1 /* $NetBSD: eval.c,v 1.189 2023/04/07 10:34:13 kre Exp $ */ 2 3 /*- 4 * Copyright (c) 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95"; 39 #else 40 __RCSID("$NetBSD: eval.c,v 1.189 2023/04/07 10:34:13 kre Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <stdbool.h> 45 #include <stdlib.h> 46 #include <signal.h> 47 #include <stdio.h> 48 #include <string.h> 49 #include <errno.h> 50 #include <limits.h> 51 #include <unistd.h> 52 #include <sys/fcntl.h> 53 #include <sys/stat.h> 54 #include <sys/times.h> 55 #include <sys/param.h> 56 #include <sys/types.h> 57 #include <sys/wait.h> 58 #include <sys/sysctl.h> 59 60 /* 61 * Evaluate a command. 62 */ 63 64 #include "shell.h" 65 #include "nodes.h" 66 #include "syntax.h" 67 #include "expand.h" 68 #include "parser.h" 69 #include "jobs.h" 70 #include "eval.h" 71 #include "builtins.h" 72 #include "options.h" 73 #include "exec.h" 74 #include "redir.h" 75 #include "input.h" 76 #include "output.h" 77 #include "trap.h" 78 #include "var.h" 79 #include "memalloc.h" 80 #include "error.h" 81 #include "show.h" 82 #include "mystring.h" 83 #include "main.h" 84 #ifndef SMALL 85 #include "nodenames.h" 86 #include "myhistedit.h" 87 #endif 88 89 90 STATIC struct skipsave s_k_i_p; 91 #define evalskip (s_k_i_p.state) 92 #define skipcount (s_k_i_p.count) 93 94 STATIC int loopnest; /* current loop nesting level */ 95 STATIC int funcnest; /* depth of function calls */ 96 STATIC int builtin_flags; /* evalcommand flags for builtins */ 97 /* 98 * Base function nesting level inside a dot command. Set to 0 initially 99 * and to (funcnest + 1) before every dot command to enable 100 * 1) detection of being in a file sourced by a dot command and 101 * 2) counting of function nesting in that file for the implementation 102 * of the return command. 103 * The value is reset to its previous value after the dot command. 104 */ 105 STATIC int dot_funcnest; 106 107 108 const char *commandname; 109 struct strlist *cmdenviron; 110 int exitstatus; /* exit status of last command */ 111 int back_exitstatus; /* exit status of backquoted command */ 112 113 114 STATIC void evalloop(union node *, int); 115 STATIC void evalfor(union node *, int); 116 STATIC void evalcase(union node *, int); 117 STATIC void evalsubshell(union node *, int); 118 STATIC void expredir(union node *); 119 STATIC void evalredir(union node *, int); 120 STATIC void evalpipe(union node *); 121 STATIC void evalcommand(union node *, int, struct backcmd *); 122 STATIC void prehash(union node *); 123 124 STATIC char *find_dot_file(char *); 125 126 /* 127 * Called to reset things after an exception. 128 */ 129 130 #ifdef mkinit 131 INCLUDE "eval.h" 132 133 RESET { 134 reset_eval(); 135 } 136 137 SHELLPROC { 138 exitstatus = 0; 139 } 140 #endif 141 142 void 143 reset_eval(void) 144 { 145 evalskip = SKIPNONE; 146 dot_funcnest = 0; 147 loopnest = 0; 148 funcnest = 0; 149 } 150 151 static int 152 sh_pipe(int fds[2]) 153 { 154 int nfd; 155 156 if (pipe(fds)) 157 return -1; 158 159 if (fds[0] < 3) { 160 nfd = fcntl(fds[0], F_DUPFD, 3); 161 if (nfd != -1) { 162 close(fds[0]); 163 fds[0] = nfd; 164 } 165 } 166 167 if (fds[1] < 3) { 168 nfd = fcntl(fds[1], F_DUPFD, 3); 169 if (nfd != -1) { 170 close(fds[1]); 171 fds[1] = nfd; 172 } 173 } 174 return 0; 175 } 176 177 178 /* 179 * The eval command. 