export(char **argv) 790{ 791 const char *value; 792 char *name = argv[1]; 793 794 if (name == NULL) { 795 // TODO: 796 // ash emits: export VAR='VAL' 797 // bash: declare -x VAR="VAL" 798 // (both also escape as needed (quotes, $, etc)) 799 char **e = environ; 800 if (e) 801 while (*e) 802 puts(*e++); 803 return EXIT_SUCCESS; 804 } 805 806 value = strchr(name, '='); 807 if (!value) { 808 /* They are exporting something without a =VALUE */ 809 struct variable *var; 810 811 var = get_local_var(name); 812 if (var) { 813 var->flg_export = 1; 814 putenv(var->varstr); 815 } 816 /* bash does not return an error when trying to export 817 * an undefined variable. Do likewise. */ 818 return EXIT_SUCCESS; 819 } 820 821 set_local_var(xstrdup(name), 1); 822 return EXIT_SUCCESS; 823} 824 825#if ENABLE_HUSH_JOB 826/* built-in 'fg' and 'bg' handler */ 827static int builtin_fg_bg(char **argv) 828{ 829 int i, jobnum; 830 struct pipe *pi; 831 832 if (!interactive_fd) 833 return EXIT_FAILURE; 834 /* If they gave us no args, assume they want the last backgrounded task */ 835 if (!argv[1]) { 836 for (pi = job_list; pi; pi = pi->next) { 837 if (pi->jobid == last_jobid) { 838 goto found; 839 } 840 } 841 bb_error_msg("%s: no current job", argv[0]); 842 return EXIT_FAILURE; 843 } 844 if (sscanf(argv[1], "%%%d", &jobnum) != 1) { 845 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]); 846 return EXIT_FAILURE; 847 } 848 for (pi = job_list; pi; pi = pi->next) { 849 if (pi->jobid == jobnum) { 850 goto found; 851 } 852 } 853 bb_error_msg("%s: %d: no such job", argv[0], jobnum); 854 return EXIT_FAILURE; 855 found: 856 // TODO: bash prints a string representation 857 // of job being foregrounded (like "sleep 1 | cat") 858 if (*argv[0] == 'f') { 859 /* Put the job into the foreground. */ 860 tcsetpgrp(interactive_fd, pi->pgrp); 861 } 862 863 /* Restart the processes in the job */ 864 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp); 865 for (i = 0; i < pi->num_progs; i++) { 866 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid); 867 pi->progs[i].is_stopped = 0; 868 } 869 pi->stopped_progs = 0; 870 871 i = kill(- pi->pgrp, SIGCONT); 872 if (i < 0) { 873 if (errno == ESRCH) { 874 delete_finished_bg_job(pi); 875 return EXIT_SUCCESS; 876 } else { 877 bb_perror_msg("kill (SIGCONT)"); 878 } 879 } 880 881 if (*argv[0] == 'f') { 882 remove_bg_job(pi); 883 return checkjobs_and_fg_shell(pi); 884 } 885 return EXIT_SUCCESS; 886} 887#endif 888 889/* built-in 'help' handler */ 890#if ENABLE_HUSH_HELP 891static int builtin_help(char **argv ATTRIBUTE_UNUSED) 892{ 893 const struct built_in_command *x; 894 895 printf("\nBuilt-in commands:\n"); 896 printf("-------------------\n"); 897 for (x = bltins; x->cmd; x++) { 898 printf("%s\t%s\n", x->cmd, x->descr); 899 } 900 printf("\n\n"); 901 return EXIT_SUCCESS; 902} 903#endif 904 905#if ENABLE_HUSH_JOB 906/* built-in 'jobs' handler */ 907static int builtin_jobs(char **argv ATTRIBUTE_UNUSED) 908{ 909 struct pipe *job; 910 const char *status_string; 911 912 for (job = job_list; job; job = job->next) { 913 if (job->running_progs == job->stopped_progs) 914 status_string = "Stopped"; 915 else 916 status_string = "Running"; 917 918 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext); 919 } 920 return EXIT_SUCCESS; 921} 922#endif 923 924/* built-in 'pwd' handler */ 925static int builtin_pwd(char **argv ATTRIBUTE_UNUSED) 926{ 927 puts(set_cwd()); 928 return EXIT_SUCCESS; 929} 930 931/* built-in 'read VAR' handler */ 932static int builtin_read(char **argv) 933{ 934 char *string; 935 const char *name = argv[1] ? argv[1] : "REPLY"; 936 937 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name)); 938 return set_local_var(string, 0); 939} 940 941/* built-in 'set [VAR=value]' handler */ 942static int builtin_set(char **argv) 943{ 944 char *temp = argv[1]; 945 struct variable *e; 946 947 if (temp == NULL) 948 for (e = top_var; e; e = e->next) 949 puts(e->varstr); 950 else 951 set_local_var(xstrdup(temp), 0); 952 953 return EXIT_SUCCESS; 954} 955 956 957/* Built-in 'shift' handler */ 958static int builtin_shift(char **argv) 959{ 960 int n = 1; 961 if (argv[1]) { 962 n = atoi(argv[1]); 963 } 964 if (n >= 0 && n < global_argc) { 965 global_argv[n] = global_argv[0]; 966 global_argc -= n; 967 global_argv += n; 968 return EXIT_SUCCESS; 969 } 970 return EXIT_FAILURE; 971} 972 973/* Built-in '.' handler (read-in and execute commands from file) */ 974static int builtin_source(char **argv) 975{ 976 FILE *input; 977 int status; 978 979 if (argv[1] == NULL) 980 return EXIT_FAILURE; 981 982 input = fopen(argv[1], "r"); 983 if (!input) { 984 bb_error_msg("cannot open '%s'", argv[1]); 985 return EXIT_FAILURE; 986 } 987 988 /* Now run the file */ 989 mark_open(fileno(input)); 990 status = parse_and_run_file(input); 991 mark_closed(fileno(input)); 992 fclose(input); 993 return status; 994} 995 996static int builtin_umask(char **argv) 997{ 998 mode_t new_umask; 999 const char *arg = argv[1]; 1000 char *end; 1001 if (arg) { 1002 new_umask = strtoul(arg, &end, 8); 1003 if (*end != '\0' || end == arg) { 1004 return EXIT_FAILURE; 1005 } 1006 } else { 1007 new_umask = umask(0); 1008 printf("%.3o\n", (unsigned) new_umask); 1009 } 1010 umask(new_umask); 1011 return EXIT_SUCCESS; 1012} 1013 1014/* built-in 'unset VAR' handler */ 1015static int builtin_unset(char **argv) 1016{ 1017 /* bash always returns true */ 1018 unset_local_var(argv[1]); 1019 return EXIT_SUCCESS; 1020} 1021 1022//static int builtin_not_written(char **argv) 1023//{ 1024// printf("builtin_%s not written\n", argv[0]); 1025// return EXIT_FAILURE; 1026//} 1027 1028static int b_check_space(o_string *o, int len) 1029{ 1030 /* It would be easy to drop a more restrictive policy 1031 * in here, such as setting a maximum string length */ 1032 if (o->length + len > o->maxlen) { 1033 /* assert(data == NULL || o->maxlen != 0); */ 1034 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK); 1035 o->data = xrealloc(o->data, 1 + o->maxlen); 1036 } 1037 return o->data == NULL; 1038} 1039 1040static int b_addchr(o_string *o, int ch) 1041{ 1042 debug_printf("b_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o); 1043 if (b_check_space(o, 1)) 1044 return B_NOSPAC; 1045 o->data[o->length] = ch; 1046 o->length++; 1047 o->data[o->length] = '\0'; 1048 return 0; 1049} 1050 1051static void b_reset(o_string *o) 1052{ 1053 o->length = 0; 1054 o->nonnull = 0; 1055 if (o->data != NULL) 1056 *o->data = '\0'; 1057} 1058 1059static void b_free(o_string *o) 1060{ 1061 b_reset(o); 1062 free(o->data); 1063 o->data = NULL; 1064 o->maxlen = 0; 1065} 1066 1067/* My analysis of quoting semantics tells me that state information 1068 * is associated with a destination, not a source. 1069 */ 1070static int b_addqchr(o_string *o, int ch, int quote) 1071{ 1072 if (quote && strchr("*?[\\", ch)) { 1073 int rc; 1074 rc = b_addchr(o, '\\'); 1075 if (rc) 1076 return rc; 1077 } 1078 return b_addchr(o, ch); 1079} 1080 1081static int static_get(struct in_str *i) 1082{ 1083 int ch = *i->p++; 1084 if (ch == '\0') return EOF; 1085 return ch; 1086} 1087 1088static int static_peek(struct in_str *i) 1089{ 1090 return *i->p; 1091} 1092 1093#if ENABLE_HUSH_INTERACTIVE 1094#if ENABLE_FEATURE_EDITING 1095static void cmdedit_set_initial_prompt(void) 1096{ 1097#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT 1098 PS1 = NULL; 1099#else 1100 PS1 = getenv("PS1"); 1101 if (PS1 == NULL) 1102 PS1 = "\\w \\$ "; 1103#endif 1104} 1105#endif /* EDITING */ 1106 1107static const char* setup_prompt_string(int promptmode) 1108{ 1109 const char *prompt_str; 1110 debug_printf("setup_prompt_string %d ", promptmode); 1111#if !ENABLE_FEATURE_EDITING_FANCY_PROMPT 1112 /* Set up the prompt */ 1113 if (promptmode == 0) { /* PS1 */ 1114 free((char*)PS1); 1115 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#'); 1116 prompt_str = PS1; 1117 } else { 1118 prompt_str = PS2; 1119 } 1120#else 1121 prompt_str = (promptmode == 0) ? PS1 : PS2; 1122#endif 1123 debug_printf("result '%s'\n", prompt_str); 1124 return prompt_str; 1125} 1126 1127static void get_user_input(struct in_str *i) 1128{ 1129 int r; 1130 const char *prompt_str; 1131 1132 prompt_str = setup_prompt_string(i->promptmode); 1133#if ENABLE_FEATURE_EDITING 1134 /* Enable command line editing only while a command line 1135 * is actually being read; otherwise, we'll end up bequeathing 1136 * atexit() handlers and other unwanted stuff to our 1137 * child processes (rob@sysgo.de) */ 1138 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state); 1139 i->eof_flag = (r < 0); 1140 if (i->eof_flag) { /* EOF/error detected */ 1141 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */ 1142 user_input_buf[1] = '\0'; 1143 } 1144#else 1145 fputs(prompt_str, stdout); 1146 fflush(stdout); 1147 user_input_buf[0] = r = fgetc(i->file); 1148 /*user_input_buf[1] = '\0'; - already is and never changed */ 1149 i->eof_flag = (r == EOF); 1150#endif 1151 i->p = user_input_buf; 1152} 1153#endif /* INTERACTIVE */ 1154 1155/* This is the magic location that prints prompts 1156 * and gets data back from the user */ 1157static int file_get(struct in_str *i) 1158{ 1159 int ch; 1160 1161 /* If there is data waiting, eat it up */ 1162 if (i->p && *i->p) { 1163#if ENABLE_HUSH_INTERACTIVE 1164 take_cached: 1165#endif 1166 ch = *i->p++; 1167 if (i->eof_flag && !*i->p) 1168 ch = EOF; 1169 } else { 1170 /* need to double check i->file because we might be doing something 1171 * more complicated by now, like sourcing or substituting. */ 1172#if ENABLE_HUSH_INTERACTIVE 1173 if (interactive_fd && i->promptme && i->file == stdin) { 1174 do { 1175 get_user_input(i); 1176 } while (!*i->p); /* need non-empty line */ 1177 i->promptmode = 1; /* PS2 */ 1178 i->promptme = 0; 1179 goto take_cached; 1180 } 1181#endif 1182 ch = fgetc(i->file); 1183 } 1184 debug_printf("file_get: got a '%c' %d\n", ch, ch); 1185#if ENABLE_HUSH_INTERACTIVE 1186 if (ch == '\n') 1187 i->promptme = 1; 1188#endif 1189 return ch; 1190} 1191 1192/* All the callers guarantee this routine will never be 1193 * used right after a newline, so prompting is not needed. 