eval.c revision 197820
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 197820 2009-10-06 22:00:14Z 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 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 405 forkshell(jp = makejob(n, 1), 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 const char *p; 646 out2str(ps4val()); 647 for (sp = varlist.list ; sp ; sp = sp->next) { 648 if (sep != 0) 649 outc(' ', &errout); 650 p = sp->text; 651 while (*p != '=' && *p != '\0') 652 out2c(*p++); 653 if (*p != '\0') { 654 out2c(*p++); 655 out2qstr(p); 656 } 657 sep = ' '; 658 } 659 for (sp = arglist.list ; sp ; sp = sp->next) { 660 if (sep != 0) 661 outc(' ', &errout); 662 /* Disambiguate command looking like assignment. */ 663 if (sp == arglist.list && 664 strchr(sp->text, '=') != NULL && 665 strchr(sp->text, '\'') == NULL) { 666 out2c('\''); 667 out2str(sp->text); 668 out2c('\''); 669 } else 670 out2qstr(sp->text); 671 sep = ' '; 672 } 673 outc('\n', &errout); 674 flushout(&errout); 675 } 676 677 /* Now locate the command. */ 678 if (argc == 0) { 679 /* Variable assignment(s) without command */ 680 cmdentry.cmdtype = CMDBUILTIN; 681 cmdentry.u.index = BLTINCMD; 682 cmdentry.special = 1; 683 } else { 684 static const char PATH[] = "PATH="; 685 char *path = pathval(); 686 687 /* 688 * Modify the command lookup path, if a PATH= assignment 689 * is present 690 */ 691 for (sp = varlist.list ; sp ; sp = sp->next) 692 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 693 path = sp->text + sizeof(PATH) - 1; 694 /* 695 * On `PATH=... command`, we need to make 696 * sure that the command isn't using the 697 * non-updated hash table of the outer PATH 698 * setting and we need to make sure that 699 * the hash table isn't filled with items 700 * from the temporary setting. 701 * 702 * It would be better to forbit using and 703 * updating the table while this command 704 * runs, by the command finding mechanism 705 * is heavily integrated with hash handling, 706 * so we just delete the hash before and after 707 * the command runs. Partly deleting like 708 * changepatch() does doesn't seem worth the 709 * bookinging effort, since most such runs add 710 * directories in front of the new PATH. 711 */ 712 clearcmdentry(0); 713 do_clearcmdentry = 1; 714 } 715 716 find_command(argv[0], &cmdentry, 0, path); 717 /* implement the bltin builtin here */ 718 if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 719 for (;;) { 720 argv++; 721 if (--argc == 0) 722 break; 723 if ((cmdentry.u.index = find_builtin(*argv, 724 &cmdentry.special)) < 0) { 725 outfmt(&errout, "%s: not found\n", *argv); 726 exitstatus = 127; 727 flushout(&errout); 728 return; 729 } 730 if (cmdentry.u.index != BLTINCMD) 731 break; 732 } 733 } 734 } 735 736 /* Fork off a child process if necessary. */ 737 if (cmd->ncmd.backgnd 738 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 739 && ((flags & EV_EXIT) == 0 || have_traps())) 740 || ((flags & EV_BACKCMD) != 0 741 && (cmdentry.cmdtype != CMDBUILTIN 742 || cmdentry.u.index == CDCMD 743 || cmdentry.u.index == DOTCMD 744 || cmdentry.u.index == EVALCMD)) 745 || (cmdentry.cmdtype == CMDBUILTIN && 746 cmdentry.u.index == COMMANDCMD)) { 747 jp = makejob(cmd, 1); 748 mode = cmd->ncmd.backgnd; 749 if (flags & EV_BACKCMD) { 750 mode = FORK_NOJOB; 751 if (pipe(pip) < 0) 752 error("Pipe call failed: %s", strerror(errno)); 753 } 754 if (forkshell(jp, cmd, mode) != 0) 755 goto parent; /* at end of routine */ 756 if (flags & EV_BACKCMD) { 757 FORCEINTON; 758 close(pip[0]); 759 if (pip[1] != 1) { 760 dup2(pip[1], 1); 761 close(pip[1]); 762 } 763 } 764 flags |= EV_EXIT; 765 } 766 767 /* This is the child process if a fork occurred. */ 768 /* Execute the command. */ 769 if (cmdentry.cmdtype == CMDFUNCTION) { 770#ifdef DEBUG 771 trputs("Shell function: "); trargs(argv); 772#endif 773 redirect(cmd->ncmd.redirect, REDIR_PUSH); 774 saveparam = shellparam; 775 shellparam.malloc = 0; 776 shellparam.reset = 1; 777 shellparam.nparam = argc - 1; 778 shellparam.p = argv + 1; 779 shellparam.optnext = NULL; 780 INTOFF; 781 savelocalvars = localvars; 782 localvars = NULL; 783 reffunc(cmdentry.u.func); 784 INTON; 785 savehandler = handler; 786 if (setjmp(jmploc.loc)) { 787 if (exception == EXSHELLPROC) 788 freeparam(&saveparam); 789 else { 790 freeparam(&shellparam); 791 shellparam = saveparam; 792 } 793 unreffunc(cmdentry.u.func); 794 poplocalvars(); 795 localvars = savelocalvars; 796 handler = savehandler; 797 longjmp(handler->loc, 1); 798 } 799 handler = &jmploc; 800 for (sp = varlist.list ; sp ; sp = sp->next) 801 mklocal(sp->text); 802 funcnest++; 803 exitstatus = oexitstatus; 804 if (flags & EV_TESTED) 805 evaltree(getfuncnode(cmdentry.u.func), EV_TESTED); 806 else 807 evaltree(getfuncnode(cmdentry.u.func), 0); 808 funcnest--; 809 INTOFF; 810 unreffunc(cmdentry.u.func); 811 poplocalvars(); 812 localvars = savelocalvars; 813 freeparam(&shellparam); 814 shellparam = saveparam; 815 handler = savehandler; 816 popredir(); 817 INTON; 818 if (evalskip == SKIPFUNC) { 819 evalskip = 0; 820 skipcount = 0; 821 } 822 if (flags & EV_EXIT) 823 exitshell(exitstatus); 824 } else if (cmdentry.cmdtype == CMDBUILTIN) { 825#ifdef DEBUG 826 trputs("builtin command: "); trargs(argv); 827#endif 828 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 829 if (flags == EV_BACKCMD) { 830 memout.nleft = 0; 831 memout.nextc = memout.buf; 832 memout.bufsize = 64; 833 mode |= REDIR_BACKQ; 834 } 835 savecmdname = commandname; 836 cmdenviron = varlist.list; 837 e = -1; 838 savehandler = handler; 839 if (setjmp(jmploc.loc)) { 840 e = exception; 841 exitstatus = (e == EXINT)? SIGINT+128 : 2; 842 goto cmddone; 843 } 844 handler = &jmploc; 845 redirect(cmd->ncmd.redirect, mode); 846 if (cmdentry.special) 847 listsetvar(cmdenviron); 848 commandname = argv[0]; 849 argptr = argv + 1; 850 optptr = NULL; /* initialize nextopt */ 851 builtin_flags = flags; 852 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 853 flushall(); 854cmddone: 855 cmdenviron = NULL; 856 out1 = &output; 857 out2 = &errout; 858 freestdout(); 859 if (e != EXSHELLPROC) { 860 commandname = savecmdname; 861 if (flags & EV_EXIT) { 862 exitshell(exitstatus); 863 } 864 } 865 handler = savehandler; 866 if (e != -1) { 867 if ((e != EXERROR && e != EXEXEC) 868 || cmdentry.special) 869 exraise(e); 870 FORCEINTON; 871 } 872 if (cmdentry.u.index != EXECCMD) 873 popredir(); 874 if (flags == EV_BACKCMD) { 875 backcmd->buf = memout.buf; 876 backcmd->nleft = memout.nextc - memout.buf; 877 memout.buf = NULL; 878 } 879 } else { 880#ifdef DEBUG 881 trputs("normal command: "); trargs(argv); 882#endif 883 clearredir(); 884 redirect(cmd->ncmd.redirect, 0); 885 for (sp = varlist.list ; sp ; sp = sp->next) 886 setvareq(sp->text, VEXPORT|VSTACK); 887 envp = environment(); 888 shellexec(argv, envp, pathval(), cmdentry.u.index); 889 /*NOTREACHED*/ 890 } 891 goto out; 892 893parent: /* parent process gets here (if we forked) */ 894 if (mode == 0) { /* argument to fork */ 895 INTOFF; 896 exitstatus = waitforjob(jp, &realstatus); 897 INTON; 898 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 899 evalskip = SKIPBREAK; 900 skipcount = loopnest; 901 } 902 } else if (mode == 2) { 903 backcmd->fd = pip[0]; 904 close(pip[1]); 905 backcmd->jp = jp; 906 } 907 908out: 909 if (lastarg) 910 setvar("_", lastarg, 0); 911 if (do_clearcmdentry) 912 clearcmdentry(0); 913 popstackmark(&smark); 914} 915 916 917 918/* 919 * Search for a command. This is called before we fork so that the 920 * location of the command will be available in the parent as well as 921 * the child. The check for "goodname" is an overly conservative 922 * check that the name will not be subject to expansion. 923 */ 924 925STATIC void 926prehash(union node *n) 927{ 928 struct cmdentry entry; 929 930 if (n && n->type == NCMD && n->ncmd.args) 931 if (goodname(n->ncmd.args->narg.text)) 932 find_command(n->ncmd.args->narg.text, &entry, 0, 933 pathval()); 934} 935 936 937 938/* 939 * Builtin commands. Builtin commands whose functions are closely 940 * tied to evaluation are implemented here. 941 */ 942 943/* 944 * No command given, or a bltin command with no arguments. 