180 */ 181 182 int 183 evalcmd(int argc, char **argv) 184 { 185 char *p; 186 char *concat; 187 char **ap; 188 189 if (argc > 1) { 190 p = argv[1]; 191 if (argc > 2) { 192 STARTSTACKSTR(concat); 193 ap = argv + 2; 194 for (;;) { 195 while (*p) 196 STPUTC(*p++, concat); 197 if ((p = *ap++) == NULL) 198 break; 199 STPUTC(' ', concat); 200 } 201 STPUTC('\0', concat); 202 p = grabstackstr(concat); 203 } 204 evalstring(p, builtin_flags & EV_TESTED); 205 } else 206 exitstatus = 0; 207 return exitstatus; 208 } 209 210 211 /* 212 * Execute a command or commands contained in a string. 213 */ 214 215 void 216 evalstring(char *s, int flag) 217 { 218 union node *n; 219 struct stackmark smark; 220 int last; 221 int any; 222 223 last = flag & EV_EXIT; 224 flag &= ~EV_EXIT; 225 226 setstackmark(&smark); 227 setinputstring(s, 1, line_number); 228 229 any = 0; /* to determine if exitstatus will have been set */ 230 while ((n = parsecmd(0)) != NEOF) { 231 XTRACE(DBG_EVAL, ("evalstring: "), showtree(n)); 232 if (n && nflag == 0) { 233 if (last && at_eof()) 234 evaltree(n, flag | EV_EXIT); 235 else 236 evaltree(n, flag); 237 any = 1; 238 if (evalskip) 239 break; 240 } 241 rststackmark(&smark); 242 } 243 popfile(); 244 popstackmark(&smark); 245 if (!any) 246 exitstatus = 0; 247 if (last) 248 exraise(EXEXIT); 249 } 250 251 252 253 /* 254 * Evaluate a parse tree. The value is left in the global variable 255 * exitstatus. 256 */ 257 258 void 259 evaltree(union node *n, int flags) 260 { 261 bool do_etest; 262 int sflags = flags & ~EV_EXIT; 263 union node *next; 264 struct stackmark smark; 265 266 do_etest = false; 267 if (n == NULL || nflag) { 268 VTRACE(DBG_EVAL, ("evaltree(%s) called\n", 269 n == NULL ? "NULL" : "-n")); 270 if (nflag == 0) 271 exitstatus = 0; 272 goto out2; 273 } 274 275 setstackmark(&smark); 276 do { 277 #ifndef SMALL 278 displayhist = 1; /* show history substitutions done with fc */ 279 #endif 280 next = NULL; 281 CTRACE(DBG_EVAL, ("pid %d, evaltree(%p: %s(%d), %#x) called\n", 282 getpid(), n, NODETYPENAME(n->type), n->type, flags)); 283 /* 284 if (n->type != NCMD && traps_invalid) 285 free_traps(); 286 */ 287 switch (n->type) { 288 case NSEMI: 289 evaltree(n->nbinary.ch1, sflags); 290 if (nflag || evalskip) 291 goto out1; 292 next = n->nbinary.ch2; 293 break; 294 case NAND: 295 evaltree(n->nbinary.ch1, EV_TESTED); 296 if (nflag || evalskip || exitstatus != 0) 297 goto out1; 298 next = n->nbinary.ch2; 299 break; 300 case NOR: 301 evaltree(n->nbinary.ch1, EV_TESTED); 302 if (nflag || evalskip || exitstatus == 0) 303 goto out1; 304 next = n->nbinary.ch2; 305 break; 306 case NREDIR: 307 if (traps_invalid) 308 free_traps(); 309 evalredir(n, flags); 310 break; 311 case NSUBSHELL: 312 evalsubshell(n, flags); 313 do_etest = !(flags & EV_TESTED); 314 break; 315 case NBACKGND: 316 if (traps_invalid) 317 free_traps(); 318 evalsubshell(n, flags); 319 break; 320 case NIF: { 321 if (traps_invalid) 322 free_traps(); 323 evaltree(n->nif.test, EV_TESTED); 324 if (nflag || evalskip) 325 goto out1; 326 if (exitstatus == 0) 327 next = n->nif.ifpart; 328 else if (n->nif.elsepart) 329 next = n->nif.elsepart; 330 else 331 exitstatus = 0; 332 break; 333 } 334 case NWHILE: 335 case NUNTIL: 336 if (traps_invalid) 337 free_traps(); 338 evalloop(n, sflags); 339 break; 340 case NFOR: 341 if (traps_invalid) 342 free_traps(); 343 evalfor(n, sflags); 344 break; 345 case NCASE: 346 if (traps_invalid) 347 free_traps(); 348 evalcase(n, sflags); 349 