1 /*- 2 * Copyright (c) 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <paths.h> 42 #include <signal.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 #include <sys/resource.h> 46 #include <sys/wait.h> /* For WIFSIGNALED(status) */ 47 #include <errno.h> 48 49 /* 50 * Evaluate a command. 51 */ 52 53 #include "shell.h" 54 #include "nodes.h" 55 #include "syntax.h" 56 #include "expand.h" 57 #include "parser.h" 58 #include "jobs.h" 59 #include "eval.h" 60 #include "builtins.h" 61 #include "options.h" 62 #include "exec.h" 63 #include "redir.h" 64 #include "input.h" 65 #include "output.h" 66 #include "trap.h" 67 #include "var.h" 68 #include "memalloc.h" 69 #include "error.h" 70 #include "show.h" 71 #include "mystring.h" 72 #ifndef NO_HISTORY 73 #include "myhistedit.h" 74 #endif 75 76 77 int evalskip; /* set if we are skipping commands */ 78 int skipcount; /* number of levels to skip */ 79 MKINIT int loopnest; /* current loop nesting level */ 80 int funcnest; /* depth of function calls */ 81 static int builtin_flags; /* evalcommand flags for builtins */ 82 83 84 char *commandname; 85 struct strlist *cmdenviron; 86 int exitstatus; /* exit status of last command */ 87 int oexitstatus; /* saved exit status */ 88 89 90 static void evalloop(union node *, int); 91 static void evalfor(union node *, int); 92 static union node *evalcase(union node *); 93 static void evalsubshell(union node *, int); 94 static void evalredir(union node *, int); 95 static void 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 #endif 115 116 117 118 /* 119 * The eval command. 120 */ 121 122 int 123 evalcmd(int argc, char **argv) 124 { 125 char *p; 126 char *concat; 127 char **ap; 128 129 if (argc > 1) { 130 p = argv[1]; 131 if (argc > 2) { 132 STARTSTACKSTR(concat); 133 ap = argv + 2; 134 for (;;) { 135 STPUTS(p, concat); 136 if ((p = *ap++) == NULL) 137 break; 138 STPUTC(' ', concat); 139 } 140 STPUTC('\0', concat); 141 p = grabstackstr(concat); 142 } 143 evalstring(p, builtin_flags); 144 } else 145 exitstatus = 0; 146 return exitstatus; 147 } 148 149 150 /* 151 * Execute a command or commands contained in a string. 152 */ 153 154 void 155 evalstring(char *s, int flags) 156 { 157 union node *n; 158 struct stackmark smark; 159 int flags_exit; 160 int any; 161 162 flags_exit = flags & EV_EXIT; 163 flags &= ~EV_EXIT; 164 any = 0; 165 setstackmark(&smark); 166 setinputstring(s, 1); 167 while ((n = parsecmd(0)) != NEOF) { 168 if (n != NULL && !nflag) { 169 if (flags_exit && preadateof()) 170 evaltree(n, flags | EV_EXIT); 171 else 172 evaltree(n, flags); 173 any = 1; 174 } 175 popstackmark(&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; 196 197 do_etest = 0; 198 if (n == NULL) { 199 TRACE(("evaltree(NULL) called\n")); 200 exitstatus = 0; 201 goto out; 202 } 203 do { 204 next = NULL; 205 #ifndef NO_HISTORY 206 displayhist = 1; /* show history substitutions done with fc */ 207 #endif 208 TRACE(("evaltree(%p: %d) called\n", (void *)n, n->type)); 209 switch (n->type) { 210 case NSEMI: 211 evaltree(n->nbinary.ch1, flags & ~EV_EXIT); 212 if (evalskip) 213 goto out; 214 next = n->nbinary.ch2; 215 break; 216 case NAND: 217 evaltree(n->nbinary.ch1, EV_TESTED); 218 if (evalskip || exitstatus != 0) { 219 goto out; 220 } 221 next = n->nbinary.ch2; 222 break; 223 case NOR: 224 evaltree(n->nbinary.ch1, EV_TESTED); 225 if (evalskip || exitstatus == 0) 226 goto out; 227 next = n->nbinary.ch2; 228 break; 229 case NREDIR: 230 evalredir(n, flags); 231 break; 232 case NSUBSHELL: 233 evalsubshell(n, flags); 234 do_etest = !