eval.c revision 267654
1156230Smux/*- 2156230Smux * Copyright (c) 1993 3156230Smux * The Regents of the University of California. All rights reserved. 4156230Smux * 5156230Smux * This code is derived from software contributed to Berkeley by 6156230Smux * Kenneth Almquist. 7156230Smux * 8156230Smux * Redistribution and use in source and binary forms, with or without 9156230Smux * modification, are permitted provided that the following conditions 10156230Smux * are met: 11156230Smux * 1. Redistributions of source code must retain the above copyright 12156230Smux * notice, this list of conditions and the following disclaimer. 13156230Smux * 2. Redistributions in binary form must reproduce the above copyright 14156230Smux * notice, this list of conditions and the following disclaimer in the 15156230Smux * documentation and/or other materials provided with the distribution. 16156230Smux * 4. Neither the name of the University nor the names of its contributors 17156230Smux * may be used to endorse or promote products derived from this software 18156230Smux * without specific prior written permission. 19156230Smux * 20156230Smux * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21156230Smux * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22156230Smux * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23156230Smux * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24156230Smux * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25156230Smux * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26156230Smux * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27156230Smux * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28156230Smux * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29156230Smux * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30156230Smux * SUCH DAMAGE. 31156230Smux */ 32156230Smux 33156230Smux#ifndef lint 34156230Smux#if 0 35156230Smuxstatic char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 36156230Smux#endif 37156230Smux#endif /* not lint */ 38156230Smux#include <sys/cdefs.h> 39156230Smux__FBSDID("$FreeBSD: releng/9.3/bin/sh/eval.c 264423 2014-04-13 21:49:44Z jilles $"); 40156230Smux 41156230Smux#include <paths.h> 42156230Smux#include <signal.h> 43156230Smux#include <stdlib.h> 44156230Smux#include <unistd.h> 45#include <sys/resource.h> 46#include <sys/wait.h> /* For WIFSIGNALED(status) */ 47#include <errno.h> 48 49/* 50 * Evaluate a command. 51 */ 52 53#include "shell.h" 54#include "nodes.h" 55#include "syntax.h" 56#include "expand.h" 57#include "parser.h" 58#include "jobs.h" 59#include "eval.h" 60#include "builtins.h" 61#include "options.h" 62#include "exec.h" 63#include "redir.h" 64#include "input.h" 65#include "output.h" 66#include "trap.h" 67#include "var.h" 68#include "memalloc.h" 69#include "error.h" 70#include "show.h" 71#include "mystring.h" 72#ifndef NO_HISTORY 73#include "myhistedit.h" 74#endif 75 76 77int evalskip; /* set if we are skipping commands */ 78int skipcount; /* number of levels to skip */ 79MKINIT int loopnest; /* current loop nesting level */ 80int funcnest; /* depth of function calls */ 81static int builtin_flags; /* evalcommand flags for builtins */ 82 83 84char *commandname; 85struct strlist *cmdenviron; 86int exitstatus; /* exit status of last command */ 87int oexitstatus; /* saved exit status */ 88 89 90static void evalloop(union node *, int); 91static void evalfor(union node *, int); 92static void evalcase(union node *, int); 93static void evalsubshell(union node *, int); 94static void evalredir(union node *, int); 95static void expredir(union node *); 96static void evalpipe(union node *); 97static int is_valid_fast_cmdsubst(union node *n); 98static void evalcommand(union node *, int, struct backcmd *); 99static void prehash(union node *); 100 101 102/* 103 * Called to reset things after an exception. 104 */ 105 106#ifdef mkinit 107INCLUDE "eval.h" 108 109RESET { 110 evalskip = 0; 111 loopnest = 0; 112 funcnest = 0; 113} 114#endif 115 116 117 118/* 119 * The eval command. 