break; 350 case NDEFUN: 351 if (traps_invalid) 352 free_traps(); 353 CTRACE(DBG_EVAL, ("Defining fn %s @%d%s\n", 354 n->narg.text, n->narg.lineno, 355 fnline1 ? " LINENO=1" : "")); 356 defun(n->narg.text, n->narg.next, n->narg.lineno); 357 exitstatus = 0; 358 break; 359 case NNOT: 360 evaltree(n->nnot.com, EV_TESTED); 361 exitstatus = !exitstatus; 362 break; 363 case NDNOT: 364 evaltree(n->nnot.com, EV_TESTED); 365 if (exitstatus != 0) 366 exitstatus = 1; 367 break; 368 case NPIPE: 369 if (traps_invalid) 370 free_traps(); 371 evalpipe(n); 372 do_etest = !(flags & EV_TESTED); 373 break; 374 case NCMD: 375 evalcommand(n, flags, NULL); 376 do_etest = !(flags & EV_TESTED); 377 break; 378 default: 379 #ifdef NODETYPENAME 380 out1fmt("Node type = %d(%s)\n", 381 n->type, NODETYPENAME(n->type)); 382 #else 383 out1fmt("Node type = %d\n", n->type); 384 #endif 385 flushout(&output); 386 break; 387 } 388 n = next; 389 rststackmark(&smark); 390 } while(n != NULL); 391 out1: 392 popstackmark(&smark); 393 out2: 394 if (pendingsigs) 395 dotrap(); 396 if (eflag && exitstatus != 0 && do_etest) 397 exitshell(exitstatus); 398 if (flags & EV_EXIT) 399 exraise(EXEXIT); 400 } 401 402 403 STATIC void 404 evalloop(union node *n, int flags) 405 { 406 int status; 407 408 loopnest++; 409 status = 0; 410 411 CTRACE(DBG_EVAL, ("evalloop %s:", NODETYPENAME(n->type))); 412 VXTRACE(DBG_EVAL, (" "), showtree(n->nbinary.ch1)); 413 VXTRACE(DBG_EVAL, ("evalloop do: "), showtree(n->nbinary.ch2)); 414 VTRACE(DBG_EVAL, ("evalloop done\n")); 415 CTRACE(DBG_EVAL, ("\n")); 416 417 for (;;) { 418 evaltree(n->nbinary.ch1, EV_TESTED); 419 if (nflag) 420 break; 421 if (evalskip) { 422 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 423 evalskip = SKIPNONE; 424 continue; 425 } 426 if (evalskip == SKIPBREAK && --skipcount <= 0) 427 evalskip = SKIPNONE; 428 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 429 status = exitstatus; 430 break; 431 } 432 if (n->type == NWHILE) { 433 if (exitstatus != 0) 434 break; 435 } else { 436 if (exitstatus == 0) 437 break; 438 } 439 evaltree(n->nbinary.ch2, flags & EV_TESTED); 440 status = exitstatus; 441 if (evalskip) 442 goto skipping; 443 } 444 loopnest--; 445 exitstatus = status; 446 } 447 448 449 450 STATIC void 451 evalfor(union node *n, int flags) 452 { 453 struct arglist arglist; 454 union node *argp; 455 struct strlist *sp; 456 struct stackmark smark; 457 int status; 458 459 status = nflag ? exitstatus : 0; 460 461 setstackmark(&smark); 462 arglist.lastp = &arglist.list; 463 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 464 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 465 if (evalskip) 466 goto out; 467 } 468 *arglist.lastp = NULL; 469 470 loopnest++; 471 for (sp = arglist.list ; sp ; sp = sp->next) { 472 line_number = n->nfor.lineno; 473 if (xflag) { 474 outxstr(expandstr(ps4val(), line_number)); 475 outxstr("for "); 476 outxstr(n->nfor.var); 477 outxc('='); 478 outxshstr(sp->text); 479 outxc('\n'); 480 flushout(outx); 481 } 482 483 setvar(n->nfor.var, sp->text, 0); 484 evaltree(n->nfor.body, flags & EV_TESTED); 485 status = exitstatus; 486 if (nflag) 487 break; 488 if (evalskip) { 489 if (evalskip == SKIPCONT && --skipcount <= 0) { 490 evalskip = SKIPNONE; 491 continue; 492 } 493 if (evalskip == SKIPBREAK && --skipcount <= 0) 494 evalskip = SKIPNONE; 495 break; 496 } 497 } 498 loopnest--; 499 exitstatus = status; 