eval.c revision 194765
1/*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#ifndef lint 34#if 0 35static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: head/bin/sh/eval.c 194765 2009-06-23 20:45:12Z jilles $"); 40 41#include <paths.h> 42#include <signal.h> 43#include <stdlib.h> 44#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 77MKINIT int evalskip; /* set if we are skipping commands */ 78STATIC int 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 expredir(union node *); 95STATIC void evalpipe(union node *); 96STATIC void evalcommand(union node *, int, struct backcmd *); 97STATIC void prehash(union node *); 98 99 100/* 101 * Called to reset things after an exception. 102 */ 103 104#ifdef mkinit 105INCLUDE "eval.h" 106 107RESET { 108 evalskip = 0; 109 loopnest = 0; 110 funcnest = 0; 111} 112 113SHELLPROC { 114 exitstatus = 0; 115} 116#endif 117 118 119 120/* 121 * The eval command. 122 */ 123 124int 125evalcmd(int argc, char **argv) 126{ 127 char *p; 128 char *concat; 129 char **ap; 130 131 if (argc > 1) { 132 p = argv[1]; 133 if (argc > 2) { 134 STARTSTACKSTR(concat); 135 ap = argv + 2; 136 for (;;) { 137 while (*p) 138 STPUTC(*p++, concat); 139 if ((p = *ap++) == NULL) 140 break; 141 STPUTC(' ', concat); 142 } 143 STPUTC('\0', concat); 144 p = grabstackstr(concat); 145 } 146 evalstring(p, builtin_flags & EV_TESTED); 147 } 148 return exitstatus; 149} 150 151 152/* 153 * Execute a command or commands contained in a string. 154 */ 155 156void 157evalstring(char *s, int flags) 158{ 159 union node *n; 160 struct stackmark smark; 161 int flags_exit; 162 163 flags_exit = flags & EV_EXIT; 164 flags &= ~EV_EXIT; 165 setstackmark(&smark); 166 setinputstring(s, 1); 167 while ((n = parsecmd(0)) != NEOF) { 168 if (n != NULL) { 169 if (flags_exit && preadateof()) 170 evaltree(n, flags | EV_EXIT); 171 else 172 evaltree(n, flags); 173 } 174 popstackmark(&smark); 175 } 176 popfile(); 177 popstackmark(&smark); 178 if (flags_exit) 179 exitshell(exitstatus); 180} 181 182 183/* 184 * Evaluate a parse tree. The value is left in the global variable 185 * exitstatus. 186 */ 187 188void 189evaltree(union node *n, int flags) 190{ 191 int do_etest; 192 193 do_etest = 0; 194 if (n == NULL) { 195 TRACE(("evaltree(NULL) called\n")); 196 exitstatus = 0; 197 goto out; 198 } 199#ifndef NO_HISTORY 200 displayhist = 1; /* show history substitutions done with fc */ 201#endif 202 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 203 switch (n->type) { 204 case NSEMI: 205 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 206 if (evalskip) 207 goto out; 208 evaltree(n->nbinary.ch2, flags); 209 break; 210 case NAND: 211 evaltree(n->nbinary.ch1, EV_TESTED); 212 if (evalskip || exitstatus != 0) { 213 goto out; 214 } 215 evaltree(n->nbinary.ch2, flags); 216 break; 217 case NOR: 218 evaltree(n->nbinary.ch1, EV_TESTED); 219 if (evalskip || exitstatus == 0) 220 goto out; 221 evaltree(n->nbinary.ch2, flags); 222 break; 223 case NREDIR: 224 expredir(n->nredir.redirect); 225 redirect(n->nredir.redirect, REDIR_PUSH); 226 evaltree(n->nredir.n, flags); 227 popredir(); 228 break; 229 case NSUBSHELL: 230 evalsubshell(n, flags); 231 do_etest = !