120 */ 121 122int 123evalcmd(int argc, char **argv) 124{ 125 char *p; 126 char *concat; 127 char **ap; 128 129 if (argc > 1) { 130 p = argv[1]; 131 if (argc > 2) { 132 STARTSTACKSTR(concat); 133 ap = argv + 2; 134 for (;;) { 135 STPUTS(p, concat); 136 if ((p = *ap++) == NULL) 137 break; 138 STPUTC(' ', concat); 139 } 140 STPUTC('\0', concat); 141 p = grabstackstr(concat); 142 } 143 evalstring(p, builtin_flags); 144 } else 145 exitstatus = 0; 146 return exitstatus; 147} 148 149 150/* 151 * Execute a command or commands contained in a string. 152 */ 153 154void 155evalstring(char *s, int flags) 156{ 157 union node *n; 158 struct stackmark smark; 159 int flags_exit; 160 int any; 161 162 flags_exit = flags & EV_EXIT; 163 flags &= ~EV_EXIT; 164 any = 0; 165 setstackmark(&smark); 166 setinputstring(s, 1); 167 while ((n = parsecmd(0)) != NEOF) { 168 if (n != NULL && !nflag) { 169 if (flags_exit && preadateof()) 170 evaltree(n, flags | EV_EXIT); 171 else 172 evaltree(n, flags); 173 any = 1; 174 } 175 popstackmark(&smark); 176 } 177 popfile(); 178 popstackmark(&smark); 179 if (!any) 180 exitstatus = 0; 181 if (flags_exit) 182 exraise(EXEXIT); 183} 184 185 186/* 187 * Evaluate a parse tree. The value is left in the global variable 188 * exitstatus. 189 */ 190 191void 192evaltree(union node *n, int flags) 193{ 194 int do_etest; 195 union node *next; 196 197 do_etest = 0; 198 if (n == NULL) { 199 TRACE(("evaltree(NULL) called\n")); 200 exitstatus = 0; 201 goto out; 202 } 203 do { 204 next = NULL; 205#ifndef NO_HISTORY 206 displayhist = 1; /* show history substitutions done with fc */ 207#endif 208 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 209 switch (n->type) { 210 case NSEMI: 211 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 212 if (evalskip) 213 goto out; 214 next = n->nbinary.ch2; 215 break; 216 case NAND: 217 evaltree(n->nbinary.ch1, EV_TESTED); 218 if (evalskip || exitstatus != 0) { 219 goto out; 220 } 221 next = n->nbinary.ch2; 222 break; 223 case NOR: 224 evaltree(n->nbinary.ch1, EV_TESTED); 225 if (evalskip || exitstatus == 0) 226 goto out; 227 next = n->nbinary.ch2; 228 break; 229 case NREDIR: 230 evalredir(n, flags); 231 break; 232 case NSUBSHELL: 233 evalsubshell(n, flags); 234 do_etest = !(flags & EV_TESTED); 235 break; 236 case NBACKGND: 237 evalsubshell(n, flags); 238 break; 239 case NIF: { 240 evaltree(n->nif.test, EV_TESTED); 241 if (evalskip) 242 goto out; 243 if (exitstatus == 0) 244 next = n->nif.ifpart; 245 else if (n->nif.elsepart) 246 next = n->nif.elsepart; 247 else 248 exitstatus = 0; 249 break; 250 } 251 case NWHILE: 252 case NUNTIL: 253 evalloop(n, flags & ~EV_EXIT); 254 break; 255 case NFOR: 256 evalfor(n, flags & ~EV_EXIT); 257 break; 258 case NCASE: 259 evalcase(n, flags); 260 break; 261 case NDEFUN: 262 defun(n->narg.text, n->narg.next); 263 exitstatus = 0; 264 break; 265 case NNOT: 266 evaltree(n->nnot.com, EV_TESTED); 267 exitstatus = !exitstatus; 268 break; 269 270 case NPIPE: 271 evalpipe(n); 272 do_etest = !(flags & EV_TESTED); 273 break; 274 case NCMD: 275 evalcommand(n, flags, (struct backcmd *)NULL); 276 do_etest = !(flags & EV_TESTED); 277 break; 278 default: 279 out1fmt("Node type = %d\n", n->type); 280 flushout(&output); 281 break; 282 } 283 n = next; 284 } while (n != NULL); 285out: 286 if (pendingsigs) 287 dotrap(); 288 if (eflag && exitstatus != 0 && do_etest) 289 exitshell(exitstatus); 290 if (flags & EV_EXIT) 291 exraise(EXEXIT); 292} 293 294 295static void 296evalloop(union node *n, int flags) 297{ 298 int status; 299 300 loopnest++; 301 status = 0; 302 for (;;) { 303 evaltree(n->nbinary.ch1, EV_TESTED); 304 if (evalskip) { 305skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 306 evalskip = 0; 307 continue; 308 } 309 if (evalskip == SKIPBREAK && --skipcount <= 0) 310 evalskip = 0; 311 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 312 status = exitstatus; 313 break; 314 } 315 if (n->type == NWHILE) { 316 if (exitstatus != 0) 317 break; 318 } else { 319 if (exitstatus == 0) 320 break; 321 } 322 evaltree(n->nbinary.ch2, flags); 323 status = exitstatus; 324 if (evalskip) 325 goto skipping; 326 } 327 loopnest--; 328 exitstatus = status; 329} 330 331 332 333static void 334evalfor(union node *n, int