1194 */ 1195static int file_peek(struct in_str *i) 1196{ 1197 int ch; 1198 if (i->p && *i->p) { 1199 if (i->eof_flag && !i->p[1]) 1200 return EOF; 1201 return *i->p; 1202 } 1203 ch = fgetc(i->file); 1204 i->eof_flag = (ch == EOF); 1205 i->peek_buf[0] = ch; 1206 i->peek_buf[1] = '\0'; 1207 i->p = i->peek_buf; 1208 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p); 1209 return ch; 1210} 1211 1212static void setup_file_in_str(struct in_str *i, FILE *f) 1213{ 1214 i->peek = file_peek; 1215 i->get = file_get; 1216#if ENABLE_HUSH_INTERACTIVE 1217 i->promptme = 1; 1218 i->promptmode = 0; /* PS1 */ 1219#endif 1220 i->file = f; 1221 i->p = NULL; 1222} 1223 1224static void setup_string_in_str(struct in_str *i, const char *s) 1225{ 1226 i->peek = static_peek; 1227 i->get = static_get; 1228#if ENABLE_HUSH_INTERACTIVE 1229 i->promptme = 1; 1230 i->promptmode = 0; /* PS1 */ 1231#endif 1232 i->p = s; 1233 i->eof_flag = 0; 1234} 1235 1236static void mark_open(int fd) 1237{ 1238 struct close_me *new = xmalloc(sizeof(struct close_me)); 1239 new->fd = fd; 1240 new->next = close_me_head; 1241 close_me_head = new; 1242} 1243 1244static void mark_closed(int fd) 1245{ 1246 struct close_me *tmp; 1247 if (close_me_head == NULL || close_me_head->fd != fd) 1248 bb_error_msg_and_die("corrupt close_me"); 1249 tmp = close_me_head; 1250 close_me_head = close_me_head->next; 1251 free(tmp); 1252} 1253 1254static void close_all(void) 1255{ 1256 struct close_me *c; 1257 for (c = close_me_head; c; c = c->next) { 1258 close(c->fd); 1259 } 1260 close_me_head = NULL; 1261} 1262 1263/* squirrel != NULL means we squirrel away copies of stdin, stdout, 1264 * and stderr if they are redirected. */ 1265static int setup_redirects(struct child_prog *prog, int squirrel[]) 1266{ 1267 int openfd, mode; 1268 struct redir_struct *redir; 1269 1270 for (redir = prog->redirects; redir; redir = redir->next) { 1271 if (redir->dup == -1 && redir->word.gl_pathv == NULL) { 1272 /* something went wrong in the parse. Pretend it didn't happen */ 1273 continue; 1274 } 1275 if (redir->dup == -1) { 1276 mode = redir_table[redir->type].mode; 1277 openfd = open_or_warn(redir->word.gl_pathv[0], mode); 1278 if (openfd < 0) { 1279 /* this could get lost if stderr has been redirected, but 1280 bash and ash both lose it as well (though zsh doesn't!) */ 1281 return 1; 1282 } 1283 } else { 1284 openfd = redir->dup; 1285 } 1286 1287 if (openfd != redir->fd) { 1288 if (squirrel && redir->fd < 3) { 1289 squirrel[redir->fd] = dup(redir->fd); 1290 } 1291 if (openfd == -3) { 1292 close(openfd); 1293 } else { 1294 dup2(openfd, redir->fd); 1295 if (redir->dup == -1) 1296 close(openfd); 1297 } 1298 } 1299 } 1300 return 0; 1301} 1302 1303static void restore_redirects(int squirrel[]) 1304{ 1305 int i, fd; 1306 for (i = 0; i < 3; i++) { 1307 fd = squirrel[i]; 1308 if (fd != -1) { 1309 /* We simply die on error */ 1310 xmove_fd(fd, i); 1311 } 1312 } 1313} 1314 1315/* never returns */ 1316static void pseudo_exec_argv(char **argv) 1317{ 1318 int i, rcode; 1319 char *p; 1320 const struct built_in_command *x; 1321 1322 for (i = 0; is_assignment(argv[i]); i++) { 1323 debug_printf_exec("pid %d environment modification: %s\n", 1324 getpid(), argv[i]); 1325 p = expand_string_to_string(argv[i]); 1326 putenv(p); 1327 } 1328 argv += i; 1329 /* If a variable is assigned in a forest, and nobody listens, 1330 * was it ever really set? 1331 */ 1332 if (argv[0] == NULL) { 1333 _exit(EXIT_SUCCESS); 1334 } 1335 1336 argv = expand_strvec_to_strvec(argv); 1337 1338 /* 1339 * Check if the command matches any of the builtins. 1340 * Depending on context, this might be redundant. But it's 1341 * easier to waste a few CPU cycles than it is to figure out 1342 * if this is one of those cases. 1343 */ 1344 for (x = bltins; x->cmd; x++) { 1345 if (strcmp(argv[0], x->cmd) == 0) { 1346 debug_printf_exec("running builtin '%s'\n", argv[0]); 1347 rcode = x->function(argv); 1348 fflush(stdout); 1349 _exit(rcode); 1350 } 1351 } 1352 1353 /* Check if the command matches any busybox applets */ 1354#if ENABLE_FEATURE_SH_STANDALONE 1355 if (strchr(argv[0], '/') == NULL) { 1356 const struct bb_applet *a = find_applet_by_name(argv[0]); 1357 if (a) { 1358 if (a->noexec) { 1359 current_applet = a; 1360 debug_printf_exec("running applet '%s'\n", argv[0]); 1361// is it ok that run_current_applet_and_exit() does exit(), not _exit()? 1362 run_current_applet_and_exit(argv); 1363 } 1364 /* re-exec ourselves with the new arguments */ 1365 debug_printf_exec("re-execing applet '%s'\n", argv[0]); 1366 execvp(bb_busybox_exec_path, argv); 1367 /* If they called chroot or otherwise made the binary no longer 1368 * executable, fall through */ 1369 } 1370 } 1371#endif 1372 1373 debug_printf_exec("execing '%s'\n", argv[0]); 1374 execvp(argv[0], argv); 1375 bb_perror_msg("cannot exec '%s'", argv[0]); 1376 _exit(1); 1377} 1378 1379static void pseudo_exec(struct child_prog *child) 1380{ 1381// until it does exec/_exit, but currently it does. 1382 int rcode; 1383 1384 if (child->argv) { 1385 pseudo_exec_argv(child->argv); 1386 } 1387 1388 if (child->group) { 1389#if ENABLE_HUSH_INTERACTIVE 1390 debug_printf_exec("pseudo_exec: setting interactive_fd=0\n"); 1391 interactive_fd = 0; /* crucial!!!! */ 1392#endif 1393 debug_printf_exec("pseudo_exec: run_list_real\n"); 1394 rcode = run_list_real(child->group); 1395 /* OK to leak memory by not calling free_pipe_list, 1396 * since this process is about to exit */ 1397 _exit(rcode); 1398 } 1399 1400 /* Can happen. See what bash does with ">foo" by itself. */ 1401 debug_printf("trying to pseudo_exec null command\n"); 1402 _exit(EXIT_SUCCESS); 1403} 1404 1405#if ENABLE_HUSH_JOB 1406static const char *get_cmdtext(struct pipe *pi) 1407{ 1408 char **argv; 1409 char *p; 1410 int len; 1411 1412 /* This is subtle. ->cmdtext is created only on first backgrounding. 1413 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...) 1414 * On subsequent bg argv is trashed, but we won't use it */ 1415 if (pi->cmdtext) 1416 return pi->cmdtext; 1417 argv = pi->progs[0].argv; 1418 if (!argv || !argv[0]) 1419 return (pi->cmdtext = xzalloc(1)); 1420 1421 len = 0; 1422 do len += strlen(*argv) + 1; while (*++argv); 1423 pi->cmdtext = p = xmalloc(len); 1424 argv = pi->progs[0].argv; 1425 do { 1426 len = strlen(*argv); 1427 memcpy(p, *argv, len); 1428 p += len; 1429 *p++ = ' '; 1430 } while (*++argv); 1431 p[-1] = '\0'; 1432 return pi->cmdtext; 1433} 1434 1435static void insert_bg_job(struct pipe *pi) 1436{ 1437 struct pipe *thejob; 1438 int i; 1439 1440 /* Linear search for the ID of the job to use */ 1441 pi->jobid = 1; 1442 for (thejob = job_list; thejob; thejob = thejob->next) 1443 if (thejob->jobid >= pi->jobid) 1444 pi->jobid = thejob->jobid + 1; 1445 1446 /* Add thejob to the list of running jobs */ 1447 if (!job_list) { 1448 thejob = job_list = xmalloc(sizeof(*thejob)); 1449 } else { 1450 for (thejob = job_list; thejob->next; thejob = thejob->next) 1451 continue; 1452 thejob->next = xmalloc(sizeof(*thejob)); 1453 thejob = thejob->next; 1454 } 1455 1456 /* Physically copy the struct job */ 1457 memcpy(thejob, pi, sizeof(struct pipe)); 1458 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs); 1459 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */ 1460 for (i = 0; i < pi->num_progs; i++) { 1461// TODO: do we really need to have so many fields which are just dead weight 1462// at execution stage? 1463 thejob->progs[i].pid = pi->progs[i].pid; 1464 /* all other fields are not used and stay zero */ 1465 } 1466 thejob->next = NULL; 1467 thejob->cmdtext = xstrdup(get_cmdtext(pi)); 1468 1469 /* We don't wait for background thejobs to return -- append it 1470 to the list of backgrounded thejobs and leave it alone */ 1471 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext); 1472 last_bg_pid = thejob->progs[0].pid; 1473 last_jobid = thejob->jobid; 1474} 1475 1476static void remove_bg_job(struct pipe *pi) 1477{ 1478 struct pipe *prev_pipe; 1479 1480 if (pi == job_list) { 1481 job_list = pi->next; 1482 } else { 1483 prev_pipe = job_list; 1484 while (prev_pipe->next != pi) 1485 prev_pipe = prev_pipe->next; 1486 prev_pipe->next = pi->next; 1487 } 1488 if (job_list) 1489 last_jobid = job_list->jobid; 1490 else 1491 last_jobid = 0; 1492} 1493 1494/* remove a backgrounded job */ 1495static void delete_finished_bg_job(struct pipe *pi) 1496{ 1497 remove_bg_job(pi); 1498 pi->stopped_progs = 0; 1499 free_pipe(pi, 0); 1500 free(pi); 1501} 1502#endif /* JOB */ 1503 1504/* Checks to see if any processes have exited -- if they 1505 have, figure out why and see if a job has completed */ 1506static int checkjobs(struct pipe* fg_pipe) 1507{ 1508 int attributes; 1509 int status; 1510#if ENABLE_HUSH_JOB 1511 int prognum = 0; 1512 struct pipe *pi; 1513#endif 1514 pid_t childpid; 1515 int rcode = 0; 1516 1517 attributes = WUNTRACED; 1518 if (fg_pipe == NULL) { 1519 attributes |= WNOHANG; 1520 } 1521 1522/* Do we do this right? 1523 * bash-3.00# sleep 20 | false 1524 * <ctrl-Z pressed> 1525 * [3]+ Stopped sleep 20 | false 1526 * bash-3.00# echo $? 1527 * 1 <========== bg pipe is not fully done, but exitcode is already known! 1528 */ 1529 1530//are stopped. Testcase: "cat | cat" in a script (not on command line) 1531// + killall -STOP cat 1532 1533 wait_more: 1534 while ((childpid = waitpid(-1, &status, attributes)) > 0) { 1535 const int dead = WIFEXITED(status) || WIFSIGNALED(status); 1536 1537#ifdef DEBUG_SHELL_JOBS 1538 if (WIFSTOPPED(status)) 1539 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", 1540 childpid, WSTOPSIG(status), WEXITSTATUS(status)); 1541 if (WIFSIGNALED(status)) 1542 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", 1543 childpid, WTERMSIG(status), WEXITSTATUS(status)); 1544 if (WIFEXITED(status)) 1545 debug_printf_jobs("pid %d exited, exitcode %d\n", 1546 childpid, WEXITSTATUS(status)); 1547#endif 1548 /* Were we asked to wait for fg pipe? */ 1549 if (fg_pipe) { 1550 int i; 1551 for (i = 0; i < fg_pipe->num_progs; i++) { 1552 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid); 1553 if (fg_pipe->progs[i].pid == childpid) { 1554 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */ 1555 if (dead) { 1556 fg_pipe->progs[i].pid = 0; 1557 fg_pipe->running_progs--; 1558 if (i == fg_pipe->num_progs-1) 1559 /* last process gives overall exitstatus */ 1560 rcode = WEXITSTATUS(status); 1561 } else { 1562 fg_pipe->progs[i].is_stopped = 1; 1563 fg_pipe->stopped_progs++; 1564 } 1565 debug_printf_jobs("fg_pipe: running_progs %d stopped_progs %d\n", 1566 fg_pipe->running_progs, fg_pipe->stopped_progs); 1567 if (fg_pipe->running_progs - fg_pipe->stopped_progs <= 0) { 1568 /* All processes in fg pipe have exited/stopped */ 1569#if ENABLE_HUSH_JOB 1570 if (fg_pipe->running_progs) 1571 insert_bg_job(fg_pipe); 1572#endif 1573 return rcode; 1574 } 1575 /* There are still running processes in the fg pipe */ 1576 goto wait_more; 1577 } 1578 } 1579 /* fall through to searching process in bg pipes */ 1580 } 1581 1582#if ENABLE_HUSH_JOB 1583 /* We asked to wait for bg or orphaned children */ 1584 /* No need to remember exitcode in this case */ 1585 for (pi = job_list; pi; pi = pi->next) { 1586 prognum = 0; 1587 while (prognum < pi->num_progs) { 1588 if (pi->progs[prognum].pid == childpid) 1589 goto found_pi_and_prognum; 1590 prognum++; 1591 } 1592 } 1593#endif 1594 1595 /* Happens when shell is used as init process (init=/bin/sh) */ 1596 debug_printf("checkjobs: pid %d was not in our list!