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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)eval.c 8.9 (Berkeley) 6/8/95 37 * $FreeBSD: src/bin/sh/eval.c,v 1.53 2006/06/15 07:57:05 stefanf Exp $ 38 * $DragonFly: src/bin/sh/eval.c,v 1.11 2007/01/14 17:29:58 pavalos Exp $ 39 */ 40 41 #include <sys/resource.h> 42 #include <sys/wait.h> /* For WIFSIGNALED(status) */ 43 44 #include <errno.h> 45 #include <paths.h> 46 #include <signal.h> 47 #include <stdlib.h> 48 #include <unistd.h> 49 50 /* 51 * Evaluate a command. 52 */ 53 54 #include "shell.h" 55 #include "nodes.h" 56 #include "syntax.h" 57 #include "expand.h" 58 #include "parser.h" 59 #include "jobs.h" 60 #include "eval.h" 61 #include "builtins.h" 62 #include "options.h" 63 #include "exec.h" 64 #include "redir.h" 65 #include "input.h" 66 #include "output.h" 67 #include "trap.h" 68 #include "var.h" 69 #include "memalloc.h" 70 #include "error.h" 71 #include "show.h" 72 #include "mystring.h" 73 #ifndef NO_HISTORY 74 #include "myhistedit.h" 75 #endif 76 77 78 /* flags in argument to evaltree */ 79 #define EV_EXIT 01 /* exit after evaluating tree */ 80 #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ 81 #define EV_BACKCMD 04 /* command executing within back quotes */ 82 83 int evalskip; /* set if we are skipping commands */ 84 STATIC int skipcount; /* number of levels to skip */ 85 MKINIT int loopnest; /* current loop nesting level */ 86 int funcnest; /* depth of function calls */ 87 88 89 const char *commandname; 90 struct strlist *cmdenviron; 91 int exitstatus; /* exit status of last command */ 92 int oexitstatus; /* saved exit status */ 93 94 95 STATIC void evalloop(union node *, int); 96 STATIC void evalfor(union node *, int); 97 STATIC void evalcase(union node *, int); 98 STATIC void evalsubshell(union node *, int); 99 STATIC void expredir(union node *); 100 STATIC void evalpipe(union node *); 101 STATIC void evalcommand(union node *, int, struct backcmd *); 102 STATIC void prehash(union node *); 103 104 105 /* 106 * Called to reset things after an exception. 107 */ 108 109 #ifdef mkinit 110 INCLUDE "eval.h" 111 112 RESET { 113 evalskip = 0; 114 loopnest = 0; 115 funcnest = 0; 116 } 117 118 SHELLPROC { 119 exitstatus = 0; 120 } 121 #endif 122 123 124 125 /* 126 * The eval command. 127 */ 128 129 int 130 evalcmd(int argc, char **argv) 131 { 132 char *p; 133 char *concat; 134 char **ap; 135 136 if (argc > 1) { 137 p = argv[1]; 138 if (argc > 2) { 139 STARTSTACKSTR(concat); 140 ap = argv + 2; 141 for (;;) { 142 while (*p) 143 STPUTC(*p++, concat); 144 if ((p = *ap++) == NULL) 145 break; 146 STPUTC(' ', concat); 147 } 148 STPUTC('\0', concat); 149 p = grabstackstr(concat); 150 } 151 evalstring(p); 152 } 153 return exitstatus; 154 } 155 156 157 /* 158 * Execute a command or commands contained in a string. 159 */ 160 161 void 162 evalstring(char *s) 163 { 164 union node *n; 165 struct stackmark smark; 166 167 setstackmark(&smark); 168 setinputstring(s, 1); 169 while ((n = parsecmd(0)) != NEOF) { 170 evaltree(n, 0); 171 popstackmark(&smark); 172 } 173 popfile(); 174 popstackmark(&smark); 175 } 176 177 178 179 /* 180 * Evaluate a parse tree. The value is left in the global variable 181 * exitstatus. 