flags) 335{ 336 struct arglist arglist; 337 union node *argp; 338 struct strlist *sp; 339 struct stackmark smark; 340 341 setstackmark(&smark); 342 arglist.lastp = &arglist.list; 343 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 344 oexitstatus = exitstatus; 345 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 346 if (evalskip) 347 goto out; 348 } 349 *arglist.lastp = NULL; 350 351 exitstatus = 0; 352 loopnest++; 353 for (sp = arglist.list ; sp ; sp = sp->next) { 354 setvar(n->nfor.var, sp->text, 0); 355 evaltree(n->nfor.body, flags); 356 if (evalskip) { 357 if (evalskip == SKIPCONT && --skipcount <= 0) { 358 evalskip = 0; 359 continue; 360 } 361 if (evalskip == SKIPBREAK && --skipcount <= 0) 362 evalskip = 0; 363 break; 364 } 365 } 366 loopnest--; 367out: 368 popstackmark(&smark); 369} 370 371 372 373static void 374evalcase(union node *n, int flags) 375{ 376 union node *cp; 377 union node *patp; 378 struct arglist arglist; 379 struct stackmark smark; 380 381 setstackmark(&smark); 382 arglist.lastp = &arglist.list; 383 oexitstatus = exitstatus; 384 exitstatus = 0; 385 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 386 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 387 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 388 if (casematch(patp, arglist.list->text)) { 389 while (cp->nclist.next && 390 cp->type == NCLISTFALLTHRU) { 391 if (evalskip != 0) 392 break; 393 evaltree(cp->nclist.body, 394 flags & ~EV_EXIT); 395 cp = cp->nclist.next; 396 } 397 if (evalskip == 0) { 398 evaltree(cp->nclist.body, flags); 399 } 400 goto out; 401 } 402 } 403 } 404out: 405 popstackmark(&smark); 406} 407 408 409 410/* 411 * Kick off a subshell to evaluate a tree. 412 */ 413 414static void 415evalsubshell(union node *n, int flags) 416{ 417 struct job *jp; 418 int backgnd = (n->type == NBACKGND); 419 420 oexitstatus = exitstatus; 421 expredir(n->nredir.redirect); 422 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 423 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 424 if (backgnd) 425 flags &=~ EV_TESTED; 426 redirect(n->nredir.redirect, 0); 427 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 428 } else if (! backgnd) { 429 INTOFF; 430 exitstatus = waitforjob(jp, (int *)NULL); 431 INTON; 432 } else 433 exitstatus = 0; 434} 435 436 437/* 438 * Evaluate a redirected compound command. 439 */ 440 441static void 442evalredir(union node *n, int flags) 443{ 444 struct jmploc jmploc; 445 struct jmploc *savehandler; 446 volatile int in_redirect = 1; 447 448 oexitstatus = exitstatus; 449 expredir(n->nredir.redirect); 450 savehandler = handler; 451 if (setjmp(jmploc.loc)) { 452 int e; 453 454 handler = savehandler; 455 e = exception; 456 popredir(); 457 if (e == EXERROR || e == EXEXEC) { 458 if (in_redirect) { 459 exitstatus = 2; 460 return; 461 } 462 } 463 longjmp(handler->loc, 1); 464 } else { 465 INTOFF; 466 handler = &jmploc; 467 redirect(n->nredir.redirect, REDIR_PUSH); 468 in_redirect = 0; 469 INTON; 470 evaltree(n->nredir.n, flags); 471 } 472 INTOFF; 473 handler = savehandler; 474 popredir(); 475 INTON; 476} 477 478 479/* 480 * Compute the names of the files in a redirection list. 481 */ 482 483static void 484expredir(union node *n) 485{ 486 union node *redir; 487 488 for (redir = n ; redir ; redir = redir->nfile.next) { 489 struct arglist fn; 490 fn.lastp = &fn.list; 491 switch (redir->type) { 492 case NFROM: 493 case NTO: 494 case NFROMTO: 495 case NAPPEND: 496 case NCLOBBER: 497 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 498 redir->nfile.expfname = fn.list->text; 499 break; 500 case NFROMFD: 501 case NTOFD: 502 if (redir->ndup.vname) { 503 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 504 fixredir(redir, fn.list->text, 1); 505 } 506 break; 507 } 508 } 509} 510 511 512 513/* 514 * Evaluate a pipeline. All the processes in the pipeline are children 515 * of the process creating the pipeline. (This differs from some versions 516 * of the shell, which make the last process in a pipeline the parent 517 * of all the rest.) 518 */ 519 520static void 521evalpipe(union node *n) 522{ 523 struct job *jp; 524 struct nodelist *lp; 525 int pipelen; 526 int prevfd; 527 int pip[2]; 528 529 TRACE(("evalpipe(%p) called\n", (void *)n)); 530 pipelen = 0; 531 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 532 pipelen++; 533 INTOFF; 534 jp = makejob(n, pipelen); 535 prevfd = -1; 536 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 537 prehash(lp->n); 538 pip[1] = -1; 539 if (lp->next) { 540 if (pipe(pip) < 0) { 541 close(prevfd); 542 error("Pipe call failed: %s", strerror(errno)); 543 } 544 } 545 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 546 INTON; 547 if (prevfd > 0) { 548 dup2(prevfd, 0); 549 close(prevfd); 550 } 551 if (pip[1] >= 0) { 552 if (!(prevfd >= 0 && pip[0] == 0)) 553 close(pip[0]); 554 if (pip[1] != 1) { 555 dup2(pip[1], 1); 556 close(pip[1]); 557 } 558 } 559 evaltree(lp->n, EV_EXIT); 560 } 561 if (prevfd >= 0) 562 close(prevfd); 563 prevfd = pip[0]; 564 if (pip[1] != -1) 565 close(pip[1]); 566 } 567 INTON; 568 if (n->npipe.backgnd == 0) { 569 INTOFF; 570 exitstatus = waitforjob(jp, (int *)NULL); 571 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 572 INTON; 573 } else 574 exitstatus = 0; 575} 576 577 578 579static int 580is_valid_fast_cmdsubst(union node *n) 581{ 582 583 return (n->type == NCMD); 584} 585 586/* 587 * Execute a command inside back quotes. If it's a builtin command, we 588 * want to save its output in a block obtained from malloc. Otherwise 589 * we fork off a subprocess and get the output of the command via a pipe. 590 * Should be called with interrupts off. 591 */ 592 593void 594evalbackcmd(union node *n, struct backcmd *result) 595{ 596 int pip[2]; 597 struct job *jp; 598 struct stackmark smark; /* unnecessary */ 599 struct jmploc jmploc; 600 struct jmploc *savehandler; 601 struct localvar *savelocalvars; 602 603 setstackmark(&smark); 604 result->fd = -1; 605 result->buf = NULL; 606 result->nleft = 0; 607 result->jp = NULL; 608 if (n == NULL) { 609 exitstatus = 0; 610 goto out; 611 } 612 if (is_valid_fast_cmdsubst(n)) { 613 exitstatus = oexitstatus; 614 savelocalvars = localvars; 615 localvars = NULL; 616 forcelocal++; 617 savehandler = handler; 618 if (setjmp(jmploc.loc)) { 619 if (exception == EXERROR || exception == EXEXEC) 620 exitstatus = 2; 621 else if (exception != 0) { 622 handler = savehandler; 623 forcelocal--; 624 poplocalvars(); 625 localvars = savelocalvars; 626 longjmp(handler->loc, 1); 627 } 628 } else { 629 handler = &jmploc; 630 evalcommand(n, EV_BACKCMD, result); 631 } 632 handler = savehandler; 633 forcelocal--; 634 poplocalvars(); 635 localvars = savelocalvars; 636 } else { 637 exitstatus = 0; 638 if (pipe(pip) < 0) 639 error("Pipe call failed: %s", strerror(errno)); 640 jp = makejob(n, 1); 641 if (forkshell(jp, n, FORK_NOJOB) == 0) { 642 FORCEINTON; 643 close(pip[0]); 644 if (pip[1] != 1) { 645 dup2(pip[1], 1); 646 close(pip[1]); 647 } 648 evaltree(n, EV_EXIT); 649 } 650 close(pip[1]); 651 result->fd = pip[0]; 652 result->jp = jp; 653 } 654out: 655 popstackmark(&smark); 656 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 657 result->fd, result->buf, result->nleft, result->jp)); 658} 659 660static int 661mustexpandto(const char *argtext, const char *mask) 662{ 663 for (;;) { 664 if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) { 665 argtext++; 666 continue; 667 } 668 if (*argtext == CTLESC) 669 argtext++; 670 else if (BASESYNTAX[(int)*argtext] == CCTL) 671 return (0); 672 if (*argtext != *mask) 673 return (0); 674 if (*argtext == '\0') 675 return (1); 676 argtext++; 677 mask++; 678 } 679} 680 681static int 682isdeclarationcmd(struct narg *arg) 683{ 684 int have_command = 0; 685 686 if (arg == NULL) 687 return (0); 688 while (mustexpandto(arg->text, "command")) { 689 have_command = 1; 690 arg = &arg->next->narg; 691 if (arg == NULL) 692 return (0); 693 /* 694 * To also allow "command -p" and "command --" as part of 695 * a declaration command, add code here. 696 * We do not do this, as ksh does not do it either and it 697 * is not required by POSIX. 