500 out: 501 popstackmark(&smark); 502 } 503 504 505 506 STATIC void 507 evalcase(union node *n, int flags) 508 { 509 union node *cp, *ncp; 510 union node *patp; 511 struct arglist arglist; 512 struct stackmark smark; 513 int status = 0; 514 515 setstackmark(&smark); 516 arglist.lastp = &arglist.list; 517 line_number = n->ncase.lineno; 518 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 519 for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) { 520 for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) { 521 line_number = patp->narg.lineno; 522 if (casematch(patp, arglist.list->text)) { 523 while (cp != NULL && evalskip == 0 && 524 nflag == 0) { 525 if (cp->type == NCLISTCONT) 526 ncp = cp->nclist.next; 527 else 528 ncp = NULL; 529 line_number = cp->nclist.lineno; 530 evaltree(cp->nclist.body, flags); 531 status = exitstatus; 532 cp = ncp; 533 } 534 goto out; 535 } 536 } 537 } 538 out: 539 exitstatus = status; 540 popstackmark(&smark); 541 } 542 543 544 545 /* 546 * Kick off a subshell to evaluate a tree. 547 */ 548 549 STATIC void 550 evalsubshell(union node *n, int flags) 551 { 552 struct job *jp= NULL; 553 int backgnd = (n->type == NBACKGND); 554 555 expredir(n->nredir.redirect); 556 if (xflag && n->nredir.redirect) { 557 union node *rn; 558 559 outxstr(expandstr(ps4val(), line_number)); 560 outxstr("using redirections:"); 561 for (rn = n->nredir.redirect; rn; rn = rn->nfile.next) 562 (void) outredir(outx, rn, ' '); 563 outxstr(" do subshell ("/*)*/); 564 if (backgnd) 565 outxstr(/*(*/") &"); 566 outxc('\n'); 567 flushout(outx); 568 } 569 INTOFF; 570 if ((!backgnd && flags & EV_EXIT && !have_traps() && !anyjobs()) || 571 forkshell(jp = makejob(n, 1), n, backgnd?FORK_BG:FORK_FG) == 0) { 572 if (backgnd) 573 flags &=~ EV_TESTED; 574 INTON; 575 redirect(n->nredir.redirect, REDIR_KEEP); 576 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 577 } else if (backgnd) 578 exitstatus = 0; 579 else 580 exitstatus = waitforjob(jp); 581 INTON; 582 583 if (!backgnd && xflag && n->nredir.redirect) { 584 outxstr(expandstr(ps4val(), line_number)); 585 outxstr(/*(*/") done subshell\n"); 586 flushout(outx); 587 } 588 } 589 590 591 592 /* 593 * Compute the names of the files in a redirection list. 594 */ 595 596 STATIC void 597 expredir(union node *n) 598 { 599 union node *redir; 600 601 for (redir = n ; redir ; redir = redir->nfile.next) { 602 struct arglist fn; 603 604 fn.lastp = &fn.list; 605 switch (redir->type) { 606 case NFROMTO: 607 case NFROM: 608 case NTO: 609 case NCLOBBER: 610 case NAPPEND: 611 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 612 redir->nfile.expfname = fn.list->text; 613 break; 614 case NFROMFD: 615 case NTOFD: 616 if (redir->ndup.vname) { 617 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 618 fixredir(redir, fn.list->text, 1); 619 } 620 break; 621 case NHERE: 622 redir->nhere.text = redir->nhere.doc->narg.text; 623 break; 624 case NXHERE: 625 redir->nhere.text = expandhere(redir->nhere.doc); 626 break; 627 } 628 } 629 } 630 631 /* 632 * Perform redirections for a compound command, and then do it (and restore) 633 */ 634 STATIC void 635 evalredir(union node *n, int flags) 636 { 637 struct jmploc jmploc; 638 struct jmploc * const savehandler = handler; 639 volatile int in_redirect = 1; 640 const char * volatile PS4 = NULL; 641 642 expredir(n->nredir.redirect); 643 644 if (xflag && n->nredir.redirect) { 