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 * @(#)eval.c 8.9 (Berkeley) 6/8/95 33 * $FreeBSD: head/bin/sh/eval.c 253658 2013-07-25 19:48:15Z jilles $ 34 */ 35 36 #include <sys/time.h> 37 #include <sys/resource.h> 38 #include <sys/wait.h> /* For WIFSIGNALED(status) */ 39 40 #include <errno.h> 41 #include <paths.h> 42 #include <signal.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 46 /* 47 * Evaluate a command. 48 */ 49 50 #include "shell.h" 51 #include "nodes.h" 52 #include "syntax.h" 53 #include "expand.h" 54 #include "parser.h" 55 #include "jobs.h" 56 #include "eval.h" 57 #include "builtins.h" 58 #include "options.h" 59 #include "exec.h" 60 #include "redir.h" 61 #include "input.h" 62 #include "output.h" 63 #include "trap.h" 64 #include "var.h" 65 #include "memalloc.h" 66 #include "error.h" 67 #include "show.h" 68 #include "mystring.h" 69 #ifndef NO_HISTORY 70 #include "myhistedit.h" 71 #endif 72 73 74 int evalskip; /* set if we are skipping commands */ 75 int skipcount; /* number of levels to skip */ 76 static int loopnest; /* current loop nesting level */ 77 int funcnest; /* depth of function calls */ 78 static int builtin_flags; /* evalcommand flags for builtins */ 79 80 81 const char *commandname; 82 struct strlist *cmdenviron; 83 int exitstatus; /* exit status of last command */ 84 int oexitstatus; /* saved exit status */ 85 86 87 static void evalloop(union node *, int); 88 static void evalfor(union node *, int); 89 static union node *evalcase(union node *); 90 static void evalsubshell(union node *, int); 91 static void evalredir(union node *, int); 92 static void exphere(union node *, struct arglist *); 93 static void expredir(union node *); 94 static void evalpipe(union node *); 95 static int is_valid_fast_cmdsubst(union node *n); 96 static void evalcommand(union node *, int, struct backcmd *); 97 static void prehash(union node *); 98 99 100 /* 101 * Called to reset things after an exception. 102 */ 103 104 void 105 reseteval(void) 106 { 107 evalskip = 0; 108 loopnest = 0; 109 funcnest = 0; 110 } 111 112 113 /* 114 * The eval command. 115 */ 116 117 int 118 evalcmd(int argc, char **argv) 119 { 120 char *p; 121 char *concat; 122 char **ap; 123 124 if (argc > 1) { 125 p = argv[1]; 126 if (argc > 2) { 127 STARTSTACKSTR(concat); 128 ap = argv + 2; 129 for (;;) { 130 STPUTS(p, concat); 131 if ((p = *ap++) == NULL) 132 break; 133 STPUTC(' ', concat); 134 } 135 STPUTC('\0', concat); 136 p = grabstackstr(concat); 137 } 138 evalstring(p, builtin_flags); 139 } else 140 exitstatus = 0; 141 return exitstatus; 142 } 143 144 145 /* 146 * Execute a command or commands contained in a string. 147 */ 148 149 void 150 evalstring(char *s, int flags) 151 { 152 union node *n; 153 struct stackmark smark; 154 int flags_exit; 155 int any; 156 157 flags_exit = flags & EV_EXIT; 158 flags &= ~EV_EXIT; 159 any = 0; 160 setstackmark(&smark); 161 setinputstring(s, 1); 162 while ((n = parsecmd(0)) != NEOF) { 163 if (n != NULL && !nflag) { 164 if (flags_exit && preadateof()) 165 evaltree(n, flags | EV_EXIT); 166 else 167 evaltree(n, flags); 168 any = 1; 169 } 170 popstackmark(&smark); 171 setstackmark(&smark); 172 } 173 popfile(); 174 popstackmark(&smark); 175 if (!any) 176 exitstatus = 0; 177 if (flags_exit) 178 exraise(EXEXIT); 179 } 180 181 182 /* 183 * Evaluate a parse tree. The value is left in the global variable 184 * exitstatus. 