698 */ 699 } 700 return (mustexpandto(arg->text, "export") || 701 mustexpandto(arg->text, "readonly") || 702 (mustexpandto(arg->text, "local") && 703 (have_command || !isfunc("local")))); 704} 705 706/* 707 * Check if a builtin can safely be executed in the same process, 708 * even though it should be in a subshell (command substitution). 709 * Note that jobid, jobs, times and trap can show information not 710 * available in a child process; this is deliberate. 711 * The arguments should already have been expanded. 712 */ 713static int 714safe_builtin(int idx, int argc, char **argv) 715{ 716 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 717 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 718 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 719 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 720 idx == TYPECMD) 721 return (1); 722 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 723 idx == UMASKCMD) 724 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 725 if (idx == SETCMD) 726 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 727 argv[1][0] == '+') && argv[1][1] == 'o' && 728 argv[1][2] == '\0')); 729 return (0); 730} 731 732/* 733 * Execute a simple command. 734 * Note: This may or may not return if (flags & EV_EXIT). 735 */ 736 737static void 738evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 739{ 740 struct stackmark smark; 741 union node *argp; 742 struct arglist arglist; 743 struct arglist varlist; 744 char **argv; 745 int argc; 746 char **envp; 747 int varflag; 748 struct strlist *sp; 749 int mode; 750 int pip[2]; 751 struct cmdentry cmdentry; 752 struct job *jp; 753 struct jmploc jmploc; 754 struct jmploc *savehandler; 755 char *savecmdname; 756 struct shparam saveparam; 757 struct localvar *savelocalvars; 758 struct parsefile *savetopfile; 759 volatile int e; 760 char *lastarg; 761 int realstatus; 762 int do_clearcmdentry; 763 const char *path = pathval(); 764 765 /* First expand the arguments. */ 766 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 767 setstackmark(&smark); 768 arglist.lastp = &arglist.list; 769 varlist.lastp = &varlist.list; 770 varflag = 1; 771 jp = NULL; 772 do_clearcmdentry = 0; 773 oexitstatus = exitstatus; 774 exitstatus = 0; 775 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 776 if (varflag && isassignment(argp->narg.text)) { 777 expandarg(argp, varflag == 1 ? &varlist : &arglist, 778 EXP_VARTILDE); 779 continue; 780 } else if (varflag == 1) 781 varflag = isdeclarationcmd(&argp->narg) ? 2 : 0; 782 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 783 } 784 *arglist.lastp = NULL; 785 *varlist.lastp = NULL; 786 expredir(cmd->ncmd.redirect); 787 argc = 0; 788 for (sp = arglist.list ; sp ; sp = sp->next) 789 argc++; 790 /* Add one slot at the beginning for tryexec(). */ 791 argv = stalloc(sizeof (char *) * (argc + 2)); 792 argv++; 793 794 for (sp = arglist.list ; sp ; sp = sp->next) { 795 TRACE(("evalcommand arg: %s\n", sp->text)); 796 *argv++ = sp->text; 797 } 798 *argv = NULL; 799 lastarg = NULL; 800 if (iflag && funcnest == 0 && argc > 0) 801 lastarg = argv[-1]; 802 argv -= argc; 803 804 /* Print the command if xflag is set. */ 805 if (xflag) { 806 char sep = 0; 807 const char *p, *ps4; 808 ps4 = expandstr(ps4val()); 809 out2str(ps4 != NULL ? ps4 : ps4val()); 810 for (sp = varlist.list ; sp ; sp = sp->next) { 811 if (sep != 0) 812 out2c(' '); 813 p = strchr(sp->text, '='); 814 if (p != NULL) { 815 p++; 816 outbin(sp->text, p - sp->text, out2); 817 out2qstr(p); 818 } else 819 out2qstr(sp->text); 820 sep = ' '; 821 } 822 for (sp = arglist.list ; sp ; sp = sp->next) { 823 if (sep != 0) 824 out2c(' '); 825 /* Disambiguate command looking like assignment. */ 826 if (sp == arglist.list && 827 strchr(sp->text, '=') != NULL && 828 strchr(sp->text, '\'') == NULL) { 829 out2c('\''); 830 out2str(sp->text); 831 out2c('\''); 832 } else 833 out2qstr(sp->text); 834 sep = ' '; 835 } 836 out2c('\n'); 837 flushout(&errout); 838 } 839 840 /* Now locate the command. */ 841 if (argc == 0) { 842 /* Variable assignment(s) without command */ 843 cmdentry.cmdtype = CMDBUILTIN; 844 cmdentry.u.index = BLTINCMD; 845 cmdentry.special = 0; 846 } else { 847 static const char PATH[] = "PATH="; 848 int cmd_flags = 0, bltinonly = 0; 849 850 /* 851 * Modify the command lookup path, if a PATH= assignment 852 * is present 853 */ 854 for (sp = varlist.list ; sp ; sp = sp->next) 855 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 856 path = sp->text + sizeof(PATH) - 1; 857 /* 858 * On `PATH=... command`, we need to make 859 * sure that the command isn't using the 860 * non-updated hash table of the outer PATH 861 * setting and we need to make sure that 862 * the hash table isn't filled with items 863 * from the temporary setting. 