645 union node *rn; 646 647 outxstr(PS4 = expandstr(ps4val(), line_number)); 648 outxstr("using redirections:"); 649 for (rn = n->nredir.redirect; rn != NULL; rn = rn->nfile.next) 650 (void) outredir(outx, rn, ' '); 651 outxstr(" do {\n"); /* } */ 652 flushout(outx); 653 } 654 655 if (setjmp(jmploc.loc)) { 656 int e; 657 658 handler = savehandler; 659 e = exception; 660 popredir(); 661 if (PS4 != NULL) { 662 outxstr(PS4); 663 /* { */ outxstr("} failed\n"); 664 flushout(outx); 665 } 666 if (e == EXERROR || e == EXEXEC) { 667 if (in_redirect) { 668 exitstatus = 2; 669 return; 670 } 671 } 672 longjmp(handler->loc, 1); 673 } else { 674 INTOFF; 675 handler = &jmploc; 676 redirect(n->nredir.redirect, REDIR_PUSH | REDIR_KEEP); 677 in_redirect = 0; 678 INTON; 679 evaltree(n->nredir.n, flags); 680 } 681 INTOFF; 682 handler = savehandler; 683 popredir(); 684 INTON; 685 686 if (PS4 != NULL) { 687 outxstr(PS4); 688 /* { */ outxstr("} done\n"); 689 flushout(outx); 690 } 691 } 692 693 694 /* 695 * Evaluate a pipeline. All the processes in the pipeline are children 696 * of the process creating the pipeline. (This differs from some versions 697 * of the shell, which make the last process in a pipeline the parent 698 * of all the rest.) 699 */ 700 701 STATIC void 702 evalpipe(union node *n) 703 { 704 struct job *jp; 705 struct nodelist *lp; 706 int pipelen; 707 int prevfd; 708 int pip[2]; 709 710 CTRACE(DBG_EVAL, ("evalpipe(%p) called\n", n)); 711 pipelen = 0; 712 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 713 pipelen++; 714 INTOFF; 715 jp = makejob(n, pipelen); 716 prevfd = -1; 717 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 718 prehash(lp->n); 719 pip[1] = -1; 720 if (lp->next) { 721 if (sh_pipe(pip) < 0) { 722 if (prevfd >= 0) 723 close(prevfd); 724 error("Pipe call failed: %s", strerror(errno)); 725 } 726 } 727 if (forkshell(jp, lp->n, 728 n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) { 729 INTON; 730 if (prevfd > 0) 731 movefd(prevfd, 0); 732 if (pip[1] >= 0) { 733 close(pip[0]); 734 movefd(pip[1], 1); 735 } 736 evaltree(lp->n, EV_EXIT); 737 } 738 if (prevfd >= 0) 739 close(prevfd); 740 prevfd = pip[0]; 741 close(pip[1]); 742 } 743 if (n->npipe.backgnd == 0) { 744 exitstatus = waitforjob(jp); 745 CTRACE(DBG_EVAL, ("evalpipe: job done exit status %d\n", 746 exitstatus)); 747 } else 748 exitstatus = 0; 749 INTON; 750 } 751 752 753 754 /* 755 * Execute a command inside back quotes. If it's a builtin command, we 756 * want to save its output in a block obtained from malloc. Otherwise 757 * we fork off a subprocess and get the output of the command via a pipe. 758 * Should be called with interrupts off. 759 */ 760 761 void 762 evalbackcmd(union node *n, struct backcmd *result) 763 { 764 int pip[2]; 765 struct job *jp; 766 struct stackmark smark; /* unnecessary (because we fork) */ 767 768 result->fd = -1; 769 result->buf = NULL; 770 result->nleft = 0; 771 result->jp = NULL; 772 773 if (nflag || n == NULL) 774 goto out; 775 776 setstackmark(&smark); 777 778 #ifdef notyet 779 /* 780 * For now we disable executing builtins in the same 781 * context as the shell, because we are not keeping 782 * enough state to recover from changes that are 783 * supposed only to affect subshells. eg. echo "`cd /`" 784 */ 785 if (n->type == NCMD) { 786 exitstatus = oexitstatus; /* XXX o... no longer exists */ 787 evalcommand(n, EV_BACKCMD, result); 