(flags & EV_TESTED); 232 break; 233 case NBACKGND: 234 evalsubshell(n, flags); 235 break; 236 case NIF: { 237 evaltree(n->nif.test, EV_TESTED); 238 if (evalskip) 239 goto out; 240 if (exitstatus == 0) 241 evaltree(n->nif.ifpart, flags); 242 else if (n->nif.elsepart) 243 evaltree(n->nif.elsepart, flags); 244 else 245 exitstatus = 0; 246 break; 247 } 248 case NWHILE: 249 case NUNTIL: 250 evalloop(n, flags & ~EV_EXIT); 251 break; 252 case NFOR: 253 evalfor(n, flags & ~EV_EXIT); 254 break; 255 case NCASE: 256 evalcase(n, flags); 257 break; 258 case NDEFUN: 259 defun(n->narg.text, n->narg.next); 260 exitstatus = 0; 261 break; 262 case NNOT: 263 evaltree(n->nnot.com, EV_TESTED); 264 exitstatus = !exitstatus; 265 break; 266 267 case NPIPE: 268 evalpipe(n); 269 do_etest = !(flags & EV_TESTED); 270 break; 271 case NCMD: 272 evalcommand(n, flags, (struct backcmd *)NULL); 273 do_etest = !(flags & EV_TESTED); 274 break; 275 default: 276 out1fmt("Node type = %d\n", n->type); 277 flushout(&output); 278 break; 279 } 280out: 281 if (pendingsigs) 282 dotrap(); 283 if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest)) 284 exitshell(exitstatus); 285} 286 287 288STATIC void 289evalloop(union node *n, int flags) 290{ 291 int status; 292 293 loopnest++; 294 status = 0; 295 for (;;) { 296 evaltree(n->nbinary.ch1, EV_TESTED); 297 if (evalskip) { 298skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 299 evalskip = 0; 300 continue; 301 } 302 if (evalskip == SKIPBREAK && --skipcount <= 0) 303 evalskip = 0; 304 break; 305 } 306 if (n->type == NWHILE) { 307 if (exitstatus != 0) 308 break; 309 } else { 310 if (exitstatus == 0) 311 break; 312 } 313 evaltree(n->nbinary.ch2, flags); 314 status = exitstatus; 315 if (evalskip) 316 goto skipping; 317 } 318 loopnest--; 319 exitstatus = status; 320} 321 322 323 324STATIC void 325evalfor(union node *n, int flags) 326{ 327 struct arglist arglist; 328 union node *argp; 329 struct strlist *sp; 330 struct stackmark smark; 331 332 setstackmark(&smark); 333 arglist.lastp = &arglist.list; 334 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 335 oexitstatus = exitstatus; 336 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 337 if (evalskip) 338 goto out; 339 } 340 *arglist.lastp = NULL; 341 342 exitstatus = 0; 343 loopnest++; 344 for (sp = arglist.list ; sp ; sp = sp->next) { 345 setvar(n->nfor.var, sp->text, 0); 346 evaltree(n->nfor.body, flags); 347 if (evalskip) { 348 if (evalskip == SKIPCONT && --skipcount <= 0) { 349 evalskip = 0; 350 continue; 351 } 352 if (evalskip == SKIPBREAK && --skipcount <= 0) 353 evalskip = 0; 354 break; 355 } 356 } 357 loopnest--; 358out: 359 popstackmark(&smark); 360} 361 362 363 364STATIC void 365evalcase(union node *n, int flags) 366{ 367 union node *cp; 368 union node *patp; 369 struct arglist arglist; 370 struct stackmark smark; 371 372 setstackmark(&smark); 373 arglist.lastp = &arglist.list; 374 oexitstatus = exitstatus; 375 exitstatus = 0; 376 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 377 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 378 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 379 if (casematch(patp, arglist.list->text)) { 380 if (evalskip == 0) { 381 evaltree(cp->nclist.body, flags); 382 } 383 goto out; 384 } 385 } 386 } 387out: 388 popstackmark(&smark); 389} 390 391 392 393/* 394 * Kick off a subshell to evaluate a tree. 395 */ 396 397STATIC void 398evalsubshell(union node *n, int flags) 399{ 400 struct job *jp; 401 int backgnd = (n->type == NBACKGND); 402 403 expredir(n->nredir.redirect); 404 jp = makejob(n, 1); 405 if (forkshell(jp, n, backgnd) == 0) { 406 if (backgnd) 407 