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 expredir(union node *); 95 STATIC void evalpipe(union node *); 96 STATIC void evalcommand(union node *, int, struct backcmd *); 97 STATIC void prehash(union node *); 98 99 100 /* 101 * Called to reset things after an exception. 102 */ 103 104 #ifdef mkinit 105 INCLUDE "eval.h" 106 107 RESET { 108 evalskip = 0; 109 loopnest = 0; 110 funcnest = 0; 111 } 112 113 SHELLPROC { 114 exitstatus = 0; 115 } 116 #endif 117 118 119 120 /* 121 * The eval command. 122 */ 123 124 int 125 evalcmd(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 */ 155 156 void 157 evalstring(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 */ 187 188 void 189 evaltree(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 } 280 out: 281 if (pendingsigs) 282 dotrap(); 283 if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest)) 284 exitshell(exitstatus); 285 } 286 287 288 STATIC void 289 evalloop(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) { 298 skipping: 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 } 321 322 323 324 STATIC void 325 evalfor(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--; 358 out: 359 popstackmark(&smark); 360 } 361 362 363 364 STATIC void 365 evalcase(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 } 387 out: 388 popstackmark(&smark); 389 } 390 391 392 393 /* 394 * Kick off a subshell to evaluate a tree. 395 */ 396 397 STATIC void 398 evalsubshell(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 } else if (! backgnd) { 411 INTOFF; 412 exitstatus = waitforjob(jp, (int *)NULL); 413 INTON; 414 } 415 } 416 417 418 419 /* 420 * Compute the names of the files in a redirection list. 421 */ 422 423 STATIC void 424 expredir(union node *n) 425 { 426 union node *redir; 427 428 for (redir = n ; redir ; redir = redir->nfile.next) { 429 struct arglist fn; 430 fn.lastp = &fn.list; 431 oexitstatus = exitstatus; 432 switch (redir->type) { 433 case NFROM: 434 case NTO: 435 case NFROMTO: 436 case NAPPEND: 437 case NCLOBBER: 438 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 439 redir->nfile.expfname = fn.list->text; 440 break; 441 case NFROMFD: 442 case NTOFD: 443 if (redir->ndup.vname) { 444 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 445 fixredir(redir, fn.list->text, 1); 446 } 447 break; 448 } 449 } 450 } 451 452 453 454 /* 455 * Evaluate a pipeline. All the processes in the pipeline are children 456 * of the process creating the pipeline. (This differs from some versions 457 * of the shell, which make the last process in a pipeline the parent 458 * of all the rest.) 459 */ 460 461 STATIC void 462 evalpipe(union node *n) 463 { 464 struct job *jp; 465 struct nodelist *lp; 466 int pipelen; 467 int prevfd; 468 int pip[2]; 469 470 TRACE(("evalpipe(%p) called\n", (void *)n)); 471 pipelen = 0; 472 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 473 pipelen++; 474 INTOFF; 475 jp = makejob(n, pipelen); 476 prevfd = -1; 477 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 478 prehash(lp->n); 479 pip[1] = -1; 480 if (lp->next) { 481 if (pipe(pip) < 0) { 482 close(prevfd); 483 error("Pipe call failed: %s", strerror(errno)); 484 } 485 } 486 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 487 INTON; 488 if (prevfd > 0) { 489 dup2(prevfd, 0); 490 close(prevfd); 491 } 492 if (pip[1] >= 0) { 493 if (!(prevfd >= 0 && pip[0] == 0)) 494 close(pip[0]); 495 if (pip[1] != 1) { 496 dup2(pip[1], 1); 497 close(pip[1]); 498 } 499 } 500 evaltree(lp->n, EV_EXIT); 501 } 502 if (prevfd >= 0) 503 close(prevfd); 504 prevfd = pip[0]; 505 close(pip[1]); 506 } 507 INTON; 508 if (n->npipe.backgnd == 0) { 509 INTOFF; 510 exitstatus = waitforjob(jp, (int *)NULL); 511 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 512 INTON; 513 } 514 } 515 516 517 518 /* 519 * Execute a command inside back quotes. If it's a builtin command, we 520 * want to save its output in a block obtained from malloc. Otherwise 521 * we fork off a subprocess and get the output of the command via a pipe. 522 * Should be called with interrupts off. 523 */ 524 525 void 526 evalbackcmd(union node *n, struct backcmd *result) 527 { 528 int pip[2]; 529 struct job *jp; 530 struct stackmark smark; /* unnecessary */ 531 532 setstackmark(&smark); 533 result->fd = -1; 534 result->buf = NULL; 535 result->nleft = 0; 536 