1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. 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 static 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 void 108 reseteval(void) 109 { 110 evalskip = 0; 111 loopnest = 0; 112 } 113 114 115 /* 116 * The eval command. 117 */ 118 119 int 120 evalcmd(int argc, char **argv) 121 { 122 char *p; 123 char *concat; 124 char **ap; 125 126 if (argc > 1) { 127 p = argv[1]; 128 if (argc > 2) { 129 STARTSTACKSTR(concat); 130 ap = argv + 2; 131 for (;;) { 132 STPUTS(p, concat); 133 if ((p = *ap++) == NULL) 134 break; 135 STPUTC(' ', concat); 136 } 137 STPUTC('\0', concat); 138 p = grabstackstr(concat); 139 } 140 evalstring(p, builtin_flags); 141 } else 142 exitstatus = 0; 143 return exitstatus; 144 } 145 146 147 /* 148 * Execute a command or commands contained in a string. 149 */ 150 151 void 152 evalstring(const char *s, int flags) 153 { 154 union node *n; 155 struct stackmark smark; 156 int flags_exit; 157 int any; 158 159 flags_exit = flags & EV_EXIT; 160 flags &= ~EV_EXIT; 161 any = 0; 162 setstackmark(&smark); 163 setinputstring(s, 1); 164 while ((n = parsecmd(0)) != NEOF) { 165 if (n != NULL && !nflag) { 166 if (flags_exit && preadateof()) 167 evaltree(n, flags | EV_EXIT); 168 else 169 evaltree(n, flags); 170 any = 1; 171 if (evalskip) 172 break; 173 } 174 popstackmark(&smark); 175 setstackmark(&smark); 176 } 177 popfile(); 178 popstackmark(&smark); 179 if (!any) 180 exitstatus = 0; 181 if (flags_exit) 182 exraise(EXEXIT); 183 } 184 185 186 /* 187 * Evaluate a parse tree. The value is left in the global variable 188 * exitstatus. 189 */ 190 191 void 192 evaltree(union node *n, int flags) 193 { 194 int do_etest; 195 union node *next; 196 struct stackmark smark; 197 198 setstackmark(&smark); 199 do_etest = 0; 200 if (n == NULL) { 201 TRACE(("evaltree(NULL) called\n")); 202 exitstatus = 0; 203 goto out; 204 } 205 do { 206 next = NULL; 207 #ifndef NO_HISTORY 208 displayhist = 1; /* show history substitutions done with fc */ 209 #endif 210 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 211 switch (n->type) { 212 case NSEMI: 213 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 214 if (evalskip) 215 goto out; 216 next = n->nbinary.ch2; 217 break; 218 case NAND: 219 evaltree(n->nbinary.ch1, EV_TESTED); 220 if (evalskip || exitstatus != 0) { 221 goto out; 222 } 223 next = n->nbinary.ch2; 224 break; 225 case NOR: 226 evaltree(n->nbinary.ch1, EV_TESTED); 227 if (evalskip || exitstatus == 0) 228 goto out; 229 next = n->nbinary.ch2; 230 break; 231 case NREDIR: 232 evalredir(n, flags); 233 break; 234 case NSUBSHELL: 235 evalsubshell(n, flags); 236 do_etest = !(flags & EV_TESTED); 237 break; 238 case NBACKGND: 239 evalsubshell(n, flags); 240 break; 241 case NIF: { 242 evaltree(n->nif.test, EV_TESTED); 243 if (evalskip) 244 goto out; 245 if (exitstatus == 0) 246 next = n->nif.ifpart; 247 else if (n->nif.elsepart) 248 next = n->nif.elsepart; 249 else 250 exitstatus = 0; 251 break; 252 } 253 case NWHILE: 254 case NUNTIL: 255 evalloop(n, flags & ~EV_EXIT); 256 break; 257 case NFOR: 258 evalfor(n, flags & ~EV_EXIT); 259 break; 260 case NCASE: 261 next = evalcase(n); 262 break; 263 case NCLIST: 264 next = n->nclist.body; 265 break; 266 case NCLISTFALLTHRU: 267 if (n->nclist.body) { 268 evaltree(n->nclist.body, flags & ~EV_EXIT); 269 if (evalskip) 270 goto out; 271 } 272 next = n->nclist.next; 273 break; 274 case NDEFUN: 275 defun(n->narg.text, n->narg.next); 276 exitstatus = 0; 277 break; 278 case NNOT: 279 evaltree(n->nnot.com, EV_TESTED); 280 if (evalskip) 281 goto out; 282 exitstatus = !exitstatus; 283 break; 284 285 case NPIPE: 286 evalpipe(n); 287 do_etest = !