flags &=~ EV_TESTED; 408 redirect(n->nredir.redirect, 0); 409 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 410 } 411 if (! backgnd) { 412 INTOFF; 413 exitstatus = waitforjob(jp, (int *)NULL); 414 INTON; 415 } 416} 417 418 419 420/* 421 * Compute the names of the files in a redirection list. 422 */ 423 424STATIC void 425expredir(union node *n) 426{ 427 union node *redir; 428 429 for (redir = n ; redir ; redir = redir->nfile.next) { 430 struct arglist fn; 431 fn.lastp = &fn.list; 432 oexitstatus = exitstatus; 433 switch (redir->type) { 434 case NFROM: 435 case NTO: 436 case NFROMTO: 437 case NAPPEND: 438 case NCLOBBER: 439 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 440 redir->nfile.expfname = fn.list->text; 441 break; 442 case NFROMFD: 443 case NTOFD: 444 if (redir->ndup.vname) { 445 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 446 fixredir(redir, fn.list->text, 1); 447 } 448 break; 449 } 450 } 451} 452 453 454 455/* 456 * Evaluate a pipeline. All the processes in the pipeline are children 457 * of the process creating the pipeline. (This differs from some versions 458 * of the shell, which make the last process in a pipeline the parent 459 * of all the rest.) 460 */ 461 462STATIC void 463evalpipe(union node *n) 464{ 465 struct job *jp; 466 struct nodelist *lp; 467 int pipelen; 468 int prevfd; 469 int pip[2]; 470 471 TRACE(("evalpipe(%p) called\n", (void *)n)); 472 pipelen = 0; 473 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 474 pipelen++; 475 INTOFF; 476 jp = makejob(n, pipelen); 477 prevfd = -1; 478 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 479 prehash(lp->n); 480 pip[1] = -1; 481 if (lp->next) { 482 if (pipe(pip) < 0) { 483 close(prevfd); 484 error("Pipe call failed: %s", strerror(errno)); 485 } 486 } 487 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 488 INTON; 489 if (prevfd > 0) { 490 dup2(prevfd, 0); 491 close(prevfd); 492 } 493 if (pip[1] >= 0) { 494 if (!(prevfd >= 0 && pip[0] == 0)) 495 close(pip[0]); 496 if (pip[1] != 1) { 497 dup2(pip[1], 1); 498 close(pip[1]); 499 } 500 } 501 evaltree(lp->n, EV_EXIT); 502 } 503 if (prevfd >= 0) 504 close(prevfd); 505 prevfd = pip[0]; 506 close(pip[1]); 507 } 508 INTON; 509 if (n->npipe.backgnd == 0) { 510 INTOFF; 511 exitstatus = waitforjob(jp, (int *)NULL); 512 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 513 INTON; 514 } 515} 516 517 518 519/* 520 * Execute a command inside back quotes. If it's a builtin command, we 521 * want to save its output in a block obtained from malloc. Otherwise 522 * we fork off a subprocess and get the output of the command via a pipe. 523 * Should be called with interrupts off. 524 */ 525 526void 527evalbackcmd(union node *n, struct backcmd *result) 528{ 529 int pip[2]; 530 struct job *jp; 531 struct stackmark smark; /* unnecessary */ 532 533 setstackmark(&smark); 534 result->fd = -1; 535 result->buf = NULL; 536 result->nleft = 0; 537 result->jp = NULL; 538 if (n == NULL) { 539 exitstatus = 0; 540 goto out; 541 } 542 if (n->type == NCMD) { 543 exitstatus = oexitstatus; 544 evalcommand(n, EV_BACKCMD, result); 545 } else { 546 exitstatus = 0; 547 if (pipe(pip) < 0) 548 error("Pipe call failed: %s", strerror(errno)); 549 jp = makejob(n, 1); 550 if (forkshell(jp, n, FORK_NOJOB) == 0) { 551 FORCEINTON; 552 close(pip[0]); 553 if (pip[1] != 1) { 554 dup2(pip[1], 1); 555 close(pip[1]); 556 } 557 evaltree(n, EV_EXIT); 558 } 559 close(pip[1]); 560 result->fd = pip[0]; 561 result->jp = jp; 562 } 563out: 564 popstackmark(&smark); 565 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 566 result->fd, result->buf, result->nleft, result->jp)); 567} 568 569 570 571/* 572 * Execute a simple command. 