(flags & EV_TESTED); 235 break; 236 case NBACKGND: 237 evalsubshell(n, flags); 238 break; 239 case NIF: { 240 evaltree(n->nif.test, EV_TESTED); 241 if (evalskip) 242 goto out; 243 if (exitstatus == 0) 244 next = n->nif.ifpart; 245 else if (n->nif.elsepart) 246 next = n->nif.elsepart; 247 else 248 exitstatus = 0; 249 break; 250 } 251 case NWHILE: 252 case NUNTIL: 253 evalloop(n, flags & ~EV_EXIT); 254 break; 255 case NFOR: 256 evalfor(n, flags & ~EV_EXIT); 257 break; 258 case NCASE: 259 next = evalcase(n); 260 break; 261 case NCLIST: 262 next = n->nclist.body; 263 break; 264 case NCLISTFALLTHRU: 265 if (n->nclist.body) { 266 evaltree(n->nclist.body, flags & ~EV_EXIT); 267 if (evalskip) 268 goto out; 269 } 270 next = n->nclist.next; 271 break; 272 case NDEFUN: 273 defun(n->narg.text, n->narg.next); 274 exitstatus = 0; 275 break; 276 case NNOT: 277 evaltree(n->nnot.com, EV_TESTED); 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, (struct backcmd *)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 } while (n != NULL); 296 out: 297 if (pendingsigs) 298 dotrap(); 299 if (eflag && exitstatus != 0 && do_etest) 300 exitshell(exitstatus); 301 if (flags & EV_EXIT) 302 exraise(EXEXIT); 303 } 304 305 306 static void 307 evalloop(union node *n, int flags) 308 { 309 int status; 310 311 loopnest++; 312 status = 0; 313 for (;;) { 314 evaltree(n->nbinary.ch1, EV_TESTED); 315 if (evalskip) { 316 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 317 evalskip = 0; 318 continue; 319 } 320 if (evalskip == SKIPBREAK && --skipcount <= 0) 321 evalskip = 0; 322 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 323 status = exitstatus; 324 break; 325 } 326 if (n->type == NWHILE) { 327 if (exitstatus != 0) 328 break; 329 } else { 330 if (exitstatus == 0) 331 break; 332 } 333 evaltree(n->nbinary.ch2, flags); 334 status = exitstatus; 335 if (evalskip) 336 goto skipping; 337 } 338 loopnest--; 339 exitstatus = status; 340 } 341 342 343 344 static void 345 evalfor(union node *n, int flags) 346 { 347 struct arglist arglist; 348 union node *argp; 349 struct strlist *sp; 350 struct stackmark smark; 351 int status; 352 353 setstackmark(&smark); 354 arglist.lastp = &arglist.list; 355 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 356 oexitstatus = exitstatus; 357 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 358 } 359 *arglist.lastp = NULL; 360 361 loopnest++; 362 status = 0; 363 for (sp = arglist.list ; sp ; sp = sp->next) { 364 setvar(n->nfor.var, sp->text, 0); 365 evaltree(n->nfor.body, flags); 366 status = exitstatus; 367 if (evalskip) { 368 if (evalskip == SKIPCONT && --skipcount <= 0) { 369 evalskip = 0; 370 continue; 371 } 372 if (evalskip == SKIPBREAK && --skipcount <= 0) 373 evalskip = 0; 374 break; 375 } 376 } 377 loopnest--; 378 popstackmark(&smark); 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 struct stackmark smark; 396 397 setstackmark(&smark); 398 arglist.lastp = &arglist.list; 399 oexitstatus = exitstatus; 400 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 401 for (cp = n->ncase.cases ; cp ; cp = cp->nclist.next) { 402 for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { 403 if (casematch(patp, arglist.list->text)) { 404 popstackmark(&smark); 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 popstackmark(&smark); 419 exitstatus = 0; 420 return (NULL); 421 } 422 423 424 425 /* 426 * Kick off a subshell to evaluate a tree. 427 */ 428 429 static void 430 evalsubshell(union node *n, int flags) 431 { 432 struct job *jp; 433 int backgnd = (n->type == NBACKGND); 434 435 oexitstatus = exitstatus; 436 expredir(n->nredir.redirect); 437 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 438 forkshell(jp = makejob(n, 1), n, backgnd) == 0) { 439 if (backgnd) 440 flags &=~ EV_TESTED; 441 redirect(n->nredir.redirect, 0); 442 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 443 } else if (! backgnd) { 444 INTOFF; 445 exitstatus = waitforjob(jp, (int *)NULL); 446 INTON; 447 } else 448 exitstatus = 0; 449 } 450 451 452 /* 453 * Evaluate a redirected compound command. 