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 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 union node *evalcase(union node *); 93 static void evalsubshell(union node *, int); 94 static void evalredir(union node *, int); 95 static void exphere(union node *, struct arglist *); 96 static void expredir(union node *); 97 static void evalpipe(union node *); 98 static int is_valid_fast_cmdsubst(union node *n); 99 static void evalcommand(union node *, int, struct backcmd *); 100 static void prehash(union node *); 101 102 103 /* 104 * Called to reset things after an exception. 105 */ 106 107 #ifdef mkinit 108 INCLUDE "eval.h" 109 110 RESET { 111 evalskip = 0; 112 loopnest = 0; 113 funcnest = 0; 114 } 115 #endif 116 117 118 119 /* 120 * The eval command. 121 */ 122 123 int 124 evalcmd(int argc, char **argv) 125 { 126 char *p; 127 char *concat; 128 char **ap; 129 130 if (argc > 1) { 131 p = argv[1]; 132 if (argc > 2) { 133 STARTSTACKSTR(concat); 134 ap = argv + 2; 135 for (;;) { 136 STPUTS(p, concat); 137 if ((p = *ap++) == NULL) 138 break; 139 STPUTC(' ', concat); 140 } 141 STPUTC('\0', concat); 142 p = grabstackstr(concat); 143 } 144 evalstring(p, builtin_flags); 145 } else 146 exitstatus = 0; 147 return exitstatus; 148 } 149 150 151 /* 152 * Execute a command or commands contained in a string. 153 */ 154 155 void 156 evalstring(char *s, int flags) 157 { 158 union node *n; 159 struct stackmark smark; 160 int flags_exit; 161 int any; 162 163 flags_exit = flags & EV_EXIT; 164 flags &= ~EV_EXIT; 165 any = 0; 166 setstackmark(&smark); 167 setinputstring(s, 1); 168 while ((n = parsecmd(0)) != NEOF) { 169 if (n != NULL && !nflag) { 170 if (flags_exit && preadateof()) 171 evaltree(n, flags | EV_EXIT); 172 else 173 evaltree(n, flags); 174 any = 1; 175 } 176 popstackmark(&smark); 177 setstackmark(&smark); 178 } 179 popfile(); 180 popstackmark(&smark); 181 if (!any) 182 exitstatus = 0; 183 if (flags_exit) 184 exraise(EXEXIT); 185 } 186 187 188 /* 189 * Evaluate a parse tree. The value is left in the global variable 190 * exitstatus. 191 */ 192 193 void 194 evaltree(union node *n, int flags) 195 { 196 int do_etest; 197 union node *next; 198 struct stackmark smark; 199 200 setstackmark(&smark); 201 do_etest = 0; 202 if (n == NULL) { 203 TRACE(("evaltree(NULL) called\n")); 204 exitstatus = 0; 205 goto out; 206 } 207 do { 208 next = NULL; 209 #ifndef NO_HISTORY 210 displayhist = 1; /* show history substitutions done with fc */ 211 #endif 212 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 213 switch (n->type) { 214 case NSEMI: 215 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 216 if (evalskip) 217 goto out; 218 next = n->nbinary.ch2; 219 break; 220 case NAND: 221 evaltree(n->nbinary.ch1, EV_TESTED); 222 if (evalskip || exitstatus != 0) { 223 goto out; 224 } 225 next = n->nbinary.ch2; 226 break; 227 case NOR: 228 evaltree(n->nbinary.ch1, EV_TESTED); 229 if (evalskip || exitstatus == 0) 230 goto out; 231 next = n->nbinary.ch2; 232 break; 233 case NREDIR: 234 evalredir(n, flags); 235 break; 236 case NSUBSHELL: 237 evalsubshell(n, flags); 238 do_etest = !(flags & EV_TESTED); 239 break; 240 case NBACKGND: 241 evalsubshell(n, flags); 242 break; 243 case NIF: { 244 evaltree(n->nif.test, EV_TESTED); 245 if (evalskip) 246 goto out; 247 if (exitstatus == 0) 248 next = n->nif.ifpart; 249 else if (n->nif.elsepart) 250 next = n->nif.elsepart; 251 else 252 exitstatus = 0; 253 break; 254 } 255 case NWHILE: 256 case NUNTIL: 257 evalloop(n, flags & ~EV_EXIT); 258 break; 259 case NFOR: 260 evalfor(n, flags & ~EV_EXIT); 261 break; 262 case NCASE: 263 next = evalcase(n); 264 break; 265 case NCLIST: 266 next = n->nclist.body; 267 break; 268 case NCLISTFALLTHRU: 269 if (n->nclist.body) { 270 evaltree(n->nclist.body, flags & ~EV_EXIT); 271 if (evalskip) 272 goto out; 273 } 274 next = n->nclist.next; 275 break; 276 case NDEFUN: 277 defun(n->narg.text, n->narg.next); 278 exitstatus = 0; 279 break; 280 case NNOT: 281 evaltree(n->nnot.com, EV_TESTED); 282 if (evalskip) 283 goto out; 284 exitstatus = !exitstatus; 285 break; 286 287 case NPIPE: 288 evalpipe(n); 289 do_etest = !