182 */ 183 184 void 185 evaltree(union node *n, int flags) 186 { 187 int do_etest; 188 189 do_etest = 0; 190 if (n == NULL) { 191 TRACE(("evaltree(NULL) called\n")); 192 exitstatus = 0; 193 goto out; 194 } 195 #ifndef NO_HISTORY 196 displayhist = 1; /* show history substitutions done with fc */ 197 #endif 198 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 199 switch (n->type) { 200 case NSEMI: 201 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 202 if (evalskip) 203 goto out; 204 evaltree(n->nbinary.ch2, flags); 205 break; 206 case NAND: 207 evaltree(n->nbinary.ch1, EV_TESTED); 208 if (evalskip || exitstatus != 0) { 209 goto out; 210 } 211 evaltree(n->nbinary.ch2, flags); 212 break; 213 case NOR: 214 evaltree(n->nbinary.ch1, EV_TESTED); 215 if (evalskip || exitstatus == 0) 216 goto out; 217 evaltree(n->nbinary.ch2, flags); 218 break; 219 case NREDIR: 220 expredir(n->nredir.redirect); 221 redirect(n->nredir.redirect, REDIR_PUSH); 222 evaltree(n->nredir.n, flags); 223 popredir(); 224 break; 225 case NSUBSHELL: 226 evalsubshell(n, flags); 227 do_etest = !(flags & EV_TESTED); 228 break; 229 case NBACKGND: 230 evalsubshell(n, flags); 231 break; 232 case NIF: { 233 evaltree(n->nif.test, EV_TESTED); 234 if (evalskip) 235 goto out; 236 if (exitstatus == 0) 237 evaltree(n->nif.ifpart, flags); 238 else if (n->nif.elsepart) 239 evaltree(n->nif.elsepart, flags); 240 else 241 exitstatus = 0; 242 break; 243 } 244 case NWHILE: 245 case NUNTIL: 246 evalloop(n, flags & ~EV_EXIT); 247 break; 248 case NFOR: 249 evalfor(n, flags & ~EV_EXIT); 250 break; 251 case NCASE: 252 evalcase(n, flags); 253 break; 254 case NDEFUN: 255 defun(n->narg.text, n->narg.next); 256 exitstatus = 0; 257 break; 258 case NNOT: 259 evaltree(n->nnot.com, EV_TESTED); 260 exitstatus = !exitstatus; 261 break; 262 263 case NPIPE: 264 evalpipe(n); 265 do_etest = !(flags & EV_TESTED); 266 break; 267 case NCMD: 268 evalcommand(n, flags, (struct backcmd *)NULL); 269 do_etest = !(flags & EV_TESTED); 270 break; 271 default: 272 out1fmt("Node type = %d\n", n->type); 273 flushout(&output); 274 break; 275 } 276 out: 277 if (pendingsigs) 278 dotrap(); 279 if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest)) 280 exitshell(exitstatus); 281 } 282 283 284 STATIC void 285 evalloop(union node *n, int flags) 286 { 287 int status; 288 289 loopnest++; 290 status = 0; 291 for (;;) { 292 evaltree(n->nbinary.ch1, EV_TESTED); 293 if (evalskip) { 294 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 295 evalskip = 0; 296 continue; 297 } 298 if (evalskip == SKIPBREAK && --skipcount <= 0) 299 evalskip = 0; 300 break; 301 } 302 if (n->type == NWHILE) { 303 if (exitstatus != 0) 304 break; 305 } else { 306 if (exitstatus == 0) 307 break; 308 } 309 evaltree(n->nbinary.ch2, flags); 310 status = exitstatus; 311 if (evalskip) 312 goto skipping; 313 } 314 loopnest--; 315 exitstatus = status; 316 } 317 318 319 320 STATIC void 321 evalfor(union node *n, int flags) 322 { 323 struct arglist arglist; 324 union node *argp; 325 struct strlist *sp; 326 struct stackmark smark; 327 328 setstackmark(&smark); 329 arglist.lastp = &arglist.list; 330 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 331 oexitstatus = exitstatus; 332 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 333 if (evalskip) 334 goto out; 335 } 336 *arglist.lastp = NULL; 337 338 exitstatus = 0; 339 loopnest++; 340 for (sp = arglist.list ; sp ; sp = sp->next) { 341 setvar(n->nfor.var, sp->text, 0); 342 evaltree(n->nfor.body, flags); 343 if (evalskip) { 344 if (evalskip == SKIPCONT && --skipcount <= 0) { 345 evalskip = 0; 346 continue; 347 } 348 if (evalskip == SKIPBREAK && --skipcount <= 0) 349 evalskip = 0; 350 break; 351 } 352 } 353 loopnest--; 354 out: 355 popstackmark(&smark); 356 } 357 358 359 360 STATIC void 361 evalcase(union node *n, int flags) 362 { 363 union node *cp; 364 union node *patp; 365 struct arglist arglist; 366 struct stackmark smark; 367 368 setstackmark(&smark); 369 