573 */ 574 575STATIC void 576evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 577{ 578 struct stackmark smark; 579 union node *argp; 580 struct arglist arglist; 581 struct arglist varlist; 582 char **argv; 583 int argc; 584 char **envp; 585 int varflag; 586 struct strlist *sp; 587 int mode; 588 int pip[2]; 589 struct cmdentry cmdentry; 590 struct job *jp; 591 struct jmploc jmploc; 592 struct jmploc *savehandler; 593 char *savecmdname; 594 struct shparam saveparam; 595 struct localvar *savelocalvars; 596 volatile int e; 597 char *lastarg; 598 int realstatus; 599 int do_clearcmdentry; 600 601 /* First expand the arguments. */ 602 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 603 setstackmark(&smark); 604 arglist.lastp = &arglist.list; 605 varlist.lastp = &varlist.list; 606 varflag = 1; 607 do_clearcmdentry = 0; 608 oexitstatus = exitstatus; 609 exitstatus = 0; 610 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 611 char *p = argp->narg.text; 612 if (varflag && is_name(*p)) { 613 do { 614 p++; 615 } while (is_in_name(*p)); 616 if (*p == '=') { 617 expandarg(argp, &varlist, EXP_VARTILDE); 618 continue; 619 } 620 } 621 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 622 varflag = 0; 623 } 624 *arglist.lastp = NULL; 625 *varlist.lastp = NULL; 626 expredir(cmd->ncmd.redirect); 627 argc = 0; 628 for (sp = arglist.list ; sp ; sp = sp->next) 629 argc++; 630 argv = stalloc(sizeof (char *) * (argc + 1)); 631 632 for (sp = arglist.list ; sp ; sp = sp->next) { 633 TRACE(("evalcommand arg: %s\n", sp->text)); 634 *argv++ = sp->text; 635 } 636 *argv = NULL; 637 lastarg = NULL; 638 if (iflag && funcnest == 0 && argc > 0) 639 lastarg = argv[-1]; 640 argv -= argc; 641 642 /* Print the command if xflag is set. */ 643 if (xflag) { 644 char sep = 0; 645 out2str(ps4val()); 646 for (sp = varlist.list ; sp ; sp = sp->next) { 647 if (sep != 0) 648 outc(' ', &errout); 649 out2str(sp->text); 650 sep = ' '; 651 } 652 for (sp = arglist.list ; sp ; sp = sp->next) { 653 if (sep != 0) 654 outc(' ', &errout); 655 out2str(sp->text); 656 sep = ' '; 657 } 658 outc('\n', &errout); 659 flushout(&errout); 660 } 661 662 /* Now locate the command. */ 663 if (argc == 0) { 664 /* Variable assignment(s) without command */ 665 cmdentry.cmdtype = CMDBUILTIN; 666 cmdentry.u.index = BLTINCMD; 667 cmdentry.special = 1; 668 } else { 669 static const char PATH[] = "PATH="; 670 char *path = pathval(); 671 672 /* 673 * Modify the command lookup path, if a PATH= assignment 674 * is present 675 */ 676 for (sp = varlist.list ; sp ; sp = sp->next) 677 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 678 path = sp->text + sizeof(PATH) - 1; 679 /* 680 * On `PATH=... command`, we need to make 681 * sure that the command isn't using the 682 * non-updated hash table of the outer PATH 683 * setting and we need to make sure that 684 * the hash table isn't filled with items 685 * from the temporary setting. 