1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <paths.h> 42 #include <signal.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 #include <sys/resource.h> 46 #include <sys/wait.h> /* For WIFSIGNALED(status) */ 47 #include <errno.h> 48 49 /* 50 * Evaluate a command. 51 */ 52 53 #include "shell.h" 54 #include "nodes.h" 55 #include "syntax.h" 56 #include "expand.h" 57 #include "parser.h" 58 #include "jobs.h" 59 #include "eval.h" 60 #include "builtins.h" 61 #include "options.h" 62 #include "exec.h" 63 #include "redir.h" 64 #include "input.h" 65 #include "output.h" 66 #include "trap.h" 67 #include "var.h" 68 #include "memalloc.h" 69 #include "error.h" 70 #include "show.h" 71 #include "mystring.h" 72 #ifndef NO_HISTORY 73 #include "myhistedit.h" 74 #endif 75 76 77 int evalskip; /* set if we are skipping commands */ 78 static int skipcount; /* number of levels to skip */ 79 MKINIT int loopnest; /* current loop nesting level */ 80 int funcnest; /* depth of function calls */ 81 static int builtin_flags; /* evalcommand flags for builtins */ 82 83 84 char *commandname; 85 struct strlist *cmdenviron; 86 int exitstatus; /* exit status of last command */ 87 int oexitstatus; /* saved exit status */ 88 89 90 static void evalloop(union node *, int); 91 static void evalfor(union node *, int); 92 static void evalcase(union node *, int); 93 static void evalsubshell(union node *, int); 94 static void evalredir(union node *, int); 95 static void expredir(union node *); 96 static void evalpipe(union node *); 97 static int is_valid_fast_cmdsubst(union node *n); 98 static void evalcommand(union node *, int, struct backcmd *); 99 static void prehash(union node *); 100 101 102 /* 103 * Called to reset things after an exception. 104 */ 105 106 #ifdef mkinit 107 INCLUDE "eval.h" 108 109 RESET { 110 evalskip = 0; 111 loopnest = 0; 112 funcnest = 0; 113 } 114 115 SHELLPROC { 116 exitstatus = 0; 117 } 118 #endif 119 120 121 122 /* 123 * The eval command. 124 */ 125 126 int 127 evalcmd(int argc, char **argv) 128 { 129 char *p; 130 char *concat; 131 char **ap; 132 133 if (argc > 1) { 134 p = argv[1]; 135 if (argc > 2) { 136 STARTSTACKSTR(concat); 137 ap = argv + 2; 138 for (;;) { 139 STPUTS(p, concat); 140 if ((p = *ap++) == NULL) 141 break; 142 STPUTC(' ', concat); 143 } 144 STPUTC('\0', concat); 145 p = grabstackstr(concat); 146 } 147 evalstring(p, builtin_flags & EV_TESTED); 148 } else 149 exitstatus = 0; 150 return exitstatus; 151 } 152 153 154 /* 155 * Execute a command or commands contained in a string. 156 */ 157 158 void 159 evalstring(char *s, int flags) 160 { 161 union node *n; 162 struct stackmark smark; 163 int flags_exit; 164 int any; 165 166 flags_exit = flags & EV_EXIT; 167 flags &= ~EV_EXIT; 168 any = 0; 169 setstackmark(&smark); 170 setinputstring(s, 1); 171 while ((n = parsecmd(0)) != NEOF) { 172 if (n != NULL) { 173 if (flags_exit && preadateof()) 174 evaltree(n, flags | EV_EXIT); 175 else 176 evaltree(n, flags); 177 any = 1; 178 } 179 popstackmark(&smark); 180 } 181 popfile(); 182 popstackmark(&smark); 183 if (!any) 184 exitstatus = 0; 185 if (flags_exit) 186 exitshell(exitstatus); 187 } 188 189 190 /* 191 * Evaluate a parse tree. The value is left in the global variable 192 * exitstatus. 193 */ 194 195 void 196 evaltree(union node *n, int flags) 197 { 198 int do_etest; 199 union node *next; 200 201 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 evalcase(n, flags); 264 break; 265 case NDEFUN: 266 defun(n->narg.text, n->narg.next); 267 exitstatus = 0; 268 break; 269 case NNOT: 270 evaltree(n->nnot.com, EV_TESTED); 271 exitstatus = !exitstatus; 272 break; 273 274 case NPIPE: 275 evalpipe(n); 276 do_etest = !