eval.c revision 194128
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 194128 2009-06-13 21:17:45Z 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 *volatile savehandler; 593 char *volatile savecmdname; 594 volatile struct shparam saveparam; 595 struct localvar *volatile savelocalvars; 596 volatile int e; 597 char *lastarg; 598 int realstatus; 599 int do_clearcmdentry; 600#ifdef __GNUC__ 601 /* Avoid longjmp clobbering */ 602 (void) &argv; 603 (void) &argc; 604 (void) &lastarg; 605 (void) &flags; 606 (void) &do_clearcmdentry; 607#endif 608 609 /* First expand the arguments. */ 610 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 611 setstackmark(&smark); 612 arglist.lastp = &arglist.list; 613 varlist.lastp = &varlist.list; 614 varflag = 1; 615 do_clearcmdentry = 0; 616 oexitstatus = exitstatus; 617 exitstatus = 0; 618 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 619 char *p = argp->narg.text; 620 if (varflag && is_name(*p)) { 621 do { 622 p++; 623 } while (is_in_name(*p)); 624 if (*p == '=') { 625 expandarg(argp, &varlist, EXP_VARTILDE); 626 continue; 627 } 628 } 629 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 630 varflag = 0; 631 } 632 *arglist.lastp = NULL; 633 *varlist.lastp = NULL; 634 expredir(cmd->ncmd.redirect); 635 argc = 0; 636 for (sp = arglist.list ; sp ; sp = sp->next) 637 argc++; 638 argv = stalloc(sizeof (char *) * (argc + 1)); 639 640 for (sp = arglist.list ; sp ; sp = sp->next) { 641 TRACE(("evalcommand arg: %s\n", sp->text)); 642 *argv++ = sp->text; 643 } 644 *argv = NULL; 645 lastarg = NULL; 646 if (iflag && funcnest == 0 && argc > 0) 647 lastarg = argv[-1]; 648 argv -= argc; 649 650 /* Print the command if xflag is set. */ 651 if (xflag) { 652 char sep = 0; 653 out2str(ps4val()); 654 for (sp = varlist.list ; sp ; sp = sp->next) { 655 if (sep != 0) 656 outc(' ', &errout); 657 out2str(sp->text); 658 sep = ' '; 659 } 660 for (sp = arglist.list ; sp ; sp = sp->next) { 661 if (sep != 0) 662 outc(' ', &errout); 663 out2str(sp->text); 664 sep = ' '; 665 } 666 outc('\n', &errout); 667 flushout(&errout); 668 } 669 670 /* Now locate the command. */ 671 if (argc == 0) { 672 /* Variable assignment(s) without command */ 673 cmdentry.cmdtype = CMDBUILTIN; 674 cmdentry.u.index = BLTINCMD; 675 cmdentry.special = 1; 676 } else { 677 static const char PATH[] = "PATH="; 678 char *path = pathval(); 679 680 /* 681 * Modify the command lookup path, if a PATH= assignment 682 * is present 683 */ 684 for (sp = varlist.list ; sp ; sp = sp->next) 685 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 686 path = sp->text + sizeof(PATH) - 1; 687 /* 688 * On `PATH=... command`, we need to make 689 * sure that the command isn't using the 690 * non-updated hash table of the outer PATH 691 * setting and we need to make sure that 692 * the hash table isn't filled with items 693 * from the temporary setting. 