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 35 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 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 77 int evalskip; /* set if we are skipping commands */ 78 static int skipcount; /* number of levels to skip */ 79 MKINIT int loopnest; /* current loop nesting level */ 80 int funcnest; /* depth of function calls */ 81 static int builtin_flags; /* evalcommand flags for builtins */ 82 83 84 char *commandname; 85 struct strlist *cmdenviron; 86 int exitstatus; /* exit status of last command */ 87 int oexitstatus; /* saved exit status */ 88 89 90 static void evalloop(union node *, int); 91 static void evalfor(union node *, int); 92 static void evalcase(union node *, int); 93 static void evalsubshell(union node *, int); 94 static void evalredir(union node *, int); 95 static void expredir(union node *); 96 static void evalpipe(union node *); 97 static void evalcommand(union node *, int, struct backcmd *); 98 static void prehash(union node *); 99 100 101 /* 102 * Called to reset things after an exception. 103 */ 104 105 #ifdef mkinit 106 INCLUDE "eval.h" 107 108 RESET { 109 evalskip = 0; 110 loopnest = 0; 111 funcnest = 0; 112 } 113 114 SHELLPROC { 115 exitstatus = 0; 116 } 117 #endif 118 119 120 121 /* 122 * The eval command. 123 */ 124 125 int 126 evalcmd(int argc, char **argv) 127 { 128 char *p; 129 char *concat; 130 char **ap; 131 132 if (argc > 1) { 133 p = argv[1]; 134 if (argc > 2) { 135 STARTSTACKSTR(concat); 136 ap = argv + 2; 137 for (;;) { 138 STPUTS(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 } else 148 exitstatus = 0; 149 return exitstatus; 150 } 151 152 153 /* 154 * Execute a command or commands contained in a string. 155 */ 156 157 void 158 evalstring(char *s, int flags) 159 { 160 union node *n; 161 struct stackmark smark; 162 int flags_exit; 163 int any; 164 165 flags_exit = flags & EV_EXIT; 166 flags &= ~EV_EXIT; 167 any = 0; 168 setstackmark(&smark); 169 setinputstring(s, 1); 170 while ((n = parsecmd(0)) != NEOF) { 171 if (n != NULL) { 172 if (flags_exit && preadateof()) 173 evaltree(n, flags | EV_EXIT); 174 else 175 evaltree(n, flags); 176 any = 1; 177 } 178 popstackmark(&smark); 179 } 180 popfile(); 181 popstackmark(&smark); 182 if (!any) 183 exitstatus = 0; 184 if (flags_exit) 185 exitshell(exitstatus); 186 } 187 188 189 /* 190 * Evaluate a parse tree. The value is left in the global variable 191 * exitstatus. 192 */ 193 194 void 195 evaltree(union node *n, int flags) 196 { 197 int do_etest; 198 union node *next; 199 200 do_etest = 0; 201 if (n == NULL) { 202 TRACE(("evaltree(NULL) called\n")); 203 exitstatus = 0; 204 goto out; 205 } 206 do { 207 next = NULL; 208 #ifndef NO_HISTORY 209 displayhist = 1; /* show history substitutions done with fc */ 210 #endif 211 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 212 switch (n->type) { 213 case NSEMI: 214 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 215 if (evalskip) 216 goto out; 217 next = n->nbinary.ch2; 218 break; 219 case NAND: 220 evaltree(n->nbinary.ch1, EV_TESTED); 221 if (evalskip || exitstatus != 0) { 222 goto out; 223 } 224 next = n->nbinary.ch2; 225 break; 226 case NOR: 227 evaltree(n->nbinary.ch1, EV_TESTED); 228 if (evalskip || exitstatus == 0) 229 goto out; 230 next = n->nbinary.ch2; 231 break; 232 case NREDIR: 233 evalredir(n, flags); 234 break; 235 case NSUBSHELL: 236 evalsubshell(n, flags); 237 do_etest = !