(flags & EV_TESTED); 288 break; 289 case NCMD: 290 evalcommand(n, flags, (struct backcmd *)NULL); 291 do_etest = !(flags & EV_TESTED); 292 break; 293 default: 294 out1fmt("Node type = %d\n", n->type); 295 flushout(&output); 296 break; 297 } 298 n = next; 299 popstackmark(&smark); 300 setstackmark(&smark); 301 } while (n != NULL); 302 out: 303 popstackmark(&smark); 304 if (pendingsig) 305 dotrap(); 306 if (eflag && exitstatus != 0 && do_etest) 307 exitshell(exitstatus); 308 if (flags & EV_EXIT) 309 exraise(EXEXIT); 310 } 311 312 313 static void 314 evalloop(union node *n, int flags) 315 { 316 int status; 317 318 loopnest++; 319 status = 0; 320 for (;;) { 321 if (!evalskip) 322 evaltree(n->nbinary.ch1, EV_TESTED); 323 if (evalskip) { 324 if (evalskip == SKIPCONT && --skipcount <= 0) { 325 evalskip = 0; 326 continue; 327 } 328 if (evalskip == SKIPBREAK && --skipcount <= 0) 329 evalskip = 0; 330 if (evalskip == SKIPRETURN) 331 status = exitstatus; 332 break; 333 } 334 if (n->type == NWHILE) { 335 if (exitstatus != 0) 336 break; 337 } else { 338 if (exitstatus == 0) 339 break; 340 } 341 evaltree(n->nbinary.ch2, flags); 342 status = exitstatus; 343 } 344 loopnest--; 345 exitstatus = status; 346 } 347 348 349 350 static void 351 evalfor(union node *n, int flags) 352 { 353 struct arglist arglist; 354 union node *argp; 355 struct strlist *sp; 356 int status; 357 358 arglist.lastp = &arglist.list; 359 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 360 oexitstatus = exitstatus; 361 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 362 } 363 *arglist.lastp = NULL; 364 365 loopnest++; 366 status = 0; 367 for (sp = arglist.list ; sp ; sp = sp->next) { 368 setvar(n->nfor.var, sp->text, 0); 369 evaltree(n->nfor.body, flags); 370 status = exitstatus; 371 if (evalskip) { 372 if (evalskip == SKIPCONT && --skipcount <= 0) { 373 evalskip = 0; 374 continue; 375 } 376 if (evalskip == SKIPBREAK && --skipcount <= 0) 377 evalskip = 0; 378 break; 379 } 380 } 381 loopnest--; 382 exitstatus = status; 383 } 384 385 386 /* 387 * Evaluate a case statement, returning the selected tree. 388 * 389 * The exit status needs care to get right. 390 */ 391 392 static union node * 393 evalcase(union node *n) 394 { 395 union node *cp; 396 union node *patp; 397 struct arglist arglist; 398 399 arglist.lastp = &arglist.list; 400 oexitstatus = exitstatus; 401 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 402 for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) { 403 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 404 if (casematch(patp, arglist.list->text)) { 405 while (cp->nclist.next && 406 cp->type == NCLISTFALLTHRU && 407 cp->nclist.body == NULL) 408 cp = cp->nclist.next; 409 if (cp->nclist.next && 410 cp->type == NCLISTFALLTHRU) 411 return (cp); 412 if (cp->nclist.body == NULL) 413 exitstatus = 0; 414 return (cp->nclist.body); 415 } 416 } 417 } 418 exitstatus = 0; 419 return (NULL); 420 } 421 422 423 424 /* 425 * Kick off a subshell to