694 * 695 * It would be better to forbit using and 696 * updating the table while this command 697 * runs, by the command finding mechanism 698 * is heavily integrated with hash handling, 699 * so we just delete the hash before and after 700 * the command runs. Partly deleting like 701 * changepatch() does doesn't seem worth the 702 * bookinging effort, since most such runs add 703 * directories in front of the new PATH. 704 */ 705 clearcmdentry(0); 706 do_clearcmdentry = 1; 707 } 708 709 find_command(argv[0], &cmdentry, 1, path); 710 if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 711 exitstatus = 127; 712 flushout(&errout); 713 return; 714 } 715 /* implement the bltin builtin here */ 716 if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 717 for (;;) { 718 argv++; 719 if (--argc == 0) 720 break; 721 if ((cmdentry.u.index = find_builtin(*argv, 722 &cmdentry.special)) < 0) { 723 outfmt(&errout, "%s: not found\n", *argv); 724 exitstatus = 127; 725 flushout(&errout); 726 return; 727 } 728 if (cmdentry.u.index != BLTINCMD) 729 break; 730 } 731 } 732 } 733 734 /* Fork off a child process if necessary. */ 735 if (cmd->ncmd.backgnd 736 || (cmdentry.cmdtype == CMDNORMAL 737 && ((flags & EV_EXIT) == 0 || have_traps())) 738 || ((flags & EV_BACKCMD) != 0 739 && (cmdentry.cmdtype != CMDBUILTIN 740 || cmdentry.u.index == CDCMD 741 || cmdentry.u.index == DOTCMD 742 || cmdentry.u.index == EVALCMD)) 743 || (cmdentry.cmdtype == CMDBUILTIN && 744 cmdentry.u.index == COMMANDCMD)) { 745 jp = makejob(cmd, 1); 746 mode = cmd->ncmd.backgnd; 747 if (flags & EV_BACKCMD) { 748 mode = FORK_NOJOB; 749 if (pipe(pip) < 0) 750 error("Pipe call failed: %s", strerror(errno)); 751 } 752 if (forkshell(jp, cmd, mode) != 0) 753 goto parent; /* at end of routine */ 754 if (flags & EV_BACKCMD) { 755 FORCEINTON; 756 close(pip[0]); 757 if (pip[1] != 1) { 758 dup2(pip[1], 1); 759 close(pip[1]); 760 } 761 } 762 flags |= EV_EXIT; 763 } 764 765 /* This is the child process if a fork occurred. */ 766 /* Execute the command. */ 767 if (cmdentry.cmdtype == CMDFUNCTION) { 768#ifdef DEBUG 769 trputs("Shell function: "); trargs(argv); 770#endif 771 redirect(cmd->ncmd.redirect, REDIR_PUSH); 772 saveparam = shellparam; 773 shellparam.malloc = 0; 774 shellparam.reset = 1; 775 shellparam.nparam = argc - 1; 776 shellparam.p = argv + 1; 777 shellparam.optnext = NULL; 778 INTOFF; 779 savelocalvars = localvars; 780 localvars = NULL; 781 INTON; 782 if (setjmp(jmploc.loc)) { 783 if (exception == EXSHELLPROC) 784 freeparam((struct shparam *)&saveparam); 785 else { 786 freeparam(&shellparam); 787 shellparam = saveparam; 788 } 789 poplocalvars(); 790 localvars = savelocalvars; 791 handler = savehandler; 792 longjmp(handler->loc, 1); 793 } 794 savehandler = handler; 795 handler = &jmploc; 796 for (sp = varlist.list ; sp ; sp = sp->next) 797 mklocal(sp->text); 798 funcnest++; 799 exitstatus = oexitstatus; 800 if (flags & EV_TESTED) 801 evaltree(cmdentry.u.func, EV_TESTED); 802 else 803 evaltree(cmdentry.u.func, 0); 804 funcnest--; 805 INTOFF; 806 poplocalvars(); 807 localvars = savelocalvars; 808 freeparam(&shellparam); 809 shellparam = saveparam; 810 handler = savehandler; 811 popredir(); 812 INTON; 813 if (evalskip == SKIPFUNC) { 814 evalskip = 0; 815 skipcount = 0; 816 } 817 if (flags & EV_EXIT) 818 exitshell(exitstatus); 819 } else if (cmdentry.cmdtype == CMDBUILTIN) { 820#ifdef DEBUG 821 trputs("builtin command: "); trargs(argv); 822#endif 823 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 824 if (flags == EV_BACKCMD) { 825 memout.nleft = 0; 826 memout.nextc = memout.buf; 827 memout.bufsize = 64; 828 mode |= REDIR_BACKQ; 829 } 830 savecmdname = commandname; 831 cmdenviron = varlist.list; 832 e = -1; 833 if (setjmp(jmploc.loc)) { 834 e = exception; 835 