454 */ 455 456 static void 457 evalredir(union node *n, int flags) 458 { 459 struct jmploc jmploc; 460 struct jmploc *savehandler; 461 volatile int in_redirect = 1; 462 463 oexitstatus = exitstatus; 464 expredir(n->nredir.redirect); 465 savehandler = handler; 466 if (setjmp(jmploc.loc)) { 467 int e; 468 469 handler = savehandler; 470 e = exception; 471 popredir(); 472 if (e == EXERROR || e == EXEXEC) { 473 if (in_redirect) { 474 exitstatus = 2; 475 return; 476 } 477 } 478 longjmp(handler->loc, 1); 479 } else { 480 INTOFF; 481 handler = &jmploc; 482 redirect(n->nredir.redirect, REDIR_PUSH); 483 in_redirect = 0; 484 INTON; 485 evaltree(n->nredir.n, flags); 486 } 487 INTOFF; 488 handler = savehandler; 489 popredir(); 490 INTON; 491 } 492 493 494 /* 495 * Compute the names of the files in a redirection list. 496 */ 497 498 static void 499 expredir(union node *n) 500 { 501 union node *redir; 502 503 for (redir = n ; redir ; redir = redir->nfile.next) { 504 struct arglist fn; 505 fn.lastp = &fn.list; 506 switch (redir->type) { 507 case NFROM: 508 case NTO: 509 case NFROMTO: 510 case NAPPEND: 511 case NCLOBBER: 512 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 513 redir->nfile.expfname = fn.list->text; 514 break; 515 case NFROMFD: 516 case NTOFD: 517 if (redir->ndup.vname) { 518 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 519 fixredir(redir, fn.list->text, 1); 520 } 521 break; 522 } 523 } 524 } 525 526 527 528 /* 529 * Evaluate a pipeline. All the processes in the pipeline are children 530 * of the process creating the pipeline. (This differs from some versions 531 * of the shell, which make the last process in a pipeline the parent 532 * of all the rest.) 533 */ 534 535 static void 536 evalpipe(union node *n) 537 { 538 struct job *jp; 539 struct nodelist *lp; 540 int pipelen; 541 int prevfd; 542 int pip[2]; 543 544 TRACE(("evalpipe(%p) called\n", (void *)n)); 545 pipelen = 0; 546 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 547 pipelen++; 548 INTOFF; 549 jp = makejob(n, pipelen); 550 prevfd = -1; 551 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 552 prehash(lp->n); 553 pip[1] = -1; 554 if (lp->next) { 555 if (pipe(pip) < 0) { 556 close(prevfd); 557 error("Pipe call failed: %s", strerror(errno)); 558 } 559 } 560 if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { 561 INTON; 562 if (prevfd > 0) { 563 dup2(prevfd, 0); 564 close(prevfd); 565 } 566 if (pip[1] >= 0) { 567 if (!(prevfd >= 0 && pip[0] == 0)) 568 close(pip[0]); 569 if (pip[1] != 1) { 570 dup2(pip[1], 1); 571 close(pip[1]); 572 } 573 } 574 evaltree(lp->n, EV_EXIT); 575 } 576 if (prevfd >= 0) 577 close(prevfd); 578 prevfd = pip[0]; 579 if (pip[1] != -1) 580 close(pip[1]); 581 } 582 INTON; 583 if (n->npipe.backgnd == 0) { 584 INTOFF; 585 exitstatus = waitforjob(jp, (int *)NULL); 586 TRACE(("evalpipe: job done exit status %d\n", exitstatus)); 587 INTON; 588 } else 589 exitstatus = 0; 590 } 591 592 593 594 static int 595 is_valid_fast_cmdsubst(union node *n) 596 { 597 598 return (n->type == NCMD); 599 } 600 601 /* 602 * Execute a command inside back quotes. If it's a builtin command, we 603 * want to save its