(flags & EV_TESTED); 238 break; 239 case NBACKGND: 240 evalsubshell(n, flags); 241 break; 242 case NIF: { 243 evaltree(n->nif.test, EV_TESTED); 244 if (evalskip) 245 goto out; 246 if (exitstatus == 0) 247 next = n->nif.ifpart; 248 else if (n->nif.elsepart) 249 next = n->nif.elsepart; 250 else 251 exitstatus = 0; 252 break; 253 } 254 case NWHILE: 255 case NUNTIL: 256 evalloop(n, flags & ~EV_EXIT); 257 break; 258 case NFOR: 259 evalfor(n, flags & ~EV_EXIT); 260 break; 261 case NCASE: 262 evalcase(n, flags); 263 break; 264 case NDEFUN: 265 defun(n->narg.text, n->narg.next); 266 exitstatus = 0; 267 break; 268 case NNOT: 269 evaltree(n->nnot.com, EV_TESTED); 270 exitstatus = !exitstatus; 271 break; 272 273 case NPIPE: 274 evalpipe(n); 275 do_etest = !(flags & EV_TESTED); 276 break; 277 case NCMD: 278 evalcommand(n, flags, (struct backcmd *)NULL); 279 do_etest = !(flags & EV_TESTED); 280 break; 281 default: 282 out1fmt("Node type = %d\n", n->type); 283 flushout(&output); 284 break; 285 } 286 n = next; 287 } while (n != NULL); 288 out: 289 if (pendingsigs) 290 dotrap(); 291 if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest)) 292 exitshell(exitstatus); 293 } 294 295 296 static void 297 evalloop(union node *n, int flags) 298 { 299 int status; 300 301 loopnest++; 302 status = 0; 303 for (;;) { 304 evaltree(n->nbinary.ch1, EV_TESTED); 305 if (evalskip) { 306 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 307 evalskip = 0; 308 continue; 309 } 310 if (evalskip == SKIPBREAK && --skipcount <= 0) 311 evalskip = 0; 312 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 313 status = exitstatus; 314 break; 315 } 316 if (n->type == NWHILE) { 317 if (exitstatus != 0) 318 break; 319 } else { 320 if (exitstatus == 0) 321 break; 322 } 323 evaltree(n->nbinary.ch2, flags); 324 status = exitstatus; 325 if (evalskip) 326 goto skipping; 327 } 328 loopnest--; 329 exitstatus = status; 330 } 331 332 333 334 static void 335 evalfor(union node *n, int flags) 336 { 337 struct arglist arglist; 338 union node *argp; 339 struct strlist *sp; 340 struct stackmark smark; 341 342 setstackmark(&smark); 343 arglist.lastp = &arglist.list; 344 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 345 oexitstatus = exitstatus; 346 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 347 if (evalskip) 348 goto out; 349 } 350 *arglist.lastp = NULL; 351 352 exitstatus = 0; 353 loopnest++; 354 for (sp = arglist.list ; sp ; sp = sp->next) { 355 setvar(n->nfor.var, sp->text, 0); 356 evaltree(n->nfor.body, flags); 357 if (evalskip) { 358 if (evalskip == SKIPCONT && --skipcount <= 0) { 359 evalskip = 0; 360 continue; 361 } 362 if (evalskip == SKIPBREAK && --skipcount <= 0) 363 evalskip = 0; 364 break; 365 } 366 } 367 loopnest--; 368 out: 369 popstackmark(&smark); 370 } 371 372 373 374 static void 375 evalcase(union node *n, int flags) 376 { 377 union node *cp; 378 union node *patp; 379 struct arglist arglist; 380 struct stackmark smark; 381 382 setstackmark(&smark); 383 arglist.lastp = &arglist.list; 384 oexitstatus = exitstatus; 385 exitstatus = 0; 386 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 387 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 388 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 389 if (casematch(patp, arglist.list->text)) { 390 if (evalskip == 0) { 391 evaltree(cp->nclist.body, flags); 392 } 393 goto out; 394 } 395 } 396 } 397 out: 398 popstackmark(&smark); 399 } 400 401 402 403 /* 404 * Kick off a subshell to evaluate a tree. 405 */ 406 407 static void 408 evalsubshell(union node *n, int flags) 409 { 410 struct job *jp; 411 int backgnd = (n->type == NBACKGND); 412 413 expredir(n->nredir.redirect); 414 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 415 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 416 if (backgnd) 417 flags &=~ EV_TESTED; 418 redirect(n->nredir.redirect, 0); 419 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 420 } else if (! backgnd) { 421 INTOFF; 422 exitstatus = waitforjob(jp, (int *)NULL); 423 INTON; 424 } 425 } 426 427 428 /* 429 * Evaluate a redirected compound command. 430 */ 431 432 static void 433 evalredir(union node *n, int flags) 434 { 435 struct jmploc jmploc; 436 struct jmploc *savehandler; 437 volatile int in_redirect = 1; 438 439 expredir(n->nredir.redirect); 440 savehandler = handler; 441 if (setjmp(jmploc.loc)) { 442 int e; 443 444 handler = savehandler; 445 e = exception; 446 if (e == EXERROR || e == EXEXEC) { 447 popredir(); 448 if (in_redirect) { 449 exitstatus = 2; 450 return; 451 } 452 } 453 longjmp(handler->loc, 1); 454 } else { 455 INTOFF; 456 handler = &jmploc; 457 redirect(n->nredir.redirect, REDIR_PUSH); 458 in_redirect = 0; 459 INTON; 460 evaltree(n->nredir.n, flags); 461 } 462 INTOFF; 463 handler = savehandler; 464 popredir(); 465 INTON; 466 } 467 468 469 /* 470 * Compute the names of the files in a redirection list. 471 */ 472 473 static void 474 expredir(union node *n) 475 { 476 union node *redir; 477 478 for (redir = n ; redir ; redir = redir->nfile.next) { 479 struct arglist fn; 480 fn.lastp = &fn.list; 481 oexitstatus = exitstatus; 482 switch (redir->type) { 483 case NFROM: 484 case NTO: 485 case NFROMTO: 486 case NAPPEND: 487 case NCLOBBER: 488 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 489 redir->nfile.expfname = fn.list->text; 490 break; 491 case NFROMFD: 492 case NTOFD: 493 if (redir->ndup.vname) { 494 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 495 fixredir(redir, fn.list->text, 1); 496 } 497 break; 498 } 499 } 500 } 501 502 503 504 /* 505 * Evaluate a pipeline. All the processes in the pipeline are children 506 * of the process creating the pipeline. (This differs from some versions 507 * of the shell, which make the last process in a pipeline the parent 508 * of all the rest.) 509 */ 510 511 static void 512 evalpipe(union node *n) 513 { 514 struct job *jp; 515 struct nodelist *lp; 516 int pipelen; 517 int prevfd; 518 int pip[2]; 519 520 TRACE(("evalpipe(%p) called\n", (void *)n)); 521 pipelen = 0; 522 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 523 pipelen++; 524 INTOFF; 525 jp = makejob(n, pipelen); 526 prevfd = -1; 527 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 528 prehash(lp->n); 529 pip[1] = -1; 530 if (lp->next) { 531 if (pipe(pip) < 0) { 532 close(prevfd); 533 error("Pipe call failed: %s", strerror(errno)); 534 } 535 } 536 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 537 INTON; 538 if (prevfd > 0) { 539 dup2(prevfd, 0); 540 close(prevfd); 541 } 542 if (pip[1] >= 0) { 543 if (!