\n", childpid); 1597 goto wait_more; 1598 1599#if ENABLE_HUSH_JOB 1600 found_pi_and_prognum: 1601 if (dead) { 1602 /* child exited */ 1603 pi->progs[prognum].pid = 0; 1604 pi->running_progs--; 1605 if (!pi->running_progs) { 1606 printf(JOB_STATUS_FORMAT, pi->jobid, 1607 "Done", pi->cmdtext); 1608 delete_finished_bg_job(pi); 1609 } 1610 } else { 1611 /* child stopped */ 1612 pi->stopped_progs++; 1613 pi->progs[prognum].is_stopped = 1; 1614 } 1615#endif 1616 } 1617 1618 /* wait found no children or failed */ 1619 1620 if (childpid && errno != ECHILD) 1621 bb_perror_msg("waitpid"); 1622 return rcode; 1623} 1624 1625#if ENABLE_HUSH_JOB 1626static int checkjobs_and_fg_shell(struct pipe* fg_pipe) 1627{ 1628 pid_t p; 1629 int rcode = checkjobs(fg_pipe); 1630 /* Job finished, move the shell to the foreground */ 1631 p = getpgid(0); /* pgid of our process */ 1632 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p); 1633 if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY) 1634 bb_perror_msg("tcsetpgrp-4a"); 1635 return rcode; 1636} 1637#endif 1638 1639/* run_pipe_real() starts all the jobs, but doesn't wait for anything 1640 * to finish. See checkjobs(). 1641 * 1642 * return code is normally -1, when the caller has to wait for children 1643 * to finish to determine the exit status of the pipe. If the pipe 1644 * is a simple builtin command, however, the action is done by the 1645 * time run_pipe_real returns, and the exit code is provided as the 1646 * return value. 1647 * 1648 * The input of the pipe is always stdin, the output is always 1649 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus, 1650 * because it tries to avoid running the command substitution in 1651 * subshell, when that is in fact necessary. The subshell process 1652 * now has its stdout directed to the input of the appropriate pipe, 1653 * so this routine is noticeably simpler. 1654 * 1655 * Returns -1 only if started some children. IOW: we have to 1656 * mask out retvals of builtins etc with 0xff! 1657 */ 1658static int run_pipe_real(struct pipe *pi) 1659{ 1660 int i; 1661 int nextin, nextout; 1662 int pipefds[2]; /* pipefds[0] is for reading */ 1663 struct child_prog *child; 1664 const struct built_in_command *x; 1665 char *p; 1666 /* it is not always needed, but we aim to smaller code */ 1667 int squirrel[] = { -1, -1, -1 }; 1668 int rcode; 1669 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG); 1670 1671 debug_printf_exec("run_pipe_real start: single_fg=%d\n", single_fg); 1672 1673 nextin = 0; 1674#if ENABLE_HUSH_JOB 1675 pi->pgrp = -1; 1676#endif 1677 pi->running_progs = 1; 1678 pi->stopped_progs = 0; 1679 1680 /* Check if this is a simple builtin (not part of a pipe). 1681 * Builtins within pipes have to fork anyway, and are handled in 1682 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either. 1683 */ 1684 child = &(pi->progs[0]); 1685 if (single_fg && child->group && child->subshell == 0) { 1686 debug_printf("non-subshell grouping\n"); 1687 setup_redirects(child, squirrel); 1688 debug_printf_exec(": run_list_real\n"); 1689 rcode = run_list_real(child->group); 1690 restore_redirects(squirrel); 1691 debug_printf_exec("run_pipe_real return %d\n", rcode); 1692 return rcode; // do we need to add '... & 0xff' ? 1693 } 1694 1695 if (single_fg && child->argv != NULL) { 1696 char **argv_expanded; 1697 char **argv = child->argv; 1698 1699 for (i = 0; is_assignment(argv[i]); i++) 1700 continue; 1701 if (i != 0 && argv[i] == NULL) { 1702 /* assignments, but no command: set the local environment */ 1703 for (i = 0; argv[i] != NULL; i++) { 1704 debug_printf("local environment set: %s\n", argv[i]); 1705 p = expand_string_to_string(argv[i]); 1706 set_local_var(p, 0); 1707 } 1708 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */ 1709 } 1710 for (i = 0; is_assignment(argv[i]); i++) { 1711 p = expand_string_to_string(argv[i]); 1712 //sp: child->sp--; 1713 putenv(p); 1714 } 1715 for (x = bltins; x->cmd; x++) { 1716 if (strcmp(argv[i], x->cmd) == 0) { 1717 if (x->function == builtin_exec && argv[i+1] == NULL) { 1718 debug_printf("magic exec\n"); 1719 setup_redirects(child, NULL); 1720 return EXIT_SUCCESS; 1721 } 1722 debug_printf("builtin inline %s\n", argv[0]); 1723 setup_redirects(child, squirrel); 1724 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]); 1725 //sp: if (child->sp) /* btw we can do it unconditionally... */ 1726 argv_expanded = expand_strvec_to_strvec(argv + i); 1727 rcode = x->function(argv_expanded) & 0xff; 1728 free(argv_expanded); 1729 restore_redirects(squirrel); 1730 debug_printf_exec("run_pipe_real return %d\n", rcode); 1731 return rcode; 1732 } 1733 } 1734#if ENABLE_FEATURE_SH_STANDALONE 1735 { 1736 const struct bb_applet *a = find_applet_by_name(argv[i]); 1737 if (a && a->nofork) { 1738 setup_redirects(child, squirrel); 1739 save_nofork_data(&nofork_save); 1740 argv_expanded = argv + i; 1741 //sp: if (child->sp) 1742 argv_expanded = expand_strvec_to_strvec(argv + i); 1743 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]); 1744 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded) & 0xff; 1745 free(argv_expanded); 1746 restore_redirects(squirrel); 1747 debug_printf_exec("run_pipe_real return %d\n", rcode); 1748 return rcode; 1749 } 1750 } 1751#endif 1752 } 1753 1754 /* Going to fork a child per each pipe member */ 1755 pi->running_progs = 0; 1756 1757 /* Disable job control signals for shell (parent) and 1758 * for initial child code after fork */ 1759 set_jobctrl_sighandler(SIG_IGN); 1760 1761 for (i = 0; i < pi->num_progs; i++) { 1762 child = &(pi->progs[i]); 1763 if (child->argv) 1764 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]); 1765 else 1766 debug_printf_exec(": pipe member with no argv\n"); 1767 1768 /* pipes are inserted between pairs of commands */ 1769 if ((i + 1) < pi->num_progs) { 1770 pipe(pipefds); 1771 nextout = pipefds[1]; 1772 } else { 1773 nextout = 1; 1774 pipefds[0] = -1; 1775 } 1776 1777#if BB_MMU 1778 child->pid = fork(); 1779#else 1780 child->pid = vfork(); 1781#endif 1782 if (!child->pid) { /* child */ 1783 /* Every child adds itself to new process group 1784 * with pgid == pid of first child in pipe */ 1785#if ENABLE_HUSH_JOB 1786 if (run_list_level == 1 && interactive_fd) { 1787 /* Don't do pgrp restore anymore on fatal signals */ 1788 set_fatal_sighandler(SIG_DFL); 1789 if (pi->pgrp < 0) /* true for 1st process only */ 1790 pi->pgrp = getpid(); 1791 if (setpgid(0, pi->pgrp) == 0 && pi->followup != PIPE_BG) { 1792 /* We do it in *every* child, not just first, 1793 * to avoid races */ 1794 tcsetpgrp(interactive_fd, pi->pgrp); 1795 } 1796 } 1797#endif 1798 /* in non-interactive case fatal sigs are already SIG_DFL */ 1799 close_all(); 1800 if (nextin != 0) { 1801 dup2(nextin, 0); 1802 close(nextin); 1803 } 1804 if (nextout != 1) { 1805 dup2(nextout, 1); 1806 close(nextout); 1807 } 1808 if (pipefds[0] != -1) { 1809 close(pipefds[0]); /* opposite end of our output pipe */ 1810 } 1811 /* Like bash, explicit redirects override pipes, 1812 * and the pipe fd is available for dup'ing. */ 1813 setup_redirects(child, NULL); 1814 1815 /* Restore default handlers just prior to exec */ 1816 set_jobctrl_sighandler(SIG_DFL); 1817 set_misc_sighandler(SIG_DFL); 1818 signal(SIGCHLD, SIG_DFL); 1819 pseudo_exec(child); 1820 } 1821 1822 pi->running_progs++; 1823 1824#if ENABLE_HUSH_JOB 1825 /* Second and next children need to know pid of first one */ 1826 if (pi->pgrp < 0) 1827 pi->pgrp = child->pid; 1828#endif 1829 if (nextin != 0) 1830 close(nextin); 1831 if (nextout != 1) 1832 close(nextout); 1833 1834 /* If there isn't another process, nextin is garbage 1835 but it doesn't matter */ 1836 nextin = pipefds[0]; 1837 } 1838 debug_printf_exec("run_pipe_real return -1\n"); 1839 return -1; 1840} 1841 1842#ifndef debug_print_tree 1843static void debug_print_tree(struct pipe *pi, int lvl) 1844{ 1845 static const char *PIPE[] = { 1846 [PIPE_SEQ] = "SEQ", 1847 [PIPE_AND] = "AND", 1848 [PIPE_OR ] = "OR" , 1849 [PIPE_BG ] = "BG" , 1850 }; 1851 static const char *RES[] = { 1852 [RES_NONE ] = "NONE" , 1853#if ENABLE_HUSH_IF 1854 [RES_IF ] = "IF" , 1855 [RES_THEN ] = "THEN" , 1856 [RES_ELIF ] = "ELIF" , 1857 [RES_ELSE ] = "ELSE" , 1858 [RES_FI ] = "FI" , 1859#endif 1860#if ENABLE_HUSH_LOOPS 1861 [RES_FOR ] = "FOR" , 1862 [RES_WHILE] = "WHILE", 1863 [RES_UNTIL] = "UNTIL", 1864 [RES_DO ] = "DO" , 1865 [RES_DONE ] = "DONE" , 1866 [RES_IN ] = "IN" , 1867#endif 1868 [RES_XXXX ] = "XXXX" , 1869 [RES_SNTX ] = "SNTX" , 1870 }; 1871 1872 int pin, prn; 1873 1874 pin = 0; 1875 while (pi) { 1876 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "", 1877 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]); 1878 prn = 0; 1879 while (prn < pi->num_progs) { 1880 struct child_prog *child = &pi->progs[prn]; 1881 char **argv = child->argv; 1882 1883 fprintf(stderr, "%*s prog %d", lvl*2, "", prn); 1884 if (child->group) { 1885 fprintf(stderr, " group %s: (argv=%p)\n", 1886 (child->subshell ? "()" : "{}"), 1887 argv); 1888 debug_print_tree(child->group, lvl+1); 1889 prn++; 1890 continue; 1891 } 1892 if (argv) while (*argv) { 1893 fprintf(stderr, " '%s'", *argv); 1894 argv++; 1895 } 1896 fprintf(stderr, "\n"); 1897 prn++; 1898 } 1899 pi = pi->next; 1900 pin++; 1901 } 1902} 1903#endif 1904 1905/* NB: called by pseudo_exec, and therefore must not modify any 1906 * global data until exec/_exit (we can be a child after vfork!) */ 1907static int run_list_real(struct pipe *pi) 1908{ 1909 struct pipe *rpipe; 1910#if ENABLE_HUSH_LOOPS 1911 char *for_varname = NULL; 1912 char **for_lcur = NULL; 1913 char **for_list = NULL; 1914 int flag_rep = 0; 1915#endif 1916 int save_num_progs; 1917 int flag_skip = 1; 1918 int rcode = 0; /* probably for gcc only */ 1919 int flag_restore = 0; 1920#if ENABLE_HUSH_IF 1921 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */ 1922#else 1923 enum { if_code = 0, next_if_code = 0 }; 1924#endif 1925 reserved_style rword; 1926 reserved_style skip_more_for_this_rword = RES_XXXX; 1927 1928 debug_printf_exec("run_list_real start lvl %d\n", run_list_level + 1); 1929 1930#if ENABLE_HUSH_LOOPS 1931 /* check syntax for "for" */ 1932 for (rpipe = pi; rpipe; rpipe = rpipe->next) { 1933 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR) 1934 && (rpipe->next == NULL) 1935 ) { 1936 syntax("malformed for"); /* no IN or no commands after IN */ 1937 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level); 1938 return 1; 1939 } 1940 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL) 1941 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN) 1942 ) { 1943 /* TODO: what is tested in the first condition? */ 1944 syntax("malformed for"); /* 2nd condition: not followed by IN */ 1945 debug_printf_exec("run_list_real lvl %d return 1\n", run_list_level); 1946 return 1; 1947 } 1948 } 1949#else 1950 rpipe = NULL; 1951#endif 1952 1953#if ENABLE_HUSH_JOB 1954 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done". 