788 } else 789 #endif 790 { 791 INTOFF; 792 if (sh_pipe(pip) < 0) 793 error("Pipe call failed"); 794 jp = makejob(n, 1); 795 if (forkshell(jp, n, FORK_NOJOB) == 0) { 796 FORCEINTON; 797 close(pip[0]); 798 movefd(pip[1], 1); 799 evaltree(n, EV_EXIT); 800 /* NOTREACHED */ 801 } 802 close(pip[1]); 803 result->fd = pip[0]; 804 result->jp = jp; 805 INTON; 806 } 807 popstackmark(&smark); 808 out: 809 CTRACE(DBG_EVAL, ("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", 810 result->fd, result->buf, result->nleft, result->jp)); 811 } 812 813 const char * 814 syspath(void) 815 { 816 static char *sys_path = NULL; 817 static int mib[] = {CTL_USER, USER_CS_PATH}; 818 static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin"; 819 size_t len; 820 821 if (sys_path == NULL) { 822 if (sysctl(mib, 2, 0, &len, 0, 0) != -1 && 823 (sys_path = ckmalloc(len + 5)) != NULL && 824 sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) { 825 memcpy(sys_path, "PATH=", 5); 826 } else { 827 ckfree(sys_path); 828 /* something to keep things happy */ 829 sys_path = def_path; 830 } 831 } 832 return sys_path; 833 } 834 835 static int 836 parse_command_args(int argc, char **argv, int *use_syspath) 837 { 838 int sv_argc = argc; 839 char *cp, c; 840 841 *use_syspath = 0; 842 843 for (;;) { 844 argv++; 845 if (--argc == 0) 846 break; 847 cp = *argv; 848 if (*cp++ != '-') 849 break; 850 if (*cp == '-' && cp[1] == 0) { 851 argv++; 852 argc--; 853 break; 854 } 855 while ((c = *cp++)) { 856 switch (c) { 857 case 'p': 858 *use_syspath = 1; 859 break; 860 default: 861 /* run 'typecmd' for other options */ 862 return 0; 863 } 864 } 865 } 866 return sv_argc - argc; 867 } 868 869 int vforked = 0; 870 871 /* 872 * Execute a simple command. 873 */ 874 875 STATIC void 876 evalcommand(union node *cmd, int flgs, struct backcmd *backcmd) 877 { 878 struct stackmark smark; 879 union node *argp; 880 struct arglist arglist; 881 struct arglist varlist; 882 volatile int flags = flgs; 883 char ** volatile argv; 884 volatile int argc; 885 char **envp; 886 int varflag; 887 struct strlist *sp; 888 volatile int mode; 889 int pip[2]; 890 struct cmdentry cmdentry; 891 struct job * volatile jp; 892 struct jmploc jmploc; 893 struct jmploc *volatile savehandler = NULL; 894 const char *volatile savecmdname; 895 volatile struct shparam saveparam; 896 struct localvar *volatile savelocalvars; 897 struct parsefile *volatile savetopfile; 898 volatile int e; 899 char * volatile lastarg; 900 const char * volatile path = pathval(); 901 volatile int temp_path; 902 const int savefuncline = funclinebase; 903 const int savefuncabs = funclineabs; 904 volatile int cmd_flags = 0; 905 906 vforked = 0; 907 /* First expand the arguments. */ 908 CTRACE(DBG_EVAL, ("evalcommand(%p, %d) called [%s]\n", cmd, flags, 909 cmd->ncmd.args ? cmd->ncmd.args->narg.text : "")); 910 setstackmark(&smark); 911 back_exitstatus = 0; 912 913 line_number = cmd->ncmd.lineno; 914 915 arglist.lastp = &arglist.list; 916 varflag = 1; 917 /* Expand arguments, ignoring the initial 'name=value' ones */ 918 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 919 if (varflag && isassignment(argp->narg.text)) 920 continue; 921 varflag = 0; 922 line_number = argp->narg.lineno; 923 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 924 } 925 *arglist.lastp = NULL; 926 927 expredir(cmd->ncmd.redirect); 928 929 /* Now do the