(prevfd >= 0 && pip[0] == 0)) 544 close(pip[0]); 545 if (pip[1] != 1) { 546 dup2(pip[1], 1); 547 close(pip[1]); 548 } 549 } 550 evaltree(lp->n, EV_EXIT); 551 } 552 if (prevfd >= 0) 553 close(prevfd); 554 prevfd = pip[0]; 555 close(pip[1]); 556 } 557 INTON; 558 if (n->npipe.backgnd == 0) { 559 INTOFF; 560 exitstatus = waitforjob(jp, (int *)NULL); 561 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 562 INTON; 563 } 564 } 565 566 567 568 /* 569 * Execute a command inside back quotes. If it's a builtin command, we 570 * want to save its output in a block obtained from malloc. Otherwise 571 * we fork off a subprocess and get the output of the command via a pipe. 572 * Should be called with interrupts off. 573 */ 574 575 void 576 evalbackcmd(union node *n, struct backcmd *result) 577 { 578 int pip[2]; 579 struct job *jp; 580 struct stackmark smark; /* unnecessary */ 581 582 setstackmark(&smark); 583 result->fd = -1; 584 result->buf = NULL; 585 result->nleft = 0; 586 result->jp = NULL; 587 if (n == NULL) { 588 exitstatus = 0; 589 goto out; 590 } 591 if (n->type == NCMD) { 592 exitstatus = oexitstatus; 593 evalcommand(n, EV_BACKCMD, result); 594 } else { 595 exitstatus = 0; 596 if (pipe(pip) < 0) 597 error("Pipe call failed: %s", strerror(errno)); 598 jp = makejob(n, 1); 599 if (forkshell(jp, n, FORK_NOJOB) == 0) { 600 FORCEINTON; 601 close(pip[0]); 602 if (pip[1] != 1) { 603 dup2(pip[1], 1); 604 close(pip[1]); 605 } 606 evaltree(n, EV_EXIT); 607 } 608 close(pip[1]); 609 result->fd = pip[0]; 610 result->jp = jp; 611 } 612 out: 613 popstackmark(&smark); 614 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 615 result->fd, result->buf, result->nleft, result->jp)); 616 } 617 618 619 620 /* 621 * Execute a simple command. 622 */ 623 624 static void 625 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 626 { 627 struct stackmark smark; 628 union node *argp; 629 struct arglist arglist; 630 struct arglist varlist; 631 char **argv; 632 int argc; 633 char **envp; 634 int varflag; 635 struct strlist *sp; 636 int mode; 637 int pip[2]; 638 struct cmdentry cmdentry; 639 struct job *jp; 640 struct jmploc jmploc; 641 struct jmploc *savehandler; 642 char *savecmdname; 643 struct shparam saveparam; 644 struct localvar *savelocalvars; 645 struct parsefile *savetopfile; 646 volatile int e; 647 char *lastarg; 648 int realstatus; 649 int do_clearcmdentry; 650 const char *path = pathval(); 651 652 /* First expand the arguments. */ 653 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 654 setstackmark(&smark); 655 arglist.lastp = &arglist.list; 656 varlist.lastp = &varlist.list; 657 varflag = 1; 658 do_clearcmdentry = 0; 659 oexitstatus = exitstatus; 660 exitstatus = 0; 661 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 662 char *p = argp->narg.text; 663 if (varflag && is_name(*p)) { 664 do { 665 p++; 666 } while (is_in_name(*p)); 667 if (*p == '=') { 668 expandarg(argp, &varlist, EXP_VARTILDE); 669 continue; 670 } 671 } 672 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 673 varflag = 0; 674 } 675 *arglist.lastp = NULL; 676 *varlist.lastp = NULL; 677 expredir(cmd->ncmd.redirect); 678 argc = 0; 679 for (sp = arglist.list ; sp ; sp = sp->next) 680 argc++; 681 argv = stalloc(sizeof (char *) * (argc + 1)); 682 683 for (sp = arglist.list ; sp ; sp = sp->next) { 684 TRACE(("evalcommand arg: %s\n", sp->text)); 685 *argv++ = sp->text; 686 } 687 *argv = NULL; 688 lastarg = NULL; 689 if (iflag && funcnest == 0 && argc > 0) 690 lastarg = argv[-1]; 691 argv -= argc; 692 693 /* Print the command if xflag is set. */ 694 if (xflag) { 695 char sep = 0; 696 const char *p; 697 out2str(ps4val()); 698 for (sp = varlist.list ; sp ; sp = sp->next) { 699 if (sep != 0) 700 out2c(' '); 701 p = strchr(sp->text, '='); 702 if (p != NULL) { 703 p++; 704 outbin(sp->text, p - sp->text, out2); 705 out2qstr(p); 706 } else 707 out2qstr(sp->text); 708 sep = ' '; 709 } 710 for (sp = arglist.list ; sp ; sp = sp->next) { 711 if (sep != 0) 712 out2c(' '); 713 /* Disambiguate command looking like assignment. */ 714 if (sp == arglist.list && 715 strchr(sp->text, '=') != NULL && 716 strchr(sp->text, '\'') == NULL) { 717 out2c('\''); 718 out2str(sp->text); 719 out2c('\''); 720 } else 721 out2qstr(sp->text); 722 sep = ' '; 723 } 724 out2c('\n'); 725 flushout(&errout); 726 } 727 728 /* Now locate the command. */ 729 if (argc == 0) { 730 /* Variable assignment(s) without command */ 731 cmdentry.cmdtype = CMDBUILTIN; 732 cmdentry.u.index = BLTINCMD; 733 cmdentry.special = 0; 734 } else { 735 static const char PATH[] = "PATH="; 736 int cmd_flags = 0, bltinonly = 0; 737 738 /* 739 * Modify the command lookup path, if a PATH= assignment 740 * is present 741 */ 742 for (sp = varlist.list ; sp ; sp = sp->next) 743 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 744 path = sp->text + sizeof(PATH) - 1; 745 /* 746 * On `PATH=... command`, we need to make 747 * sure that the command isn't using the 748 * non-updated hash table of the outer PATH 749 * setting and we need to make sure that 750 * the hash table isn't filled with items 751 * from the temporary setting. 752 * 753 * It would be better to forbit using and 754 * updating the table while this command 755 * runs, by the command finding mechanism 756 * is heavily integrated with hash handling, 757 * so we just delete the hash before and after 758 * the command runs. Partly deleting like 759 * changepatch() does doesn't seem worth the 760 * bookinging effort, since most such runs add 761 * directories in front of the new PATH. 762 */ 763 clearcmdentry(0); 764 do_clearcmdentry = 1; 765 } 766 767 for (;;) { 768 if (bltinonly) { 769 cmdentry.u.index = find_builtin(*argv, &cmdentry.special); 770 if (cmdentry.u.index < 0) { 771 cmdentry.u.index = BLTINCMD; 772 argv--; 773 argc++; 774 break; 775 } 776 } else 777 find_command(argv[0], &cmdentry, cmd_flags, path); 778 /* implement the bltin and command builtins here */ 779 if (cmdentry.cmdtype != CMDBUILTIN) 780 break; 781 if (cmdentry.u.index == BLTINCMD) { 782 if (argc == 1) 783 break; 784 argv++; 785 argc--; 786 bltinonly = 1; 787 } else if (cmdentry.u.index == COMMANDCMD) { 788 if (argc == 1) 789 break; 790 if (!strcmp(argv[1], "-p")) { 791 if (argc == 2) 792 break; 793 if (argv[2][0] == '-') { 794 if (strcmp(argv[2], "--")) 795 break; 796 if (argc == 3) 797 break; 798 argv += 3; 799 argc -= 3; 800 } else { 801 argv += 2; 802 argc -= 2; 803 } 804 path = _PATH_STDPATH; 805 clearcmdentry(0); 806 do_clearcmdentry = 1; 807 } else if (!strcmp(argv[1], "--")) { 808 if (argc == 2) 809 break; 810 argv += 2; 811 argc -= 2; 812 } else if (argv[1][0] == '-') 813 break; 814 else { 815 argv++; 816 argc--; 817 } 818 cmd_flags |= DO_NOFUNC; 819 bltinonly = 0; 820 } else 821 break; 822 } 823 /* 824 * Special builtins lose their special properties when 825 * called via 'command'. 