864 * 865 * It would be better to forbit using and 866 * updating the table while this command 867 * runs, by the command finding mechanism 868 * is heavily integrated with hash handling, 869 * so we just delete the hash before and after 870 * the command runs. Partly deleting like 871 * changepatch() does doesn't seem worth the 872 * bookinging effort, since most such runs add 873 * directories in front of the new PATH. 874 */ 875 clearcmdentry(); 876 do_clearcmdentry = 1; 877 } 878 879 for (;;) { 880 if (bltinonly) { 881 cmdentry.u.index = find_builtin(*argv, &cmdentry.special); 882 if (cmdentry.u.index < 0) { 883 cmdentry.u.index = BLTINCMD; 884 argv--; 885 argc++; 886 break; 887 } 888 } else 889 find_command(argv[0], &cmdentry, cmd_flags, path); 890 /* implement the bltin and command builtins here */ 891 if (cmdentry.cmdtype != CMDBUILTIN) 892 break; 893 if (cmdentry.u.index == BLTINCMD) { 894 if (argc == 1) 895 break; 896 argv++; 897 argc--; 898 bltinonly = 1; 899 } else if (cmdentry.u.index == COMMANDCMD) { 900 if (argc == 1) 901 break; 902 if (!strcmp(argv[1], "-p")) { 903 if (argc == 2) 904 break; 905 if (argv[2][0] == '-') { 906 if (strcmp(argv[2], "--")) 907 break; 908 if (argc == 3) 909 break; 910 argv += 3; 911 argc -= 3; 912 } else { 913 argv += 2; 914 argc -= 2; 915 } 916 path = _PATH_STDPATH; 917 clearcmdentry(); 918 do_clearcmdentry = 1; 919 } else if (!strcmp(argv[1], "--")) { 920 if (argc == 2) 921 break; 922 argv += 2; 923 argc -= 2; 924 } else if (argv[1][0] == '-') 925 break; 926 else { 927 argv++; 928 argc--; 929 } 930 cmd_flags |= DO_NOFUNC; 931 bltinonly = 0; 932 } else 933 break; 934 } 935 /* 936 * Special builtins lose their special properties when 937 * called via 'command'. 938 */ 939 if (cmd_flags & DO_NOFUNC) 940 cmdentry.special = 0; 941 } 942 943 /* Fork off a child process if necessary. */ 944 if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 945 && ((flags & EV_EXIT) == 0 || have_traps())) 946 || ((flags & EV_BACKCMD) != 0 947 && (cmdentry.cmdtype != CMDBUILTIN || 948 !safe_builtin(cmdentry.u.index, argc, argv)))) { 949 jp = makejob(cmd, 1); 950 mode = FORK_FG; 951 if (flags & EV_BACKCMD) { 952 mode = FORK_NOJOB; 953 if (pipe(pip) < 0) 954 error("Pipe call failed: %s", strerror(errno)); 955 } 956 if (cmdentry.cmdtype == CMDNORMAL && 957 cmd->ncmd.redirect == NULL && 958 varlist.list == NULL && 959 (mode == FORK_FG || mode == FORK_NOJOB) && 960 !disvforkset() && !iflag && !mflag) { 961 vforkexecshell(jp, argv, environment(), path, 962 cmdentry.u.index, flags & EV_BACKCMD ? pip : NULL); 963 goto parent; 964 } 965 if (forkshell(jp, cmd, mode) != 0) 966 goto parent; /* at end of routine */ 967 if (flags & EV_BACKCMD) { 968 FORCEINTON; 969 close(pip[0]); 970 if (pip[1] != 1) { 971 dup2(pip[1], 1); 972 close(pip[1]); 973 } 974 flags &= ~EV_BACKCMD; 975 } 976 flags |= EV_EXIT; 977 } 978 979 /* This is the child process if a fork occurred. */ 980 /* Execute the command. */ 981 if (cmdentry.cmdtype == CMDFUNCTION) { 982#ifdef DEBUG 983 trputs("Shell function: "); trargs(argv); 984#endif 985 saveparam = shellparam; 986 shellparam.malloc = 0; 987 shellparam.reset = 1; 988 shellparam.nparam = argc - 1; 989 shellparam.p = argv + 1; 990 shellparam.optnext = NULL; 991 INTOFF; 992 savelocalvars = localvars; 993 localvars = NULL; 994 reffunc(cmdentry.u.func); 995 savehandler = handler; 996 if (setjmp(jmploc.loc)) { 997 freeparam(&shellparam); 998 shellparam = saveparam; 999 popredir(); 1000 unreffunc(cmdentry.u.func); 1001 poplocalvars(); 1002 localvars = savelocalvars; 1003 funcnest--; 1004 handler = savehandler; 1005 longjmp(handler->loc, 