185 */ 186 187 void 188 evaltree(union node *n, int flags) 189 { 190 int do_etest; 191 union node *next; 192 struct stackmark smark; 193 194 setstackmark(&smark); 195 do_etest = 0; 196 if (n == NULL) { 197 TRACE(("evaltree(NULL) called\n")); 198 exitstatus = 0; 199 goto out; 200 } 201 do { 202 next = NULL; 203 #ifndef NO_HISTORY 204 displayhist = 1; /* show history substitutions done with fc */ 205 #endif 206 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 207 switch (n->type) { 208 case NSEMI: 209 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 210 if (evalskip) 211 goto out; 212 next = n->nbinary.ch2; 213 break; 214 case NAND: 215 evaltree(n->nbinary.ch1, EV_TESTED); 216 if (evalskip || exitstatus != 0) { 217 goto out; 218 } 219 next = n->nbinary.ch2; 220 break; 221 case NOR: 222 evaltree(n->nbinary.ch1, EV_TESTED); 223 if (evalskip || exitstatus == 0) 224 goto out; 225 next = n->nbinary.ch2; 226 break; 227 case NREDIR: 228 evalredir(n, flags); 229 break; 230 case NSUBSHELL: 231 evalsubshell(n, flags); 232 do_etest = !(flags & EV_TESTED); 233 break; 234 case NBACKGND: 235 evalsubshell(n, flags); 236 break; 237 case NIF: { 238 evaltree(n->nif.test, EV_TESTED); 239 if (evalskip) 240 goto out; 241 if (exitstatus == 0) 242 next = n->nif.ifpart; 243 else if (n->nif.elsepart) 244 next = n->nif.elsepart; 245 else 246 exitstatus = 0; 247 break; 248 } 249 case NWHILE: 250 case NUNTIL: 251 evalloop(n, flags & ~EV_EXIT); 252 break; 253 case NFOR: 254 evalfor(n, flags & ~EV_EXIT); 255 break; 256 case NCASE: 257 next = evalcase(n); 258 break; 259 case NCLIST: 260 next = n->nclist.body; 261 break; 262 case NCLISTFALLTHRU: 263 if (n->nclist.body) { 264 evaltree(n->nclist.body, flags & ~EV_EXIT); 265 if (evalskip) 266 goto out; 267 } 268 next = n->nclist.next; 269 break; 270 case NDEFUN: 271 defun(n->narg.text, n->narg.next); 272 exitstatus = 0; 273 break; 274 case NNOT: 275 evaltree(n->nnot.com, EV_TESTED); 276 if (evalskip) 277 goto out; 278 exitstatus = !exitstatus; 279 break; 280 281 case NPIPE: 282 evalpipe(n); 283 do_etest = !(flags & EV_TESTED); 284 break; 285 case NCMD: 286 evalcommand(n, flags, NULL); 287 do_etest = !(flags & EV_TESTED); 288 break; 289 default: 290 out1fmt("Node type = %d\n", n->type); 291 flushout(&output); 292 break; 293 } 294 n = next; 295 popstackmark(&smark); 296 setstackmark(&smark); 297 } while (n != NULL); 298 out: 299 popstackmark(&smark); 300 if (pendingsig) 301 dotrap(); 302 if (eflag && exitstatus != 0 && do_etest) 303 exitshell(exitstatus); 304 if (flags & EV_EXIT) 305 exraise(EXEXIT); 306 } 307 308 309 static void 310 evalloop(union node *n, int flags) 311 { 312 int status; 313 314 loopnest++; 315 status = 0; 316 for (;;) { 317 evaltree(n->nbinary.ch1, EV_TESTED); 318 if (evalskip) { 319 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 320 evalskip = 0; 321 continue; 322 } 323 if (evalskip == SKIPBREAK && --skipcount <= 0) 324 evalskip = 0; 325 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 326 status = exitstatus; 327 break; 328 } 329 if (n->type == NWHILE) { 330 if (exitstatus != 0) 331 break; 332 } else { 333 if (exitstatus == 0) 334 break; 335 } 336 evaltree(n->nbinary.ch2, flags); 337 status = exitstatus; 338 if (evalskip) 339 goto skipping; 340 } 341 loopnest--; 342 exitstatus = status; 343 } 344 345 346 347 static void 348 evalfor(union node *n, int flags) 349 { 350 struct arglist arglist; 351 union node *argp; 352 struct strlist *sp; 353 int status; 354 355 arglist.lastp = &arglist.list; 356 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 357 oexitstatus = exitstatus; 358 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 