826 */ 827 if (cmd_flags & DO_NOFUNC) 828 cmdentry.special = 0; 829 } 830 831 /* Fork off a child process if necessary. */ 832 if (cmd->ncmd.backgnd 833 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 834 && ((flags & EV_EXIT) == 0 || have_traps())) 835 || ((flags & EV_BACKCMD) != 0 836 && (cmdentry.cmdtype != CMDBUILTIN 837 || cmdentry.u.index == CDCMD 838 || cmdentry.u.index == DOTCMD 839 || cmdentry.u.index == EVALCMD))) { 840 jp = makejob(cmd, 1); 841 mode = cmd->ncmd.backgnd; 842 if (flags & EV_BACKCMD) { 843 mode = FORK_NOJOB; 844 if (pipe(pip) < 0) 845 error("Pipe call failed: %s", strerror(errno)); 846 } 847 if (forkshell(jp, cmd, mode) != 0) 848 goto parent; /* at end of routine */ 849 if (flags & EV_BACKCMD) { 850 FORCEINTON; 851 close(pip[0]); 852 if (pip[1] != 1) { 853 dup2(pip[1], 1); 854 close(pip[1]); 855 } 856 } 857 flags |= EV_EXIT; 858 } 859 860 /* This is the child process if a fork occurred. */ 861 /* Execute the command. */ 862 if (cmdentry.cmdtype == CMDFUNCTION) { 863 #ifdef DEBUG 864 trputs("Shell function: "); trargs(argv); 865 #endif 866 saveparam = shellparam; 867 shellparam.malloc = 0; 868 shellparam.reset = 1; 869 shellparam.nparam = argc - 1; 870 shellparam.p = argv + 1; 871 shellparam.optnext = NULL; 872 INTOFF; 873 savelocalvars = localvars; 874 localvars = NULL; 875 reffunc(cmdentry.u.func); 876 savehandler = handler; 877 if (setjmp(jmploc.loc)) { 878 if (exception == EXSHELLPROC) 879 freeparam(&saveparam); 880 else { 881 freeparam(&shellparam); 882 shellparam = saveparam; 883 if (exception == EXERROR || exception == EXEXEC) 884 popredir(); 885 } 886 unreffunc(cmdentry.u.func); 887 poplocalvars(); 888 localvars = savelocalvars; 889 funcnest--; 890 handler = savehandler; 891 longjmp(handler->loc, 1); 892 } 893 handler = &jmploc; 894 funcnest++; 895 redirect(cmd->ncmd.redirect, REDIR_PUSH); 896 INTON; 897 for (sp = varlist.list ; sp ; sp = sp->next) 898 mklocal(sp->text); 899 exitstatus = oexitstatus; 900 if (flags & EV_TESTED) 901 evaltree(getfuncnode(cmdentry.u.func), EV_TESTED); 902 else 903 evaltree(getfuncnode(cmdentry.u.func), 0); 904 INTOFF; 905 unreffunc(cmdentry.u.func); 906 poplocalvars(); 907 localvars = savelocalvars; 908 freeparam(&shellparam); 909 shellparam = saveparam; 910 handler = savehandler; 911 funcnest--; 912 popredir(); 913 INTON; 914 if (evalskip == SKIPFUNC) { 915 evalskip = 0; 916 skipcount = 0; 917 } 918 if (flags & EV_EXIT) 919 exitshell(exitstatus); 920 } else if (cmdentry.cmdtype == CMDBUILTIN) { 921 #ifdef DEBUG 922 trputs("builtin command: "); trargs(argv); 923 #endif 924 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 925 if (flags == EV_BACKCMD) { 926 memout.nleft = 0; 927 memout.nextc = memout.buf; 928 memout.bufsize = 64; 929 mode |= REDIR_BACKQ; 930 cmdentry.special = 0; 931 } 932 savecmdname = commandname; 933 savetopfile = getcurrentfile(); 934 cmdenviron = varlist.list; 935 e = -1; 936 savehandler = handler; 937 if (setjmp(jmploc.loc)) { 938 e = exception; 939 exitstatus = (e == EXINT)? SIGINT+128 : 2; 940 goto cmddone; 941 } 942 handler = &jmploc; 943 redirect(cmd->ncmd.redirect, mode); 944 /* 945 * If there is no command word, redirection errors should 946 * not be fatal but assignment errors should. 947 */ 948 if (argc == 0 && !