945 */ 946 947int 948bltincmd(int argc __unused, char **argv __unused) 949{ 950 /* 951 * Preserve exitstatus of a previous possible redirection 952 * as POSIX mandates 953 */ 954 return exitstatus; 955} 956 957 958/* 959 * Handle break and continue commands. Break, continue, and return are 960 * all handled by setting the evalskip flag. The evaluation routines 961 * above all check this flag, and if it is set they start skipping 962 * commands rather than executing them. The variable skipcount is 963 * the number of loops to break/continue, or the number of function 964 * levels to return. (The latter is always 1.) It should probably 965 * be an error to break out of more loops than exist, but it isn't 966 * in the standard shell so we don't make it one here. 967 */ 968 969int 970breakcmd(int argc, char **argv) 971{ 972 int n = argc > 1 ? number(argv[1]) : 1; 973 974 if (n > loopnest) 975 n = loopnest; 976 if (n > 0) { 977 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 978 skipcount = n; 979 } 980 return 0; 981} 982 983/* 984 * The `command' command. 985 */ 986int 987commandcmd(int argc, char **argv) 988{ 989 static char stdpath[] = _PATH_STDPATH; 990 struct jmploc loc, *old; 991 struct strlist *sp; 992 char *path; 993 int ch; 994 int cmd = -1; 995 996 for (sp = cmdenviron; sp ; sp = sp->next) 997 setvareq(sp->text, VEXPORT|VSTACK); 998 path = pathval(); 999 1000 optind = optreset = 1; 1001 opterr = 0; 1002 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1003 switch (ch) { 1004 case 'p': 1005 path = stdpath; 1006 break; 1007 case 'v': 1008 cmd = TYPECMD_SMALLV; 1009 break; 1010 case 'V': 1011 cmd = TYPECMD_BIGV; 1012 break; 1013 case '?': 1014 default: 1015 error("unknown option: -%c", optopt); 1016 } 1017 } 1018 argc -= optind; 1019 argv += optind; 1020 1021 if (cmd != -1) { 1022 if (argc != 1) 1023 error("wrong number of arguments"); 1024 return typecmd_impl(2, argv - 1, cmd); 1025 } 1026 if (argc != 0) { 1027 old = handler; 1028 handler = &loc; 1029 if (setjmp(handler->loc) == 0) 1030 shellexec(argv, environment(), path, 0); 1031 handler = old; 1032 if (exception == EXEXEC) 1033 exit(exerrno); 1034 exraise(exception); 1035 } 1036 1037 /* 1038 * Do nothing successfully if no command was specified; 1039 * ksh also does this. 1040 */ 1041 exit(0); 1042} 1043 1044 1045/* 1046 * The return command. 1047 */ 1048 1049int 1050returncmd(int argc, char **argv) 1051{ 1052 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1053 1054 if (funcnest) { 1055 evalskip = SKIPFUNC; 1056 skipcount = 1; 1057 } else { 1058 /* skip the rest of the file */ 1059 evalskip = SKIPFILE; 1060 skipcount = 1; 1061 } 1062 return ret; 1063} 1064 1065 1066int 1067falsecmd(int argc __unused, char **argv __unused) 1068{ 1069 return 1; 1070} 1071 1072 1073int 1074truecmd(int argc __unused, char **argv __unused) 1075{ 1076 return 0; 1077} 1078 1079 1080int 1081execcmd(int argc, char **argv) 1082{ 1083 if (argc > 1) { 1084 struct strlist *sp; 1085 1086 iflag = 0; /* exit on error */ 1087 mflag = 0; 1088 optschanged(); 1089 for (sp = cmdenviron; sp ; sp = sp->next) 1090 setvareq(sp->text, VEXPORT|VSTACK); 1091 shellexec(argv + 1, environment(), pathval(), 0); 1092 1093 } 1094 return 0; 1095} 1096 1097 1098int 1099timescmd(int argc __unused, char **argv __unused) 1100{ 1101 struct rusage ru; 1102 long shumins, shsmins, chumins, chsmins; 1103 double shusecs, shssecs, chusecs, chssecs; 1104 1105 if (getrusage(RUSAGE_SELF, &ru) < 0) 1106 return 1; 1107 shumins = ru.ru_utime.tv_sec / 60; 1108 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1109 shsmins = ru.ru_stime.tv_sec / 60; 1110 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1111 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1112 return 1; 1113 chumins = ru.ru_utime.tv_sec / 60; 1114 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1115 chsmins = ru.ru_stime.tv_sec / 60; 1116 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1117 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1118 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1119 return 0; 1120} 1121