1955 * We are saving state before entering outermost list ("while...done") 1956 * so that ctrl-Z will correctly background _entire_ outermost list, 1957 * not just a part of it (like "sleep 1 | exit 2") */ 1958 if (++run_list_level == 1 && interactive_fd) { 1959 if (sigsetjmp(toplevel_jb, 1)) { 1960 /* ctrl-Z forked and we are parent; or ctrl-C. 1961 * Sighandler has longjmped us here */ 1962 signal(SIGINT, SIG_IGN); 1963 signal(SIGTSTP, SIG_IGN); 1964 /* Restore level (we can be coming from deep inside 1965 * nested levels) */ 1966 run_list_level = 1; 1967#if ENABLE_FEATURE_SH_STANDALONE 1968 if (nofork_save.saved) { /* if save area is valid */ 1969 debug_printf_jobs("exiting nofork early\n"); 1970 restore_nofork_data(&nofork_save); 1971 } 1972#endif 1973 if (ctrl_z_flag) { 1974 /* ctrl-Z has forked and stored pid of the child in pi->pid. 1975 * Remember this child as background job */ 1976 insert_bg_job(pi); 1977 } else { 1978 /* ctrl-C. We just stop doing whatever we were doing */ 1979 putchar('\n'); 1980 } 1981 rcode = 0; 1982 goto ret; 1983 } 1984 /* ctrl-Z handler will store pid etc in pi */ 1985 toplevel_list = pi; 1986 ctrl_z_flag = 0; 1987#if ENABLE_FEATURE_SH_STANDALONE 1988 nofork_save.saved = 0; /* in case we will run a nofork later */ 1989#endif 1990 signal_SA_RESTART(SIGTSTP, handler_ctrl_z); 1991 signal(SIGINT, handler_ctrl_c); 1992 } 1993#endif 1994 1995 for (; pi; pi = flag_restore ? rpipe : pi->next) { 1996 rword = pi->res_word; 1997#if ENABLE_HUSH_LOOPS 1998 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) { 1999 flag_restore = 0; 2000 if (!rpipe) { 2001 flag_rep = 0; 2002 rpipe = pi; 2003 } 2004 } 2005#endif 2006 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n", 2007 rword, if_code, next_if_code, skip_more_for_this_rword); 2008 if (rword == skip_more_for_this_rword && flag_skip) { 2009 if (pi->followup == PIPE_SEQ) 2010 flag_skip = 0; 2011 continue; 2012 } 2013 flag_skip = 1; 2014 skip_more_for_this_rword = RES_XXXX; 2015#if ENABLE_HUSH_IF 2016 if (rword == RES_THEN || rword == RES_ELSE) 2017 if_code = next_if_code; 2018 if (rword == RES_THEN && if_code) 2019 continue; 2020 if (rword == RES_ELSE && !if_code) 2021 continue; 2022 if (rword == RES_ELIF && !if_code) 2023 break; 2024#endif 2025#if ENABLE_HUSH_LOOPS 2026 if (rword == RES_FOR && pi->num_progs) { 2027 if (!for_lcur) { 2028 /* if no variable values after "in" we skip "for" */ 2029 if (!pi->next->progs->argv) 2030 continue; 2031 /* create list of variable values */ 2032 for_list = expand_strvec_to_strvec(pi->next->progs->argv); 2033 for_lcur = for_list; 2034 for_varname = pi->progs->argv[0]; 2035 pi->progs->argv[0] = NULL; 2036 flag_rep = 1; 2037 } 2038 free(pi->progs->argv[0]); 2039 if (!*for_lcur) { 2040 free(for_list); 2041 for_lcur = NULL; 2042 flag_rep = 0; 2043 pi->progs->argv[0] = for_varname; 2044 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0]; 2045 continue; 2046 } 2047 /* insert next value from for_lcur */ 2048 /* vda: does it need escaping? */ 2049 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++); 2050 pi->progs->glob_result.gl_pathv[0] = pi->progs->argv[0]; 2051 } 2052 if (rword == RES_IN) 2053 continue; 2054 if (rword == RES_DO) { 2055 if (!flag_rep) 2056 continue; 2057 } 2058 if (rword == RES_DONE) { 2059 if (flag_rep) { 2060 flag_restore = 1; 2061 } else { 2062 rpipe = NULL; 2063 } 2064 } 2065#endif 2066 if (pi->num_progs == 0) 2067 continue; 2068 save_num_progs = pi->num_progs; /* save number of programs */ 2069 debug_printf_exec(": run_pipe_real with %d members\n", pi->num_progs); 2070 rcode = run_pipe_real(pi); 2071 if (rcode != -1) { 2072 /* We only ran a builtin: rcode was set by the return value 2073 * of run_pipe_real(), and we don't need to wait for anything. */ 2074 } else if (pi->followup == PIPE_BG) { 2075 /* What does bash do with attempts to background builtins? */ 2076 /* Even bash 3.2 doesn't do that well with nested bg: 2077 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &". 2078 * I'm NOT treating inner &'s as jobs */ 2079#if ENABLE_HUSH_JOB 2080 if (run_list_level == 1) 2081 insert_bg_job(pi); 2082#endif 2083 rcode = EXIT_SUCCESS; 2084 } else { 2085#if ENABLE_HUSH_JOB 2086 /* Paranoia, just "interactive_fd" should be enough? */ 2087 if (run_list_level == 1 && interactive_fd) { 2088 /* waits for completion, then fg's main shell */ 2089 rcode = checkjobs_and_fg_shell(pi); 2090 } else 2091#endif 2092 { 2093 /* this one just waits for completion */ 2094 rcode = checkjobs(pi); 2095 } 2096 debug_printf_exec(": checkjobs returned %d\n", rcode); 2097 } 2098 debug_printf_exec(": setting last_return_code=%d\n", rcode); 2099 last_return_code = rcode; 2100 pi->num_progs = save_num_progs; /* restore number of programs */ 2101#if ENABLE_HUSH_IF 2102 if (rword == RES_IF || rword == RES_ELIF) 2103 next_if_code = rcode; /* can be overwritten a number of times */ 2104#endif 2105#if ENABLE_HUSH_LOOPS 2106 if (rword == RES_WHILE) 2107 flag_rep = !last_return_code; 2108 if (rword == RES_UNTIL) 2109 flag_rep = last_return_code; 2110#endif 2111 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR) 2112 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND) 2113 ) { 2114 skip_more_for_this_rword = rword; 2115 } 2116 checkjobs(NULL); 2117 } 2118 2119#if ENABLE_HUSH_JOB 2120 if (ctrl_z_flag) { 2121 /* ctrl-Z forked somewhere in the past, we are the child, 2122 * and now we completed running the list. Exit. */ 2123 exit(rcode); 2124 } 2125 ret: 2126 if (!--run_list_level && interactive_fd) { 2127 signal(SIGTSTP, SIG_IGN); 2128 signal(SIGINT, SIG_IGN); 2129 } 2130#endif 2131 debug_printf_exec("run_list_real lvl %d return %d\n", run_list_level + 1, rcode); 2132 return rcode; 2133} 2134 2135/* return code is the exit status of the pipe */ 2136static int free_pipe(struct pipe *pi, int indent) 2137{ 2138 char **p; 2139 struct child_prog *child; 2140 struct redir_struct *r, *rnext; 2141 int a, i, ret_code = 0; 2142 2143 if (pi->stopped_progs > 0) 2144 return ret_code; 2145 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid()); 2146 for (i = 0; i < pi->num_progs; i++) { 2147 child = &pi->progs[i]; 2148 debug_printf_clean("%s command %d:\n", indenter(indent), i); 2149 if (child->argv) { 2150 for (a = 0, p = child->argv; *p; a++, p++) { 2151 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p); 2152 } 2153 globfree(&child->glob_result); 2154 child->argv = NULL; 2155 } else if (child->group) { 2156 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell); 2157 ret_code = free_pipe_list(child->group, indent+3); 2158 debug_printf_clean("%s end group\n", indenter(indent)); 2159 } else { 2160 debug_printf_clean("%s (nil)\n", indenter(indent)); 2161 } 2162 for (r = child->redirects; r; r = rnext) { 2163 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->type].descrip); 2164 if (r->dup == -1) { 2165 /* guard against the case >$FOO, where foo is unset or blank */ 2166 if (r->word.gl_pathv) { 2167 debug_printf_clean(" %s\n", *r->word.gl_pathv); 2168 globfree(&r->word); 2169 } 2170 } else { 2171 debug_printf_clean("&%d\n", r->dup); 2172 } 2173 rnext = r->next; 2174 free(r); 2175 } 2176 child->redirects = NULL; 2177 } 2178 free(pi->progs); /* children are an array, they get freed all at once */ 2179 pi->progs = NULL; 2180#if ENABLE_HUSH_JOB 2181 free(pi->cmdtext); 2182 pi->cmdtext = NULL; 2183#endif 2184 return ret_code; 2185} 2186 2187static int free_pipe_list(struct pipe *head, int indent) 2188{ 2189 int rcode = 0; /* if list has no members */ 2190 struct pipe *pi, *next; 2191 2192 for (pi = head; pi; pi = next) { 2193 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word); 2194 rcode = free_pipe(pi, indent); 2195 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup); 2196 next = pi->next; 2197 /*pi->next = NULL;*/ 2198 free(pi); 2199 } 2200 return rcode; 2201} 2202 2203/* Select which version we will use */ 2204static int run_list(struct pipe *pi) 2205{ 2206 int rcode = 0; 2207 debug_printf_exec("run_list entered\n"); 2208 if (fake_mode == 0) { 2209 debug_printf_exec(": run_list_real with %d members\n", pi->num_progs); 2210 rcode = run_list_real(pi); 2211 } 2212 /* free_pipe_list has the side effect of clearing memory. 2213 * In the long run that function can be merged with run_list_real, 2214 * but doing that now would hobble the debugging effort. */ 2215 free_pipe_list(pi, 0); 2216 debug_printf_exec("run_list return %d\n", rcode); 2217 return rcode; 2218} 2219 2220static int globhack(const char *src, int flags, glob_t *pglob) 2221{ 2222 int cnt = 0, pathc; 2223 const char *s; 2224 char *dest; 2225 for (cnt = 1, s = src; s && *s; s++) { 2226 if (*s == '\\') s++; 2227 cnt++; 2228 } 2229 dest = xmalloc(cnt); 2230 if (!(flags & GLOB_APPEND)) { 2231 pglob->gl_pathv = NULL; 2232 pglob->gl_pathc = 0; 2233 pglob->gl_offs = 0; 2234 pglob->gl_offs = 0; 2235 } 2236 pathc = ++pglob->gl_pathc; 2237 pglob->gl_pathv = xrealloc(pglob->gl_pathv, (pathc+1) * sizeof(*pglob->gl_pathv)); 2238 pglob->gl_pathv[pathc-1] = dest; 2239 pglob->gl_pathv[pathc] = NULL; 2240 for (s = src; s && *s; s++, dest++) { 2241 if (*s == '\\') s++; 2242 *dest = *s; 2243 } 2244 *dest = '\0'; 2245 return 0; 2246} 2247 2248static int glob_needed(const char *s) 2249{ 2250 for (; *s; s++) { 2251 if (*s == '\\') s++; 2252 if (strchr("*[?", *s)) return 1; 2253 } 2254 return 0; 2255} 2256 2257static int xglob(o_string *dest, int flags, glob_t *pglob) 2258{ 2259 int gr; 2260 2261 /* short-circuit for null word */ 2262 /* we can code this better when the debug_printf's are gone */ 2263 if (dest->length == 0) { 2264 if (dest->nonnull) { 2265 /* bash man page calls this an "explicit" null */ 2266 gr = globhack(dest->data, flags, pglob); 2267 debug_printf("globhack returned %d\n", gr); 2268 } else { 2269 return 0; 2270 } 2271 } else if (glob_needed(dest->data)) { 2272 gr = glob(dest->data, flags, NULL, pglob); 2273 debug_printf("glob returned %d\n", gr); 2274 if (gr == GLOB_NOMATCH) { 2275 /* quote removal, or more accurately, backslash removal */ 2276 gr = globhack(dest->data, flags, pglob); 2277 debug_printf("globhack returned %d\n", gr); 2278 } 2279 } else { 2280 gr = globhack(dest->data, flags, pglob); 2281 debug_printf("globhack returned %d\n", gr); 2282 } 2283 if (gr == GLOB_NOSPACE) 2284 bb_error_msg_and_die("out of memory during glob"); 2285 if (gr != 0) { /* GLOB_ABORTED ? */ 2286 bb_error_msg("glob(3) error %d", gr); 2287 } 2288 /* globprint(glob_target); */ 2289 return gr; 2290} 2291 2292/* expand_strvec_to_strvec() takes a list of strings, expands 2293 * all variable references within and returns a pointer to 2294 * a list of expanded strings, possibly with larger number 2295 * of strings. (Think VAR="a b"; echo $VAR). 2296 * This new list is allocated as a single malloc block. 2297 * NULL-terminated list of char* pointers is at the beginning of it, 2298 * followed by strings themself. 2299 * Caller can deallocate entire list by single free(list). */ 2300 2301/* Helpers first: 2302 * count_XXX estimates size of the block we need. It's okay 2303 * to over-estimate sizes a bit, if it makes code simpler */ 2304static int count_ifs(const char *str) 2305{ 2306 int cnt = 0; 2307 debug_printf_expand("count_ifs('%s') ifs='%s'", str, ifs); 2308 while (1) { 2309 str += strcspn(str, ifs); 2310 if (!