(flags & EV_TESTED); 277 break; 278 case NCMD: 279 evalcommand(n, flags, (struct backcmd *)NULL); 280 do_etest = !(flags & EV_TESTED); 281 break; 282 default: 283 out1fmt("Node type = %d\n", n->type); 284 flushout(&output); 285 break; 286 } 287 n = next; 288 } while (n != NULL); 289 out: 290 if (pendingsigs) 291 dotrap(); 292 if ((flags & EV_EXIT) || (eflag && exitstatus != 0 && do_etest)) 293 exitshell(exitstatus); 294 } 295 296 297 static void 298 evalloop(union node *n, int flags) 299 { 300 int status; 301 302 loopnest++; 303 status = 0; 304 for (;;) { 305 evaltree(n->nbinary.ch1, EV_TESTED); 306 if (evalskip) { 307 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 308 evalskip = 0; 309 continue; 310 } 311 if (evalskip == SKIPBREAK && --skipcount <= 0) 312 evalskip = 0; 313 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 314 status = exitstatus; 315 break; 316 } 317 if (n->type == NWHILE) { 318 if (exitstatus != 0) 319 break; 320 } else { 321 if (exitstatus == 0) 322 break; 323 } 324 evaltree(n->nbinary.ch2, flags); 325 status = exitstatus; 326 if (evalskip) 327 goto skipping; 328 } 329 loopnest--; 330 exitstatus = status; 331 } 332 333 334 335 static void 336 evalfor(union node *n, int flags) 337 { 338 struct arglist arglist; 339 union node *argp; 340 struct strlist *sp; 341 struct stackmark smark; 342 343 setstackmark(&smark); 344 arglist.lastp = &arglist.list; 345 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 346 oexitstatus = exitstatus; 347 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 348 if (evalskip) 349 goto out; 350 } 351 *arglist.lastp = NULL; 352 353 exitstatus = 0; 354 loopnest++; 355 for (sp = arglist.list ; sp ; sp = sp->next) { 356 setvar(n->nfor.var, sp->text, 0); 357 evaltree(n->nfor.body, flags); 358 if (evalskip) { 359 if (evalskip == SKIPCONT && --skipcount <= 0) { 360 evalskip = 0; 361 continue; 362 } 363 if (evalskip == SKIPBREAK && --skipcount <= 0) 364 evalskip = 0; 365 break; 366 } 367 } 368 loopnest--; 369 out: 370 popstackmark(&smark); 371 } 372 373 374 375 static void 376 evalcase(union node *n, int flags) 377 { 378 union node *cp; 379 union node *patp; 380 struct arglist arglist; 381 struct stackmark smark; 382 383 setstackmark(&smark); 384 arglist.lastp = &arglist.list; 385 oexitstatus = exitstatus; 386 exitstatus = 0; 387 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 388 for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { 389 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 390 if (casematch(patp, arglist.list->text)) { 391 if (evalskip == 0) { 392 evaltree(cp->nclist.body, flags); 393 } 394 goto out; 395 } 396 } 397 } 398 out: 399 popstackmark(&smark); 400 } 401 402 403 404 /* 405 * Kick off a subshell to evaluate a tree. 406 */ 407 408 static void 409 evalsubshell(union node *n, int flags) 410 { 411 struct job *jp; 412 int backgnd = (n->type == NBACKGND); 413 414 expredir(n->nredir.redirect); 415 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 416 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 417 if (backgnd) 418 flags &=~ EV_TESTED; 419 redirect(n->nredir.redirect, 0); 420 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 421 } else if (! backgnd) { 422 INTOFF; 423 exitstatus = waitforjob(jp, (int *)NULL); 424 INTON; 425 } 426 } 427 428 429 /* 430 * Evaluate a redirected compound command. 