output in a block obtained from malloc. Otherwise 604 * we fork off a subprocess and get the output of the command via a pipe. 605 * Should be called with interrupts off. 606 */ 607 608 void 609 evalbackcmd(union node *n, struct backcmd *result) 610 { 611 int pip[2]; 612 struct job *jp; 613 struct stackmark smark; /* unnecessary */ 614 struct jmploc jmploc; 615 struct jmploc *savehandler; 616 struct localvar *savelocalvars; 617 618 setstackmark(&smark); 619 result->fd = -1; 620 result->buf = NULL; 621 result->nleft = 0; 622 result->jp = NULL; 623 if (n == NULL) { 624 exitstatus = 0; 625 goto out; 626 } 627 if (is_valid_fast_cmdsubst(n)) { 628 exitstatus = oexitstatus; 629 savelocalvars = localvars; 630 localvars = NULL; 631 forcelocal++; 632 savehandler = handler; 633 if (setjmp(jmploc.loc)) { 634 if (exception == EXERROR || exception == EXEXEC) 635 exitstatus = 2; 636 else if (exception != 0) { 637 handler = savehandler; 638 forcelocal--; 639 poplocalvars(); 640 localvars = savelocalvars; 641 longjmp(handler->loc, 1); 642 } 643 } else { 644 handler = &jmploc; 645 evalcommand(n, EV_BACKCMD, result); 646 } 647 handler = savehandler; 648 forcelocal--; 649 poplocalvars(); 650 localvars = savelocalvars; 651 } else { 652 exitstatus = 0; 653 if (pipe(pip) < 0) 654 error("Pipe call failed: %s", strerror(errno)); 655 jp = makejob(n, 1); 656 if (forkshell(jp, n, FORK_NOJOB) == 0) { 657 FORCEINTON; 658 close(pip[0]); 659 if (pip[1] != 1) { 660 dup2(pip[1], 1); 661 close(pip[1]); 662 } 663 evaltree(n, EV_EXIT); 664 } 665 close(pip[1]); 666 result->fd = pip[0]; 667 result->jp = jp; 668 } 669 out: 670 popstackmark(&smark); 671 TRACE(("evalbackcmd done: fd=%d buf=%p nleft=%d jp=%p\n", 672 result->fd, result->buf, result->nleft, result->jp)); 673 } 674 675 /* 676 * Check if a builtin can safely be executed in the same process, 677 * even though it should be in a subshell (command substitution). 678 * Note that jobid, jobs, times and trap can show information not 679 * available in a child process; this is deliberate. 680 * The arguments should already have been expanded. 681 */ 682 static int 683 safe_builtin(int idx, int argc, char **argv) 684 { 685 if (idx == BLTINCMD || idx == COMMANDCMD || idx == ECHOCMD || 686 idx == FALSECMD || idx == JOBIDCMD || idx == JOBSCMD || 687 idx == KILLCMD || idx == PRINTFCMD || idx == PWDCMD || 688 idx == TESTCMD || idx == TIMESCMD || idx == TRUECMD || 689 idx == TYPECMD) 690 return (1); 691 if (idx == EXPORTCMD || idx == TRAPCMD || idx == ULIMITCMD || 692 idx == UMASKCMD) 693 return (argc <= 1 || (argc == 2 && argv[1][0] == '-')); 694 if (idx == SETCMD) 695 return (argc <= 1 || (argc == 2 && (argv[1][0] == '-' || 696 argv[1][0] == '+') && argv[1][1] == 'o' && 697 argv[1][2] == '\0')); 698 return (0); 699 } 700 701 /* 702 * Execute a simple command. 703 * Note: This may or may not return if (flags & EV_EXIT). 704 */ 705 706 static void 707 evalcommand(union node *cmd, int flags, struct backcmd *backcmd) 708 { 709 struct stackmark smark; 710 union node *argp; 711 struct arglist arglist; 712 struct arglist varlist; 713 char **argv; 714 int argc; 715 char **envp; 716 int varflag; 717 struct strlist *sp; 718 int mode; 719 int pip[2]; 720 struct cmdentry cmdentry; 721 struct job *jp; 722 struct jmploc jmploc; 723 struct jmploc *savehandler; 724 char *savecmdname; 725 struct shparam saveparam; 726 struct localvar *savelocalvars; 727 struct parsefile *savetopfile; 728 volatile int e; 729 char *lastarg; 730 int realstatus; 731 int do_clearcmdentry; 732 const char *path = pathval(); 733 734 /* First expand the