exitstatus = (e == EXINT)? SIGINT+128 : 2; 836 goto cmddone; 837 } 838 savehandler = handler; 839 handler = &jmploc; 840 redirect(cmd->ncmd.redirect, mode); 841 if (cmdentry.special) 842 listsetvar(cmdenviron); 843 commandname = argv[0]; 844 argptr = argv + 1; 845 optptr = NULL; /* initialize nextopt */ 846 builtin_flags = flags; 847 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 848 flushall(); 849cmddone: 850 cmdenviron = NULL; 851 out1 = &output; 852 out2 = &errout; 853 freestdout(); 854 if (e != EXSHELLPROC) { 855 commandname = savecmdname; 856 if (flags & EV_EXIT) { 857 exitshell(exitstatus); 858 } 859 } 860 handler = savehandler; 861 if (e != -1) { 862 if ((e != EXERROR && e != EXEXEC) 863 || cmdentry.special) 864 exraise(e); 865 FORCEINTON; 866 } 867 if (cmdentry.u.index != EXECCMD) 868 popredir(); 869 if (flags == EV_BACKCMD) { 870 backcmd->buf = memout.buf; 871 backcmd->nleft = memout.nextc - memout.buf; 872 memout.buf = NULL; 873 } 874 } else { 875#ifdef DEBUG 876 trputs("normal command: "); trargs(argv); 877#endif 878 clearredir(); 879 redirect(cmd->ncmd.redirect, 0); 880 for (sp = varlist.list ; sp ; sp = sp->next) 881 setvareq(sp->text, VEXPORT|VSTACK); 882 envp = environment(); 883 shellexec(argv, envp, pathval(), cmdentry.u.index); 884 /*NOTREACHED*/ 885 } 886 goto out; 887 888parent: /* parent process gets here (if we forked) */ 889 if (mode == 0) { /* argument to fork */ 890 INTOFF; 891 exitstatus = waitforjob(jp, &realstatus); 892 INTON; 893 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 894 evalskip = SKIPBREAK; 895 skipcount = loopnest; 896 } 897 } else if (mode == 2) { 898 backcmd->fd = pip[0]; 899 close(pip[1]); 900 backcmd->jp = jp; 901 } 902 903out: 904 if (lastarg) 905 setvar("_", lastarg, 0); 906 if (do_clearcmdentry) 907 clearcmdentry(0); 908 popstackmark(&smark); 909} 910 911 912 913/* 914 * Search for a command. This is called before we fork so that the 915 * location of the command will be available in the parent as well as 916 * the child. The check for "goodname" is an overly conservative 917 * check that the name will not be subject to expansion. 918 */ 919 920STATIC void 921prehash(union node *n) 922{ 923 struct cmdentry entry; 924 925 if (n && n->type == NCMD && n->ncmd.args) 926 if (goodname(n->ncmd.args->narg.text)) 927 find_command(n->ncmd.args->narg.text, &entry, 0, 928 pathval()); 929} 930 931 932 933/* 934 * Builtin commands. Builtin commands whose functions are closely 935 * tied to evaluation are implemented here. 936 */ 937 938/* 939 * No command given, or a bltin command with no arguments. 940 */ 941 942int 943bltincmd(int argc __unused, char **argv __unused) 944{ 945 /* 946 * Preserve exitstatus of a previous possible redirection 947 * as POSIX mandates 948 */ 949 return exitstatus; 950} 951 952 953/* 954 * Handle break and continue commands. Break, continue, and return are 955 * all handled by setting the evalskip flag. The evaluation routines 956 * above all check this flag, and if it is set they start skipping 957 * commands rather than executing them. The variable skipcount is 958 * the number of loops to break/continue, or the number of function 959 * levels to return. (The latter is always 1.) It should probably 960 * be an error to break out of more loops than exist, but it isn't 961 * in the standard shell so we don't make it one here. 962 */ 963 964int 965breakcmd(int argc, char **argv) 966{ 967 int n = argc > 1 ? number(argv[1]) : 1; 968 969 if (n > loopnest) 970 n = loopnest; 971 if (n > 0) { 972 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 973 skipcount = n; 974 } 975 return 0; 976} 977 978/* 979 * The `command' command. 