evaluate a tree. 426 */ 427 428 static void 429 evalsubshell(union node *n, int flags) 430 { 431 struct job *jp; 432 int backgnd = (n->type == NBACKGND); 433 434 oexitstatus = exitstatus; 435 expredir(n->nredir.redirect); 436 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 437 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 438 if (backgnd) 439 flags &=~ EV_TESTED; 440 redirect(n->nredir.redirect, 0); 441 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 442 } else if (!backgnd) { 443 INTOFF; 444 exitstatus = waitforjob(jp, (int *)NULL); 445 INTON; 446 } else 447 exitstatus = 0; 448 } 449 450 451 /* 452 * Evaluate a redirected compound command. 453 */ 454 455 static void 456 evalredir(union node *n, int flags) 457 { 458 struct jmploc jmploc; 459 struct jmploc *savehandler; 460 volatile int in_redirect = 1; 461 462 oexitstatus = exitstatus; 463 expredir(n->nredir.redirect); 464 savehandler = handler; 465 if (setjmp(jmploc.loc)) { 466 int e; 467 468 handler = savehandler; 469 e = exception; 470 popredir(); 471 if (e == EXERROR || e == EXEXEC) { 472 if (in_redirect) { 473 exitstatus = 2; 474 return; 475 } 476 } 477 longjmp(handler->loc, 1); 478 } else { 479 INTOFF; 480 handler = &jmploc; 481 redirect(n->nredir.redirect, REDIR_PUSH); 482 in_redirect = 0; 483 INTON; 484 evaltree(n->nredir.n, flags); 485 } 486 INTOFF; 487 handler = savehandler; 488 popredir(); 489 INTON; 490 } 491 492 493 static void 494 exphere(union node *redir, struct arglist *fn) 495 { 496 struct jmploc jmploc; 497 struct jmploc *savehandler; 498 struct localvar *savelocalvars; 499 int need_longjmp = 0; 500 501 redir->nhere.expdoc = ""; 502 savelocalvars = localvars; 503 localvars = NULL; 504 forcelocal++; 505 savehandler = handler; 506 if (setjmp(jmploc.loc)) 507 need_longjmp = exception != EXERROR && exception != EXEXEC; 508 else { 509 handler = &jmploc; 510 expandarg(redir->nhere.doc, fn, 0); 511 redir->nhere.expdoc = fn->list->text; 512 INTOFF; 513 } 514 handler = savehandler; 515 forcelocal--; 516 poplocalvars(); 517 localvars = savelocalvars; 518 if (need_longjmp) 519 longjmp(handler->loc, 1); 520 INTON; 521 } 522 523 524 /* 525 * Compute the names of the files in a redirection list. 526 */ 527 528 static void 529 expredir(union node *n) 530 { 531 union node *redir; 532 533 for (redir = n ; redir ; redir = redir->nfile.next) { 534 struct arglist fn; 535 fn.lastp = &fn.list; 536 switch (redir->type) { 537 case NFROM: 538 case NTO: 539 case NFROMTO: 540 case NAPPEND: 541 case NCLOBBER: 542 expandarg(redir->nfile.fname, &fn, EXP_TILDE); 543 redir->nfile.expfname = fn.list->text; 544 break; 545 case NFROMFD: 546 case NTOFD: 547 if (redir->ndup.vname) { 548 expandarg(redir->ndup.vname, &fn, EXP_TILDE); 549 fixredir(redir, fn.list->text, 1); 550 } 551 break; 552 case NXHERE: 553 exphere(redir, &fn); 554 break; 555 } 556 } 557 } 558 559 560 561 /* 562 * Evaluate a pipeline. All the processes in the pipeline are children 563 * of the process creating the pipeline. (This differs from some versions 564 * of the shell, which make the last process in a pipeline the parent 565 * of all the rest.) 566 */ 567 568 static void 569 evalpipe(union node *n) 570 { 571 struct job *jp; 572 struct nodelist *lp; 573 int pipelen; 574 int prevfd; 575 int pip[2]; 576 577 TRACE(("evalpipe(%p) called\n", (void *)n)); 578 pipelen = 0; 579 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 580 pipelen++; 581 INTOFF; 582 jp = makejob(n, pipelen); 583 prevfd = -1; 584 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 585 prehash(lp->n); 586 pip[1] = -1; 587 if (lp->next) { 588 if (pipe(pip) < 0) { 589 if (prevfd >= 0) 590 close(prevfd); 591 error("Pipe call failed: %s", strerror(errno)); 592 } 593 } 594 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 595 INTON; 596 if (prevfd > 0) { 597 dup2(prevfd, 0); 598 close(prevfd); 599 } 600 if (pip[1] >= 0) { 601 if (!(prevfd >= 0 && pip[0] == 0)) 602 close(pip[0]); 603 if (pip[1] != 1) { 604 dup2(pip[1], 1); 605 close(pip[1]); 606 } 607 } 608 evaltree(lp->n, EV_EXIT); 609 } 610 if (prevfd >= 0) 611 close(prevfd); 612 prevfd = pip[0]; 613 if (pip[1] != -1) 614 close(pip[1]); 615 } 616 INTON; 617 if (n->npipe.backgnd == 0) { 618 INTOFF; 619 exitstatus = waitforjob(jp, (int *)NULL); 620 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 621 INTON; 622 } else 623 exitstatus = 0; 624 } 625 626 627 628 static int 629 is_valid_fast_cmdsubst(union node *n) 630 { 631 632 return (n->type == NCMD); 633 } 634 635 /* 636 * Execute a command inside back quotes. If it's a builtin command, we 637 * want to save its output in a block obtained from malloc. Otherwise 638 * we fork off a subprocess and get the output of the command via a pipe. 639 * Should be called with interrupts off. 640 */ 641 642 void 643 evalbackcmd(union node *n, struct backcmd *result) 644 { 645 int pip[2]; 646 struct job *jp; 647 struct stackmark smark; 648 struct jmploc jmploc; 649 struct jmploc *savehandler; 650 struct localvar *savelocalvars; 651 652 result->fd = -1; 653 result->buf = NULL; 654 result->nleft = 0; 655 result->jp = NULL; 656 if (n == NULL) { 657 exitstatus = 0; 658 return; 659 } 660 setstackmark(&smark); 661 exitstatus = oexitstatus; 662 if (is_valid_fast_cmdsubst(n)) { 663 savelocalvars = localvars; 664 localvars = NULL; 665 forcelocal++; 666 savehandler = handler; 667 if (setjmp(jmploc.loc)) { 668 if (exception == EXERROR || exception == EXEXEC) 669 exitstatus = 2; 670 else if (exception != 0) { 671 handler = savehandler; 672 forcelocal--; 673 poplocalvars(); 674 localvars = savelocalvars; 675 longjmp(handler->loc, 1); 676 } 677 } else { 678 handler = &jmploc; 679 evalcommand(n, EV_BACKCMD, result); 680 } 681 handler = savehandler; 682 forcelocal--; 683 poplocalvars(); 684 localvars = savelocalvars; 685 } else { 686 if (pipe(pip) < 0) 687 error("Pipe call failed: %s", strerror(errno)); 688 jp = makejob(n, 1); 689 if (forkshell(jp, n, FORK_NOJOB) == 0) { 690 FORCEINTON; 691 close(pip[0]); 692 if (pip[1] != 1) { 693 dup2(pip[1], 1); 694 close(pip[1]); 695 } 696 evaltree(n, EV_EXIT); 697 } 698 close(pip[1]); 699 result->fd = pip[0]; 700 result->jp = jp; 701 } 702 popstackmark(&smark); 703 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 704 result->fd, result->buf, result->nleft, result->jp)); 705 } 706 707 static int 708 mustexpandto(const char *argtext, const char *mask) 709 { 710 for (;;) { 711 if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) { 712 argtext++; 713 continue; 714 } 715 if (*argtext == CTLESC) 716 argtext++; 717 else if (BASESYNTAX[(int)*argtext] == CCTL) 718 return (0); 719 if (*argtext != *mask) 720 return (0); 721 if (*argtext == '\0') 722 return (1); 723 argtext++; 724 mask++; 725 } 726 } 727 728 static int 729 isdeclarationcmd(struct narg *arg) 730 { 731 int have_command = 0; 732 733 if (arg == NULL) 734 return (0); 735 while (mustexpandto(arg->text, "command")) { 736 have_command = 1; 737 arg = &arg->next->narg; 738 if (arg == NULL) 739 return (0); 740 /* 741 * To also allow "command -p" and "command --" as part of 742 * a declaration command, add code here. 743 * We do not do this, as ksh does not do it either and it 744 * is not required by POSIX. 745 */ 746 } 747 return (mustexpandto(arg->text, "export") || 748 mustexpandto(arg->text, "readonly") || 749 (mustexpandto(arg->text, "local") && 750 (have_command || !isfunc("local")))); 751 } 752 753 static void 754 xtracecommand(struct arglist *varlist, struct arglist *arglist) 755 { 756 struct strlist *sp; 757 char sep = 0; 758 const char *p, *ps4; 759 760 ps4 = expandstr(ps4val()); 761 out2str(ps4 != NULL ? ps4 : ps4val()); 762 for (sp = varlist->list ; sp ; sp = sp->next) { 763 if (sep != 0) 764 out2c(' '); 765 p = strchr(sp->text, '='); 766 if (p != NULL) { 767 p++; 768 outbin(sp->text, p - sp->text, out2); 769 out2qstr(p); 770 } else 771 out2qstr(sp->text); 772 sep = ' '; 773 } 774 for (sp = arglist->list ; sp ; sp = sp->next) { 775 if (sep != 0) 776 out2c(' '); 777 out2qstr(sp->text); 778 sep = ' '; 779 } 780 out2c('\n'); 781 flushout(&errout); 782 } 783 784 /* 785 * Check if a builtin can safely be executed in the same process, 786 * even though it should be in a subshell (command substitution). 787 * Note that jobid, jobs, times and trap can show information not 788 * available in a child process; this is deliberate. 789 * The arguments should already have been expanded. 790 */ 791 static int 792 safe_builtin(int idx, int argc, char **argv) 793 { 794 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 795 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 796 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 797 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 798 idx == TYPECMD) 799 return (1); 800 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 801 idx == UMASKCMD) 802 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 803 if (idx == SETCMD) 804 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 805 argv[1][0] == '+') && argv[1][1] == 'o' && 806 argv[1][2] == '\0')); 807 return (0); 808 } 809 810 /* 811 * Execute a simple command. 812 * Note: This may or may not return if (flags & EV_EXIT). 813 */ 814 815 static void 816 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 817 { 818 union node *argp; 819 struct arglist arglist; 820 struct arglist varlist; 821 char **argv; 822 int argc; 823 char **envp; 824 int varflag; 825 struct strlist *sp; 826 int mode; 827 int pip[2]; 828 struct cmdentry cmdentry; 829 struct job *jp; 830 struct jmploc jmploc; 831 struct jmploc *savehandler; 832 char *savecmdname; 833 struct shparam saveparam; 834 struct localvar *savelocalvars; 835 struct parsefile *savetopfile; 836 volatile int e; 837 char *lastarg; 838 int realstatus; 839 int do_clearcmdentry; 840 const char *path = pathval(); 841 842 /* First expand the arguments. */ 843 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 844 arglist.lastp = &arglist.list; 845 varlist.lastp = &varlist.list; 846 varflag = 1; 847 jp = NULL; 848 do_clearcmdentry = 0; 849 oexitstatus = exitstatus; 850 exitstatus = 0; 851 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 852 if (varflag && isassignment(argp->narg.text)) { 853 expandarg(argp, varflag == 1 ? &varlist : &arglist, 854 EXP_VARTILDE); 855 continue; 856 } else if (varflag == 1) 857 varflag = isdeclarationcmd(&argp->narg) ? 