1); 1006 } 1007 handler = &jmploc; 1008 funcnest++; 1009 redirect(cmd->ncmd.redirect, REDIR_PUSH); 1010 INTON; 1011 for (sp = varlist.list ; sp ; sp = sp->next) 1012 mklocal(sp->text); 1013 exitstatus = oexitstatus; 1014 evaltree(getfuncnode(cmdentry.u.func), 1015 flags & (EV_TESTED | EV_EXIT)); 1016 INTOFF; 1017 unreffunc(cmdentry.u.func); 1018 poplocalvars(); 1019 localvars = savelocalvars; 1020 freeparam(&shellparam); 1021 shellparam = saveparam; 1022 handler = savehandler; 1023 funcnest--; 1024 popredir(); 1025 INTON; 1026 if (evalskip == SKIPFUNC) { 1027 evalskip = 0; 1028 skipcount = 0; 1029 } 1030 if (jp) 1031 exitshell(exitstatus); 1032 } else if (cmdentry.cmdtype == CMDBUILTIN) { 1033#ifdef DEBUG 1034 trputs("builtin command: "); trargs(argv); 1035#endif 1036 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 1037 if (flags == EV_BACKCMD) { 1038 memout.nleft = 0; 1039 memout.nextc = memout.buf; 1040 memout.bufsize = 64; 1041 mode |= REDIR_BACKQ; 1042 } 1043 savecmdname = commandname; 1044 savetopfile = getcurrentfile(); 1045 cmdenviron = varlist.list; 1046 e = -1; 1047 savehandler = handler; 1048 if (setjmp(jmploc.loc)) { 1049 e = exception; 1050 if (e == EXINT) 1051 exitstatus = SIGINT+128; 1052 else if (e != EXEXIT) 1053 exitstatus = 2; 1054 goto cmddone; 1055 } 1056 handler = &jmploc; 1057 redirect(cmd->ncmd.redirect, mode); 1058 /* 1059 * If there is no command word, redirection errors should 1060 * not be fatal but assignment errors should. 1061 */ 1062 if (argc == 0) 1063 cmdentry.special = 1; 1064 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); 1065 if (argc > 0) 1066 bltinsetlocale(); 1067 commandname = argv[0]; 1068 argptr = argv + 1; 1069 nextopt_optptr = NULL; /* initialize nextopt */ 1070 builtin_flags = flags; 1071 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 1072 flushall(); 1073cmddone: 1074 if (argc > 0) 1075 bltinunsetlocale(); 1076 cmdenviron = NULL; 1077 out1 = &output; 1078 out2 = &errout; 1079 freestdout(); 1080 handler = savehandler; 1081 commandname = savecmdname; 1082 if (jp) 1083 exitshell(exitstatus); 1084 if (flags == EV_BACKCMD) { 1085 backcmd->buf = memout.buf; 1086 backcmd->nleft = memout.nextc - memout.buf; 1087 memout.buf = NULL; 1088 } 1089 if (cmdentry.u.index != EXECCMD) 1090 popredir(); 1091 if (e != -1) { 1092 if ((e != EXERROR && e != EXEXEC) 1093 || cmdentry.special) 1094 exraise(e); 1095 popfilesupto(savetopfile); 1096 if (flags != EV_BACKCMD) 1097 FORCEINTON; 1098 } 1099 } else { 1100#ifdef DEBUG 1101 trputs("normal command: "); trargs(argv); 1102#endif 1103 redirect(cmd->ncmd.redirect, 0); 1104 for (sp = varlist.list ; sp ; sp = sp->next) 1105 setvareq(sp->text, VEXPORT|VSTACK); 1106 envp = environment(); 1107 shellexec(argv, envp, path, cmdentry.u.index); 1108 /*NOTREACHED*/ 1109 } 1110 goto out; 1111 1112parent: /* parent process gets here (if we forked) */ 1113 if (mode == FORK_FG) { /* argument to fork */ 1114 INTOFF; 1115 exitstatus = waitforjob(jp, &realstatus); 1116 INTON; 1117 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1118 evalskip = SKIPBREAK; 1119 skipcount = loopnest; 1120 } 1121 } else if (mode == FORK_NOJOB) { 1122 backcmd->fd = pip[0]; 1123 close(pip[1]); 1124 backcmd->jp = jp; 1125 } 1126 1127out: 1128 if (lastarg) 1129 setvar("_", lastarg, 0); 1130 if (do_clearcmdentry) 1131 clearcmdentry(); 1132 popstackmark(&smark); 1133} 1134 1135 1136 1137/* 1138 * Search for a command. This is called before we fork so that the 1139 * location of the command will be available in the parent as well as 1140 * the child. The check for "goodname" is an overly conservative 1141 * check that the name will not be subject to expansion. 