arguments. */ 735 TRACE(("evalcommand(%p, %d) called\n", (void *)cmd, flags)); 736 setstackmark(&smark); 737 arglist.lastp = &arglist.list; 738 varlist.lastp = &varlist.list; 739 varflag = 1; 740 jp = NULL; 741 do_clearcmdentry = 0; 742 oexitstatus = exitstatus; 743 exitstatus = 0; 744 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 745 if (varflag && isassignment(argp->narg.text)) { 746 expandarg(argp, &varlist, EXP_VARTILDE); 747 continue; 748 } 749 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 750 varflag = 0; 751 } 752 *arglist.lastp = NULL; 753 *varlist.lastp = NULL; 754 expredir(cmd->ncmd.redirect); 755 argc = 0; 756 for (sp = arglist.list ; sp ; sp = sp->next) 757 argc++; 758 /* Add one slot at the beginning for tryexec(). */ 759 argv = stalloc(sizeof (char *) * (argc + 2)); 760 argv++; 761 762 for (sp = arglist.list ; sp ; sp = sp->next) { 763 TRACE(("evalcommand arg: %s\n", sp->text)); 764 *argv++ = sp->text; 765 } 766 *argv = NULL; 767 lastarg = NULL; 768 if (iflag && funcnest == 0 && argc > 0) 769 lastarg = argv[-1]; 770 argv -= argc; 771 772 /* Print the command if xflag is set. */ 773 if (xflag) { 774 char sep = 0; 775 const char *p, *ps4; 776 ps4 = expandstr(ps4val()); 777 out2str(ps4 != NULL ? ps4 : ps4val()); 778 for (sp = varlist.list ; sp ; sp = sp->next) { 779 if (sep != 0) 780 out2c(' '); 781 p = strchr(sp->text, '='); 782 if (p != NULL) { 783 p++; 784 outbin(sp->text, p - sp->text, out2); 785 out2qstr(p); 786 } else 787 out2qstr(sp->text); 788 sep = ' '; 789 } 790 for (sp = arglist.list ; sp ; sp = sp->next) { 791 if (sep != 0) 792 out2c(' '); 793 /* Disambiguate command looking like assignment. */ 794 if (sp == arglist.list && 795 strchr(sp->text, '=') != NULL && 796 strchr(sp->text, '\'') == NULL) { 797 out2c('\''); 798 out2str(sp->text); 799 out2c('\''); 800 } else 801 out2qstr(sp->text); 802 sep = ' '; 803 } 804 out2c('\n'); 805 flushout(&errout); 806 } 807 808 /* Now locate the command. */ 809 if (argc == 0) { 810 /* Variable assignment(s) without command */ 811 cmdentry.cmdtype = CMDBUILTIN; 812 cmdentry.u.index = BLTINCMD; 813 cmdentry.special = 0; 814 } else { 815 static const char PATH[] = "PATH="; 816 int cmd_flags = 0, bltinonly = 0; 817 818 /* 819 * Modify the command lookup path, if a PATH= assignment 820 * is present 821 */ 822 for (sp = varlist.list ; sp ; sp = sp->next) 823 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) { 824 path = sp->text + sizeof(PATH) - 1; 825 /* 826 * On `PATH=... command`, we need to make 827 * sure that the command isn't using the 828 * non-updated hash table of the outer PATH 829 * setting and we need to make sure that 830 * the hash table isn't filled with items 831 * from the temporary setting. 832 * 833 * It would be better to forbit using and 834 * updating the table while this command 835 * runs, by the command finding mechanism 836 * is heavily integrated with hash handling, 837 * so we just delete the hash before and after 838 * the command runs. Partly deleting like 839 * changepatch() does doesn't seem worth the 840 * bookinging effort, since most such runs add 841 * directories in front of the new PATH. 842 */ 843 clearcmdentry(); 844 do_clearcmdentry = 1; 845 } 846 847 for (;;) { 848 if (bltinonly) { 849 cmdentry.u.index = find_builtin(*argv, &cmdentry.special); 850 if (cmdentry.u.index < 0) { 851 cmdentry.u.index = BLTINCMD; 852 argv--; 853 argc++; 854 break; 855 } 856 } else 857 find_command(argv[0], &cmdentry, cmd_flags, path); 858 /* implement the bltin and command builtins here */ 859 if (cmdentry.cmdtype != CMDBUILTIN) 860 break; 