*str) break; 2311 str++; /* str += strspn(str, ifs); */ 2312 cnt++; /* cnt += strspn(str, ifs); - but this code is larger */ 2313 } 2314 debug_printf_expand(" return %d\n", cnt); 2315 return cnt; 2316} 2317 2318static void count_var_expansion_space(int *countp, int *lenp, char *arg) 2319{ 2320 char first_ch; 2321 int i; 2322 int len = *lenp; 2323 int count = *countp; 2324 const char *val; 2325 char *p; 2326 2327 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { 2328 len += p - arg; 2329 arg = ++p; 2330 p = strchr(p, SPECIAL_VAR_SYMBOL); 2331 first_ch = arg[0]; 2332 2333 switch (first_ch & 0x7f) { 2334 /* high bit in 1st_ch indicates that var is double-quoted */ 2335 case '$': /* pid */ 2336 case '!': /* bg pid */ 2337 case '?': /* exitcode */ 2338 case '#': /* argc */ 2339 len += sizeof(int)*3 + 1; /* enough for int */ 2340 break; 2341 case '*': 2342 case '@': 2343 for (i = 1; i < global_argc; i++) { 2344 len += strlen(global_argv[i]) + 1; 2345 count++; 2346 if (!(first_ch & 0x80)) 2347 count += count_ifs(global_argv[i]); 2348 } 2349 break; 2350 default: 2351 *p = '\0'; 2352 arg[0] = first_ch & 0x7f; 2353 if (isdigit(arg[0])) { 2354 i = xatoi_u(arg); 2355 val = NULL; 2356 if (i < global_argc) 2357 val = global_argv[i]; 2358 } else 2359 val = lookup_param(arg); 2360 arg[0] = first_ch; 2361 *p = SPECIAL_VAR_SYMBOL; 2362 2363 if (val) { 2364 len += strlen(val) + 1; 2365 if (!(first_ch & 0x80)) 2366 count += count_ifs(val); 2367 } 2368 } 2369 arg = ++p; 2370 } 2371 2372 len += strlen(arg) + 1; 2373 count++; 2374 *lenp = len; 2375 *countp = count; 2376} 2377 2378/* Store given string, finalizing the word and starting new one whenever 2379 * we encounter ifs char(s). This is used for expanding variable values. 2380 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */ 2381static int expand_on_ifs(char **list, int n, char **posp, const char *str) 2382{ 2383 char *pos = *posp; 2384 while (1) { 2385 int word_len = strcspn(str, ifs); 2386 if (word_len) { 2387 memcpy(pos, str, word_len); /* store non-ifs chars */ 2388 pos += word_len; 2389 str += word_len; 2390 } 2391 if (!*str) /* EOL - do not finalize word */ 2392 break; 2393 *pos++ = '\0'; 2394 if (n) debug_printf_expand("expand_on_ifs finalized list[%d]=%p '%s' " 2395 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2396 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2397 list[n++] = pos; 2398 str += strspn(str, ifs); /* skip ifs chars */ 2399 } 2400 *posp = pos; 2401 return n; 2402} 2403 2404/* Expand all variable references in given string, adding words to list[] 2405 * at n, n+1,... positions. Return updated n (so that list[n] is next one 2406 * to be filled). This routine is extremely tricky: has to deal with 2407 * variables/parameters with whitespace, $* and $@, and constructs like 2408 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */ 2409/* NB: another bug is that we cannot detect empty strings yet: 2410 * "" or $empty"" expands to zero words, has to expand to empty word */ 2411static int expand_vars_to_list(char **list, int n, char **posp, char *arg, char or_mask) 2412{ 2413 /* or_mask is either 0 (normal case) or 0x80 2414 * (expansion of right-hand side of assignment == 1-element expand) */ 2415 2416 char first_ch, ored_ch; 2417 int i; 2418 const char *val; 2419 char *p; 2420 char *pos = *posp; 2421 2422 ored_ch = 0; 2423 2424 if (n) debug_printf_expand("expand_vars_to_list finalized list[%d]=%p '%s' " 2425 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2426 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2427 list[n++] = pos; 2428 2429 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL))) { 2430 memcpy(pos, arg, p - arg); 2431 pos += (p - arg); 2432 arg = ++p; 2433 p = strchr(p, SPECIAL_VAR_SYMBOL); 2434 2435 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */ 2436 ored_ch |= first_ch; 2437 val = NULL; 2438 switch (first_ch & 0x7f) { 2439 /* Highest bit in first_ch indicates that var is double-quoted */ 2440 case '$': /* pid */ 2441 val = utoa(getpid()); 2442 break; 2443 case '!': /* bg pid */ 2444 val = last_bg_pid ? utoa(last_bg_pid) : (char*)""; 2445 break; 2446 case '?': /* exitcode */ 2447 val = utoa(last_return_code); 2448 break; 2449 case '#': /* argc */ 2450 val = utoa(global_argc ? global_argc-1 : 0); 2451 break; 2452 case '*': 2453 case '@': 2454 i = 1; 2455 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */ 2456 while (i < global_argc) { 2457 n = expand_on_ifs(list, n, &pos, global_argv[i]); 2458 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1); 2459 if (global_argv[i++][0] && i < global_argc) { 2460 /* this argv[] is not empty and not last: 2461 * put terminating NUL, start new word */ 2462 *pos++ = '\0'; 2463 if (n) debug_printf_expand("expand_vars_to_list 2 finalized list[%d]=%p '%s' " 2464 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2465 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2466 list[n++] = pos; 2467 } 2468 } 2469 } else 2470 /* If or_mask is nonzero, we handle assignment 'a=....$@.....' 2471 * and in this case should theat it like '$*' */ 2472 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */ 2473 while (1) { 2474 strcpy(pos, global_argv[i]); 2475 pos += strlen(global_argv[i]); 2476 if (++i >= global_argc) 2477 break; 2478 *pos++ = '\0'; 2479 if (n) debug_printf_expand("expand_vars_to_list 3 finalized list[%d]=%p '%s' " 2480 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2481 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2482 list[n++] = pos; 2483 } 2484 } else { /* quoted $*: add as one word */ 2485 while (1) { 2486 strcpy(pos, global_argv[i]); 2487 pos += strlen(global_argv[i]); 2488 if (++i >= global_argc) 2489 break; 2490 if (ifs[0]) 2491 *pos++ = ifs[0]; 2492 } 2493 } 2494 break; 2495 default: 2496 *p = '\0'; 2497 arg[0] = first_ch & 0x7f; 2498 if (isdigit(arg[0])) { 2499 i = xatoi_u(arg); 2500 val = NULL; 2501 if (i < global_argc) 2502 val = global_argv[i]; 2503 } else 2504 val = lookup_param(arg); 2505 arg[0] = first_ch; 2506 *p = SPECIAL_VAR_SYMBOL; 2507 if (!(first_ch & 0x80)) { /* unquoted $VAR */ 2508 if (val) { 2509 n = expand_on_ifs(list, n, &pos, val); 2510 val = NULL; 2511 } 2512 } /* else: quoted $VAR, val will be appended at pos */ 2513 } 2514 if (val) { 2515 strcpy(pos, val); 2516 pos += strlen(val); 2517 } 2518 arg = ++p; 2519 } 2520 debug_printf_expand("expand_vars_to_list adding tail '%s' at %p\n", arg, pos); 2521 strcpy(pos, arg); 2522 pos += strlen(arg) + 1; 2523 if (pos == list[n-1] + 1) { /* expansion is empty */ 2524 if (!(ored_ch & 0x80)) { /* all vars were not quoted... */ 2525 debug_printf_expand("expand_vars_to_list list[%d] empty, going back\n", n); 2526 pos--; 2527 n--; 2528 } 2529 } 2530 2531 *posp = pos; 2532 return n; 2533} 2534 2535static char **expand_variables(char **argv, char or_mask) 2536{ 2537 int n; 2538 int count = 1; 2539 int len = 0; 2540 char *pos, **v, **list; 2541 2542 v = argv; 2543 if (!*v) debug_printf_expand("count_var_expansion_space: " 2544 "argv[0]=NULL count=%d len=%d alloc_space=%d\n", 2545 count, len, sizeof(char*) * count + len); 2546 while (*v) { 2547 count_var_expansion_space(&count, &len, *v); 2548 debug_printf_expand("count_var_expansion_space: " 2549 "'%s' count=%d len=%d alloc_space=%d\n", 2550 *v, count, len, sizeof(char*) * count + len); 2551 v++; 2552 } 2553 len += sizeof(char*) * count; /* total to alloc */ 2554 list = xmalloc(len); 2555 pos = (char*)(list + count); 2556 debug_printf_expand("list=%p, list[0] should be %p\n", list, pos); 2557 n = 0; 2558 v = argv; 2559 while (*v) 2560 n = expand_vars_to_list(list, n, &pos, *v++, or_mask); 2561 2562 if (n) debug_printf_expand("finalized list[%d]=%p '%s' " 2563 "strlen=%d next=%p pos=%p\n", n-1, list[n-1], list[n-1], 2564 strlen(list[n-1]), list[n-1] + strlen(list[n-1]) + 1, pos); 2565 list[n] = NULL; 2566 2567#ifdef DEBUG_EXPAND 2568 { 2569 int m = 0; 2570 while (m <= n) { 2571 debug_printf_expand("list[%d]=%p '%s'\n", m, list[m], list[m]); 2572 m++; 2573 } 2574 debug_printf_expand("used_space=%d\n", pos - (char*)list); 2575 } 2576#endif 2577 if (ENABLE_HUSH_DEBUG) 2578 if (pos - (char*)list > len) 2579 bb_error_msg_and_die("BUG in varexp"); 2580 return list; 2581} 2582 2583static char **expand_strvec_to_strvec(char **argv) 2584{ 2585 return expand_variables(argv, 0); 2586} 2587 2588static char *expand_string_to_string(const char *str) 2589{ 2590 char *argv[2], **list; 2591 2592 argv[0] = (char*)str; 2593 argv[1] = NULL; 2594 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */ 2595 if (ENABLE_HUSH_DEBUG) 2596 if (!list[0] || list[1]) 2597 bb_error_msg_and_die("BUG in varexp2"); 2598 /* actually, just move string 2*sizeof(char*) bytes back */ 2599 strcpy((char*)list, list[0]); 2600 debug_printf_expand("string_to_string='%s'\n", (char*)list); 2601 return (char*)list; 2602} 2603 2604static char* expand_strvec_to_string(char **argv) 2605{ 2606 char **list; 2607 2608 list = expand_variables(argv, 0x80); 2609 /* Convert all NULs to spaces */ 2610 if (list[0]) { 2611 int n = 1; 2612 while (list[n]) { 2613 if (ENABLE_HUSH_DEBUG) 2614 if (list[n-1] + strlen(list[n-1]) + 1 != list[n]) 2615 bb_error_msg_and_die("BUG in varexp3"); 2616 list[n][-1] = ' '; /* TODO: or to ifs[0]? */ 2617 n++; 2618 } 2619 } 2620 strcpy((char*)list, list[0]); 2621 debug_printf_expand("strvec_to_string='%s'\n", (char*)list); 2622 return (char*)list; 2623} 2624 2625/* This is used to get/check local shell variables */ 2626static struct variable *get_local_var(const char *name) 2627{ 2628 struct variable *cur; 2629 int len; 2630 2631 if (!name) 2632 return NULL; 2633 len = strlen(name); 2634 for (cur = top_var; cur; cur = cur->next) { 2635 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=') 2636 return cur; 2637 } 2638 return NULL; 2639} 2640 2641/* str holds "NAME=VAL" and is expected to be malloced. 2642 * We take ownership of it. */ 2643static int set_local_var(char *str, int flg_export) 2644{ 2645 struct variable *cur; 2646 char *value; 2647 int name_len; 2648 2649 value = strchr(str, '='); 2650 if (!value) { /* not expected to ever happen? */ 2651 free(str); 2652 return -1; 2653 } 2654 2655 name_len = value - str + 1; /* including '=' */ 2656 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */ 2657 while (1) { 2658 if (strncmp(cur->varstr, str, name_len) != 0) { 2659 if (!cur->next) { 2660 /* Bail out. Note that now cur points 2661 * to last var in linked list */ 2662 break; 2663 } 2664 cur = cur->next; 2665 continue; 2666 } 2667 /* We found an existing var with this name */ 2668 *value = '\0'; 2669 if (cur->flg_read_only) { 2670 bb_error_msg("%s: readonly variable", str); 2671 free(str); 2672 return -1; 2673 } 2674 unsetenv(str); /* just in case */ 2675 *value = '='; 2676 if (strcmp(cur->varstr, str) == 0) { 2677 free_and_exp: 2678 free(str); 2679 goto exp; 2680 } 2681 if (cur->max_len >= strlen(str)) { 2682 /* This one is from startup env, reuse space */ 2683 strcpy(cur->varstr, str); 2684 goto free_and_exp; 2685 } 2686 /* max_len == 0 signifies "malloced" var, which we can 2687 * (and has to) free */ 2688 if (!cur->max_len) 2689 free(cur->varstr); 2690 cur->max_len = 0; 2691 goto set_str_and_exp; 2692 } 2693 2694 /* Not found - create next variable struct */ 2695 cur->next = xzalloc(sizeof(*cur)); 2696 cur = cur->next; 2697 2698 set_str_and_exp: 2699 cur->varstr = str; 2700 exp: 2701 if (flg_export) 2702 cur->flg_export = 1; 2703 if (cur->flg_export) 2704 return putenv(cur->varstr); 2705 return 0; 2706} 2707 2708static void unset_local_var(const char *name) 2709{ 2710 struct variable *cur; 2711 struct variable *prev = prev; /* for gcc */ 2712 int name_len; 2713 2714 if (!name) 2715 return; 2716 name_len = strlen(name); 2717 cur = top_var; 2718 while (cur) { 2719 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') { 2720 if (cur->flg_read_only) { 2721 bb_error_msg("%s: readonly variable", name); 2722 return; 2723 } 2724 /* prev is ok to use here because 1st variable, HUSH_VERSION, 2725 * is ro, and we cannot reach this code on the 1st pass */ 2726 prev->next = cur->next; 2727 unsetenv(cur->varstr); 2728 if (!cur->max_len) 2729 free(cur->varstr); 2730 free(cur); 2731 return; 2732 } 2733 prev = cur; 2734 cur = cur->next; 2735 } 2736} 2737 2738static int is_assignment(const char *s) 2739{ 2740 if (!s || !isalpha(*s)) 2741 return 0; 2742 s++; 2743 while (isalnum(*s) || *s == '_') 2744 s++; 2745 return *s == '='; 2746} 2747 2748/* the src parameter allows us to peek forward to a possible &n syntax 2749 * for file descriptor duplication, e.g., "2>&1". 