1142 */ 1143 1144static void 1145prehash(union node *n) 1146{ 1147 struct cmdentry entry; 1148 1149 if (n && n->type == NCMD && n->ncmd.args) 1150 if (goodname(n->ncmd.args->narg.text)) 1151 find_command(n->ncmd.args->narg.text, &entry, 0, 1152 pathval()); 1153} 1154 1155 1156 1157/* 1158 * Builtin commands. Builtin commands whose functions are closely 1159 * tied to evaluation are implemented here. 1160 */ 1161 1162/* 1163 * No command given, a bltin command with no arguments, or a bltin command 1164 * with an invalid name. 1165 */ 1166 1167int 1168bltincmd(int argc, char **argv) 1169{ 1170 if (argc > 1) { 1171 out2fmt_flush("%s: not found\n", argv[1]); 1172 return 127; 1173 } 1174 /* 1175 * Preserve exitstatus of a previous possible redirection 1176 * as POSIX mandates 1177 */ 1178 return exitstatus; 1179} 1180 1181 1182/* 1183 * Handle break and continue commands. Break, continue, and return are 1184 * all handled by setting the evalskip flag. The evaluation routines 1185 * above all check this flag, and if it is set they start skipping 1186 * commands rather than executing them. The variable skipcount is 1187 * the number of loops to break/continue, or the number of function 1188 * levels to return. (The latter is always 1.) It should probably 1189 * be an error to break out of more loops than exist, but it isn't 1190 * in the standard shell so we don't make it one here. 1191 */ 1192 1193int 1194breakcmd(int argc, char **argv) 1195{ 1196 int n = argc > 1 ? number(argv[1]) : 1; 1197 1198 if (n > loopnest) 1199 n = loopnest; 1200 if (n > 0) { 1201 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1202 skipcount = n; 1203 } 1204 return 0; 1205} 1206 1207/* 1208 * The `command' command. 1209 */ 1210int 1211commandcmd(int argc, char **argv) 1212{ 1213 const char *path; 1214 int ch; 1215 int cmd = -1; 1216 1217 path = bltinlookup("PATH", 1); 1218 1219 optind = optreset = 1; 1220 opterr = 0; 1221 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1222 switch (ch) { 1223 case 'p': 1224 path = _PATH_STDPATH; 1225 break; 1226 case 'v': 1227 cmd = TYPECMD_SMALLV; 1228 break; 1229 case 'V': 1230 cmd = TYPECMD_BIGV; 1231 break; 1232 case '?': 1233 default: 1234 error("unknown option: -%c", optopt); 1235 } 1236 } 1237 argc -= optind; 1238 argv += optind; 1239 1240 if (cmd != -1) { 1241 if (argc != 1) 1242 error("wrong number of arguments"); 1243 return typecmd_impl(2, argv - 1, cmd, path); 1244 } 1245 if (argc != 0) 1246 error("commandcmd bad call"); 1247 1248 /* 1249 * Do nothing successfully if no command was specified; 1250 * ksh also does this. 1251 */ 1252 return 0; 1253} 1254 1255 1256/* 1257 * The return command. 1258 */ 1259 1260int 1261returncmd(int argc, char **argv) 1262{ 1263 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1264 1265 if (funcnest) { 1266 evalskip = SKIPFUNC; 1267 skipcount = 1; 1268 } else { 1269 /* skip the rest of the file */ 1270 evalskip = SKIPFILE; 1271 skipcount = 1; 1272 } 1273 return ret; 1274} 1275 1276 1277int 1278falsecmd(int argc __unused, char **argv __unused) 1279{ 1280 return 1; 1281} 1282 1283 1284int 1285truecmd(int argc __unused, char **argv __unused) 1286{ 1287 return 0; 1288} 1289 1290 1291int 1292execcmd(int argc, char **argv) 1293{ 1294 /* 1295 * Because we have historically not supported any options, 1296 * only treat "--" specially. 1297 */ 1298 if (argc > 1 && strcmp(argv[1], "--") == 0) 1299 argc--, argv++; 1300 if (argc > 1) { 1301 struct strlist *sp; 1302 1303 iflag = 0; /* exit on error */ 1304 mflag = 0; 1305 optschanged(); 1306 for (sp = cmdenviron; sp ; sp = sp->next) 1307 setvareq(sp->text, VEXPORT|VSTACK); 1308 shellexec(argv + 1, environment(), pathval(), 0); 1309 1310 } 1311 return 0; 1312} 1313 1314 1315int 1316timescmd(int argc __unused, char **argv __unused) 1317{ 1318 struct rusage ru; 1319 long shumins, shsmins, chumins, chsmins; 1320 double shusecs, shssecs, chusecs, chssecs; 1321 1322 if (getrusage(RUSAGE_SELF, &ru) < 0) 1323 return 1; 1324 shumins = ru.ru_utime.tv_sec / 60; 1325 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1326 shsmins = ru.ru_stime.tv_sec / 60; 1327 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1328 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1329 return 1; 1330 chumins = ru.ru_utime.tv_sec / 60; 1331 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1332 chsmins = ru.ru_stime.tv_sec / 60; 1333 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1334 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1335 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1336 return 0; 1337} 1338