arglist.lastp = &arglist.list; 370 oexitstatus = exitstatus; 371 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 372 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 373 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 374 if (casematch(patp, arglist.list->text)) { 375 if (evalskip == 0) { 376 evaltree(cp->nclist.body, flags); 377 } 378 goto out; 379 } 380 } 381 } 382 out: 383 popstackmark(&smark); 384 } 385 386 387 388 /* 389 * Kick off a subshell to evaluate a tree. 390 */ 391 392 STATIC void 393 evalsubshell(union node *n, int flags) 394 { 395 struct job *jp; 396 int backgnd = (n->type == NBACKGND); 397 398 expredir(n->nredir.redirect); 399 jp = makejob(n, 1); 400 if (forkshell(jp, n, backgnd) == 0) { 401 if (backgnd) 402 flags &=~ EV_TESTED; 403 redirect(n->nredir.redirect, 0); 404 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 405 } 406 if (! backgnd) { 407 INTOFF; 408 exitstatus = waitforjob(jp, (int *)NULL); 409 INTON; 410 } 411 } 412 413 414 415 /* 416 * Compute the names of the files in a redirection list. 417 */ 418 419 STATIC void 420 expredir(union node *n) 421 { 422 union node *redir; 423 424 for (redir = n ; redir ; redir = redir->nfile.next) { 425 struct arglist fn; 426 fn.lastp = &fn.list; 427 oexitstatus = exitstatus; 428 switch (redir->type) { 429 case NFROM: 430 case NTO: 431 case NFROMTO: 432 case NAPPEND: 433 case NCLOBBER: 434 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 435 redir->nfile.expfname = fn.list->text; 436 break; 437 case NFROMFD: 438 case NTOFD: 439 if (redir->ndup.vname) { 440 expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE); 441 fixredir(redir, fn.list->text, 1); 442 } 443 break; 444 } 445 } 446 } 447 448 449 450 /* 451 * Evaluate a pipeline. All the processes in the pipeline are children 452 * of the process creating the pipeline. (This differs from some versions 453 * of the shell, which make the last process in a pipeline the parent 454 * of all the rest.) 455 */ 456 457 STATIC void 458 evalpipe(union node *n) 459 { 460 struct job *jp; 461 struct nodelist *lp; 462 int pipelen; 463 int prevfd; 464 int pip[2]; 465 466 TRACE(("evalpipe(%p) called\n", (void *)n)); 467 pipelen = 0; 468 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 469 pipelen++; 470 INTOFF; 471 jp = makejob(n, pipelen); 472 prevfd = -1; 473 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 474 prehash(lp->n); 475 pip[1] = -1; 476 if (lp->next) { 477 if (pipe(pip) < 0) { 478 if (prevfd >= 0) 479 close(prevfd); 480 error("Pipe call failed: %s", strerror(errno)); 481 } 482 } 483 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 484 INTON; 485 if (prevfd > 0) { 486 dup2(prevfd, 0); 487 close(prevfd); 488 } 489 if (pip[1] >= 0) { 490 if (!(prevfd >= 0 && pip[0] == 0)) 491 close(pip[0]); 492 if (pip[1] != 1) { 493 dup2(pip[1], 1); 494 close(pip[1]); 495 } 496 } 497 evaltree(lp->n, EV_EXIT); 498 } 499 if (prevfd >= 0) 500 close(prevfd); 501 prevfd = pip[0]; 502 close(pip[1]); 503 } 504 INTON; 505 if (n->npipe.backgnd == 0) { 506 INTOFF; 507 exitstatus = waitforjob(jp, (int *)NULL); 508 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 509 INTON; 510 } 511 } 512 513 514 515 /* 516 * Execute a command inside back quotes. If it's a builtin command, we 517 * want to save its output in a block obtained from malloc. Otherwise 518 * we fork off a subprocess and get the output of the command via a pipe. 519 * Should be called with interrupts off. 520 */ 521 522 void 523 evalbackcmd(union node *n, struct backcmd *result) 524 { 525 int pip[2]; 526 struct job *jp; 527 struct stackmark