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