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