smark; /* unnecessary */ 528 529 setstackmark(&smark); 530 result->fd = -1; 531 result->buf = NULL; 532 result->nleft = 0; 533 result->jp = NULL; 534 if (n == NULL) { 535 exitstatus = 0; 536 goto out; 537 } 538 if (n->type == NCMD) { 539 exitstatus = oexitstatus; 540 evalcommand(n, EV_BACKCMD, result); 541 } else { 542 exitstatus = 0; 543 if (pipe(pip) < 0) 544 error("Pipe call failed: %s", strerror(errno)); 545 jp = makejob(n, 1); 546 if (forkshell(jp, n, FORK_NOJOB) == 0) { 547 FORCEINTON; 548 close(pip[0]); 549 if (pip[1] != 1) { 550 dup2(pip[1], 1); 551 close(pip[1]); 552 } 553 evaltree(n, EV_EXIT); 554 } 555 close(pip[1]); 556 result->fd = pip[0]; 557 result->jp = jp; 558 } 559 out: 560 popstackmark(&smark); 561 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 562 result->fd, result->buf, result->nleft, result->jp)); 563 } 564 565 566 567 /* 568 * Execute a simple command. 569 */ 570 571 STATIC void 572 evalcommand(union node *cmd, int flgs, struct backcmd *backcmd) 573 { 574 struct stackmark smark; 575 union node *argp; 576 struct arglist arglist; 577 struct arglist varlist; 578 volatile int flags = flgs; 579 char **volatile argv; 580 volatile int argc; 581 char **envp; 582 int varflag; 583 struct strlist *sp; 584 int mode; 585 int pip[2]; 586 struct cmdentry cmdentry; 587 struct job *jp; 588 struct jmploc jmploc; 589 struct jmploc *volatile savehandler = NULL; 590 const char *volatile savecmdname; 591 volatile struct shparam saveparam; 592 struct localvar *volatile savelocalvars; 593 volatile int e; 594 char *volatile lastarg; 595 int realstatus; 596 volatile int do_clearcmdentry; 597 598 /* First expand the arguments. */ 599 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 600 setstackmark(&smark); 601 arglist.lastp = &arglist.list; 602 varlist.lastp = &varlist.list; 603 varflag = 1; 604 do_clearcmdentry = 0; 605 oexitstatus = exitstatus; 606 exitstatus = 0; 607 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 608 char *p = argp->narg.text; 609 if (varflag && is_name(*p)) { 610 do { 611 p++; 612 } while (is_in_name(*p)); 613 if (*p == '=') { 614 expandarg(argp, &varlist, EXP_VARTILDE); 615 continue; 616 } 617 } 618 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 619 varflag = 0; 620 } 621 *arglist.lastp = NULL; 622 *varlist.lastp = NULL; 623 expredir(cmd->ncmd.redirect); 624 argc = 0; 625 for (sp = arglist.list ; sp ; sp = sp->next) 626 argc++; 627 argv = stalloc(sizeof (char *) * (argc + 1)); 628 629 for (sp = arglist.list ; sp ; sp = sp->next) { 630 TRACE(("evalcommand arg: %s\n", sp->text)); 631 *argv++ = sp->text; 632 } 633 *argv = NULL; 634 lastarg = NULL; 635 if (iflag && funcnest == 0 && argc > 0) 636 lastarg = argv[-1]; 637 argv -= argc; 638 639 /* Print the command if xflag is set. */ 640 if (xflag) { 641 char sep = 0; 642 out2str(ps4val()); 643 for (sp = varlist.list ; sp ; sp = sp->next) { 644 if (sep != 0) 645 outc(' ', &errout); 646 out2str(sp->text); 647 sep = ' '; 648 } 649 for (sp = arglist.list ; sp ; sp = sp->next) { 650 if (sep != 0) 651 outc(' ', &errout); 652 out2str(sp->text); 653 sep = ' '; 654 } 655 outc('\n', &errout); 656 flushout(&errout); 657 } 658 659 /* Now locate the command. */ 660 if (argc == 0) { 661 /* Variable assignment(s) without command */ 662 cmdentry.cmdtype = CMDBUILTIN; 663 cmdentry.u.index = BLTINCMD; 664 cmdentry.special = 1; 665 } else { 666 static const char PATH[] = "PATH="; 667 const char *path = pathval(); 668 669 /* 670 * Modify the command lookup path, if a PATH= assignment 671 * is present 672 */ 673 for (sp = varlist.list ; sp ; sp = sp->next) 674 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 675 path = sp->text + sizeof(PATH) - 1; 676 /* 677 * On `PATH=... command`, we need to make 678 * sure that the command isn't using the 679 * non-updated hash table of the outer PATH 680 * setting and we need to make sure that 681 * the hash table isn't filled with items 682 * from the temporary setting. 