2 : 0; 858 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 859 } 860 *arglist.lastp = NULL; 861 *varlist.lastp = NULL; 862 expredir(cmd->ncmd.redirect); 863 argc = 0; 864 for (sp = arglist.list ; sp ; sp = sp->next) 865 argc++; 866 /* Add one slot at the beginning for tryexec(). */ 867 argv = stalloc(sizeof (char *) * (argc + 2)); 868 argv++; 869 870 for (sp = arglist.list ; sp ; sp = sp->next) { 871 TRACE(("evalcommand arg: %s\n", sp->text)); 872 *argv++ = sp->text; 873 } 874 *argv = NULL; 875 lastarg = NULL; 876 if (iflag && funcnest == 0 && argc > 0) 877 lastarg = argv[-1]; 878 argv -= argc; 879 880 /* Print the command if xflag is set. */ 881 if (xflag) 882 xtracecommand(&varlist, &arglist); 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.optp = NULL; 1035 shellparam.optnext = NULL; 1036 INTOFF; 1037 savelocalvars = localvars; 1038 localvars = NULL; 1039 reffunc(cmdentry.u.func); 1040 savehandler = handler; 1041 if (setjmp(jmploc.loc)) { 1042 freeparam(&shellparam); 1043 shellparam = saveparam; 1044 popredir(); 1045 unreffunc(cmdentry.u.func); 1046 poplocalvars(); 1047 localvars = savelocalvars; 1048 funcnest--; 1049 handler = savehandler; 1050 longjmp(handler->loc, 1); 1051 } 1052 handler = &jmploc; 1053 funcnest++; 1054 redirect(cmd->ncmd.redirect, REDIR_PUSH); 1055 INTON; 1056 for (sp = varlist.list ; sp ; sp = sp->next) 1057 mklocal(sp->text); 1058 exitstatus = oexitstatus; 1059 evaltree(getfuncnode(cmdentry.u.func), 1060 flags & (EV_TESTED | EV_EXIT)); 1061 INTOFF; 1062 unreffunc(cmdentry.u.func); 1063 poplocalvars(); 1064 localvars = savelocalvars; 1065 freeparam(&shellparam); 1066 shellparam = saveparam; 1067 handler = savehandler; 1068 funcnest--; 1069 popredir(); 1070 INTON; 1071 if (evalskip == SKIPRETURN) { 1072 evalskip = 0; 1073 skipcount = 0; 1074 } 1075 if (jp) 1076 exitshell(exitstatus); 1077 } else if (cmdentry.cmdtype == CMDBUILTIN) { 1078 #ifdef DEBUG 1079 trputs("builtin command: "); trargs(argv); 1080 #endif 1081 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 1082 if (flags == EV_BACKCMD) { 1083 memout.nleft = 0; 1084 memout.nextc = memout.buf; 1085 memout.bufsize = 64; 1086 mode |= REDIR_BACKQ; 1087 } 1088 savecmdname = commandname; 1089 savetopfile = getcurrentfile(); 1090 cmdenviron = varlist.list; 1091 e = -1; 1092 savehandler = handler; 1093 if (setjmp(jmploc.loc)) { 1094 e = exception; 1095 if (e == EXINT) 1096 exitstatus = SIGINT+128; 1097 else if (e != EXEXIT) 1098 exitstatus = 2; 1099 goto cmddone; 1100 } 1101 handler = &jmploc; 1102 redirect(cmd->ncmd.redirect, mode); 1103 outclearerror(out1); 1104 /* 1105 * If there is no command word, redirection errors should 1106 * not be fatal but assignment errors should. 