980 */ 981int 982commandcmd(int argc, char **argv) 983{ 984 static char stdpath[] = _PATH_STDPATH; 985 struct jmploc loc, *old; 986 struct strlist *sp; 987 char *path; 988 int ch; 989 int cmd = -1; 990 991 for (sp = cmdenviron; sp ; sp = sp->next) 992 setvareq(sp->text, VEXPORT|VSTACK); 993 path = pathval(); 994 995 optind = optreset = 1; 996 opterr = 0; 997 while ((ch = getopt(argc, argv, "pvV")) != -1) { 998 switch (ch) { 999 case 'p': 1000 path = stdpath; 1001 break; 1002 case 'v': 1003 cmd = TYPECMD_SMALLV; 1004 break; 1005 case 'V': 1006 cmd = TYPECMD_BIGV; 1007 break; 1008 case '?': 1009 default: 1010 error("unknown option: -%c", optopt); 1011 } 1012 } 1013 argc -= optind; 1014 argv += optind; 1015 1016 if (cmd != -1) { 1017 if (argc != 1) 1018 error("wrong number of arguments"); 1019 return typecmd_impl(2, argv - 1, cmd); 1020 } 1021 if (argc != 0) { 1022 old = handler; 1023 handler = &loc; 1024 if (setjmp(handler->loc) == 0) 1025 shellexec(argv, environment(), path, 0); 1026 handler = old; 1027 if (exception == EXEXEC) 1028 exit(exerrno); 1029 exraise(exception); 1030 } 1031 1032 /* 1033 * Do nothing successfully if no command was specified; 1034 * ksh also does this. 1035 */ 1036 exit(0); 1037} 1038 1039 1040/* 1041 * The return command. 1042 */ 1043 1044int 1045returncmd(int argc, char **argv) 1046{ 1047 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1048 1049 if (funcnest) { 1050 evalskip = SKIPFUNC; 1051 skipcount = 1; 1052 } else { 1053 /* skip the rest of the file */ 1054 evalskip = SKIPFILE; 1055 skipcount = 1; 1056 } 1057 return ret; 1058} 1059 1060 1061int 1062falsecmd(int argc __unused, char **argv __unused) 1063{ 1064 return 1; 1065} 1066 1067 1068int 1069truecmd(int argc __unused, char **argv __unused) 1070{ 1071 return 0; 1072} 1073 1074 1075int 1076execcmd(int argc, char **argv) 1077{ 1078 if (argc > 1) { 1079 struct strlist *sp; 1080 1081 iflag = 0; /* exit on error */ 1082 mflag = 0; 1083 optschanged(); 1084 for (sp = cmdenviron; sp ; sp = sp->next) 1085 setvareq(sp->text, VEXPORT|VSTACK); 1086 shellexec(argv + 1, environment(), pathval(), 0); 1087 1088 } 1089 return 0; 1090} 1091 1092 1093int 1094timescmd(int argc __unused, char **argv __unused) 1095{ 1096 struct rusage ru; 1097 long shumins, shsmins, chumins, chsmins; 1098 double shusecs, shssecs, chusecs, chssecs; 1099 1100 if (getrusage(RUSAGE_SELF, &ru) < 0) 1101 return 1; 1102 shumins = ru.ru_utime.tv_sec / 60; 1103 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1104 shsmins = ru.ru_stime.tv_sec / 60; 1105 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1106 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1107 return 1; 1108 chumins = ru.ru_utime.tv_sec / 60; 1109 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1110 chsmins = ru.ru_stime.tv_sec / 60; 1111 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1112 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1113 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1114 return 0; 1115} 1116