683 * 684 * It would be better to forbit using and 685 * updating the table while this command 686 * runs, by the command finding mechanism 687 * is heavily integrated with hash handling, 688 * so we just delete the hash before and after 689 * the command runs. Partly deleting like 690 * changepatch() does doesn't seem worth the 691 * bookinging effort, since most such runs add 692 * directories in front of the new PATH. 693 */ 694 clearcmdentry(0); 695 do_clearcmdentry = 1; 696 } 697 698 find_command(argv[0], &cmdentry, 1, path); 699 if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ 700 exitstatus = 127; 701 flushout(&errout); 702 return; 703 } 704 /* implement the bltin builtin here */ 705 if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { 706 for (;;) { 707 argv++; 708 if (--argc == 0) 709 break; 710 if ((cmdentry.u.index = find_builtin(*argv, 711 &cmdentry.special)) < 0) { 712 outfmt(&errout, "%s: not found\n", *argv); 713 exitstatus = 127; 714 flushout(&errout); 715 return; 716 } 717 if (cmdentry.u.index != BLTINCMD) 718 break; 719 } 720 } 721 } 722 723 /* Fork off a child process if necessary. */ 724 if (cmd->ncmd.backgnd 725 || (cmdentry.cmdtype == CMDNORMAL 726 && ((flags & EV_EXIT) == 0 || Tflag)) 727 || ((flags & EV_BACKCMD) != 0 728 && (cmdentry.cmdtype != CMDBUILTIN 729 || cmdentry.u.index == CDCMD 730 || cmdentry.u.index == DOTCMD 731 || cmdentry.u.index == EVALCMD)) 732 || (cmdentry.cmdtype == CMDBUILTIN && 733 cmdentry.u.index == COMMANDCMD)) { 734 jp = makejob(cmd, 1); 735 mode = cmd->ncmd.backgnd; 736 if (flags & EV_BACKCMD) { 737 mode = FORK_NOJOB; 738 if (pipe(pip) < 0) 739 error("Pipe call failed: %s", strerror(errno)); 740 } 741 if (forkshell(jp, cmd, mode) != 0) 742 goto parent; /* at end of routine */ 743 if (flags & EV_BACKCMD) { 744 FORCEINTON; 745 close(pip[0]); 746 if (pip[1] != 1) { 747 dup2(pip[1], 1); 748 close(pip[1]); 749 } 750 } 751 flags |= EV_EXIT; 752 } 753 754 /* This is the child process if a fork occurred. */ 755 /* Execute the command. */ 756 if (cmdentry.cmdtype == CMDFUNCTION) { 757 #ifdef DEBUG 758 trputs("Shell function: "); trargs(argv); 759 #endif 760 redirect(cmd->ncmd.redirect, REDIR_PUSH); 761 saveparam = shellparam; 762 shellparam.malloc = 0; 763 shellparam.reset = 1; 764 shellparam.nparam = argc - 1; 765 shellparam.p = argv + 1; 766 shellparam.optnext = NULL; 767 INTOFF; 768 savelocalvars = localvars; 769 localvars = NULL; 770 INTON; 771 if (setjmp(jmploc.loc)) { 772 if (exception == EXSHELLPROC) 773 freeparam(&saveparam); 774 else { 775 freeparam(&shellparam); 776 shellparam = saveparam; 777 } 778 poplocalvars(); 779 localvars = savelocalvars; 780 handler = savehandler; 781 longjmp(handler->loc, 1); 782 } 783 savehandler = handler; 784 handler = &jmploc; 785 for (sp = varlist.list ; sp ; sp = sp->next) 786 mklocal(sp->text); 787 funcnest++; 788 if (flags & EV_TESTED) 789 evaltree(cmdentry.u.func, EV_TESTED); 790 else 791 evaltree(cmdentry.u.func, 0); 792 funcnest--; 793 INTOFF; 794 poplocalvars(); 795 localvars = savelocalvars; 796 freeparam(&shellparam); 797 shellparam = saveparam; 798 handler = savehandler; 799 popredir(); 800 INTON; 801 if (evalskip == SKIPFUNC) { 802 evalskip = 0; 803 skipcount = 0; 804 } 805 if (flags & EV_EXIT) 806 exitshell(exitstatus); 807 } else if (cmdentry.cmdtype == CMDBUILTIN) { 808 #ifdef DEBUG 809 trputs("builtin command: "); trargs(argv); 810 #endif 811 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 812 if (flags == EV_BACKCMD) { 813 memout.nleft = 0; 814 memout.nextc = memout.buf; 815 memout.bufsize = 64; 816 mode |= REDIR_BACKQ; 817 } 818 savecmdname = commandname; 819 cmdenviron = varlist.list; 820 e = -1; 821 if (setjmp(jmploc.loc)) { 822 e = exception; 823 exitstatus = (e == EXINT)? SIGINT+128 : 2; 824 goto cmddone; 825 } 826 savehandler = handler; 827 handler = &jmploc; 828 redirect(cmd->ncmd.redirect, mode); 829 if (cmdentry.special) 830 listsetvar(cmdenviron); 831 commandname = argv[0]; 832 argptr = argv + 1; 833 optptr = NULL; /* initialize nextopt */ 834 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 835 flushall(); 836 cmddone: 837 cmdenviron = NULL; 838 out1 = &output; 839 out2 = &errout; 840 freestdout(); 841 if (e != EXSHELLPROC) { 842 commandname = savecmdname; 843 if (flags & EV_EXIT) { 844 exitshell(exitstatus); 845 } 846 } 847 handler = savehandler; 848 if (e != -1) { 849 if ((e != EXERROR && e != EXEXEC) 850 || cmdentry.special) 851 exraise(e); 852 FORCEINTON; 853 } 854 if (cmdentry.u.index != EXECCMD) 855 popredir(); 856 if (flags == EV_BACKCMD) { 857 backcmd->buf = memout.buf; 858 backcmd->nleft = memout.nextc - memout.buf; 859 memout.buf = NULL; 860 } 861 } else { 862 #ifdef DEBUG 863 trputs("normal command: "); trargs(argv); 864 #endif 865 clearredir(); 866 redirect(cmd->ncmd.redirect, 0); 867 for (sp = varlist.list ; sp ; sp = sp->next) 868 setvareq(sp->text, VEXPORT|VSTACK); 869 envp = environment(); 870 shellexec(argv, envp, pathval(), cmdentry.u.index); 871 /*NOTREACHED*/ 872 } 873 goto out; 874 875 parent: /* parent process gets here (if we forked) */ 876 if (mode == 0) { /* argument to fork */ 877 INTOFF; 878 exitstatus = waitforjob(jp, &realstatus); 879 INTON; 880 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 881 evalskip = SKIPBREAK; 882 skipcount = loopnest; 883 } 884 } else if (mode == 2) { 885 backcmd->fd = pip[0]; 886 close(pip[1]); 887 backcmd->jp = jp; 888 } 889 890 out: 891 if (lastarg) 892 setvar("_", lastarg, 0); 893 if (do_clearcmdentry) 894 clearcmdentry(0); 895 popstackmark(&smark); 896 } 897 898 899 900 /* 901 * Search for a command. This is called before we fork so that the 902 * location of the command will be available in the parent as well as 903 * the child. The check for "goodname" is an overly conservative 904 * check that the name will not be subject to expansion. 905 */ 906 907 STATIC void 908 prehash(union node *n) 909 { 910 struct cmdentry entry; 911 912 if (n && n->type == NCMD && n->ncmd.args) 913 if (goodname(n->ncmd.args->narg.text)) 914 find_command(n->ncmd.args->narg.text, &entry, 0, 915 pathval()); 916 } 917 918 919 920 /* 921 * Builtin commands. Builtin commands whose functions are closely 922 * tied to evaluation are implemented here. 923 */ 924 925 /* 926 * No command given, or a bltin command with no arguments. 