861 if (cmdentry.u.index == BLTINCMD) { 862 if (argc == 1) 863 break; 864 argv++; 865 argc--; 866 bltinonly = 1; 867 } else if (cmdentry.u.index == COMMANDCMD) { 868 if (argc == 1) 869 break; 870 if (!strcmp(argv[1], "-p")) { 871 if (argc == 2) 872 break; 873 if (argv[2][0] == '-') { 874 if (strcmp(argv[2], "--")) 875 break; 876 if (argc == 3) 877 break; 878 argv += 3; 879 argc -= 3; 880 } else { 881 argv += 2; 882 argc -= 2; 883 } 884 path = _PATH_STDPATH; 885 clearcmdentry(); 886 do_clearcmdentry = 1; 887 } else if (!strcmp(argv[1], "--")) { 888 if (argc == 2) 889 break; 890 argv += 2; 891 argc -= 2; 892 } else if (argv[1][0] == '-') 893 break; 894 else { 895 argv++; 896 argc--; 897 } 898 cmd_flags |= DO_NOFUNC; 899 bltinonly = 0; 900 } else 901 break; 902 } 903 /* 904 * Special builtins lose their special properties when 905 * called via 'command'. 906 */ 907 if (cmd_flags & DO_NOFUNC) 908 cmdentry.special = 0; 909 } 910 911 /* Fork off a child process if necessary. */ 912 if (((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 913 && ((flags & EV_EXIT) == 0 || have_traps())) 914 || ((flags & EV_BACKCMD) != 0 915 && (cmdentry.cmdtype != CMDBUILTIN || 916 !safe_builtin(cmdentry.u.index, argc, argv)))) { 917 jp = makejob(cmd, 1); 918 mode = FORK_FG; 919 if (flags & EV_BACKCMD) { 920 mode = FORK_NOJOB; 921 if (pipe(pip) < 0) 922 error("Pipe call failed: %s", strerror(errno)); 923 } 924 if (forkshell(jp, cmd, mode) != 0) 925 goto parent; /* at end of routine */ 926 if (flags & EV_BACKCMD) { 927 FORCEINTON; 928 close(pip[0]); 929 if (pip[1] != 1) { 930 dup2(pip[1], 1); 931 close(pip[1]); 932 } 933 flags &= ~EV_BACKCMD; 934 } 935 flags |= EV_EXIT; 936 } 937 938 /* This is the child process if a fork occurred. */ 939 /* Execute the command. */ 940 if (cmdentry.cmdtype == CMDFUNCTION) { 941 #ifdef DEBUG 942 trputs("Shell function: "); trargs(argv); 943 #endif 944 saveparam = shellparam; 945 shellparam.malloc = 0; 946 shellparam.reset = 1; 947 shellparam.nparam = argc - 1; 948 shellparam.p = argv + 1; 949 shellparam.optnext = NULL; 950 INTOFF; 951 savelocalvars = localvars; 952 localvars = NULL; 953 reffunc(cmdentry.u.func); 954 savehandler = handler; 955 if (setjmp(jmploc.loc)) { 956 freeparam(&shellparam); 957 shellparam = saveparam; 958 popredir(); 959 unreffunc(cmdentry.u.func); 960 poplocalvars(); 961 localvars = savelocalvars; 962 funcnest--; 963 handler = savehandler; 964 longjmp(handler->loc, 1); 965 } 966 handler = &jmploc; 967 funcnest++; 968 redirect(cmd->ncmd.redirect, REDIR_PUSH); 969 INTON; 970 for (sp = varlist.list ; sp ; sp = sp->next) 971 mklocal(sp->text); 972 exitstatus = oexitstatus; 973 evaltree(getfuncnode(cmdentry.u.func), 974 flags & (EV_TESTED | EV_EXIT)); 975 INTOFF; 976 unreffunc(cmdentry.u.func); 977 poplocalvars(); 978 localvars = savelocalvars; 979 freeparam(&shellparam); 980 shellparam = saveparam; 981 handler = savehandler; 982 funcnest--; 983 popredir(); 984 INTON; 985 if (evalskip == SKIPFUNC) { 986 evalskip = 0; 987 skipcount = 0; 988 } 989 if (jp) 990 exitshell(exitstatus); 991 } else if (cmdentry.cmdtype == CMDBUILTIN) { 992 #ifdef DEBUG 993 trputs("builtin command: "); trargs(argv); 994 #endif 995 mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; 996 if (flags == EV_BACKCMD) { 997 memout.nleft = 0; 998 memout.nextc = memout.buf; 999 memout.bufsize = 64; 1000 mode |= REDIR_BACKQ; 1001 } 1002 savecmdname = commandname; 1003 savetopfile = getcurrentfile(); 1004 cmdenviron = varlist.list; 1005 e = -1; 1006 savehandler = handler; 1007 if (setjmp(jmploc.loc)) { 1008 e = exception; 1009 if (e == EXINT) 1010 exitstatus = SIGINT+128; 1011 else if (e != EXEXIT) 1012 exitstatus = 2; 1013 goto cmddone; 1014 } 1015 handler = &jmploc; 1016 redirect(cmd->ncmd.redirect, mode); 1017 /* 1018 * If there is no command word, redirection errors should 1019 * not be fatal but assignment errors should. 