431 */ 432 433 static void 434 evalredir(union node *n, int flags) 435 { 436 struct jmploc jmploc; 437 struct jmploc *savehandler; 438 volatile int in_redirect = 1; 439 440 expredir(n->nredir.redirect); 441 savehandler = handler; 442 if (setjmp(jmploc.loc)) { 443 int e; 444 445 handler = savehandler; 446 e = exception; 447 if (e == EXERROR || e == EXEXEC) { 448 popredir(); 449 if (in_redirect) { 450 exitstatus = 2; 451 return; 452 } 453 } 454 longjmp(handler->loc, 1); 455 } else { 456 INTOFF; 457 handler = &jmploc; 458 redirect(n->nredir.redirect, REDIR_PUSH); 459 in_redirect = 0; 460 INTON; 461 evaltree(n->nredir.n, flags); 462 } 463 INTOFF; 464 handler = savehandler; 465 popredir(); 466 INTON; 467 } 468 469 470 /* 471 * Compute the names of the files in a redirection list. 472 */ 473 474 static void 475 expredir(union node *n) 476 { 477 union node *redir; 478 479 for (redir = n ; redir ; redir = redir->nfile.next) { 480 struct arglist fn; 481 fn.lastp = &fn.list; 482 oexitstatus = exitstatus; 483 switch (redir->type) { 484 case NFROM: 485 case NTO: 486 case NFROMTO: 487 case NAPPEND: 488 case NCLOBBER: 489 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 490 redir->nfile.expfname = fn.list->text; 491 break; 492 case NFROMFD: 493 case NTOFD: 494 if (redir->ndup.vname) { 495 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 496 fixredir(redir, fn.list->text, 1); 497 } 498 break; 499 } 500 } 501 } 502 503 504 505 /* 506 * Evaluate a pipeline. All the processes in the pipeline are children 507 * of the process creating the pipeline. (This differs from some versions 508 * of the shell, which make the last process in a pipeline the parent 509 * of all the rest.) 510 */ 511 512 static void 513 evalpipe(union node *n) 514 { 515 struct job *jp; 516 struct nodelist *lp; 517 int pipelen; 518 int prevfd; 519 int pip[2]; 520 521 TRACE(("evalpipe(%p) called\n", (void *)n)); 522 pipelen = 0; 523 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 524 pipelen++; 525 INTOFF; 526 jp = makejob(n, pipelen); 527 prevfd = -1; 528 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 529 prehash(lp->n); 530 pip[1] = -1; 531 if (lp->next) { 532 if (pipe(pip) < 0) { 533 close(prevfd); 534 error("Pipe call failed: %s", strerror(errno)); 535 } 536 } 537 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 538 INTON; 539 if (prevfd > 0) { 540 dup2(prevfd, 0); 541 close(prevfd); 542 } 543 if (pip[1] >= 0) { 544 if (!(prevfd >= 0 && pip[0] == 0)) 545 close(pip[0]); 546 if (pip[1] != 1) { 547 dup2(pip[1], 1); 548 close(pip[1]); 549 } 550 } 551 evaltree(lp->n, EV_EXIT); 552 } 553 if (prevfd >= 0) 554 close(prevfd); 555 prevfd = pip[0]; 556 close(pip[1]); 557 } 558 INTON; 559 if (n->npipe.backgnd == 0) { 560 INTOFF; 561 exitstatus = waitforjob(jp, (int *)NULL); 562 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 563 INTON; 564 } 565 } 566 567 568 569 static int 570 is_valid_fast_cmdsubst(union node *n) 571 { 572 union node *argp; 573 574 if (n->type != NCMD) 575 return 0; 576 for (argp = n->ncmd.args ; argp ; argp = argp->narg.next) 577 if (expandhassideeffects(argp->narg.text)) 578 return 0; 579 return 1; 580 } 581 582 /* 583 * Execute a command inside back quotes. If it's a builtin command, we 584 * want to save its output in a block obtained from malloc. Otherwise 585 * we fork off a subprocess and get the output of the command via a pipe. 586 * Should be called with interrupts off. 587 */ 588 589 void 590 evalbackcmd(union node *n, struct backcmd *result) 591 { 592 