(flags & EV_TESTED); 290 break; 291 case NCMD: 292 evalcommand(n, flags, (struct backcmd *)NULL); 293 do_etest = !(flags & EV_TESTED); 294 break; 295 default: 296 out1fmt("Node type = %d\n", n->type); 297 flushout(&output); 298 break; 299 } 300 n = next; 301 popstackmark(&smark); 302 setstackmark(&smark); 303 } while (n != NULL); 304 out: 305 popstackmark(&smark); 306 if (pendingsig) 307 dotrap(); 308 if (eflag && exitstatus != 0 && do_etest) 309 exitshell(exitstatus); 310 if (flags & EV_EXIT) 311 exraise(EXEXIT); 312 } 313 314 315 static void 316 evalloop(union node *n, int flags) 317 { 318 int status; 319 320 loopnest++; 321 status = 0; 322 for (;;) { 323 evaltree(n->nbinary.ch1, EV_TESTED); 324 if (evalskip) { 325 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 326 evalskip = 0; 327 continue; 328 } 329 if (evalskip == SKIPBREAK && --skipcount <= 0) 330 evalskip = 0; 331 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 332 status = exitstatus; 333 break; 334 } 335 if (n->type == NWHILE) { 336 if (exitstatus != 0) 337 break; 338 } else { 339 if (exitstatus == 0) 340 break; 341 } 342 evaltree(n->nbinary.ch2, flags); 343 status = exitstatus; 344 if (evalskip) 345 goto skipping; 346 } 347 loopnest--; 348 exitstatus = status; 349 } 350 351 352 353 static void 354 evalfor(union node *n, int flags) 355 { 356 struct arglist arglist; 357 union node *argp; 358 struct strlist *sp; 359 int status; 360 361 arglist.lastp = &arglist.list; 362 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 363 oexitstatus = exitstatus; 364 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 365 } 366 *arglist.lastp = NULL; 367 368 loopnest++; 369 status = 0; 370 for (sp = arglist.list ; sp ; sp = sp->next) { 371 setvar(n->nfor.var, sp->text, 0); 372 evaltree(n->nfor.body, flags); 373 status = exitstatus; 374 if (evalskip) { 375 if (evalskip == SKIPCONT && --skipcount <= 0) { 376 evalskip = 0; 377 continue; 378 } 379 if (evalskip == SKIPBREAK && --skipcount <= 0) 380 evalskip = 0; 381 break; 382 } 383 } 384 loopnest--; 385 exitstatus = status; 386 } 387 388 389 /* 390 * Evaluate a case statement, returning the selected tree. 391 * 392 * The exit status needs care to get right. 393 */ 394 395 static union node * 396 evalcase(union node *n) 397 { 398 union node *cp; 399 union node *patp; 400 struct arglist arglist; 401 402 arglist.lastp = &arglist.list; 403 oexitstatus = exitstatus; 404 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 405 for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) { 406 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 407 if (casematch(patp, arglist.list->text)) { 408 while (cp->nclist.next && 409 cp->type == NCLISTFALLTHRU && 410 cp->nclist.body == NULL) 411 cp = cp->nclist.next; 412 if (cp->nclist.next && 413 cp->type == NCLISTFALLTHRU) 414 return (cp); 415 if (cp->nclist.body == NULL) 416 exitstatus = 0; 417 return (cp->nclist.body); 418 } 419 } 420 } 421 exitstatus = 0; 422 return (NULL); 423 } 424 425 426 427 /* 428 * Kick off a subshell to evaluate a tree. 429 */ 430 431 static void 432 evalsubshell(union node *n, int flags) 433 { 434 struct job *jp; 435 int backgnd = (n->type == NBACKGND); 436 437 oexitstatus = exitstatus; 438 expredir(n->nredir.redirect); 439 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 440 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 441 if (backgnd) 442 flags &=~ EV_TESTED; 443 redirect(n->nredir.redirect, 0); 444 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 445 } else if (! backgnd) { 446 INTOFF; 447 exitstatus = waitforjob(jp, (int *)NULL); 448 INTON; 449 } else 450 exitstatus = 0; 451 } 452 453 454 /* 455 * Evaluate a redirected compound command. 