359 } 360 *arglist.lastp = NULL; 361 362 loopnest++; 363 status = 0; 364 for (sp = arglist.list ; sp ; sp = sp->next) { 365 setvar(n->nfor.var, sp->text, 0); 366 evaltree(n->nfor.body, flags); 367 status = exitstatus; 368 if (evalskip) { 369 if (evalskip == SKIPCONT && --skipcount <= 0) { 370 evalskip = 0; 371 continue; 372 } 373 if (evalskip == SKIPBREAK && --skipcount <= 0) 374 evalskip = 0; 375 break; 376 } 377 } 378 loopnest--; 379 exitstatus = status; 380 } 381 382 383 /* 384 * Evaluate a case statement, returning the selected tree. 385 * 386 * The exit status needs care to get right. 387 */ 388 389 static union node * 390 evalcase(union node *n) 391 { 392 union node *cp; 393 union node *patp; 394 struct arglist arglist; 395 396 arglist.lastp = &arglist.list; 397 oexitstatus = exitstatus; 398 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 399 for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) { 400 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 401 if (casematch(patp, arglist.list->text)) { 402 while (cp->nclist.next && 403 cp->type == NCLISTFALLTHRU && 404 cp->nclist.body == NULL) 405 cp = cp->nclist.next; 406 if (cp->nclist.next && 407 cp->type == NCLISTFALLTHRU) 408 return (cp); 409 if (cp->nclist.body == NULL) 410 exitstatus = 0; 411 return (cp->nclist.body); 412 } 413 } 414 } 415 exitstatus = 0; 416 return (NULL); 417 } 418 419 420 421 /* 422 * Kick off a subshell to evaluate a tree. 423 */ 424 425 static void 426 evalsubshell(union node *n, int flags) 427 { 428 struct job *jp; 429 int backgnd = (n->type == NBACKGND); 430 431 oexitstatus = exitstatus; 432 expredir(n->nredir.redirect); 433 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 434 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 435 if (backgnd) 436 flags &=~ EV_TESTED; 437 redirect(n->nredir.redirect, 0); 438 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 439 } else if (!backgnd) { 440 INTOFF; 441 exitstatus = waitforjob(jp, NULL); 442 INTON; 443 } else 444 exitstatus = 0; 445 } 446 447 448 /* 449 * Evaluate a redirected compound command. 450 */ 451 452 static void 453 evalredir(union node *n, int flags) 454 { 455 struct jmploc jmploc; 456 struct jmploc *savehandler; 457 volatile int in_redirect = 1; 458 459 oexitstatus = exitstatus; 460 expredir(n->nredir.redirect); 461 savehandler = handler; 462 if (setjmp(jmploc.loc)) { 463 int e; 464 465 handler = savehandler; 466 e = exception; 467 popredir(); 468 if (e == EXERROR || e == EXEXEC) { 469 if (in_redirect) { 470 exitstatus = 2; 471 return; 472 } 473 } 474 longjmp(handler->loc, 1); 475 } else { 476 INTOFF; 477 handler = &jmploc; 478 redirect(n->nredir.redirect, REDIR_PUSH); 479 in_redirect = 0; 480 INTON; 481 evaltree(n->nredir.n, flags); 482 } 483 INTOFF; 484 handler = savehandler; 485 popredir(); 486 INTON; 487 } 488 489 490 static void 491 exphere(union node *redir, struct arglist *fn) 492 { 493 struct jmploc jmploc; 494 struct jmploc *savehandler; 495 struct localvar *savelocalvars; 496 int need_longjmp = 0; 497 498 redir->nhere.expdoc = nullstr; 499 savelocalvars = localvars; 500 localvars = NULL; 501 forcelocal++; 502 savehandler = handler; 503 if (setjmp(jmploc.loc)) 504 need_longjmp = exception != EXERROR && exception != EXEXEC; 505 else { 506 handler = &jmploc; 507 expandarg(redir->nhere.doc, fn, 0); 508 redir->nhere.expdoc = fn->list->text; 509 INTOFF; 510 } 511 handler = savehandler; 512 forcelocal--; 513 poplocalvars(); 514 localvars = savelocalvars; 515 if (need_longjmp) 516 longjmp(handler->loc, 