int pip[2]; 593 struct job *jp; 594 struct stackmark smark; /* unnecessary */ 595 struct jmploc jmploc; 596 struct jmploc *savehandler; 597 598 setstackmark(&smark); 599 result->fd = -1; 600 result->buf = NULL; 601 result->nleft = 0; 602 result->jp = NULL; 603 if (n == NULL) { 604 exitstatus = 0; 605 goto out; 606 } 607 if (is_valid_fast_cmdsubst(n)) { 608 exitstatus = oexitstatus; 609 savehandler = handler; 610 if (setjmp(jmploc.loc)) { 611 if (exception == EXERROR || exception == EXEXEC) 612 exitstatus = 2; 613 else if (exception != 0) { 614 handler = savehandler; 615 longjmp(handler->loc, 1); 616 } 617 } else { 618 handler = &jmploc; 619 evalcommand(n, EV_BACKCMD, result); 620 } 621 handler = savehandler; 622 } else { 623 exitstatus = 0; 624 if (pipe(pip) < 0) 625 error("Pipe call failed: %s", strerror(errno)); 626 jp = makejob(n, 1); 627 if (forkshell(jp, n, FORK_NOJOB) == 0) { 628 FORCEINTON; 629 close(pip[0]); 630 if (pip[1] != 1) { 631 dup2(pip[1], 1); 632 close(pip[1]); 633 } 634 evaltree(n, EV_EXIT); 635 } 636 close(pip[1]); 637 result->fd = pip[0]; 638 result->jp = jp; 639 } 640 out: 641 popstackmark(&smark); 642 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 643 result->fd, result->buf, result->nleft, result->jp)); 644 } 645 646 /* 647 * Check if a builtin can safely be executed in the same process, 648 * even though it should be in a subshell (command substitution). 649 * Note that jobid, jobs, times and trap can show information not 650 * available in a child process; this is deliberate. 651 * The arguments should already have been expanded. 652 */ 653 static int 654 safe_builtin(int idx, int argc, char **argv) 655 { 656 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 657 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 658 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 659 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 660 idx == TYPECMD) 661 return (1); 662 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 663 idx == UMASKCMD) 664 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 665 if (idx == SETCMD) 666 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 667 argv[1][0] == '+') && argv[1][1] == 'o' && 668 argv[1][2] == '\0')); 669 return (0); 670 } 671 672 /* 673 * Execute a simple command. 674 * Note: This may or may not return if (flags & EV_EXIT). 675 */ 676 677 static void 678 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 679 { 680 struct stackmark smark; 681 union node *argp; 682 struct arglist arglist; 683 struct arglist varlist; 684 char **argv; 685 int argc; 686 char **envp; 687 int varflag; 688 struct strlist *sp; 689 int mode; 690 int pip[2]; 691 struct cmdentry cmdentry; 692 struct job *jp; 693 struct jmploc jmploc; 694 struct jmploc *savehandler; 695 char *savecmdname; 696 struct shparam saveparam; 697 struct localvar *savelocalvars; 698 struct parsefile *savetopfile; 699 volatile int e; 700 char *lastarg; 701 int realstatus; 702 int do_clearcmdentry; 703 const char *path = pathval(); 704 705 /* First expand the arguments. */ 706 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 707 setstackmark(&smark); 708 arglist.lastp = &arglist.list; 709 varlist.lastp = &varlist.list; 710 varflag = 1; 711 jp = NULL; 712 do_clearcmdentry = 0; 713 oexitstatus = exitstatus; 714 exitstatus = 0; 715 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 716 char *p = argp->narg.text; 717 if (varflag && is_name(*p)) { 718 do { 719 p++; 720 } while (is_in_name(*p)); 721 if (*p == '=') { 722 