result->jp = NULL; 537 if (n == NULL) { 538 exitstatus = 0; 539 goto out; 540 } 541 if (n->type == NCMD) { 542 exitstatus = oexitstatus; 543 evalcommand(n, EV_BACKCMD, result); 544 } else { 545 exitstatus = 0; 546 if (pipe(pip) < 0) 547 error("Pipe call failed: %s", strerror(errno)); 548 jp = makejob(n, 1); 549 if (forkshell(jp, n, FORK_NOJOB) == 0) { 550 FORCEINTON; 551 close(pip[0]); 552 if (pip[1] != 1) { 553 dup2(pip[1], 1); 554 close(pip[1]); 555 } 556 evaltree(n, EV_EXIT); 557 } 558 close(pip[1]); 559 result->fd = pip[0]; 560 result->jp = jp; 561 } 562 out: 563 popstackmark(&smark); 564 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 565 result->fd, result->buf, result->nleft, result->jp)); 566 } 567 568 569 570 /* 571 * Execute a simple command. 572 */ 573 574 STATIC void 575 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 576 { 577 struct stackmark smark; 578 union node *argp; 579 struct arglist arglist; 580 struct arglist varlist; 581 char **argv; 582 int argc; 583 char **envp; 584 int varflag; 585 struct strlist *sp; 586 int mode; 587 int pip[2]; 588 struct cmdentry cmdentry; 589 struct job *jp; 590 struct jmploc jmploc; 591 struct jmploc *savehandler; 592 char *savecmdname; 593 struct shparam saveparam; 594 struct localvar *savelocalvars; 595 struct parsefile *savetopfile; 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 savehandler = handler; 785 if (setjmp(jmploc.loc)) { 786 if (exception == EXSHELLPROC) 787 freeparam(&saveparam); 788 else { 789 freeparam(&shellparam); 790 shellparam = saveparam; 791 } 792 unreffunc(cmdentry.u.func); 793 poplocalvars(); 794 localvars = savelocalvars; 795 handler = savehandler; 796 longjmp(handler->loc, 1); 797 } 798 handler = &jmploc; 799 INTON; 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 savetopfile = getcurrentfile(); 837 cmdenviron = varlist.list; 838 e = -1; 839 savehandler = handler; 840 if (setjmp(jmploc.loc)) { 841 e = exception; 842 exitstatus = (e == EXINT)? SIGINT+128 : 2; 843 goto cmddone; 844 } 845 handler = &jmploc; 846 redirect(cmd->ncmd.redirect, mode); 847 if (cmdentry.special) 848 listsetvar(cmdenviron); 849 commandname = argv[0]; 850 argptr = argv + 1; 851 nextopt_optptr = NULL; /* initialize nextopt */ 852 builtin_flags = flags; 853 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 854 flushall(); 855 cmddone: 856 cmdenviron = NULL; 857 out1 = &output; 858 out2 = &errout; 859 freestdout(); 860 if (e != EXSHELLPROC) { 861 commandname = savecmdname; 862 if (flags & EV_EXIT) { 863 exitshell(exitstatus); 864 } 865 } 866 handler = savehandler; 867 if (e != -1) { 868 if ((e != EXERROR && e != EXEXEC) 869 || cmdentry.special) 870 exraise(e); 871 popfilesupto(savetopfile); 872 FORCEINTON; 873 } 874 if (cmdentry.u.index != EXECCMD) 875 popredir(); 876 if (flags == EV_BACKCMD) { 877 backcmd->buf = memout.buf; 878 backcmd->nleft = memout.nextc - memout.buf; 879 memout.buf = NULL; 880 } 881 } else { 882 #ifdef DEBUG 883 trputs("normal command: "); trargs(argv); 884 #endif 885 redirect(cmd->ncmd.redirect, 0); 886 for (sp = varlist.list ; sp ; sp = sp->next) 887 setvareq(sp->text, VEXPORT|VSTACK); 888 envp = environment(); 889 shellexec(argv, envp, pathval(), cmdentry.u.index); 890 /*NOTREACHED*/ 891 } 892 goto out; 893 894 parent: /* parent process gets here (if we forked) */ 895 if (mode == 0) { /* argument to fork */ 896 INTOFF; 897 exitstatus = waitforjob(jp, &realstatus); 898 INTON; 899 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 900 evalskip = SKIPBREAK; 901 skipcount = loopnest; 902 } 903 } else if (mode == 2) { 904 backcmd->fd = pip[0]; 905 close(pip[1]); 906 backcmd->jp = jp; 907 } 908 909 out: 910 if (lastarg) 911 setvar("_", lastarg, 0); 912 if (do_clearcmdentry) 913 clearcmdentry(0); 914 popstackmark(&smark); 915 } 916 917 918 919 /* 920 * Search for a command. This is called before we fork so that the 921 * location of the command will be available in the parent as well as 922 * the child. The check for "goodname" is an overly conservative 923 * check that the name will not be subject to expansion. 924 */ 925 926 STATIC void 927 prehash(union node *n) 928 { 929 struct cmdentry entry; 930 931 if (n && n->type == NCMD && n->ncmd.args) 932 if (goodname(n->ncmd.args->narg.text)) 933 find_command(n->ncmd.args->narg.text, &entry, 0, 934 pathval()); 935 } 936 937 938 939 /* 940 * Builtin commands. Builtin commands whose functions are closely 941 * tied to evaluation are implemented here. 942 */ 943 944 /* 945 * No command given, or a bltin command with no arguments. 