2750 * Return code is 0 normally, 1 if a syntax error is detected in src. 2751 * Resource errors (in xmalloc) cause the process to exit */ 2752static int setup_redirect(struct p_context *ctx, int fd, redir_type style, 2753 struct in_str *input) 2754{ 2755 struct child_prog *child = ctx->child; 2756 struct redir_struct *redir = child->redirects; 2757 struct redir_struct *last_redir = NULL; 2758 2759 /* Create a new redir_struct and drop it onto the end of the linked list */ 2760 while (redir) { 2761 last_redir = redir; 2762 redir = redir->next; 2763 } 2764 redir = xmalloc(sizeof(struct redir_struct)); 2765 redir->next = NULL; 2766 redir->word.gl_pathv = NULL; 2767 if (last_redir) { 2768 last_redir->next = redir; 2769 } else { 2770 child->redirects = redir; 2771 } 2772 2773 redir->type = style; 2774 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd; 2775 2776 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip); 2777 2778 /* Check for a '2>&1' type redirect */ 2779 redir->dup = redirect_dup_num(input); 2780 if (redir->dup == -2) return 1; /* syntax error */ 2781 if (redir->dup != -1) { 2782 /* Erik had a check here that the file descriptor in question 2783 * is legit; I postpone that to "run time" 2784 * A "-" representation of "close me" shows up as a -3 here */ 2785 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup); 2786 } else { 2787 /* We do _not_ try to open the file that src points to, 2788 * since we need to return and let src be expanded first. 2789 * Set ctx->pending_redirect, so we know what to do at the 2790 * end of the next parsed word. */ 2791 ctx->pending_redirect = redir; 2792 } 2793 return 0; 2794} 2795 2796static struct pipe *new_pipe(void) 2797{ 2798 struct pipe *pi; 2799 pi = xzalloc(sizeof(struct pipe)); 2800 /*pi->num_progs = 0;*/ 2801 /*pi->progs = NULL;*/ 2802 /*pi->next = NULL;*/ 2803 /*pi->followup = 0; invalid */ 2804 if (RES_NONE) 2805 pi->res_word = RES_NONE; 2806 return pi; 2807} 2808 2809static void initialize_context(struct p_context *ctx) 2810{ 2811 ctx->child = NULL; 2812 ctx->pipe = ctx->list_head = new_pipe(); 2813 ctx->pending_redirect = NULL; 2814 ctx->res_w = RES_NONE; 2815 //only ctx->parse_type is not touched... is this intentional? 2816 ctx->old_flag = 0; 2817 ctx->stack = NULL; 2818 done_command(ctx); /* creates the memory for working child */ 2819} 2820 2821/* normal return is 0 2822 * if a reserved word is found, and processed, return 1 2823 * should handle if, then, elif, else, fi, for, while, until, do, done. 2824 * case, function, and select are obnoxious, save those for later. 2825 */ 2826#if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS 2827static int reserved_word(o_string *dest, struct p_context *ctx) 2828{ 2829 struct reserved_combo { 2830 char literal[7]; 2831 unsigned char code; 2832 int flag; 2833 }; 2834 /* Mostly a list of accepted follow-up reserved words. 2835 * FLAG_END means we are done with the sequence, and are ready 2836 * to turn the compound list into a command. 2837 * FLAG_START means the word must start a new compound list. 2838 */ 2839 static const struct reserved_combo reserved_list[] = { 2840#if ENABLE_HUSH_IF 2841 { "if", RES_IF, FLAG_THEN | FLAG_START }, 2842 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI }, 2843 { "elif", RES_ELIF, FLAG_THEN }, 2844 { "else", RES_ELSE, FLAG_FI }, 2845 { "fi", RES_FI, FLAG_END }, 2846#endif 2847#if ENABLE_HUSH_LOOPS 2848 { "for", RES_FOR, FLAG_IN | FLAG_START }, 2849 { "while", RES_WHILE, FLAG_DO | FLAG_START }, 2850 { "until", RES_UNTIL, FLAG_DO | FLAG_START }, 2851 { "in", RES_IN, FLAG_DO }, 2852 { "do", RES_DO, FLAG_DONE }, 2853 { "done", RES_DONE, FLAG_END } 2854#endif 2855 }; 2856 2857 const struct reserved_combo *r; 2858 2859 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) { 2860 if (strcmp(dest->data, r->literal) != 0) 2861 continue; 2862 debug_printf("found reserved word %s, code %d\n", r->literal, r->code); 2863 if (r->flag & FLAG_START) { 2864 struct p_context *new; 2865 debug_printf("push stack\n"); 2866#if ENABLE_HUSH_LOOPS 2867 if (ctx->res_w == RES_IN || ctx->res_w == RES_FOR) { 2868 syntax("malformed for"); /* example: 'for if' */ 2869 ctx->res_w = RES_SNTX; 2870 b_reset(dest); 2871 return 1; 2872 } 2873#endif 2874 new = xmalloc(sizeof(*new)); 2875 *new = *ctx; /* physical copy */ 2876 initialize_context(ctx); 2877 ctx->stack = new; 2878 } else if (ctx->res_w == RES_NONE || !(ctx->old_flag & (1 << r->code))) { 2879 syntax(NULL); 2880 ctx->res_w = RES_SNTX; 2881 b_reset(dest); 2882 return 1; 2883 } 2884 ctx->res_w = r->code; 2885 ctx->old_flag = r->flag; 2886 if (ctx->old_flag & FLAG_END) { 2887 struct p_context *old; 2888 debug_printf("pop stack\n"); 2889 done_pipe(ctx, PIPE_SEQ); 2890 old = ctx->stack; 2891 old->child->group = ctx->list_head; 2892 old->child->subshell = 0; 2893 *ctx = *old; /* physical copy */ 2894 free(old); 2895 } 2896 b_reset(dest); 2897 return 1; 2898 } 2899 return 0; 2900} 2901#else 2902#define reserved_word(dest, ctx) ((int)0) 2903#endif 2904 2905/* Normal return is 0. 2906 * Syntax or xglob errors return 1. */ 2907static int done_word(o_string *dest, struct p_context *ctx) 2908{ 2909 struct child_prog *child = ctx->child; 2910 glob_t *glob_target; 2911 int gr, flags = 0; 2912 2913 debug_printf_parse("done_word entered: '%s' %p\n", dest->data, child); 2914 if (dest->length == 0 && !dest->nonnull) { 2915 debug_printf_parse("done_word return 0: true null, ignored\n"); 2916 return 0; 2917 } 2918 if (ctx->pending_redirect) { 2919 glob_target = &ctx->pending_redirect->word; 2920 } else { 2921 if (child->group) { 2922 syntax(NULL); 2923 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n"); 2924 return 1; 2925 } 2926 if (!child->argv && (ctx->parse_type & PARSEFLAG_SEMICOLON)) { 2927 debug_printf_parse(": checking '%s' for reserved-ness\n", dest->data); 2928 if (reserved_word(dest, ctx)) { 2929 debug_printf_parse("done_word return %d\n", (ctx->res_w == RES_SNTX)); 2930 return (ctx->res_w == RES_SNTX); 2931 } 2932 } 2933 glob_target = &child->glob_result; 2934 if (child->argv) 2935 flags |= GLOB_APPEND; 2936 } 2937 gr = xglob(dest, flags, glob_target); 2938 if (gr != 0) { 2939 debug_printf_parse("done_word return 1: xglob returned %d\n", gr); 2940 return 1; 2941 } 2942 2943 b_reset(dest); 2944 if (ctx->pending_redirect) { 2945 ctx->pending_redirect = NULL; 2946 if (glob_target->gl_pathc != 1) { 2947 bb_error_msg("ambiguous redirect"); 2948 debug_printf_parse("done_word return 1: ambiguous redirect\n"); 2949 return 1; 2950 } 2951 } else { 2952 child->argv = glob_target->gl_pathv; 2953 } 2954#if ENABLE_HUSH_LOOPS 2955 if (ctx->res_w == RES_FOR) { 2956 done_word(dest, ctx); 2957 done_pipe(ctx, PIPE_SEQ); 2958 } 2959#endif 2960 debug_printf_parse("done_word return 0\n"); 2961 return 0; 2962} 2963 2964/* The only possible error here is out of memory, in which case 2965 * xmalloc exits. */ 2966static int done_command(struct p_context *ctx) 2967{ 2968 /* The child is really already in the pipe structure, so 2969 * advance the pipe counter and make a new, null child. */ 2970 struct pipe *pi = ctx->pipe; 2971 struct child_prog *child = ctx->child; 2972 2973 if (child) { 2974 if (child->group == NULL 2975 && child->argv == NULL 2976 && child->redirects == NULL 2977 ) { 2978 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs); 2979 return pi->num_progs; 2980 } 2981 pi->num_progs++; 2982 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs); 2983 } else { 2984 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs); 2985 } 2986 2987 /* Only real trickiness here is that the uncommitted 2988 * child structure is not counted in pi->num_progs. */ 2989 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1)); 2990 child = &pi->progs[pi->num_progs]; 2991 2992 memset(child, 0, sizeof(*child)); 2993 /*child->redirects = NULL;*/ 2994 /*child->argv = NULL;*/ 2995 /*child->is_stopped = 0;*/ 2996 /*child->group = NULL;*/ 2997 /*child->glob_result.gl_pathv = NULL;*/ 2998 child->family = pi; 2999 //sp: /*child->sp = 0;*/ 3000 //pt: child->parse_type = ctx->parse_type; 3001 3002 ctx->child = child; 3003 /* but ctx->pipe and ctx->list_head remain unchanged */ 3004 3005 return pi->num_progs; /* used only for 0/nonzero check */ 3006} 3007 3008static int done_pipe(struct p_context *ctx, pipe_style type) 3009{ 3010 struct pipe *new_p; 3011 int not_null; 3012 3013 debug_printf_parse("done_pipe entered, followup %d\n", type); 3014 not_null = done_command(ctx); /* implicit closure of previous command */ 3015 ctx->pipe->followup = type; 3016 ctx->pipe->res_word = ctx->res_w; 3017 /* Without this check, even just <enter> on command line generates 3018 * tree of three NOPs (!). Which is harmless but annoying. 3019 * IOW: it is safe to do it unconditionally. */ 3020 if (not_null) { 3021 new_p = new_pipe(); 3022 ctx->pipe->next = new_p; 3023 ctx->pipe = new_p; 3024 ctx->child = NULL; 3025 done_command(ctx); /* set up new pipe to accept commands */ 3026 } 3027 debug_printf_parse("done_pipe return 0\n"); 3028 return 0; 3029} 3030 3031/* peek ahead in the in_str to find out if we have a "&n" construct, 3032 * as in "2>&1", that represents duplicating a file descriptor. 3033 * returns either -2 (syntax error), -1 (no &), or the number found. 3034 */ 3035static int redirect_dup_num(struct in_str *input) 3036{ 3037 int ch, d = 0, ok = 0; 3038 ch = b_peek(input); 3039 if (ch != '&') return -1; 3040 3041 b_getch(input); /* get the & */ 3042 ch = b_peek(input); 3043 if (ch == '-') { 3044 b_getch(input); 3045 return -3; /* "-" represents "close me" */ 3046 } 3047 while (isdigit(ch)) { 3048 d = d*10 + (ch-'0'); 3049 ok = 1; 3050 b_getch(input); 3051 ch = b_peek(input); 3052 } 3053 if (ok) return d; 3054 3055 bb_error_msg("ambiguous redirect"); 3056 return -2; 3057} 3058 3059/* If a redirect is immediately preceded by a number, that number is 3060 * supposed to tell which file descriptor to redirect. This routine 3061 * looks for such preceding numbers. In an ideal world this routine 3062 * needs to handle all the following classes of redirects... 