(flags & EV_BACKCMD)) 949 cmdentry.special = 1; 950 if (cmdentry.special) 951 listsetvar(cmdenviron); 952 if (argc > 0) 953 bltinsetlocale(); 954 commandname = argv[0]; 955 argptr = argv + 1; 956 nextopt_optptr = NULL; /* initialize nextopt */ 957 builtin_flags = flags; 958 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 959 flushall(); 960 cmddone: 961 if (argc > 0) 962 bltinunsetlocale(); 963 cmdenviron = NULL; 964 out1 = &output; 965 out2 = &errout; 966 freestdout(); 967 if (e != EXSHELLPROC) { 968 commandname = savecmdname; 969 if (flags & EV_EXIT) { 970 exitshell(exitstatus); 971 } 972 } 973 handler = savehandler; 974 if (flags == EV_BACKCMD) { 975 backcmd->buf = memout.buf; 976 backcmd->nleft = memout.nextc - memout.buf; 977 memout.buf = NULL; 978 } 979 if (cmdentry.u.index != EXECCMD && 980 (e == -1 || e == EXERROR || e == EXEXEC)) 981 popredir(); 982 if (e != -1) { 983 if ((e != EXERROR && e != EXEXEC) 984 || cmdentry.special) 985 exraise(e); 986 popfilesupto(savetopfile); 987 if (flags != EV_BACKCMD) 988 FORCEINTON; 989 } 990 } else { 991 #ifdef DEBUG 992 trputs("normal command: "); trargs(argv); 993 #endif 994 redirect(cmd->ncmd.redirect, 0); 995 for (sp = varlist.list ; sp ; sp = sp->next) 996 setvareq(sp->text, VEXPORT|VSTACK); 997 envp = environment(); 998 shellexec(argv, envp, path, cmdentry.u.index); 999 /*NOTREACHED*/ 1000 } 1001 goto out; 1002 1003 parent: /* parent process gets here (if we forked) */ 1004 if (mode == FORK_FG) { /* argument to fork */ 1005 INTOFF; 1006 exitstatus = waitforjob(jp, &realstatus); 1007 INTON; 1008 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1009 evalskip = SKIPBREAK; 1010 skipcount = loopnest; 1011 } 1012 } else if (mode == FORK_NOJOB) { 1013 backcmd->fd = pip[0]; 1014 close(pip[1]); 1015 backcmd->jp = jp; 1016 } 1017 1018 out: 1019 if (lastarg) 1020 setvar("_", lastarg, 0); 1021 if (do_clearcmdentry) 1022 clearcmdentry(0); 1023 popstackmark(&smark); 1024 } 1025 1026 1027 1028 /* 1029 * Search for a command. This is called before we fork so that the 1030 * location of the command will be available in the parent as well as 1031 * the child. The check for "goodname" is an overly conservative 1032 * check that the name will not be subject to expansion. 1033 */ 1034 1035 static void 1036 prehash(union node *n) 1037 { 1038 struct cmdentry entry; 1039 1040 if (n && n->type == NCMD && n->ncmd.args) 1041 if (goodname(n->ncmd.args->narg.text)) 1042 find_command(n->ncmd.args->narg.text, &entry, 0, 1043 pathval()); 1044 } 1045 1046 1047 1048 /* 1049 * Builtin commands. Builtin commands whose functions are closely 1050 * tied to evaluation are implemented here. 1051 */ 1052 1053 /* 1054 * No command given, a bltin command with no arguments, or a bltin command 1055 * with an invalid name. 1056 */ 1057 1058 int 1059 bltincmd(int argc, char **argv) 1060 { 1061 if (argc > 1) { 1062 out2fmt_flush("%s: not found\n", argv[1]); 1063 return 127; 1064 } 1065 /* 1066 * Preserve exitstatus of a previous possible redirection 1067 * as POSIX mandates 1068 */ 1069 return exitstatus; 1070 } 1071 1072 1073 /* 1074 * Handle break and continue commands. Break, continue, and return are 1075 * all handled by setting the evalskip flag. The evaluation routines 1076 * above all check this flag, and if it is set they start skipping 1077 * commands rather than executing them. The variable skipcount is 1078 * the number of loops to break/continue, or the number of function 1079 * levels to return. (The latter is always 1.) It should probably 1080 * be an error to break out of more loops than exist, but it isn't 1081 * in the standard shell so we don't make it one here. 1082 */ 1083 1084 int 1085 breakcmd(int argc, char **argv) 1086 { 1087 int n = argc > 1 ? number(argv[1]) : 1; 1088 1089 if (n > loopnest) 1090 n = loopnest; 1091 if (n > 0) { 1092 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1093 skipcount = n; 1094 } 1095 return 0; 1096 } 1097 1098 /* 1099 * The `command' command. 