946 */ 947 948 int 949 bltincmd(int argc __unused, char **argv __unused) 950 { 951 /* 952 * Preserve exitstatus of a previous possible redirection 953 * as POSIX mandates 954 */ 955 return exitstatus; 956 } 957 958 959 /* 960 * Handle break and continue commands. Break, continue, and return are 961 * all handled by setting the evalskip flag. The evaluation routines 962 * above all check this flag, and if it is set they start skipping 963 * commands rather than executing them. The variable skipcount is 964 * the number of loops to break/continue, or the number of function 965 * levels to return. (The latter is always 1.) It should probably 966 * be an error to break out of more loops than exist, but it isn't 967 * in the standard shell so we don't make it one here. 968 */ 969 970 int 971 breakcmd(int argc, char **argv) 972 { 973 int n = argc > 1 ? number(argv[1]) : 1; 974 975 if (n > loopnest) 976 n = loopnest; 977 if (n > 0) { 978 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 979 skipcount = n; 980 } 981 return 0; 982 } 983 984 /* 985 * The `command' command. 986 */ 987 int 988 commandcmd(int argc, char **argv) 989 { 990 static char stdpath[] = _PATH_STDPATH; 991 struct jmploc loc, *old; 992 struct strlist *sp; 993 char *path; 994 int ch; 995 int cmd = -1; 996 997 for (sp = cmdenviron; sp ; sp = sp->next) 998 setvareq(sp->text, VEXPORT|VSTACK); 999 path = pathval(); 1000 1001 optind = optreset = 1; 1002 opterr = 0; 1003 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1004 switch (ch) { 1005 case 'p': 1006 path = stdpath; 1007 break; 1008 case 'v': 1009 cmd = TYPECMD_SMALLV; 1010 break; 1011 case 'V': 1012 cmd = TYPECMD_BIGV; 1013 break; 1014 case '?': 1015 default: 1016 error("unknown option: -%c", optopt); 1017 } 1018 } 1019 argc -= optind; 1020 argv += optind; 1021 1022 if (cmd != -1) { 1023 if (argc != 1) 1024 error("wrong number of arguments"); 1025 return typecmd_impl(2, argv - 1, cmd); 1026 } 1027 if (argc != 0) { 1028 old = handler; 1029 handler = &loc; 1030 if (setjmp(handler->loc) == 0) 1031 shellexec(argv, environment(), path, 0); 1032 handler = old; 1033 if (exception == EXEXEC) 1034 exit(exerrno); 1035 exraise(exception); 1036 } 1037 1038 /* 1039 * Do nothing successfully if no command was specified; 1040 * ksh also does this. 1041 */ 1042 exit(0); 1043 } 1044 1045 1046 /* 1047 * The return command. 1048 */ 1049 1050 int 1051 returncmd(int argc, char **argv) 1052 { 1053 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1054 1055 if (funcnest) { 1056 evalskip = SKIPFUNC; 1057 skipcount = 1; 1058 } else { 1059 /* skip the rest of the file */ 1060 evalskip = SKIPFILE; 1061 skipcount = 1; 1062 } 1063 return ret; 1064 } 1065 1066 1067 int 1068 falsecmd(int argc __unused, char **argv __unused) 1069 { 1070 return 1; 1071 } 1072 1073 1074 int 1075 truecmd(int argc __unused, char **argv __unused) 1076 { 1077 return 0; 1078 } 1079 1080 1081 int 1082 execcmd(int argc, char **argv) 1083 { 1084 if (argc > 1) { 1085 struct strlist *sp; 1086 1087 iflag = 0; /* exit on error */ 1088 mflag = 0; 1089 optschanged(); 1090 for (sp = cmdenviron; sp ; sp = sp->next) 1091 setvareq(sp->text, VEXPORT|VSTACK); 1092 shellexec(argv + 1, environment(), pathval(), 0); 1093 1094 } 1095 return 0; 1096 } 1097 1098 1099 int 1100 timescmd(int argc __unused, char **argv __unused) 1101 { 1102 struct rusage ru; 1103 long shumins, shsmins, chumins, chsmins; 1104 double shusecs, shssecs, chusecs, chssecs; 1105 1106 if (getrusage(RUSAGE_SELF, &ru) < 0) 1107 return 1; 1108 shumins = ru.ru_utime.tv_sec / 60; 1109 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1110 shsmins = ru.ru_stime.tv_sec / 60; 1111 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1112 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1113 return 1; 1114 chumins = ru.ru_utime.tv_sec / 60; 1115 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1116 chsmins = ru.ru_stime.tv_sec / 60; 1117 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1118 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1119 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1120 return 0; 1121 } 1122