1020 */ 1021 if (argc == 0) 1022 cmdentry.special = 1; 1023 listsetvar(cmdenviron, cmdentry.special ? 0 : VNOSET); 1024 if (argc > 0) 1025 bltinsetlocale(); 1026 commandname = argv[0]; 1027 argptr = argv + 1; 1028 nextopt_optptr = NULL; /* initialize nextopt */ 1029 builtin_flags = flags; 1030 exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); 1031 flushall(); 1032 cmddone: 1033 if (argc > 0) 1034 bltinunsetlocale(); 1035 cmdenviron = NULL; 1036 out1 = &output; 1037 out2 = &errout; 1038 freestdout(); 1039 handler = savehandler; 1040 commandname = savecmdname; 1041 if (jp) 1042 exitshell(exitstatus); 1043 if (flags == EV_BACKCMD) { 1044 backcmd->buf = memout.buf; 1045 backcmd->nleft = memout.nextc - memout.buf; 1046 memout.buf = NULL; 1047 } 1048 if (cmdentry.u.index != EXECCMD) 1049 popredir(); 1050 if (e != -1) { 1051 if ((e != EXERROR && e != EXEXEC) 1052 || cmdentry.special) 1053 exraise(e); 1054 popfilesupto(savetopfile); 1055 if (flags != EV_BACKCMD) 1056 FORCEINTON; 1057 } 1058 } else { 1059 #ifdef DEBUG 1060 trputs("normal command: "); trargs(argv); 1061 #endif 1062 redirect(cmd->ncmd.redirect, 0); 1063 for (sp = varlist.list ; sp ; sp = sp->next) 1064 setvareq(sp->text, VEXPORT|VSTACK); 1065 envp = environment(); 1066 shellexec(argv, envp, path, cmdentry.u.index); 1067 /*NOTREACHED*/ 1068 } 1069 goto out; 1070 1071 parent: /* parent process gets here (if we forked) */ 1072 if (mode == FORK_FG) { /* argument to fork */ 1073 INTOFF; 1074 exitstatus = waitforjob(jp, &realstatus); 1075 INTON; 1076 if (iflag && loopnest > 0 && WIFSIGNALED(realstatus)) { 1077 evalskip = SKIPBREAK; 1078 skipcount = loopnest; 1079 } 1080 } else if (mode == FORK_NOJOB) { 1081 backcmd->fd = pip[0]; 1082 close(pip[1]); 1083 backcmd->jp = jp; 1084 } 1085 1086 out: 1087 if (lastarg) 1088 setvar("_", lastarg, 0); 1089 if (do_clearcmdentry) 1090 clearcmdentry(); 1091 popstackmark(&smark); 1092 } 1093 1094 1095 1096 /* 1097 * Search for a command. This is called before we fork so that the 1098 * location of the command will be available in the parent as well as 1099 * the child. The check for "goodname" is an overly conservative 1100 * check that the name will not be subject to expansion. 1101 */ 1102 1103 static void 1104 prehash(union node *n) 1105 { 1106 struct cmdentry entry; 1107 1108 if (n && n->type == NCMD && n->ncmd.args) 1109 if (goodname(n->ncmd.args->narg.text)) 1110 find_command(n->ncmd.args->narg.text, &entry, 0, 1111 pathval()); 1112 } 1113 1114 1115 1116 /* 1117 * Builtin commands. Builtin commands whose functions are closely 1118 * tied to evaluation are implemented here. 1119 */ 1120 1121 /* 1122 * No command given, a bltin command with no arguments, or a bltin command 1123 * with an invalid name. 1124 */ 1125 1126 int 1127 bltincmd(int argc, char **argv) 1128 { 1129 if (argc > 1) { 1130 out2fmt_flush("%s: not found\n", argv[1]); 1131 return 127; 1132 } 1133 /* 1134 * Preserve exitstatus of a previous possible redirection 1135 * as POSIX mandates 1136 */ 1137 return exitstatus; 1138 } 1139 1140 1141 /* 1142 * Handle break and continue commands. Break, continue, and return are 1143 * all handled by setting the evalskip flag. The evaluation routines 1144 * above all check this flag, and if it is set they start skipping 1145 * commands