1107 */ 1108 if (argc == 0) 1109 cmdentry.special = 1; 1110 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); 1111 if (argc > 0) 1112 bltinsetlocale(); 1113 commandname = argv[0]; 1114 argptr = argv + 1; 1115 nextopt_optptr = NULL; /* initialize nextopt */ 1116 builtin_flags = flags; 1117 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 1118 flushall(); 1119 if (outiserror(out1)) { 1120 warning("write error on stdout"); 1121 if (exitstatus == 0 || exitstatus == 1) 1122 exitstatus = 2; 1123 } 1124 cmddone: 1125 if (argc > 0) 1126 bltinunsetlocale(); 1127 cmdenviron = NULL; 1128 out1 = &output; 1129 out2 = &errout; 1130 freestdout(); 1131 handler = savehandler; 1132 commandname = savecmdname; 1133 if (jp) 1134 exitshell(exitstatus); 1135 if (flags == EV_BACKCMD) { 1136 backcmd->buf = memout.buf; 1137 backcmd->nleft = memout.nextc - memout.buf; 1138 memout.buf = NULL; 1139 } 1140 if (cmdentry.u.index != EXECCMD) 1141 popredir(); 1142 if (e != -1) { 1143 if ((e != EXERROR && e != EXEXEC) 1144 || cmdentry.special) 1145 exraise(e); 1146 popfilesupto(savetopfile); 1147 if (flags != EV_BACKCMD) 1148 FORCEINTON; 1149 } 1150 } else { 1151 #ifdef DEBUG 1152 trputs("normal command: "); trargs(argv); 1153 #endif 1154 redirect(cmd->ncmd.redirect, 0); 1155 for (sp = varlist.list ; sp ; sp = sp->next) 1156 setvareq(sp->text, VEXPORT|VSTACK); 1157 envp = environment(); 1158 shellexec(argv, envp, path, cmdentry.u.index); 1159 /*NOTREACHED*/ 1160 } 1161 goto out; 1162 1163 parent: /* parent process gets here (if we forked) */ 1164 if (mode == FORK_FG) { /* argument to fork */ 1165 INTOFF; 1166 exitstatus = waitforjob(jp, &realstatus); 1167 INTON; 1168 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1169 evalskip = SKIPBREAK; 1170 skipcount = loopnest; 1171 } 1172 } else if (mode == FORK_NOJOB) { 1173 backcmd->fd = pip[0]; 1174 close(pip[1]); 1175 backcmd->jp = jp; 1176 } 1177 1178 out: 1179 if (lastarg) 1180 setvar("_", lastarg, 0); 1181 if (do_clearcmdentry) 1182 clearcmdentry(); 1183 } 1184 1185 1186 1187 /* 1188 * Search for a command. This is called before we fork so that the 1189 * location of the command will be available in the parent as well as 1190 * the child. The check for "goodname" is an overly conservative 1191 * check that the name will not be subject to expansion. 1192 */ 1193 1194 static void 1195 prehash(union node *n) 1196 { 1197 struct cmdentry entry; 1198 1199 if (n && n->type == NCMD && n->ncmd.args) 1200 if (goodname(n->ncmd.args->narg.text)) 1201 find_command(n->ncmd.args->narg.text, &entry, 0, 1202 pathval()); 1203 } 1204 1205 1206 1207 /* 1208 * Builtin commands. Builtin commands whose functions are closely 1209 * tied to evaluation are implemented here. 1210 */ 1211 1212 /* 1213 * No command given, a bltin command with no arguments, or a bltin command 1214 * with an invalid name. 1215 */ 1216 1217 int 1218 bltincmd(int argc, char **argv) 1219 { 1220 if (argc > 1) { 1221 out2fmt_flush("%s: not found\n", argv[1]); 1222 return 127; 1223 } 1224 /* 1225 * Preserve exitstatus of a previous possible redirection 1226 * as POSIX mandates 1227 */ 1228 return exitstatus; 1229 } 1230 1231 1232 /* 1233 * Handle break and continue commands. Break, continue, and return are 1234 * all handled by setting the evalskip flag. The evaluation routines 1235 * above all check this flag, and if it is set they start skipping 1236 * commands rather than executing them. The variable skipcount is 1237 * the number of loops to break/continue, or the number of function 1238 * levels to return. (The latter is always 