expandarg(argp, &varlist, EXP_VARTILDE); 723 continue; 724 } 725 } 726 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 727 varflag = 0; 728 } 729 *arglist.lastp = NULL; 730 *varlist.lastp = NULL; 731 expredir(cmd->ncmd.redirect); 732 argc = 0; 733 for (sp = arglist.list ; sp ; sp = sp->next) 734 argc++; 735 argv = stalloc(sizeof (char *) * (argc + 1)); 736 737 for (sp = arglist.list ; sp ; sp = sp->next) { 738 TRACE(("evalcommand arg: %s\n", sp->text)); 739 *argv++ = sp->text; 740 } 741 *argv = NULL; 742 lastarg = NULL; 743 if (iflag && funcnest == 0 && argc > 0) 744 lastarg = argv[-1]; 745 argv -= argc; 746 747 /* Print the command if xflag is set. */ 748 if (xflag) { 749 char sep = 0; 750 const char *p; 751 out2str(ps4val()); 752 for (sp = varlist.list ; sp ; sp = sp->next) { 753 if (sep != 0) 754 out2c(' '); 755 p = strchr(sp->text, '='); 756 if (p != NULL) { 757 p++; 758 outbin(sp->text, p - sp->text, out2); 759 out2qstr(p); 760 } else 761 out2qstr(sp->text); 762 sep = ' '; 763 } 764 for (sp = arglist.list ; sp ; sp = sp->next) { 765 if (sep != 0) 766 out2c(' '); 767 /* Disambiguate command looking like assignment. */ 768 if (sp == arglist.list && 769 strchr(sp->text, '=') != NULL && 770 strchr(sp->text, '\'') == NULL) { 771 out2c('\''); 772 out2str(sp->text); 773 out2c('\''); 774 } else 775 out2qstr(sp->text); 776 sep = ' '; 777 } 778 out2c('\n'); 779 flushout(&errout); 780 } 781 782 /* Now locate the command. */ 783 if (argc == 0) { 784 /* Variable assignment(s) without command */ 785 cmdentry.cmdtype = CMDBUILTIN; 786 cmdentry.u.index = BLTINCMD; 787 cmdentry.special = 0; 788 } else { 789 static const char PATH[] = "PATH="; 790 int cmd_flags = 0, bltinonly = 0; 791 792 /* 793 * Modify the command lookup path, if a PATH= assignment 794 * is present 795 */ 796 for (sp = varlist.list ; sp ; sp = sp->next) 797 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 798 path = sp->text + sizeof(PATH) - 1; 799 /* 800 * On `PATH=... command`, we need to make 801 * sure that the command isn't using the 802 * non-updated hash table of the outer PATH 803 * setting and we need to make sure that 804 * the hash table isn't filled with items 805 * from the temporary setting. 806 * 807 * It would be better to forbit using and 808 * updating the table while this command 809 * runs, by the command finding mechanism 810 * is heavily integrated with hash handling, 811 * so we just delete the hash before and after 812 * the command runs. Partly deleting like 813 * changepatch() does doesn't seem worth the 814 * bookinging effort, since most such runs add 815 * directories in front of the new PATH. 816 */ 817 clearcmdentry(0); 818 do_clearcmdentry = 1; 819 } 820 821 for (;;) { 822 if (bltinonly) { 823 cmdentry.u.index = find_builtin(*argv, &cmdentry.special); 824 if (cmdentry.u.index < 0) { 825 cmdentry.u.index = BLTINCMD; 826 argv--; 827 argc++; 828 break; 829 } 830 } else 831 find_command(argv[0], &cmdentry, cmd_flags, path); 832 /* implement the bltin and command builtins here */ 833 if (cmdentry.cmdtype != CMDBUILTIN) 834 break; 835 if (cmdentry.u.index == BLTINCMD) { 836 if (argc == 1) 837 break; 838 argv++; 839 argc--; 840 bltinonly = 1; 841 } else if (cmdentry.u.index == COMMANDCMD) { 842 if (argc == 1) 843 break; 844 if (!strcmp(argv[1], "-p")) { 845 if (argc == 2) 846 break; 847 if (argv[2][0] == '-') { 848 if (strcmp(argv[2], "--")) 849 break; 850 if (argc == 3) 851 break; 852 argv += 3; 853 argc -= 3; 854 } else { 855 argv += 2; 856 argc -= 2; 857 } 858 path = _PATH_STDPATH; 859 clearcmdentry(0); 860 do_clearcmdentry = 1; 861 } else if (!strcmp(argv[1], "--")) { 862 if (argc == 2) 863 break; 864 argv += 2; 865 argc -= 2; 866 } else if (argv[1][0] == '-') 867 break; 868 else { 869 argv++; 870 argc--; 871 } 872 cmd_flags |= DO_NOFUNC; 873 bltinonly = 0; 874 } else 875 break; 876 } 877 /* 878 * Special builtins lose their special properties when 879 * called via 'command'. 