456 */ 457 458 static void 459 evalredir(union node *n, int flags) 460 { 461 struct jmploc jmploc; 462 struct jmploc *savehandler; 463 volatile int in_redirect = 1; 464 465 oexitstatus = exitstatus; 466 expredir(n->nredir.redirect); 467 savehandler = handler; 468 if (setjmp(jmploc.loc)) { 469 int e; 470 471 handler = savehandler; 472 e = exception; 473 popredir(); 474 if (e == EXERROR || e == EXEXEC) { 475 if (in_redirect) { 476 exitstatus = 2; 477 return; 478 } 479 } 480 longjmp(handler->loc, 1); 481 } else { 482 INTOFF; 483 handler = &jmploc; 484 redirect(n->nredir.redirect, REDIR_PUSH); 485 in_redirect = 0; 486 INTON; 487 evaltree(n->nredir.n, flags); 488 } 489 INTOFF; 490 handler = savehandler; 491 popredir(); 492 INTON; 493 } 494 495 496 static void 497 exphere(union node *redir, struct arglist *fn) 498 { 499 struct jmploc jmploc; 500 struct jmploc *savehandler; 501 struct localvar *savelocalvars; 502 int need_longjmp = 0; 503 504 redir->nhere.expdoc = nullstr; 505 savelocalvars = localvars; 506 localvars = NULL; 507 forcelocal++; 508 savehandler = handler; 509 if (setjmp(jmploc.loc)) 510 need_longjmp = exception != EXERROR && exception != EXEXEC; 511 else { 512 handler = &jmploc; 513 expandarg(redir->nhere.doc, fn, 0); 514 redir->nhere.expdoc = fn->list->text; 515 INTOFF; 516 } 517 handler = savehandler; 518 forcelocal--; 519 poplocalvars(); 520 localvars = savelocalvars; 521 if (need_longjmp) 522 longjmp(handler->loc, 1); 523 INTON; 524 } 525 526 527 /* 528 * Compute the names of the files in a redirection list. 529 */ 530 531 static void 532 expredir(union node *n) 533 { 534 union node *redir; 535 536 for (redir = n ; redir ; redir = redir->nfile.next) { 537 struct arglist fn; 538 fn.lastp = &fn.list; 539 switch (redir->type) { 540 case NFROM: 541 case NTO: 542 case NFROMTO: 543 case NAPPEND: 544 case NCLOBBER: 545 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 546 redir->nfile.expfname = fn.list->text; 547 break; 548 case NFROMFD: 549 case NTOFD: 550 if (redir->ndup.vname) { 551 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 552 fixredir(redir, fn.list->text, 1); 553 } 554 break; 555 case NXHERE: 556 exphere(redir, &fn); 557 break; 558 } 559 } 560 } 561 562 563 564 /* 565 * Evaluate a pipeline. All the processes in the pipeline are children 566 * of the process creating the pipeline. (This differs from some versions 567 * of the shell, which make the last process in a pipeline the parent 568 * of all the rest.) 569 */ 570 571 static void 572 evalpipe(union node *n) 573 { 574 struct job *jp; 575 struct nodelist *lp; 576 int pipelen; 577 int prevfd; 578 int pip[2]; 579 580 TRACE(("evalpipe(%p) called\n", (void *)n)); 581 pipelen = 0; 582 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 583 pipelen++; 584 INTOFF; 585 jp = makejob(n, pipelen); 586 prevfd = -1; 587 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 588 prehash(lp->n); 589 pip[1] = -1; 590 if (lp->next) { 591 if (pipe(pip) < 0) { 592 if (prevfd >= 0) 593 close(prevfd); 594 error("Pipe call failed: %s", strerror(errno)); 595 } 596 } 597 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 598 INTON; 599 if (prevfd > 0) { 600 dup2(prevfd, 0); 601 close(prevfd); 602 } 603 if (pip[1] >= 0) { 604 if (!(prevfd >= 0 && pip[0] == 0)) 605 close(pip[0]); 606 if (pip[1] != 1) { 607 dup2(pip[1], 1); 608 close(pip[1]); 609 } 610 } 611 evaltree(lp->n, EV_EXIT); 612 } 613 if (prevfd >= 0) 614 close(prevfd); 615 prevfd = pip[0]; 616 if (pip[1] != -1) 617 close(pip[1]); 618 } 619 INTON; 620 if (n->npipe.backgnd == 0) { 621 INTOFF; 622 exitstatus = waitforjob(jp, (int *)NULL); 623 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 624 INTON; 625 } else 626 exitstatus = 0; 627 } 628 629 630 631 static int 632 is_valid_fast_cmdsubst(union node *n) 633 { 634 635 return (n->type == NCMD); 636 } 637 638 /* 