1.) It should probably 1239 * be an error to break out of more loops than exist, but it isn't 1240 * in the standard shell so we don't make it one here. 1241 */ 1242 1243 int 1244 breakcmd(int argc, char **argv) 1245 { 1246 long n; 1247 char *end; 1248 1249 if (argc > 1) { 1250 /* Allow arbitrarily large numbers. */ 1251 n = strtol(argv[1], &end, 10); 1252 if (!is_digit(argv[1][0]) || *end != '\0') 1253 error("Illegal number: %s", argv[1]); 1254 } else 1255 n = 1; 1256 if (n > loopnest) 1257 n = loopnest; 1258 if (n > 0) { 1259 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1260 skipcount = n; 1261 } 1262 return 0; 1263 } 1264 1265 /* 1266 * The `command' command. 1267 */ 1268 int 1269 commandcmd(int argc __unused, char **argv __unused) 1270 { 1271 const char *path; 1272 int ch; 1273 int cmd = -1; 1274 1275 path = bltinlookup("PATH", 1); 1276 1277 while ((ch = nextopt("pvV")) != '\0') { 1278 switch (ch) { 1279 case 'p': 1280 path = _PATH_STDPATH; 1281 break; 1282 case 'v': 1283 cmd = TYPECMD_SMALLV; 1284 break; 1285 case 'V': 1286 cmd = TYPECMD_BIGV; 1287 break; 1288 } 1289 } 1290 1291 if (cmd != -1) { 1292 if (*argptr == NULL || argptr[1] != NULL) 1293 error("wrong number of arguments"); 1294 return typecmd_impl(2, argptr - 1, cmd, path); 1295 } 1296 if (*argptr != NULL) 1297 error("commandcmd bad call"); 1298 1299 /* 1300 * Do nothing successfully if no command was specified; 1301 * ksh also does this. 1302 */ 1303 return 0; 1304 } 1305 1306 1307 /* 1308 * The return command. 1309 */ 1310 1311 int 1312 returncmd(int argc, char **argv) 1313 { 1314 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1315 1316 evalskip = SKIPRETURN; 1317 skipcount = 1; 1318 return ret; 1319 } 1320 1321 1322 int 1323 falsecmd(int argc __unused, char **argv __unused) 1324 { 1325 return 1; 1326 } 1327 1328 1329 int 1330 truecmd(int argc __unused, char **argv __unused) 1331 { 1332 return 0; 1333 } 1334 1335 1336 int 1337 execcmd(int argc, char **argv) 1338 { 1339 /* 1340 * Because we have historically not supported any options, 1341 * only treat "--" specially. 1342 */ 1343 if (argc > 1 && strcmp(argv[1], "--") == 0) 1344 argc--, argv++; 1345 if (argc > 1) { 1346 struct strlist *sp; 1347 1348 iflag = 0; /* exit on error */ 1349 mflag = 0; 1350 optschanged(); 1351 for (sp = cmdenviron; sp ; sp = sp->next) 1352 setvareq(sp->text, VEXPORT|VSTACK); 1353 shellexec(argv + 1, environment(), pathval(), 0); 1354 1355 } 1356 return 0; 1357 } 1358 1359 1360 int 1361 timescmd(int argc __unused, char **argv __unused) 1362 { 1363 struct rusage ru; 1364 long shumins, shsmins, chumins, chsmins; 1365 double shusecs, shssecs, chusecs, chssecs; 1366 1367 if (getrusage(RUSAGE_SELF, &ru) < 0) 1368 return 1; 1369 shumins = ru.ru_utime.tv_sec / 60; 1370 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1371 shsmins = ru.ru_stime.tv_sec / 60; 1372 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1373 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1374 return 1; 1375 chumins = ru.ru_utime.tv_sec / 60; 1376 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1377 chsmins = ru.ru_stime.tv_sec / 60; 1378 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1379 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1380 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1381 return 0; 1382 } 1383