880 */ 881 if (cmd_flags & DO_NOFUNC) 882 cmdentry.special = 0; 883 } 884 885 /* Fork off a child process if necessary. */ 886 if (cmd->ncmd.backgnd 887 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 888 && ((flags & EV_EXIT) == 0 || have_traps())) 889 || ((flags & EV_BACKCMD) != 0 890 && (cmdentry.cmdtype != CMDBUILTIN || 891 !safe_builtin(cmdentry.u.index, argc, argv)))) { 892 jp = makejob(cmd, 1); 893 mode = cmd->ncmd.backgnd; 894 if (flags & EV_BACKCMD) { 895 mode = FORK_NOJOB; 896 if (pipe(pip) < 0) 897 error("Pipe call failed: %s", strerror(errno)); 898 } 899 if (forkshell(jp, cmd, mode) != 0) 900 goto parent; /* at end of routine */ 901 if (flags & EV_BACKCMD) { 902 FORCEINTON; 903 close(pip[0]); 904 if (pip[1] != 1) { 905 dup2(pip[1], 1); 906 close(pip[1]); 907 } 908 } 909 flags |= EV_EXIT; 910 } 911 912 /* This is the child process if a fork occurred. */ 913 /* Execute the command. */ 914 if (cmdentry.cmdtype == CMDFUNCTION) { 915 #ifdef DEBUG 916 trputs("Shell function: "); trargs(argv); 917 #endif 918 saveparam = shellparam; 919 shellparam.malloc = 0; 920 shellparam.reset = 1; 921 shellparam.nparam = argc - 1; 922 shellparam.p = argv + 1; 923 shellparam.optnext = NULL; 924 INTOFF; 925 savelocalvars = localvars; 926 localvars = NULL; 927 reffunc(cmdentry.u.func); 928 savehandler = handler; 929 if (setjmp(jmploc.loc)) { 930 if (exception == EXSHELLPROC) 931 freeparam(&saveparam); 932 else { 933 freeparam(&shellparam); 934 shellparam = saveparam; 935 if (exception == EXERROR || exception == EXEXEC) 936 popredir(); 937 } 938 unreffunc(cmdentry.u.func); 939 poplocalvars(); 940 localvars = savelocalvars; 941 funcnest--; 942 handler = savehandler; 943 longjmp(handler->loc, 1); 944 } 945 handler = &jmploc; 946 funcnest++; 947 redirect(cmd->ncmd.redirect, REDIR_PUSH); 948 INTON; 949 for (sp = varlist.list ; sp ; sp = sp->next) 950 mklocal(sp->text); 951 exitstatus = oexitstatus; 952 if (flags & EV_TESTED) 953 evaltree(getfuncnode(cmdentry.u.func), EV_TESTED); 954 else 955 evaltree(getfuncnode(cmdentry.u.func), 0); 956 INTOFF; 957 unreffunc(cmdentry.u.func); 958 poplocalvars(); 959 localvars = savelocalvars; 960 freeparam(&shellparam); 961 shellparam = saveparam; 962 handler = savehandler; 963 funcnest--; 964 popredir(); 965 INTON; 966 if (evalskip == SKIPFUNC) { 967 evalskip = 0; 968 skipcount = 0; 969 } 970 if (jp) 971 exitshell(exitstatus); 972 } else if (cmdentry.cmdtype == CMDBUILTIN) { 973 #ifdef DEBUG 974 trputs("builtin command: "); trargs(argv); 975 #endif 976 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 977 if (flags == EV_BACKCMD) { 978 memout.nleft = 0; 979 memout.nextc = memout.buf; 980 memout.bufsize = 64; 981 mode |= REDIR_BACKQ; 982 cmdentry.special = 0; 983 } 984 savecmdname = commandname; 985 savetopfile = getcurrentfile(); 986 cmdenviron = varlist.list; 987 e = -1; 988 savehandler = handler; 989 if (setjmp(jmploc.loc)) { 990 e = exception; 991 exitstatus = (e == EXINT)? SIGINT+128 : 2; 992 goto cmddone; 993 } 994 handler = &jmploc; 995 redirect(cmd->ncmd.redirect, mode); 996 /* 997 * If there is no command word, redirection errors should 998 * not be fatal but assignment errors should. 