686 * 687 * It would be better to forbit using and 688 * updating the table while this command 689 * runs, by the command finding mechanism 690 * is heavily integrated with hash handling, 691 * so we just delete the hash before and after 692 * the command runs. Partly deleting like 693 * changepatch() does doesn't seem worth the 694 * bookinging effort, since most such runs add 695 * directories in front of the new PATH. 696 */ 697 clearcmdentry(0); 698 do_clearcmdentry = 1; 699 } 700 701 find_command(argv[0], &cmdentry, 1, path); 702 if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 703 exitstatus = 127; 704 flushout(&errout); 705 return; 706 } 707 /* implement the bltin builtin here */ 708 if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 709 for (;;) { 710 argv++; 711 if (--argc == 0) 712 break; 713 if ((cmdentry.u.index = find_builtin(*argv, 714 &cmdentry.special)) < 0) { 715 outfmt(&errout, "%s: not found\n", *argv); 716 exitstatus = 127; 717 flushout(&errout); 718 return; 719 } 720 if (cmdentry.u.index != BLTINCMD) 721 break; 722 } 723 } 724 } 725 726 /* Fork off a child process if necessary. */ 727 if (cmd->ncmd.backgnd 728 || (cmdentry.cmdtype == CMDNORMAL 729 && ((flags & EV_EXIT) == 0 || have_traps())) 730 || ((flags & EV_BACKCMD) != 0 731 && (cmdentry.cmdtype != CMDBUILTIN 732 || cmdentry.u.index == CDCMD 733 || cmdentry.u.index == DOTCMD 734 || cmdentry.u.index == EVALCMD)) 735 || (cmdentry.cmdtype == CMDBUILTIN && 736 cmdentry.u.index == COMMANDCMD)) { 737 jp = makejob(cmd, 1); 738 mode = cmd->ncmd.backgnd; 739 if (flags & EV_BACKCMD) { 740 mode = FORK_NOJOB; 741 if (pipe(pip) < 0) 742 error("Pipe call failed: %s", strerror(errno)); 743 } 744 if (forkshell(jp, cmd, mode) != 0) 745 goto parent; /* at end of routine */ 746 if (flags & EV_BACKCMD) { 747 FORCEINTON; 748 close(pip[0]); 749 if (pip[1] != 1) { 750 dup2(pip[1], 1); 751 close(pip[1]); 752 } 753 } 754 flags |= EV_EXIT; 755 } 756 757 /* This is the child process if a fork occurred. */ 758 /* Execute the command. */ 759 if (cmdentry.cmdtype == CMDFUNCTION) { 760#ifdef DEBUG 761 trputs("Shell function: "); trargs(argv); 762#endif 763 redirect(cmd->ncmd.redirect, REDIR_PUSH); 764 saveparam = shellparam; 765 shellparam.malloc = 0; 766 shellparam.reset = 1; 767 shellparam.nparam = argc - 1; 768 shellparam.p = argv + 1; 769 shellparam.optnext = NULL; 770 INTOFF; 771 savelocalvars = localvars; 772 localvars = NULL; 773 INTON; 774 savehandler = handler; 775 if (setjmp(jmploc.loc)) { 776 if (exception == EXSHELLPROC) 777 freeparam(&saveparam); 778 else { 779 freeparam(&shellparam); 780 shellparam = saveparam; 781 } 782 poplocalvars(); 783 localvars = savelocalvars; 784 handler = savehandler; 785 longjmp(handler->loc, 1); 786 } 787 handler = &jmploc; 788 for (sp = varlist.list ; sp ; sp = sp->next) 789 mklocal(sp->text); 790 funcnest++; 791 exitstatus = oexitstatus; 792 if (flags & EV_TESTED) 793 evaltree(cmdentry.u.func, EV_TESTED); 794 else 795 evaltree(cmdentry.u.func, 0); 796 funcnest--; 797 INTOFF; 798 poplocalvars(); 799 localvars = savelocalvars; 800 freeparam(&shellparam); 801 shellparam = saveparam; 802 handler = savehandler; 803 popredir(); 804 INTON; 805 if (evalskip == SKIPFUNC) { 806 evalskip = 0; 807 skipcount = 0; 808 } 809 if (flags & EV_EXIT) 810 exitshell(exitstatus); 811 } else if (cmdentry.cmdtype == CMDBUILTIN) { 812#ifdef DEBUG 813 trputs("builtin command: "); trargs(argv); 814#endif 815 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 816 if (flags == EV_BACKCMD) { 817 memout.nleft = 0; 818 memout.nextc = memout.buf; 819 memout.bufsize = 64; 820 