927 */ 928 929 int 930 bltincmd(int argc __unused, char **argv __unused) 931 { 932 /* 933 * Preserve exitstatus of a previous possible redirection 934 * as POSIX mandates 935 */ 936 return exitstatus; 937 } 938 939 940 /* 941 * Handle break and continue commands. Break, continue, and return are 942 * all handled by setting the evalskip flag. The evaluation routines 943 * above all check this flag, and if it is set they start skipping 944 * commands rather than executing them. The variable skipcount is 945 * the number of loops to break/continue, or the number of function 946 * levels to return. (The latter is always 1.) It should probably 947 * be an error to break out of more loops than exist, but it isn't 948 * in the standard shell so we don't make it one here. 949 */ 950 951 int 952 breakcmd(int argc, char **argv) 953 { 954 int n = argc > 1 ? number(argv[1]) : 1; 955 956 if (n > loopnest) 957 n = loopnest; 958 if (n > 0) { 959 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 960 skipcount = n; 961 } 962 return 0; 963 } 964 965 /* 966 * The `command' command. 967 */ 968 int 969 commandcmd(int argc, char **argv) 970 { 971 static char stdpath[] = _PATH_STDPATH; 972 struct jmploc loc, *old; 973 struct strlist *sp; 974 const char *volatile path; 975 int ch; 976 int cmd = -1; 977 978 for (sp = cmdenviron; sp ; sp = sp->next) 979 setvareq(sp->text, VEXPORT|VSTACK); 980 path = pathval(); 981 982 optind = optreset = 1; 983 opterr = 0; 984 while ((ch = getopt(argc, argv, "pvV")) != -1) { 985 switch (ch) { 986 case 'p': 987 path = stdpath; 988 break; 989 case 'v': 990 cmd = TYPECMD_SMALLV; 991 break; 992 case 'V': 993 cmd = TYPECMD_BIGV; 994 break; 995 case '?': 996 default: 997 error("unknown option: -%c", optopt); 998 } 999 } 1000 argc -= optind; 1001 argv += optind; 1002 1003 if (cmd != -1) { 1004 if (argc != 1) 1005 error("wrong number of arguments"); 1006 return typecmd_impl(2, argv - 1, cmd); 1007 } 1008 if (argc != 0) { 1009 old = handler; 1010 handler = &loc; 1011 if (setjmp(handler->loc) == 0) 1012 shellexec(argv, environment(), path, 0); 1013 handler = old; 1014 if (exception == EXEXEC) 1015 exit(exerrno); 1016 exraise(exception); 1017 } 1018 1019 /* 1020 * Do nothing successfully if no command was specified; 1021 * ksh also does this. 1022 */ 1023 exit(0); 1024 } 1025 1026 1027 /* 1028 * The return command. 1029 */ 1030 1031 int 1032 returncmd(int argc, char **argv) 1033 { 1034 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1035 1036 if (funcnest) { 1037 evalskip = SKIPFUNC; 1038 skipcount = 1; 1039 } else { 1040 /* skip the rest of the file */ 1041 evalskip = SKIPFILE; 1042 skipcount = 1; 1043 } 1044 return ret; 1045 } 1046 1047 1048 int 1049 falsecmd(int argc __unused, char **argv __unused) 1050 { 1051 return 1; 1052 } 1053 1054 1055 int 1056 truecmd(int argc __unused, char **argv __unused) 1057 { 1058 return 0; 1059 } 1060 1061 1062 int 1063 execcmd(int argc, char **argv) 1064 { 1065 if (argc > 1) { 1066 struct strlist *sp; 1067 1068 iflag = 0; /* exit on error */ 1069 mflag = 0; 1070 optschanged(); 1071 for (sp = cmdenviron; sp ; sp = sp->next) 1072 setvareq(sp->text, VEXPORT|VSTACK); 1073 shellexec(argv + 1, environment(), pathval(), 0); 1074 1075 } 1076 return 0; 1077 } 1078 1079 1080 int 1081 timescmd(int argc __unused, char **argv __unused) 1082 { 1083 struct rusage ru; 1084 long shumins, shsmins, chumins, chsmins; 1085 double shusecs, shssecs, chusecs, chssecs; 1086 1087 if (getrusage(RUSAGE_SELF, &ru) < 0) 1088 return 1; 1089 shumins = ru.ru_utime.tv_sec / 60; 1090 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1091 shsmins = ru.ru_stime.tv_sec / 60; 1092 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1093 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1094 return 1; 1095 chumins = ru.ru_utime.tv_sec / 60; 1096 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1097 chsmins = ru.ru_stime.tv_sec / 60; 1098 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1099 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1100 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1101 return 0; 1102 } 1103