999 */ 1000 if (argc == 0 && !(flags & EV_BACKCMD)) 1001 cmdentry.special = 1; 1002 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); 1003 if (argc > 0) 1004 bltinsetlocale(); 1005 commandname = argv[0]; 1006 argptr = argv + 1; 1007 nextopt_optptr = NULL; /* initialize nextopt */ 1008 builtin_flags = flags; 1009 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 1010 flushall(); 1011 cmddone: 1012 if (argc > 0) 1013 bltinunsetlocale(); 1014 cmdenviron = NULL; 1015 out1 = &output; 1016 out2 = &errout; 1017 freestdout(); 1018 handler = savehandler; 1019 if (e != EXSHELLPROC) { 1020 commandname = savecmdname; 1021 if (jp) 1022 exitshell(exitstatus); 1023 } 1024 if (flags == EV_BACKCMD) { 1025 backcmd->buf = memout.buf; 1026 backcmd->nleft = memout.nextc - memout.buf; 1027 memout.buf = NULL; 1028 } 1029 if (cmdentry.u.index != EXECCMD && 1030 (e == -1 || e == EXERROR || e == EXEXEC)) 1031 popredir(); 1032 if (e != -1) { 1033 if ((e != EXERROR && e != EXEXEC) 1034 || cmdentry.special) 1035 exraise(e); 1036 popfilesupto(savetopfile); 1037 if (flags != EV_BACKCMD) 1038 FORCEINTON; 1039 } 1040 } else { 1041 #ifdef DEBUG 1042 trputs("normal command: "); trargs(argv); 1043 #endif 1044 redirect(cmd->ncmd.redirect, 0); 1045 for (sp = varlist.list ; sp ; sp = sp->next) 1046 setvareq(sp->text, VEXPORT|VSTACK); 1047 envp = environment(); 1048 shellexec(argv, envp, path, cmdentry.u.index); 1049 /*NOTREACHED*/ 1050 } 1051 goto out; 1052 1053 parent: /* parent process gets here (if we forked) */ 1054 if (mode == FORK_FG) { /* argument to fork */ 1055 INTOFF; 1056 exitstatus = waitforjob(jp, &realstatus); 1057 INTON; 1058 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1059 evalskip = SKIPBREAK; 1060 skipcount = loopnest; 1061 } 1062 } else if (mode == FORK_NOJOB) { 1063 backcmd->fd = pip[0]; 1064 close(pip[1]); 1065 backcmd->jp = jp; 1066 } 1067 1068 out: 1069 if (lastarg) 1070 setvar("_", lastarg, 0); 1071 if (do_clearcmdentry) 1072 clearcmdentry(0); 1073 popstackmark(&smark); 1074 } 1075 1076 1077 1078 /* 1079 * Search for a command. This is called before we fork so that the 1080 * location of the command will be available in the parent as well as 1081 * the child. The check for "goodname" is an overly conservative 1082 * check that the name will not be subject to expansion. 1083 */ 1084 1085 static void 1086 prehash(union node *n) 1087 { 1088 struct cmdentry entry; 1089 1090 if (n && n->type == NCMD && n->ncmd.args) 1091 if (goodname(n->ncmd.args->narg.text)) 1092 find_command(n->ncmd.args->narg.text, &entry, 0, 1093 pathval()); 1094 } 1095 1096 1097 1098 /* 1099 * Builtin commands. Builtin commands whose functions are closely 1100 * tied to evaluation are implemented here. 1101 */ 1102 1103 /* 1104 * No command given, a bltin command with no arguments, or a bltin command 1105 * with an invalid name. 1106 */ 1107 1108 int 1109 bltincmd(int argc, char **argv) 1110 { 1111 if (argc > 1) { 1112 out2fmt_flush("%s: not found\n", argv[1]); 1113 return 127; 1114 } 1115 /* 1116 * Preserve exitstatus of a previous possible redirection 1117 * as POSIX mandates 1118 */ 1119 return exitstatus; 1120 } 1121 1122 1123 /* 1124 * Handle break and continue commands. Break, continue, and return are 1125 * all handled by setting the evalskip flag. The evaluation routines 1126 * above all check this flag, and if it is set they start skipping 1127 * commands rather than executing them. The