mode |= REDIR_BACKQ; 821 } 822 savecmdname = commandname; 823 cmdenviron = varlist.list; 824 e = -1; 825 savehandler = handler; 826 if (setjmp(jmploc.loc)) { 827 e = exception; 828 exitstatus = (e == EXINT)? SIGINT+128 : 2; 829 goto cmddone; 830 } 831 handler = &jmploc; 832 redirect(cmd->ncmd.redirect, mode); 833 if (cmdentry.special) 834 listsetvar(cmdenviron); 835 commandname = argv[0]; 836 argptr = argv + 1; 837 optptr = NULL; /* initialize nextopt */ 838 builtin_flags = flags; 839 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 840 flushall(); 841cmddone: 842 cmdenviron = NULL; 843 out1 = &output; 844 out2 = &errout; 845 freestdout(); 846 if (e != EXSHELLPROC) { 847 commandname = savecmdname; 848 if (flags & EV_EXIT) { 849 exitshell(exitstatus); 850 } 851 } 852 handler = savehandler; 853 if (e != -1) { 854 if ((e != EXERROR && e != EXEXEC) 855 || cmdentry.special) 856 exraise(e); 857 FORCEINTON; 858 } 859 if (cmdentry.u.index != EXECCMD) 860 popredir(); 861 if (flags == EV_BACKCMD) { 862 backcmd->buf = memout.buf; 863 backcmd->nleft = memout.nextc - memout.buf; 864 memout.buf = NULL; 865 } 866 } else { 867#ifdef DEBUG 868 trputs("normal command: "); trargs(argv); 869#endif 870 clearredir(); 871 redirect(cmd->ncmd.redirect, 0); 872 for (sp = varlist.list ; sp ; sp = sp->next) 873 setvareq(sp->text, VEXPORT|VSTACK); 874 envp = environment(); 875 shellexec(argv, envp, pathval(), cmdentry.u.index); 876 /*NOTREACHED*/ 877 } 878 goto out; 879 880parent: /* parent process gets here (if we forked) */ 881 if (mode == 0) { /* argument to fork */ 882 INTOFF; 883 exitstatus = waitforjob(jp, &realstatus); 884 INTON; 885 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 886 evalskip = SKIPBREAK; 887 skipcount = loopnest; 888 } 889 } else if (mode == 2) { 890 backcmd->fd = pip[0]; 891 close(pip[1]); 892 backcmd->jp = jp; 893 } 894 895out: 896 if (lastarg) 897 setvar("_", lastarg, 0); 898 if (do_clearcmdentry) 899 clearcmdentry(0); 900 popstackmark(&smark); 901} 902 903 904 905/* 906 * Search for a command. This is called before we fork so that the 907 * location of the command will be available in the parent as well as 908 * the child. The check for "goodname" is an overly conservative 909 * check that the name will not be subject to expansion. 910 */ 911 912STATIC void 913prehash(union node *n) 914{ 915 struct cmdentry entry; 916 917 if (n && n->type == NCMD && n->ncmd.args) 918 if (goodname(n->ncmd.args->narg.text)) 919 find_command(n->ncmd.args->narg.text, &entry, 0, 920 pathval()); 921} 922 923 924 925/* 926 * Builtin commands. Builtin commands whose functions are closely 927 * tied to evaluation are implemented here. 928 */ 929 930/* 931 * No command given, or a bltin command with no arguments. 932 */ 933 934int 935bltincmd(int argc __unused, char **argv __unused) 936{ 937 /* 938 * Preserve exitstatus of a previous possible redirection 939 * as POSIX mandates 940 */ 941 return exitstatus; 942} 943 944 945/* 946 * Handle break and continue commands. Break, continue, and return are 947 * all handled by setting the evalskip flag. The evaluation routines 948 * above all check this flag, and if it is set they start skipping 949 * commands rather than executing them. The variable skipcount is 950 * the number of loops to break/continue, or the number of function 951 * levels to return. (The latter is always 1.) It should probably 952 * be an error to break out of more loops than exist, but it isn't 953 * in the standard shell so we don't make it one here. 954 */ 955 956int 957breakcmd(int argc, char **argv) 958{ 959 int n = argc > 1 ? number(argv[1]) : 1; 960 961 if (n > loopnest) 962 n = loopnest; 963 if (n > 0) { 964 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 965 skipcount = n; 966 } 967 return 0; 968} 969 970/* 971 * The `command' command. 