rather than executing them. The variable skipcount is 1146 * the number of loops to break/continue, or the number of function 1147 * levels to return. (The latter is always 1.) It should probably 1148 * be an error to break out of more loops than exist, but it isn't 1149 * in the standard shell so we don't make it one here. 1150 */ 1151 1152 int 1153 breakcmd(int argc, char **argv) 1154 { 1155 int n = argc > 1 ? number(argv[1]) : 1; 1156 1157 if (n > loopnest) 1158 n = loopnest; 1159 if (n > 0) { 1160 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1161 skipcount = n; 1162 } 1163 return 0; 1164 } 1165 1166 /* 1167 * The `command' command. 1168 */ 1169 int 1170 commandcmd(int argc, char **argv) 1171 { 1172 const char *path; 1173 int ch; 1174 int cmd = -1; 1175 1176 path = bltinlookup("PATH", 1); 1177 1178 optind = optreset = 1; 1179 opterr = 0; 1180 while ((ch = getopt(argc, argv, "pvV")) != -1) { 1181 switch (ch) { 1182 case 'p': 1183 path = _PATH_STDPATH; 1184 break; 1185 case 'v': 1186 cmd = TYPECMD_SMALLV; 1187 break; 1188 case 'V': 1189 cmd = TYPECMD_BIGV; 1190 break; 1191 case '?': 1192 default: 1193 error("unknown option: -%c", optopt); 1194 } 1195 } 1196 argc -= optind; 1197 argv += optind; 1198 1199 if (cmd != -1) { 1200 if (argc != 1) 1201 error("wrong number of arguments"); 1202 return typecmd_impl(2, argv - 1, cmd, path); 1203 } 1204 if (argc != 0) 1205 error("commandcmd bad call"); 1206 1207 /* 1208 * Do nothing successfully if no command was specified; 1209 * ksh also does this. 1210 */ 1211 return 0; 1212 } 1213 1214 1215 /* 1216 * The return command. 1217 */ 1218 1219 int 1220 returncmd(int argc, char **argv) 1221 { 1222 int ret = argc > 1 ? number(argv[1]) : oexitstatus; 1223 1224 if (funcnest) { 1225 evalskip = SKIPFUNC; 1226 skipcount = 1; 1227 } else { 1228 /* skip the rest of the file */ 1229 evalskip = SKIPFILE; 1230 skipcount = 1; 1231 } 1232 return ret; 1233 } 1234 1235 1236 int 1237 falsecmd(int argc __unused, char **argv __unused) 1238 { 1239 return 1; 1240 } 1241 1242 1243 int 1244 truecmd(int argc __unused, char **argv __unused) 1245 { 1246 return 0; 1247 } 1248 1249 1250 int 1251 execcmd(int argc, char **argv) 1252 { 1253 /* 1254 * Because we have historically not supported any options, 1255 * only treat "--" specially. 1256 */ 1257 if (argc > 1 && strcmp(argv[1], "--") == 0) 1258 argc--, argv++; 1259 if (argc > 1) { 1260 struct strlist *sp; 1261 1262 iflag = 0; /* exit on error */ 1263 mflag = 0; 1264 optschanged(); 1265 for (sp = cmdenviron; sp ; sp = sp->next) 1266 setvareq(sp->text, VEXPORT|VSTACK); 1267 shellexec(argv + 1, environment(), pathval(), 0); 1268 1269 } 1270 return 0; 1271 } 1272 1273 1274 int 1275 timescmd(int argc __unused, char **argv __unused) 1276 { 1277 struct rusage ru; 1278 long shumins, shsmins, chumins, chsmins; 1279 double shusecs, shssecs, chusecs, chssecs; 1280 1281 if (getrusage(RUSAGE_SELF, &ru) < 0) 1282 return 1; 1283 shumins = ru.ru_utime.tv_sec / 60; 1284 shusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1285 shsmins = ru.ru_stime.tv_sec / 60; 1286 shssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1287 if (getrusage(RUSAGE_CHILDREN, &ru) < 0) 1288 return 1; 1289 chumins = ru.ru_utime.tv_sec / 60; 1290 chusecs = ru.ru_utime.tv_sec % 60 + ru.ru_utime.tv_usec / 1000000.; 1291 chsmins = ru.ru_stime.tv_sec / 60; 1292 chssecs = ru.ru_stime.tv_sec % 60 + ru.ru_stime.tv_usec / 1000000.; 1293 out1fmt("%ldm%.3fs %ldm%.3fs\n%ldm%.3fs %ldm%.3fs\n", shumins, 1294 shusecs, shsmins, shssecs, chumins, chusecs, chsmins, chssecs); 1295 return 0; 1296 } 1297