639 * Execute a command inside back quotes. If it's a builtin command, we 640 * want to save its output in a block obtained from malloc. Otherwise 641 * we fork off a subprocess and get the output of the command via a pipe. 642 * Should be called with interrupts off. 643 */ 644 645 void 646 evalbackcmd(union node *n, struct backcmd *result) 647 { 648 int pip[2]; 649 struct job *jp; 650 struct stackmark smark; 651 struct jmploc jmploc; 652 struct jmploc *savehandler; 653 struct localvar *savelocalvars; 654 655 setstackmark(&smark); 656 result->fd = -1; 657 result->buf = NULL; 658 result->nleft = 0; 659 result->jp = NULL; 660 if (n == NULL) { 661 exitstatus = 0; 662 goto out; 663 } 664 exitstatus = oexitstatus; 665 if (is_valid_fast_cmdsubst(n)) { 666 savelocalvars = localvars; 667 localvars = NULL; 668 forcelocal++; 669 savehandler = handler; 670 if (setjmp(jmploc.loc)) { 671 if (exception == EXERROR || exception == EXEXEC) 672 exitstatus = 2; 673 else if (exception != 0) { 674 handler = savehandler; 675 forcelocal--; 676 poplocalvars(); 677 localvars = savelocalvars; 678 longjmp(handler->loc, 1); 679 } 680 } else { 681 handler = &jmploc; 682 evalcommand(n, EV_BACKCMD, result); 683 } 684 handler = savehandler; 685 forcelocal--; 686 poplocalvars(); 687 localvars = savelocalvars; 688 } else { 689 if (pipe(pip) < 0) 690 error("Pipe call failed: %s", strerror(errno)); 691 jp = makejob(n, 1); 692 if (forkshell(jp, n, FORK_NOJOB) == 0) { 693 FORCEINTON; 694 close(pip[0]); 695 if (pip[1] != 1) { 696 dup2(pip[1], 1); 697 close(pip[1]); 698 } 699 evaltree(n, EV_EXIT); 700 } 701 close(pip[1]); 702 result->fd = pip[0]; 703 result->jp = jp; 704 } 705 out: 706 popstackmark(&smark); 707 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 708 result->fd, result->buf, result->nleft, result->jp)); 709 } 710 711 static int 712 mustexpandto(const char *argtext, const char *mask) 713 { 714 for (;;) { 715 if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) { 716 argtext++; 717 continue; 718 } 719 if (*argtext == CTLESC) 720 argtext++; 721 else if (BASESYNTAX[(int)*argtext] == CCTL) 722 return (0); 723 if (*argtext != *mask) 724 return (0); 725 if (*argtext == '\0') 726 return (1); 727 argtext++; 728 mask++; 729 } 730 } 731 732 static int 733 isdeclarationcmd(struct narg *arg) 734 { 735 int have_command = 0; 736 737 if (arg == NULL) 738 return (0); 739 while (mustexpandto(arg->text, "command")) { 740 have_command = 1; 741 arg = &arg->next->narg; 742 if (arg == NULL) 743 return (0); 744 /* 745 * To also allow "command -p" and "command --" as part of 746 * a declaration command, add code here. 747 * We do not do this, as ksh does not do it either and it 748 * is not required by POSIX. 749 */ 750 } 751 return (mustexpandto(arg->text, "export") || 752 mustexpandto(arg->text, "readonly") || 753 (mustexpandto(arg->text, "local") && 754 (have_command || !isfunc("local")))); 755 } 756 757 /* 758 * Check if a builtin can safely be executed in the same process, 759 * even though it should be in a subshell (command substitution). 760 * Note that jobid, jobs, times and trap can show information not 761 * available in a child process; this is deliberate. 762 * The arguments should already have been expanded. 763 */ 764 static int 765 safe_builtin(int idx, int argc, char **argv) 766 { 767 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 768 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 769 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 770 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 771 idx == TYPECMD) 772 return (1); 773 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 774 idx == UMASKCMD) 775 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 776 if (idx == SETCMD) 777 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 778 argv[1][0] == '+') && argv[1][1] == 'o' && 779 argv[1][2] == '\0')); 780 return (0); 781 } 782 783 /* 784 * Execute a simple command. 