variable skipcount is 1128 * the number of loops to break/continue, or the number of function 1129 * levels to return. (The latter is always 1.) It should probably 1130 * be an error to break out of more loops than exist, but it isn't 1131 * in the standard shell so we don't make it one here. 1132 */ 1133 1134 int 1135 breakcmd(int argc, char **argv) 1136 { 1137 int n = argc > 1 ? number(argv[1]) : 1; 1138 1139 if (n > loopnest) 1140 n = loopnest; 1141 if (n > 0) { 1142 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1143 skipcount = n; 1144 } 1145 return 0; 1146 } 1147 1148 /* 1149 * The `command' command. 1150 */ 1151 int 1152 commandcmd(int argc, char **argv) 1153 { 1154 const char *path; 1155 int ch; 1156 int cmd = -1; 1157 1158 path = bltinlookup("PATH", 1); 1159 1160 optind = optreset = 1; 1161 opterr = 0; 1162 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1163 switch (ch) { 1164 case 'p': 1165 path = _PATH_STDPATH; 1166 break; 1167 case 'v': 1168 cmd = TYPECMD_SMALLV; 1169 break; 1170 case 'V': 1171 cmd = TYPECMD_BIGV; 1172 break; 1173 case '?': 1174 default: 1175 error("unknown option: -%c", optopt); 1176 } 1177 } 1178 argc -= optind; 1179 argv += optind; 1180 1181 if (cmd != -1) { 1182 if (argc != 1) 1183 error("wrong number of arguments"); 1184 return typecmd_impl(2, argv - 1, cmd, path); 1185 } 1186 if (argc != 0) 1187 error("commandcmd bad call"); 1188 1189 /* 1190 * Do nothing successfully if no command was specified; 1191 * ksh also does this. 1192 */ 1193 return 0; 1194 } 1195 1196 1197 /* 1198 * The return command. 1199 */ 1200 1201 int 1202 returncmd(int argc, char **argv) 1203 { 1204 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1205 1206 if (funcnest) { 1207 evalskip = SKIPFUNC; 1208 skipcount = 1; 1209 } else { 1210 /* skip the rest of the file */ 1211 evalskip = SKIPFILE; 1212 skipcount = 1; 1213 } 1214 return ret; 1215 } 1216 1217 1218 int 1219 falsecmd(int argc __unused, char **argv __unused) 1220 { 1221 return 1; 1222 } 1223 1224 1225 int 1226 truecmd(int argc __unused, char **argv __unused) 1227 { 1228 return 0; 1229 } 1230 1231 1232 int 1233 execcmd(int argc, char **argv) 1234 { 1235 /* 1236 * Because we have historically not supported any options, 1237 * only treat "--" specially. 1238 */ 1239 if (argc > 1 && strcmp(argv[1], "--") == 0) 1240 argc--, argv++; 1241 if (argc > 1) { 1242 struct strlist *sp; 1243 1244 iflag = 0; /* exit on error */ 1245 mflag = 0; 1246 optschanged(); 1247 for (sp = cmdenviron; sp ; sp = sp->next) 1248 setvareq(sp->text, VEXPORT|VSTACK); 1249 shellexec(argv + 1, environment(), pathval(), 0); 1250 1251 } 1252 return 0; 1253 } 1254 1255 1256 int 1257 timescmd(int argc __unused, char **argv __unused) 1258 { 1259 struct rusage ru; 1260 long shumins, shsmins, chumins, chsmins; 1261 double shusecs, shssecs, chusecs, chssecs; 1262 1263 if (getrusage(RUSAGE_SELF, &ru) < 0) 1264 return 1; 1265 shumins = ru.ru_utime.tv_sec / 60; 1266 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1267 shsmins = ru.ru_stime.tv_sec / 60; 1268 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1269 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1270 return 1; 1271 chumins = ru.ru_utime.tv_sec / 60; 1272 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1273 chsmins = ru.ru_stime.tv_sec / 60; 1274 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1275 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1276 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1277 return 0; 1278 } 1279