1); 517 INTON; 518 } 519 520 521 /* 522 * Compute the names of the files in a redirection list. 523 */ 524 525 static void 526 expredir(union node *n) 527 { 528 union node *redir; 529 530 for (redir = n ; redir ; redir = redir->nfile.next) { 531 struct arglist fn; 532 fn.lastp = &fn.list; 533 switch (redir->type) { 534 case NFROM: 535 case NTO: 536 case NFROMTO: 537 case NAPPEND: 538 case NCLOBBER: 539 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 540 redir->nfile.expfname = fn.list->text; 541 break; 542 case NFROMFD: 543 case NTOFD: 544 if (redir->ndup.vname) { 545 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 546 fixredir(redir, fn.list->text, 1); 547 } 548 break; 549 case NXHERE: 550 exphere(redir, &fn); 551 break; 552 } 553 } 554 } 555 556 557 558 /* 559 * Evaluate a pipeline. All the processes in the pipeline are children 560 * of the process creating the pipeline. (This differs from some versions 561 * of the shell, which make the last process in a pipeline the parent 562 * of all the rest.) 563 */ 564 565 static void 566 evalpipe(union node *n) 567 { 568 struct job *jp; 569 struct nodelist *lp; 570 int pipelen; 571 int prevfd; 572 int pip[2]; 573 574 TRACE(("evalpipe(%p) called\n", (void *)n)); 575 pipelen = 0; 576 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 577 pipelen++; 578 INTOFF; 579 jp = makejob(n, pipelen); 580 prevfd = -1; 581 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 582 prehash(lp->n); 583 pip[1] = -1; 584 if (lp->next) { 585 if (pipe(pip) < 0) { 586 if (prevfd >= 0) 587 close(prevfd); 588 error("Pipe call failed: %s", strerror(errno)); 589 } 590 } 591 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 592 INTON; 593 if (prevfd > 0) { 594 dup2(prevfd, 0); 595 close(prevfd); 596 } 597 if (pip[1] >= 0) { 598 if (!(prevfd >= 0 && pip[0] == 0)) 599 close(pip[0]); 600 if (pip[1] != 1) { 601 dup2(pip[1], 1); 602 close(pip[1]); 603 } 604 } 605 evaltree(lp->n, EV_EXIT); 606 } 607 if (prevfd >= 0) 608 close(prevfd); 609 prevfd = pip[0]; 610 if (pip[1] != -1) 611 close(pip[1]); 612 } 613 INTON; 614 if (n->npipe.backgnd == 0) { 615 INTOFF; 616 exitstatus = waitforjob(jp, NULL); 617 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 618 INTON; 619 } else 620 exitstatus = 0; 621 } 622 623 624 625 static int 626 is_valid_fast_cmdsubst(union node *n) 627 { 628 629 return (n->type == NCMD); 630 } 631 632 /* 633 * Execute a command inside back quotes. If it's a builtin command, we 634 * want to save its output in a block obtained from malloc. Otherwise 635 * we fork off a subprocess and get the output of the command via a pipe. 636 * Should be called with interrupts off. 637 */ 638 639 void 640 evalbackcmd(union node *n, struct backcmd *result) 641 { 642 int pip[2]; 643 struct job *jp; 644 struct stackmark smark; 645 struct jmploc jmploc; 646 struct jmploc *savehandler; 647 struct localvar *savelocalvars; 648 649 setstackmark(&smark); 650 result->fd = -1; 651 result->buf = NULL; 652 result->nleft = 0; 653 result->jp = NULL; 654 if (n == NULL) { 655 exitstatus = 0; 656 goto out; 657 } 658 exitstatus = oexitstatus; 659 if (is_valid_fast_cmdsubst(n)) { 660 savelocalvars = localvars; 661 localvars = NULL; 662 forcelocal++; 663 savehandler = handler; 664 if (setjmp(jmploc.loc)) { 665 if (exception == EXERROR || exception == EXEXEC) 666 exitstatus = 2; 667 else if (exception != 0) { 668 handler = savehandler; 669 forcelocal--; 670 poplocalvars(); 671 localvars = savelocalvars; 672 longjmp(handler->loc, 1); 673 } 674 } else { 675 handler = &jmploc; 676 evalcommand(n, EV_BACKCMD, result); 677 } 678 handler = savehandler; 679 forcelocal--; 680 poplocalvars(); 681 localvars = savelocalvars; 682 } else { 683 if (pipe(pip) < 0) 684 error("Pipe call failed: %s", strerror(errno)); 685 jp = makejob(n, 1); 686 if (forkshell(jp, n, FORK_NOJOB) == 0) { 687 FORCEINTON; 688 close(pip[0]); 689 if (pip[1] != 1) { 690 dup2(pip[1], 1); 691 close(pip[1]); 692 } 693 evaltree(n, EV_EXIT); 694 } 695 close(pip[1]); 696 result->fd = pip[0]; 697 result->jp = jp; 698 } 699 out: 700 popstackmark(&smark); 701 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 702 result->fd, result->buf, result->nleft, result->jp)); 703 } 704 705 static int 706 mustexpandto(const char *argtext, const char *mask) 707 { 708 for (;;) { 709 if (*argtext == CTLQUOTEMARK || *argtext == CTLQUOTEEND) { 710 argtext++; 711 continue; 712 } 713 if (*argtext == CTLESC) 714 argtext++; 715 else if (BASESYNTAX[(int)*argtext] == CCTL) 716 return (0); 717 if (*argtext != *mask) 718 return (0); 719 if (*argtext == '\0') 720 return (1); 721 argtext++; 722 mask++; 723 } 724 } 725 726 static int 727 isdeclarationcmd(struct narg *arg) 728 { 729 int have_command = 0; 730 731 if (arg == NULL) 732 return (0); 733 while (mustexpandto(arg->text, "command")) { 734 have_command = 1; 735 arg = &arg->next->narg; 736 if (arg == NULL) 737 return (0); 738 /* 739 * To also allow "command -p" and "command --" as part of 740 * a declaration command, add code here. 741 * We do not do this, as ksh does not do it either and it 742 * is not required by POSIX. 743 */ 744 } 745 return (mustexpandto(arg->text, "export") || 746 mustexpandto(arg->text, "readonly") || 747 (mustexpandto(arg->text, "local") && 748 (have_command || !isfunc("local")))); 749 } 750 751 /* 752 * Check if a builtin can safely be executed in the same process, 753 * even though it should be in a subshell (command substitution). 754 * Note that jobid, jobs, times and trap can show information not 755 * available in a child process; this is deliberate. 756 * The arguments should already have been expanded. 757 */ 758 static int 759 safe_builtin(int idx, int argc, char **argv) 760 { 761 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 762 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 763 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 764 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 765 idx == TYPECMD) 766 return (1); 767 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 768 idx == UMASKCMD) 769 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 770 if (idx == SETCMD) 771 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 772 argv[1][0] == '+') && argv[1][1] == 'o' && 773 argv[1][2] == '\0')); 774 return (0); 775 } 776 777 /* 778 * Execute a simple command. 779 * Note: This may or may not return if (flags & EV_EXIT). 780 */ 781 782 static void 783 evalcommand(union node *cmd, int flgs, struct backcmd *backcmd) 784 { 785 union node *argp; 786 struct arglist arglist; 787 struct arglist varlist; 788 volatile int flags = flgs; 789 char **volatile argv; 790 volatile 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 *volatile jp; 798 struct jmploc jmploc; 799 struct jmploc *savehandler; 800 const char *savecmdname; 801 struct shparam saveparam; 802 struct localvar *savelocalvars; 803 struct parsefile *savetopfile; 804 volatile int e; 805 char *volatile lastarg; 806 int realstatus; 807 volatile 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