1100 */ 1101 int 1102 commandcmd(int argc, char **argv) 1103 { 1104 const char *path; 1105 int ch; 1106 int cmd = -1; 1107 1108 path = bltinlookup("PATH", 1); 1109 1110 optind = optreset = 1; 1111 opterr = 0; 1112 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1113 switch (ch) { 1114 case 'p': 1115 path = _PATH_STDPATH; 1116 break; 1117 case 'v': 1118 cmd = TYPECMD_SMALLV; 1119 break; 1120 case 'V': 1121 cmd = TYPECMD_BIGV; 1122 break; 1123 case '?': 1124 default: 1125 error("unknown option: -%c", optopt); 1126 } 1127 } 1128 argc -= optind; 1129 argv += optind; 1130 1131 if (cmd != -1) { 1132 if (argc != 1) 1133 error("wrong number of arguments"); 1134 return typecmd_impl(2, argv - 1, cmd, path); 1135 } 1136 if (argc != 0) 1137 error("commandcmd bad call"); 1138 1139 /* 1140 * Do nothing successfully if no command was specified; 1141 * ksh also does this. 1142 */ 1143 return 0; 1144 } 1145 1146 1147 /* 1148 * The return command. 1149 */ 1150 1151 int 1152 returncmd(int argc, char **argv) 1153 { 1154 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1155 1156 if (funcnest) { 1157 evalskip = SKIPFUNC; 1158 skipcount = 1; 1159 } else { 1160 /* skip the rest of the file */ 1161 evalskip = SKIPFILE; 1162 skipcount = 1; 1163 } 1164 return ret; 1165 } 1166 1167 1168 int 1169 falsecmd(int argc __unused, char **argv __unused) 1170 { 1171 return 1; 1172 } 1173 1174 1175 int 1176 truecmd(int argc __unused, char **argv __unused) 1177 { 1178 return 0; 1179 } 1180 1181 1182 int 1183 execcmd(int argc, char **argv) 1184 { 1185 /* 1186 * Because we have historically not supported any options, 1187 * only treat "--" specially. 1188 */ 1189 if (argc > 1 && strcmp(argv[1], "--") == 0) 1190 argc--, argv++; 1191 if (argc > 1) { 1192 struct strlist *sp; 1193 1194 iflag = 0; /* exit on error */ 1195 mflag = 0; 1196 optschanged(); 1197 for (sp = cmdenviron; sp ; sp = sp->next) 1198 setvareq(sp->text, VEXPORT|VSTACK); 1199 shellexec(argv + 1, environment(), pathval(), 0); 1200 1201 } 1202 return 0; 1203 } 1204 1205 1206 int 1207 timescmd(int argc __unused, char **argv __unused) 1208 { 1209 struct rusage ru; 1210 long shumins, shsmins, chumins, chsmins; 1211 double shusecs, shssecs, chusecs, chssecs; 1212 1213 if (getrusage(RUSAGE_SELF, &ru) < 0) 1214 return 1; 1215 shumins = ru.ru_utime.tv_sec / 60; 1216 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1217 shsmins = ru.ru_stime.tv_sec / 60; 1218 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1219 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1220 return 1; 1221 chumins = ru.ru_utime.tv_sec / 60; 1222 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1223 chsmins = ru.ru_stime.tv_sec / 60; 1224 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1225 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1226 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1227 return 0; 1228 } 1229