785 * Note: This may or may not return if (flags & EV_EXIT). 786 */ 787 788 static void 789 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 790 { 791 union node *argp; 792 struct arglist arglist; 793 struct arglist varlist; 794 char **argv; 795 int argc; 796 char **envp; 797 int varflag; 798 struct strlist *sp; 799 int mode; 800 int pip[2]; 801 struct cmdentry cmdentry; 802 struct job *jp; 803 struct jmploc jmploc; 804 struct jmploc *savehandler; 805 char *savecmdname; 806 struct shparam saveparam; 807 struct localvar *savelocalvars; 808 struct parsefile *savetopfile; 809 volatile int e; 810 char *lastarg; 811 int realstatus; 812 int do_clearcmdentry; 813 const char *path = pathval(); 814 815 /* First expand the arguments. */ 816 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 817 arglist.lastp = &arglist.list; 818 varlist.lastp = &varlist.list; 819 varflag = 1; 820 jp = NULL; 821 do_clearcmdentry = 0; 822 oexitstatus = exitstatus; 823 exitstatus = 0; 824 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 825 if (varflag && isassignment(argp->narg.text)) { 826 expandarg(argp, varflag == 1 ? &varlist : &arglist, 827 EXP_VARTILDE); 828 continue; 829 } else if (varflag == 1) 830 varflag = isdeclarationcmd(&argp->narg) ? 2 : 0; 831 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 832 } 833 *arglist.lastp = NULL; 834 *varlist.lastp = NULL; 835 expredir(cmd->ncmd.redirect); 836 argc = 0; 837 for (sp = arglist.list ; sp ; sp = sp->next) 838 argc++; 839 /* Add one slot at the beginning for tryexec(). */ 840 argv = stalloc(sizeof (char *) * (argc + 2)); 841 argv++; 842 843 for (sp = arglist.list ; sp ; sp = sp->next) { 844 TRACE(("evalcommand arg: %s\n", sp->text)); 845 *argv++ = sp->text; 846 } 847 *argv = NULL; 848 lastarg = NULL; 849 if (iflag && funcnest == 0 && argc > 0) 850 lastarg = argv[-1]; 851 argv -= argc; 852 853 /* Print the command if xflag is set. */ 854 if (xflag) { 855 char sep = 0; 856 const char *p, *ps4; 857 ps4 = expandstr(ps4val()); 858 out2str(ps4 != NULL ? ps4 : ps4val()); 859 for (sp = varlist.list ; sp ; sp = sp->next) { 860 if (sep != 0) 861 out2c(' '); 862 p = strchr(sp->text, '='); 863 if (p != NULL) { 864 p++; 865 outbin(sp->text, p - sp->text, out2); 866 out2qstr(p); 867 } else 868 out2qstr(sp->text); 869 sep = ' '; 870 } 871 for (sp = arglist.list ; sp ; sp = sp->next) { 872 if (sep != 0) 873 out2c(' '); 874 /* Disambiguate command looking like assignment. */ 875 if (sp == arglist.list && 876 strchr(sp->text, '=') != NULL && 877 strchr(sp->text, '\'') == NULL) { 878 out2c('\''); 879 out2str(sp->text); 880 out2c('\''); 881 } else 882 out2qstr(sp->text); 883 sep = ' '; 884 } 885 out2c('\n'); 886 flushout(&errout); 887 } 888 889 /* Now locate the command. */ 890 if (argc == 0) { 891 /* Variable assignment(s) without command */ 892 cmdentry.cmdtype = CMDBUILTIN; 893 cmdentry.u.index = BLTINCMD; 894 cmdentry.special = 0; 895 } else { 896 static const char PATH[] = "PATH="; 897 int cmd_flags = 0, bltinonly = 0; 898 899 /* 900 * Modify the command lookup path, if a PATH= assignment 901 * is present 902 */ 903 for (sp = varlist.list ; sp ; sp = sp->next) 904 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 905 path = sp->text + sizeof(PATH) - 1; 906 /* 907 * On `PATH=... command`, we need to make 908 * sure that the command isn't using the 909 * non-updated hash table of the outer PATH 910 * setting and we need to make sure that 911 * the hash table isn't filled with items 912 * from the temporary setting. 