972 */ 973int 974commandcmd(int argc, char **argv) 975{ 976 static char stdpath[] = _PATH_STDPATH; 977 struct jmploc loc, *old; 978 struct strlist *sp; 979 char *path; 980 int ch; 981 int cmd = -1; 982 983 for (sp = cmdenviron; sp ; sp = sp->next) 984 setvareq(sp->text, VEXPORT|VSTACK); 985 path = pathval(); 986 987 optind = optreset = 1; 988 opterr = 0; 989 while ((ch = getopt(argc, argv, "pvV")) != -1) { 990 switch (ch) { 991 case 'p': 992 path = stdpath; 993 break; 994 case 'v': 995 cmd = TYPECMD_SMALLV; 996 break; 997 case 'V': 998 cmd = TYPECMD_BIGV; 999 break; 1000 case '?': 1001 default: 1002 error("unknown option: -%c", optopt); 1003 } 1004 } 1005 argc -= optind; 1006 argv += optind; 1007 1008 if (cmd != -1) { 1009 if (argc != 1) 1010 error("wrong number of arguments"); 1011 return typecmd_impl(2, argv - 1, cmd); 1012 } 1013 if (argc != 0) { 1014 old = handler; 1015 handler = &loc; 1016 if (setjmp(handler->loc) == 0) 1017 shellexec(argv, environment(), path, 0); 1018 handler = old; 1019 if (exception == EXEXEC) 1020 exit(exerrno); 1021 exraise(exception); 1022 } 1023 1024 /* 1025 * Do nothing successfully if no command was specified; 1026 * ksh also does this. 1027 */ 1028 exit(0); 1029} 1030 1031 1032/* 1033 * The return command. 1034 */ 1035 1036int 1037returncmd(int argc, char **argv) 1038{ 1039 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1040 1041 if (funcnest) { 1042 evalskip = SKIPFUNC; 1043 skipcount = 1; 1044 } else { 1045 /* skip the rest of the file */ 1046 evalskip = SKIPFILE; 1047 skipcount = 1; 1048 } 1049 return ret; 1050} 1051 1052 1053int 1054falsecmd(int argc __unused, char **argv __unused) 1055{ 1056 return 1; 1057} 1058 1059 1060int 1061truecmd(int argc __unused, char **argv __unused) 1062{ 1063 return 0; 1064} 1065 1066 1067int 1068execcmd(int argc, char **argv) 1069{ 1070 if (argc > 1) { 1071 struct strlist *sp; 1072 1073 iflag = 0; /* exit on error */ 1074 mflag = 0; 1075 optschanged(); 1076 for (sp = cmdenviron; sp ; sp = sp->next) 1077 setvareq(sp->text, VEXPORT|VSTACK); 1078 shellexec(argv + 1, environment(), pathval(), 0); 1079 1080 } 1081 return 0; 1082} 1083 1084 1085int 1086timescmd(int argc __unused, char **argv __unused) 1087{ 1088 struct rusage ru; 1089 long shumins, shsmins, chumins, chsmins; 1090 double shusecs, shssecs, chusecs, chssecs; 1091 1092 if (getrusage(RUSAGE_SELF, &ru) < 0) 1093 return 1; 1094 shumins = ru.ru_utime.tv_sec / 60; 1095 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1096 shsmins = ru.ru_stime.tv_sec / 60; 1097 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1098 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1099 return 1; 1100 chumins = ru.ru_utime.tv_sec / 60; 1101 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1102 chsmins = ru.ru_stime.tv_sec / 60; 1103 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1104 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1105 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1106 return 0; 1107} 1108