3063 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo 3064 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo 3065 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo 3066 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo 3067 * A -1 output from this program means no valid number was found, so the 3068 * caller should use the appropriate default for this redirection. 3069 */ 3070static int redirect_opt_num(o_string *o) 3071{ 3072 int num; 3073 3074 if (o->length == 0) 3075 return -1; 3076 for (num = 0; num < o->length; num++) { 3077 if (!isdigit(*(o->data + num))) { 3078 return -1; 3079 } 3080 } 3081 /* reuse num (and save an int) */ 3082 num = atoi(o->data); 3083 b_reset(o); 3084 return num; 3085} 3086 3087#if ENABLE_HUSH_TICK 3088static FILE *generate_stream_from_list(struct pipe *head) 3089{ 3090 FILE *pf; 3091 int pid, channel[2]; 3092 3093 xpipe(channel); 3094#if BB_MMU 3095 pid = fork(); 3096#else 3097 pid = vfork(); 3098#endif 3099 if (pid < 0) { 3100 bb_perror_msg_and_die("fork"); 3101 } else if (pid == 0) { 3102 close(channel[0]); 3103 if (channel[1] != 1) { 3104 dup2(channel[1], 1); 3105 close(channel[1]); 3106 } 3107 /* Prevent it from trying to handle ctrl-z etc */ 3108#if ENABLE_HUSH_JOB 3109 run_list_level = 1; 3110#endif 3111 /* Process substitution is not considered to be usual 3112 * 'command execution'. 3113 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */ 3114 /* Not needed, we are relying on it being disabled 3115 * everywhere outside actual command execution. */ 3116 /*set_jobctrl_sighandler(SIG_IGN);*/ 3117 set_misc_sighandler(SIG_DFL); 3118 _exit(run_list_real(head)); /* leaks memory */ 3119 } 3120 close(channel[1]); 3121 pf = fdopen(channel[0], "r"); 3122 return pf; 3123} 3124 3125/* Return code is exit status of the process that is run. */ 3126static int process_command_subs(o_string *dest, struct p_context *ctx, 3127 struct in_str *input, const char *subst_end) 3128{ 3129 int retcode, ch, eol_cnt; 3130 o_string result = NULL_O_STRING; 3131 struct p_context inner; 3132 FILE *p; 3133 struct in_str pipe_str; 3134 3135 initialize_context(&inner); 3136 3137 /* recursion to generate command */ 3138 retcode = parse_stream(&result, &inner, input, subst_end); 3139 if (retcode != 0) 3140 return retcode; /* syntax error or EOF */ 3141 done_word(&result, &inner); 3142 done_pipe(&inner, PIPE_SEQ); 3143 b_free(&result); 3144 3145 p = generate_stream_from_list(inner.list_head); 3146 if (p == NULL) return 1; 3147 mark_open(fileno(p)); 3148 setup_file_in_str(&pipe_str, p); 3149 3150 /* now send results of command back into original context */ 3151 eol_cnt = 0; 3152 while ((ch = b_getch(&pipe_str)) != EOF) { 3153 if (ch == '\n') { 3154 eol_cnt++; 3155 continue; 3156 } 3157 while (eol_cnt) { 3158 b_addqchr(dest, '\n', dest->quote); 3159 eol_cnt--; 3160 } 3161 b_addqchr(dest, ch, dest->quote); 3162 } 3163 3164 debug_printf("done reading from pipe, pclose()ing\n"); 3165 /* This is the step that wait()s for the child. Should be pretty 3166 * safe, since we just read an EOF from its stdout. We could try 3167 * to do better, by using wait(), and keeping track of background jobs 3168 * at the same time. That would be a lot of work, and contrary 3169 * to the KISS philosophy of this program. */ 3170 mark_closed(fileno(p)); 3171 retcode = fclose(p); 3172 free_pipe_list(inner.list_head, 0); 3173 debug_printf("closed FILE from child, retcode=%d\n", retcode); 3174 return retcode; 3175} 3176#endif 3177 3178static int parse_group(o_string *dest, struct p_context *ctx, 3179 struct in_str *input, int ch) 3180{ 3181 int rcode; 3182 const char *endch = NULL; 3183 struct p_context sub; 3184 struct child_prog *child = ctx->child; 3185 3186 debug_printf_parse("parse_group entered\n"); 3187 if (child->argv) { 3188 syntax(NULL); 3189 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n"); 3190 return 1; 3191 } 3192 initialize_context(&sub); 3193 endch = "}"; 3194 if (ch == '(') { 3195 endch = ")"; 3196 child->subshell = 1; 3197 } 3198 rcode = parse_stream(dest, &sub, input, endch); 3199//vda: err chk? 3200 done_word(dest, &sub); /* finish off the final word in the subcontext */ 3201 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */ 3202 child->group = sub.list_head; 3203 3204 debug_printf_parse("parse_group return %d\n", rcode); 3205 return rcode; 3206 /* child remains "open", available for possible redirects */ 3207} 3208 3209/* Basically useful version until someone wants to get fancier, 3210 * see the bash man page under "Parameter Expansion" */ 3211static const char *lookup_param(const char *src) 3212{ 3213 struct variable *var = get_local_var(src); 3214 if (var) 3215 return strchr(var->varstr, '=') + 1; 3216 return NULL; 3217} 3218 3219/* return code: 0 for OK, 1 for syntax error */ 3220static int handle_dollar(o_string *dest, struct p_context *ctx, struct in_str *input) 3221{ 3222 int ch = b_peek(input); /* first character after the $ */ 3223 unsigned char quote_mask = dest->quote ? 0x80 : 0; 3224 3225 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch); 3226 if (isalpha(ch)) { 3227 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3228 //sp: ctx->child->sp++; 3229 while (1) { 3230 debug_printf_parse(": '%c'\n", ch); 3231 b_getch(input); 3232 b_addchr(dest, ch | quote_mask); 3233 quote_mask = 0; 3234 ch = b_peek(input); 3235 if (!isalnum(ch) && ch != '_') 3236 break; 3237 } 3238 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3239 } else if (isdigit(ch)) { 3240 make_one_char_var: 3241 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3242 //sp: ctx->child->sp++; 3243 debug_printf_parse(": '%c'\n", ch); 3244 b_getch(input); 3245 b_addchr(dest, ch | quote_mask); 3246 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3247 } else switch (ch) { 3248 case '$': /* pid */ 3249 case '!': /* last bg pid */ 3250 case '?': /* last exit code */ 3251 case '#': /* number of args */ 3252 case '*': /* args */ 3253 case '@': /* args */ 3254 goto make_one_char_var; 3255 case '{': 3256 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3257 //sp: ctx->child->sp++; 3258 b_getch(input); 3259 while (1) { 3260 ch = b_getch(input); 3261 if (ch == '}') 3262 break; 3263 if (!isalnum(ch) && ch != '_') { 3264 syntax("unterminated ${name}"); 3265 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n"); 3266 return 1; 3267 } 3268 debug_printf_parse(": '%c'\n", ch); 3269 b_addchr(dest, ch | quote_mask); 3270 quote_mask = 0; 3271 } 3272 b_addchr(dest, SPECIAL_VAR_SYMBOL); 3273 break; 3274#if ENABLE_HUSH_TICK 3275 case '(': 3276 b_getch(input); 3277 process_command_subs(dest, ctx, input, ")"); 3278 break; 3279#endif 3280 case '-': 3281 case '_': 3282 /* still unhandled, but should be eventually */ 3283 bb_error_msg("unhandled syntax: $%c", ch); 3284 return 1; 3285 break; 3286 default: 3287 b_addqchr(dest, '$', dest->quote); 3288 } 3289 debug_printf_parse("handle_dollar return 0\n"); 3290 return 0; 3291} 3292 3293/* return code is 0 for normal exit, 1 for syntax error */ 3294static int parse_stream(o_string *dest, struct p_context *ctx, 3295 struct in_str *input, const char *end_trigger) 3296{ 3297 int ch, m; 3298 int redir_fd; 3299 redir_type redir_style; 3300 int next; 3301 3302 /* Only double-quote state is handled in the state variable dest->quote. 3303 * A single-quote triggers a bypass of the main loop until its mate is 3304 * found. When recursing, quote state is passed in via dest->quote. */ 3305 3306 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger); 3307 3308 while (1) { 3309 m = CHAR_IFS; 3310 next = '\0'; 3311 ch = b_getch(input); 3312 if (ch != EOF) { 3313 m = charmap[ch]; 3314 if (ch != '\n') 3315 next = b_peek(input); 3316 } 3317 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n", 3318 ch, ch, m, dest->quote); 3319 if (m == CHAR_ORDINARY 3320 || (m != CHAR_SPECIAL && dest->quote) 3321 ) { 3322 if (ch == EOF) { 3323 syntax("unterminated \""); 3324 debug_printf_parse("parse_stream return 1: unterminated \"\n"); 3325 return 1; 3326 } 3327 b_addqchr(dest, ch, dest->quote); 3328 continue; 3329 } 3330 if (m == CHAR_IFS) { 3331 if (done_word(dest, ctx)) { 3332 debug_printf_parse("parse_stream return 1: done_word!=0\n"); 3333 return 1; 3334 } 3335 if (ch == EOF) 3336 break; 3337 /* If we aren't performing a substitution, treat 3338 * a newline as a command separator. 3339 * [why we don't handle it exactly like ';'? --vda] */ 3340 if (end_trigger && ch == '\n') { 3341 done_pipe(ctx, PIPE_SEQ); 3342 } 3343 } 3344 if ((end_trigger && strchr(end_trigger, ch)) 3345 && !dest->quote && ctx->res_w == RES_NONE 3346 ) { 3347 debug_printf_parse("parse_stream return 0: end_trigger char found\n"); 3348 return 0; 3349 } 3350 if (m == CHAR_IFS) 3351 continue; 3352 switch (ch) { 3353 case '#': 3354 if (dest->length == 0 && !dest->quote) { 3355 while (1) { 3356 ch = b_peek(input); 3357 if (ch == EOF || ch == '\n') 3358 break; 3359 b_getch(input); 3360 } 3361 } else { 3362 b_addqchr(dest, ch, dest->quote); 3363 } 3364 break; 3365 case '\\': 3366 if (next == EOF) { 3367 syntax("\\<eof>"); 3368 debug_printf_parse("parse_stream return 1: \\<eof>\n"); 3369 return 1; 3370 } 3371 b_addqchr(dest, '\\', dest->quote); 3372 b_addqchr(dest, b_getch(input), dest->quote); 3373 break; 3374 case '$': 3375 if (handle_dollar(dest, ctx, input) != 0) { 3376 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n"); 3377 return 1; 3378 } 3379 break; 3380 case '\'': 3381 dest->nonnull = 1; 3382 while (1) { 3383 ch = b_getch(input); 3384 if (ch == EOF || ch == '\'') 3385 break; 3386 b_addchr(dest, ch); 3387 } 3388 if (ch == EOF) { 3389 syntax("unterminated '"); 3390 debug_printf_parse("parse_stream return 1: unterminated '\n"); 3391 return 1; 3392 } 3393 break; 3394 case '"': 3395 dest->nonnull = 1; 3396 dest->quote = !dest->quote; 3397 break; 3398#if ENABLE_HUSH_TICK 3399 case '`': 3400 process_command_subs(dest, ctx, input, "`"); 3401 break; 3402#endif 3403 case '>': 3404 redir_fd = redirect_opt_num(dest); 3405 done_word(dest, ctx); 3406 redir_style = REDIRECT_OVERWRITE; 3407 if (next == '>') { 3408 redir_style = REDIRECT_APPEND; 3409 b_getch(input); 3410 } 3411 setup_redirect(ctx, redir_fd, redir_style, input); 3412 break; 3413 case '<': 3414 redir_fd = redirect_opt_num(dest); 3415 done_word(dest, ctx); 3416 redir_style = REDIRECT_INPUT; 3417 if (next == '<') { 3418 redir_style = REDIRECT_HEREIS; 3419 b_getch(input); 3420 } else if (next == '>') { 3421 redir_style = REDIRECT_IO; 3422 b_getch(input); 3423 } 3424 setup_redirect(ctx, redir_fd, redir_style, input); 3425 break; 3426 case ';': 3427 done_word(dest, ctx); 3428 done_pipe(ctx, PIPE_SEQ); 3429 break; 3430 case '&': 3431 done_word(dest, ctx); 3432 if (next == '&') { 3433 b_getch(input); 3434 done_pipe(ctx, PIPE_AND); 3435 } else { 3436 done_pipe(ctx, PIPE_BG); 3437 } 3438 break; 3439 case '|': 3440 done_word(dest, ctx); 3441 if (next == '|') { 3442 b_getch(input); 3443 done_pipe(ctx, PIPE_OR); 3444 } else { 3445 /* we could pick up a file descriptor choice here 3446 * with redirect_opt_num(), but bash doesn't do it. 3447 * "echo foo 2| cat" yields "foo 2". */ 3448 done_command(ctx); 3449 } 3450 break; 3451 case '(': 3452 case '{': 3453 if (parse_group(dest, ctx, input, ch) != 0) { 3454 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n"); 3455 return 1; 3456 } 3457 break; 3458 case ')': 3459 case '}': 3460 syntax("unexpected }"); /* Proper use of this character is caught by end_trigger */ 3461 debug_printf_parse("parse_stream return 1: unexpected '}'\n"); 3462 return 1; 3463 default: 3464 if (ENABLE_HUSH_DEBUG) 3465 bb_error_msg_and_die("BUG: unexpected %c\n", ch); 3466 } 3467 } 3468 /* Complain if quote? No, maybe we just finished a command substitution 3469 * that was quoted. Example: 3470 * $ echo "`cat foo` plus more" 3471 * and we just got the EOF generated by the subshell that ran "cat foo" 3472 * The only real complaint is if we got an EOF when end_trigger != NULL, 3473 * that is, we were really supposed to get end_trigger, and never got 3474 * one before the EOF. Can't use the standard "syntax error" return code, 3475 * so that parse_stream_outer can distinguish the EOF and exit smoothly. */ 3476 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL)); 3477 if (end_trigger) 3478 return -1; 3479 return 0; 3480} 3481 3482static void set_in_charmap(const char *set, int code) 3483{ 3484 while (*set) 3485 charmap[(unsigned char)*set++] = code; 3486} 3487 3488static void update_charmap(void) 3489{ 3490 /* char *ifs and char charmap[256] are both globals. */ 3491 ifs = getenv("IFS"); 3492 if (ifs == NULL) 3493 ifs = " \t\n"; 3494 /* Precompute a list of 'flow through' behavior so it can be treated 3495 * quickly up front. Computation is necessary because of IFS. 3496 * Special case handling of IFS == " \t\n" is not implemented. 3497 * The charmap[] array only really needs two bits each, 3498 * and on most machines that would be faster (reduced L1 cache use). 3499 */ 3500 memset(charmap, CHAR_ORDINARY, sizeof(charmap)); 3501#if ENABLE_HUSH_TICK 3502 set_in_charmap("\\$\"`", CHAR_SPECIAL); 3503#else 3504 set_in_charmap("\\$\"", CHAR_SPECIAL); 3505#endif 3506 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED); 3507 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */ 3508} 3509 3510/* most recursion does not come through here, the exception is 3511 * from builtin_source() and builtin_eval() */ 3512static int parse_and_run_stream(struct in_str *inp, int parse_flag) 3513{ 3514 struct p_context ctx; 3515 o_string temp = NULL_O_STRING; 3516 int rcode; 3517 do { 3518 ctx.parse_type = parse_flag; 3519 initialize_context(&ctx); 3520 update_charmap(); 3521 if (!(parse_flag & PARSEFLAG_SEMICOLON) || (parse_flag & PARSEFLAG_REPARSING)) 3522 set_in_charmap(";$&|", CHAR_ORDINARY); 3523#if ENABLE_HUSH_INTERACTIVE 3524 inp->promptmode = 0; /* PS1 */ 3525#endif 3526 /* We will stop & execute after each ';' or '\n'. 3527 * Example: "sleep 9999; echo TEST" + ctrl-C: 3528 * TEST should be printed */ 3529 rcode = parse_stream(&temp, &ctx, inp, ";\n"); 3530 if (rcode != 1 && ctx.old_flag != 0) { 3531 syntax(NULL); 3532 } 3533 if (rcode != 1 && ctx.old_flag == 0) { 3534 done_word(&temp, &ctx); 3535 done_pipe(&ctx, PIPE_SEQ); 3536 debug_print_tree(ctx.list_head, 0); 3537 debug_printf_exec("parse_stream_outer: run_list\n"); 3538 run_list(ctx.list_head); 3539 } else { 3540 if (ctx.old_flag != 0) { 3541 free(ctx.stack); 3542 b_reset(&temp); 3543 } 3544 temp.nonnull = 0; 3545 temp.quote = 0; 3546 inp->p = NULL; 3547 free_pipe_list(ctx.list_head, 0); 3548 } 3549 b_free(&temp); 3550 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP)); /* loop on syntax errors, return on EOF */ 3551 return 0; 3552} 3553 3554static int parse_and_run_string(const char *s, int parse_flag) 3555{ 3556 struct in_str input; 3557 setup_string_in_str(&input, s); 3558 return parse_and_run_stream(&input, parse_flag); 3559} 3560 3561static int parse_and_run_file(FILE *f) 3562{ 3563 int rcode; 3564 struct in_str input; 3565 setup_file_in_str(&input, f); 3566 rcode = parse_and_run_stream(&input, PARSEFLAG_SEMICOLON); 3567 return rcode; 3568} 3569 3570#if ENABLE_HUSH_JOB 3571/* Make sure we have a controlling tty. If we get started under a job 3572 * aware app (like bash for example), make sure we are now in charge so 3573 * we don't fight over who gets the foreground */ 3574static void setup_job_control(void) 3575{ 3576 pid_t shell_pgrp; 3577 3578 saved_task_pgrp = shell_pgrp = getpgrp(); 3579 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp); 3580 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC); 3581 3582 /* If we were ran as 'hush &', 3583 * sleep until we are in the foreground. */ 3584 while (tcgetpgrp(interactive_fd) != shell_pgrp) { 3585 /* Send TTIN to ourself (should stop us) */ 3586 kill(- shell_pgrp, SIGTTIN); 3587 shell_pgrp = getpgrp(); 3588 } 3589 3590 /* Ignore job-control and misc signals. */ 3591 set_jobctrl_sighandler(SIG_IGN); 3592 set_misc_sighandler(SIG_IGN); 3593//huh? signal(SIGCHLD, SIG_IGN); 3594 3595 /* We _must_ restore tty pgrp on fatal signals */ 3596 set_fatal_sighandler(sigexit); 3597 3598 /* Put ourselves in our own process group. */ 3599 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */ 3600 /* Grab control of the terminal. */ 3601 tcsetpgrp(interactive_fd, getpid()); 3602} 3603#endif 3604 3605int hush_main(int argc, char **argv); 3606int hush_main(int argc, char **argv) 3607{ 3608 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR; 3609 static const struct variable const_shell_ver = { 3610 .next = NULL, 3611 .varstr = (char*)version_str, 3612 .max_len = 1, /* 0 can provoke free(name) */ 3613 .flg_export = 1, 3614 .flg_read_only = 1, 3615 }; 3616 3617 int opt; 3618 FILE *input; 3619 char **e; 3620 struct variable *cur_var; 3621 3622 PTR_TO_GLOBALS = xzalloc(sizeof(G)); 3623 3624 /* Deal with HUSH_VERSION */ 3625 shell_ver = const_shell_ver; /* copying struct here */ 3626 top_var = &shell_ver; 3627 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */ 3628 /* Initialize our shell local variables with the values 3629 * currently living in the environment */ 3630 cur_var = top_var; 3631 e = environ; 3632 if (e) while (*e) { 3633 char *value = strchr(*e, '='); 3634 if (value) { /* paranoia */ 3635 cur_var->next = xzalloc(sizeof(*cur_var)); 3636 cur_var = cur_var->next; 3637 cur_var->varstr = *e; 3638 cur_var->max_len = strlen(*e); 3639 cur_var->flg_export = 1; 3640 } 3641 e++; 3642 } 3643 putenv((char *)version_str); /* reinstate HUSH_VERSION */ 3644 3645#if ENABLE_FEATURE_EDITING 3646 line_input_state = new_line_input_t(FOR_SHELL); 3647#endif 3648 global_argc = argc; 3649 global_argv = argv; 3650 /* Initialize some more globals to non-zero values */ 3651 set_cwd(); 3652#if ENABLE_HUSH_INTERACTIVE 3653#if ENABLE_FEATURE_EDITING 3654 cmdedit_set_initial_prompt(); 3655#endif 3656 PS2 = "> "; 3657#endif 3658 3659 if (EXIT_SUCCESS) /* otherwise is already done */ 3660 last_return_code = EXIT_SUCCESS; 3661 3662 if (argv[0] && argv[0][0] == '-') { 3663 debug_printf("sourcing /etc/profile\n"); 3664 input = fopen("/etc/profile", "r"); 3665 if (input != NULL) { 3666 mark_open(fileno(input)); 3667 parse_and_run_file(input); 3668 mark_closed(fileno(input)); 3669 fclose(input); 3670 } 3671 } 3672 input = stdin; 3673 3674 while ((opt = getopt(argc, argv, "c:xif")) > 0) { 3675 switch (opt) { 3676 case 'c': 3677 global_argv = argv + optind; 3678 global_argc = argc - optind; 3679 opt = parse_and_run_string(optarg, PARSEFLAG_SEMICOLON); 3680 goto final_return; 3681 case 'i': 3682 /* Well, we cannot just declare interactiveness, 3683 * we have to have some stuff (ctty, etc) */ 3684 /* interactive_fd++; */ 3685 break; 3686 case 'f': 3687 fake_mode = 1; 3688 break; 3689 default: 3690#ifndef BB_VER 3691 fprintf(stderr, "Usage: sh [FILE]...\n" 3692 " or: sh -c command [args]...\n\n"); 3693 exit(EXIT_FAILURE); 3694#else 3695 bb_show_usage(); 3696#endif 3697 } 3698 } 3699#if ENABLE_HUSH_JOB 3700 /* A shell is interactive if the '-i' flag was given, or if all of 3701 * the following conditions are met: 3702 * no -c command 3703 * no arguments remaining or the -s flag given 3704 * standard input is a terminal 3705 * standard output is a terminal 3706 * Refer to Posix.2, the description of the 'sh' utility. */ 3707 if (argv[optind] == NULL && input == stdin 3708 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) 3709 ) { 3710 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO); 3711 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp); 3712 if (saved_tty_pgrp >= 0) { 3713 /* try to dup to high fd#, >= 255 */ 3714 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); 3715 if (interactive_fd < 0) { 3716 /* try to dup to any fd */ 3717 interactive_fd = dup(STDIN_FILENO); 3718 if (interactive_fd < 0) 3719 /* give up */ 3720 interactive_fd = 0; 3721 } 3722 // TODO: track & disallow any attempts of user 3723 // to (inadvertently) close/redirect it 3724 } 3725 } 3726 debug_printf("interactive_fd=%d\n", interactive_fd); 3727 if (interactive_fd) { 3728 /* Looks like they want an interactive shell */ 3729 setup_job_control(); 3730 /* Make xfuncs do cleanup on exit */ 3731 die_sleep = -1; /* flag */ 3732 if (setjmp(die_jmp)) { 3733 /* xfunc has failed! die die die */ 3734 hush_exit(xfunc_error_retval); 3735 } 3736#if !ENABLE_FEATURE_SH_EXTRA_QUIET 3737 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner); 3738 printf("Enter 'help' for a list of built-in commands.\n\n"); 3739#endif 3740 } 3741#elif ENABLE_HUSH_INTERACTIVE 3742/* no job control compiled, only prompt/line editing */ 3743 if (argv[optind] == NULL && input == stdin 3744 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO) 3745 ) { 3746 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255); 3747 if (interactive_fd < 0) { 3748 /* try to dup to any fd */ 3749 interactive_fd = dup(STDIN_FILENO); 3750 if (interactive_fd < 0) 3751 /* give up */ 3752 interactive_fd = 0; 3753 } 3754 } 3755 3756#endif 3757 3758 if (argv[optind] == NULL) { 3759 opt = parse_and_run_file(stdin); 3760 goto final_return; 3761 } 3762 3763 debug_printf("\nrunning script '%s'\n", argv[optind]); 3764 global_argv = argv + optind; 3765 global_argc = argc - optind; 3766 input = xfopen(argv[optind], "r"); 3767 opt = parse_and_run_file(input); 3768 3769 final_return: 3770 3771#if ENABLE_FEATURE_CLEAN_UP 3772 fclose(input); 3773 if (cwd != bb_msg_unknown) 3774 free((char*)cwd); 3775 cur_var = top_var->next; 3776 while (cur_var) { 3777 struct variable *tmp = cur_var; 3778 if (!cur_var->max_len) 3779 free(cur_var->varstr); 3780 cur_var = cur_var->next; 3781 free(tmp); 3782 } 3783#endif 3784 hush_exit(opt ? opt : last_return_code); 3785} 3786