913 * 914 * It would be better to forbit using and 915 * updating the table while this command 916 * runs, by the command finding mechanism 917 * is heavily integrated with hash handling, 918 * so we just delete the hash before and after 919 * the command runs. Partly deleting like 920 * changepatch() does doesn't seem worth the 921 * bookinging effort, since most such runs add 922 * directories in front of the new PATH. 923 */ 924 clearcmdentry(); 925 do_clearcmdentry = 1; 926 } 927 928 for (;;) { 929 if (bltinonly) { 930 cmdentry.u.index = find_builtin(*argv, &cmdentry.special); 931 if (cmdentry.u.index < 0) { 932 cmdentry.u.index = BLTINCMD; 933 argv--; 934 argc++; 935 break; 936 } 937 } else 938 find_command(argv[0], &cmdentry, cmd_flags, path); 939 /* implement the bltin and command builtins here */ 940 if (cmdentry.cmdtype != CMDBUILTIN) 941 break; 942 if (cmdentry.u.index == BLTINCMD) { 943 if (argc == 1) 944 break; 945 argv++; 946 argc--; 947 bltinonly = 1; 948 } else if (cmdentry.u.index == COMMANDCMD) { 949 if (argc == 1) 950 break; 951 if (!strcmp(argv[1], "-p")) { 952 if (argc == 2) 953 break; 954 if (argv[2][0] == '-') { 955 if (strcmp(argv[2], "--")) 956 break; 957 if (argc == 3) 958 break; 959 argv += 3; 960 argc -= 3; 961 } else { 962 argv += 2; 963 argc -= 2; 964 } 965 path = _PATH_STDPATH; 966 clearcmdentry(); 967 do_clearcmdentry = 1; 968 } else if (!strcmp(argv[1], "--")) { 969 if (argc == 2) 970 break; 971 argv += 2; 972 argc -= 2; 973 } else if (argv[1][0] == '-') 974 break; 975 else { 976 argv++; 977 argc--; 978 } 979 cmd_flags |= DO_NOFUNC; 980 bltinonly = 0; 981 } else 982 break; 983 } 984 /* 985 * Special builtins lose their special properties when 986 * called via 'command'. 987 */ 988 if (cmd_flags & DO_NOFUNC) 989 cmdentry.special = 0; 990 } 991 992 /* Fork off a child process if necessary. */ 993 if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 994 && ((flags & EV_EXIT) == 0 || have_traps())) 995 || ((flags & EV_BACKCMD) != 0 996 && (cmdentry.cmdtype != CMDBUILTIN || 997 !safe_builtin(cmdentry.u.index, argc, argv)))) { 998 jp = makejob(cmd, 1); 999 mode = FORK_FG; 1000 if (flags & EV_BACKCMD) { 1001 mode = FORK_NOJOB; 1002 if (pipe(pip) < 0) 1003 error("Pipe call failed: %s", strerror(errno)); 1004 } 1005 if (cmdentry.cmdtype == CMDNORMAL && 1006 cmd->ncmd.redirect == NULL && 1007 varlist.list == NULL && 1008 (mode == FORK_FG || mode == FORK_NOJOB) && 1009 !disvforkset() && !iflag && !mflag) { 1010 vforkexecshell(jp, argv, environment(), path, 1011 cmdentry.u.index, flags & EV_BACKCMD ? pip : NULL); 1012 goto parent; 1013 } 1014 if (forkshell(jp, cmd, mode) != 0) 1015 goto parent; /* at end of routine */ 1016 if (flags & EV_BACKCMD) { 1017 FORCEINTON; 1018 close(pip[0]); 1019 if (pip[1] != 1) { 1020 dup2(pip[1], 1); 1021 close(pip[1]); 1022 } 1023 flags &= ~EV_BACKCMD; 1024 } 1025 flags |= EV_EXIT; 1026 } 1027 1028 /* This is the child process if a fork occurred. */ 1029 /* Execute the command. */ 1030 if (cmdentry.cmdtype == CMDFUNCTION) { 1031 #ifdef DEBUG 1032 trputs("Shell function: "); trargs(argv); 1033 #endif 1034 saveparam = shellparam; 1035 shellparam.malloc = 0; 1036 shellparam.reset = 1; 1037 shellparam.nparam = argc - 1; 1038 shellparam.p = argv + 1; 1039 shellparam.optnext = NULL; 1040 INTOFF; 1041 savelocalvars = localvars; 1042 localvars = NULL; 1043 reffunc(cmdentry.u.func); 1044 savehandler = handler; 1045 if (setjmp(jmploc.loc)) { 1046 freeparam(&shellparam); 1047 shellparam = saveparam; 1048 popredir(); 1049 unreffunc(cmdentry.u.func); 1050 poplocalvars(); 1051 localvars = savelocalvars; 1052 funcnest--; 1053 handler = savehandler; 1054 longjmp(handler->loc, 1); 1055 } 1056 handler = &jmploc; 1057 funcnest++; 1058 redirect(cmd->ncmd.redirect, REDIR_PUSH); 1059 INTON; 1060 for (sp = varlist.list ; sp ; sp = sp->next) 1061 mklocal(sp->text); 1062 exitstatus = oexitstatus; 1063 evaltree(getfuncnode(cmdentry.u.func), 1064 flags & (EV_TESTED | EV_EXIT)); 1065 INTOFF; 1066 unreffunc(cmdentry.u.func); 1067 poplocalvars(); 1068 localvars = savelocalvars; 1069 freeparam(&shellparam); 1070 shellparam = saveparam; 1071 handler = savehandler; 1072 funcnest--; 1073 popredir(); 1074 INTON; 1075 if (evalskip == SKIPFUNC) { 1076 evalskip = 0; 1077 skipcount = 0; 1078 } 1079 if (jp) 1080 exitshell(exitstatus); 1081 } else if (cmdentry.cmdtype == CMDBUILTIN) { 1082 #ifdef DEBUG 1083 trputs("builtin command: "); trargs(argv); 1084 #endif 1085 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 1086 if (flags == EV_BACKCMD) { 1087 memout.nleft = 0; 1088 memout.nextc = memout.buf; 1089 memout.bufsize = 64; 1090 mode |= REDIR_BACKQ; 1091 } 1092 savecmdname = commandname; 1093 savetopfile = getcurrentfile(); 1094 cmdenviron = varlist.list; 1095 e = -1; 1096 savehandler = handler; 1097 if (setjmp(jmploc.loc)) { 1098 e = exception; 1099 if (e == EXINT) 1100 exitstatus = SIGINT+128; 1101 else if (e != EXEXIT) 1102 exitstatus = 2; 1103 goto cmddone; 1104 } 1105 handler = &jmploc; 1106 redirect(cmd->ncmd.redirect, mode); 1107 outclearerror(out1); 1108 /* 1109 * If there is no command word, redirection errors should 1110 * not be fatal but assignment errors should. 1111 */ 1112 if (argc == 0) 1113 cmdentry.special = 1; 1114 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); 1115 if (argc > 0) 1116 bltinsetlocale(); 1117 commandname = argv[0]; 1118 argptr = argv + 1; 1119 nextopt_optptr = NULL; /* initialize nextopt */ 1120 builtin_flags = flags; 1121 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 1122 flushall(); 1123 if (outiserror(out1)) { 1124 warning("write error on stdout"); 1125 if (exitstatus == 0 || exitstatus == 1) 1126 exitstatus = 2; 1127 } 1128 cmddone: 1129 if (argc > 0) 1130 bltinunsetlocale(); 1131 cmdenviron = NULL; 1132 out1 = &output; 1133 out2 = &errout; 1134 freestdout(); 1135 handler = savehandler; 1136 commandname = savecmdname; 1137 if (jp) 1138 exitshell(exitstatus); 1139 if (flags == EV_BACKCMD) { 1140 backcmd->buf = memout.buf; 1141 backcmd->nleft = memout.nextc - memout.buf; 1142 memout.buf = NULL; 1143 } 1144 if (cmdentry.u.index != EXECCMD) 1145 popredir(); 1146 if (e != -1) { 1147 if ((e != EXERROR && e != EXEXEC) 1148 || cmdentry.special) 1149 exraise(e); 1150 popfilesupto(savetopfile); 1151 if (flags != EV_BACKCMD) 1152 FORCEINTON; 1153 } 1154 } else { 1155 #ifdef DEBUG 1156 trputs("normal command: "); trargs(argv); 1157 #endif 1158 redirect(cmd->ncmd.redirect, 0); 1159 for (sp = varlist.list ; sp ; sp = sp->next) 1160 setvareq(sp->text, VEXPORT|VSTACK); 1161 envp = environment(); 1162 shellexec(argv, envp, path, cmdentry.u.index); 1163 /*NOTREACHED*/ 1164 } 1165 goto out; 1166 1167 parent: /* parent process gets here (if we forked) */ 1168 if (mode == FORK_FG) { /* argument to fork */ 1169 INTOFF; 1170 exitstatus = waitforjob(jp, &realstatus); 1171 INTON; 1172 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1173 evalskip = SKIPBREAK; 1174 skipcount = loopnest; 1175 } 1176 } else if (mode == FORK_NOJOB) { 1177 backcmd->fd = pip[0]; 1178 close(pip[1]); 1179 backcmd->jp = jp; 1180 } 1181 1182 out: 1183 if (lastarg) 1184 setvar("_", lastarg, 0); 1185 if (do_clearcmdentry) 1186 clearcmdentry(); 1187 } 1188 1189 1190 1191 /* 1192 * Search for a command. This is called before we fork so that the 1193 * location of the command will be available in the parent as well as 1194 * the child. The check for "goodname" is an overly conservative 1195 * check that the name will not be subject to expansion. 1196 */ 1197 1198 static void 1199 prehash(union node *n) 1200 { 1201 struct cmdentry entry; 1202 1203 if (n && n->type == NCMD && n->ncmd.args) 1204 if (goodname(n->ncmd.args->narg.text)) 1205 find_command(n->ncmd.args->narg.text, &entry, 0, 1206 pathval()); 1207 } 1208 1209 1210 1211 /* 1212 * Builtin commands. Builtin commands whose functions are closely 1213 * tied to evaluation are implemented here. 1214 */ 1215 1216 /* 1217 * No command given, a bltin command with no arguments, or a bltin command 1218 * with an invalid name. 1219 */ 1220 1221 int 1222 bltincmd(int argc, char **argv) 1223 { 1224 if (argc > 1) { 1225 out2fmt_flush("%s: not found\n", argv[1]); 1226 return 127; 1227 } 1228 /* 1229 * Preserve exitstatus of a previous possible redirection 1230 * as POSIX mandates 1231 */ 1232 return exitstatus; 1233 } 1234 1235 1236 /* 1237 * Handle break and continue commands. Break, continue, and return are 1238 * all handled by setting the evalskip flag. The evaluation routines 1239 * above all check this flag, and if it is set they start skipping 1240 * commands rather than executing them. The variable skipcount is 1241 * the number of loops to break/continue, or the number of function 1242 * levels to return. (The latter is always 1.) It should probably 1243 * be an error to break out of more loops than exist, but it isn't 1244 * in the standard shell so we don't make it one here. 1245 */ 1246 1247 int 1248 breakcmd(int argc, char **argv) 1249 { 1250 int n = argc > 1 ? number(argv[1]) : 1; 1251 1252 if (n > loopnest) 1253 n = loopnest; 1254 if (n > 0) { 1255 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1256 skipcount = n; 1257 } 1258 return 0; 1259 } 1260 1261 /* 1262 * The `command' command. 1263 */ 1264 int 1265 commandcmd(int argc __unused, char **argv __unused) 1266 { 1267 const char *path; 1268 int ch; 1269 int cmd = -1; 1270 1271 path = bltinlookup("PATH", 1); 1272 1273 while ((ch = nextopt("pvV")) != '\0') { 1274 switch (ch) { 1275 case 'p': 1276 path = _PATH_STDPATH; 1277 break; 1278 case 'v': 1279 cmd = TYPECMD_SMALLV; 1280 break; 1281 case 'V': 1282 cmd = TYPECMD_BIGV; 1283 break; 1284 } 1285 } 1286 1287 if (cmd != -1) { 1288 if (*argptr == NULL || argptr[1] != NULL) 1289 error("wrong number of arguments"); 1290 return typecmd_impl(2, argptr - 1, cmd, path); 1291 } 1292 if (*argptr != NULL) 1293 error("commandcmd bad call"); 1294 1295 /* 1296 * Do nothing successfully if no command was specified; 1297 * ksh also does this. 1298 */ 1299 return 0; 1300 } 1301 1302 1303 /* 1304 * The return command. 1305 */ 1306 1307 int 1308 returncmd(int argc, char **argv) 1309 { 1310 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1311 1312 if (funcnest) { 1313 evalskip = SKIPFUNC; 1314 skipcount = 1; 1315 } else { 1316 /* skip the rest of the file */ 1317 evalskip = SKIPFILE; 1318 skipcount = 1; 1319 } 1320 return ret; 1321 } 1322 1323 1324 int 1325 falsecmd(int argc __unused, char **argv __unused) 1326 { 1327 return 1; 1328 } 1329 1330 1331 int 1332 truecmd(int argc __unused, char **argv __unused) 1333 { 1334 return 0; 1335 } 1336 1337 1338 int 1339 execcmd(int argc, char **argv) 1340 { 1341 /* 1342 * Because we have historically not supported any options, 1343 * only treat "--" specially. 1344 */ 1345 if (argc > 1 && strcmp(argv[1], "--") == 0) 1346 argc--, argv++; 1347 if (argc > 1) { 1348 struct strlist *sp; 1349 1350 iflag = 0; /* exit on error */ 1351 mflag = 0; 1352 optschanged(); 1353 for (sp = cmdenviron; sp ; sp = sp->next) 1354 setvareq(sp->text, VEXPORT|VSTACK); 1355 shellexec(argv + 1, environment(), pathval(), 0); 1356 1357 } 1358 return 0; 1359 } 1360 1361 1362 int 1363 timescmd(int argc __unused, char **argv __unused) 1364 { 1365 struct rusage ru; 1366 long shumins, shsmins, chumins, chsmins; 1367 double shusecs, shssecs, chusecs, chssecs; 1368 1369 if (getrusage(RUSAGE_SELF, &ru) < 0) 1370 return 1; 1371 shumins = ru.ru_utime.tv_sec / 60; 1372 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1373 shsmins = ru.ru_stime.tv_sec / 60; 1374 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1375 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1376 return 1; 1377 chumins = ru.ru_utime.tv_sec / 60; 1378 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1379 chsmins = ru.ru_stime.tv_sec / 60; 1380 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1381 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1382 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1383 return 0; 1384 } 1385