initial 'name=value' ones we skipped above */ 930 varlist.lastp = &varlist.list; 931 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 932 line_number = argp->narg.lineno; 933 if (!isassignment(argp->narg.text)) 934 break; 935 expandarg(argp, &varlist, EXP_VARTILDE); 936 } 937 *varlist.lastp = NULL; 938 939 argc = 0; 940 for (sp = arglist.list ; sp ; sp = sp->next) 941 argc++; 942 argv = stalloc(sizeof (char *) * (argc + 1)); 943 944 for (sp = arglist.list ; sp ; sp = sp->next) { 945 VTRACE(DBG_EVAL, ("evalcommand arg: %s\n", sp->text)); 946 *argv++ = sp->text; 947 } 948 *argv = NULL; 949 lastarg = NULL; 950 if (iflag && funcnest == 0 && argc > 0) 951 lastarg = argv[-1]; 952 argv -= argc; 953 954 /* Print the command if xflag is set. */ 955 if (xflag) { 956 char sep = 0; 957 union node *rn; 958 959 outxstr(expandstr(ps4val(), line_number)); 960 for (sp = varlist.list ; sp ; sp = sp->next) { 961 char *p; 962 963 if (sep != 0) 964 outxc(sep); 965 966 /* 967 * The "var=" part should not be quoted, regardless 968 * of the value, or it would not represent an 969 * assignment, but rather a command 970 */ 971 p = strchr(sp->text, '='); 972 if (p != NULL) { 973 *p = '\0'; /*XXX*/ 974 outxshstr(sp->text); 975 outxc('='); 976 *p++ = '='; /*XXX*/ 977 } else 978 p = sp->text; 979 outxshstr(p); 980 sep = ' '; 981 } 982 for (sp = arglist.list ; sp ; sp = sp->next) { 983 if (sep != 0) 984 outxc(sep); 985 outxshstr(sp->text); 986 sep = ' '; 987 } 988 for (rn = cmd->ncmd.redirect; rn; rn = rn->nfile.next) 989 if (outredir(outx, rn, sep)) 990 sep = ' '; 991 outxc('\n'); 992 flushout(outx); 993 } 994 995 /* Now locate the command. */ 996 if (argc == 0) { 997 /* 998 * the empty command begins as a normal builtin, and 999 * remains that way while redirects are processed, then 1000 * will become special before we get to doing the 1001 * var assigns. 1002 */ 1003 cmdentry.cmdtype = CMDBUILTIN; 1004 cmdentry.u.bltin = bltincmd; 1005 VTRACE(DBG_CMDS, ("No command name, assume \"comamnd\"\n")); 1006 } else { 1007 static const char PATH[] = "PATH="; 1008 1009 /* 1010 * Modify the command lookup path, if a PATH= assignment 1011 * is present 1012 */ 1013 for (sp = varlist.list; sp; sp = sp->next) 1014 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) 1015 path = sp->text + sizeof(PATH) - 1; 1016 1017 do { 1018 int argsused, use_syspath; 1019 1020 find_command(argv[0], &cmdentry, cmd_flags, path); 1021 VTRACE(DBG_CMDS, ("Command %s type %d\n", argv[0], 1022 cmdentry.cmdtype)); 1023 #if 0 1024 /* 1025 * This short circuits all of the processing that 1026 * should be done (including processing the 1027 * redirects), so just don't ... 1028 * 1029 * (eventually this whole #if'd block will vanish) 1030 */ 1031 if (cmdentry.cmdtype == CMDUNKNOWN) { 1032 exitstatus = 127; 1033 flushout(&errout); 1034 goto out; 1035 } 1036 #endif 1037 1038 /* implement the 'command' builtin here */ 1039 if (cmdentry.cmdtype != CMDBUILTIN || 1040 cmdentry.u.bltin != bltincmd) 1041 break; 1042 VTRACE(DBG_CMDS, ("Command \"command\"\n")); 1043 cmd_flags |= DO_NOFUNC; 1044 argsused = parse_command_args(argc, argv, &use_syspath); 1045 if (argsused == 0) { 1046 /* use 'type' builtin to display info */ 1047 VTRACE(DBG_CMDS, 1048 ("Command \"command\" -> \"type\"\n")); 1049 cmdentry.u.bltin = typecmd; 1050 break; 1051 } 1052 argc -= argsused; 1053 argv += argsused; 1054 if (use_syspath) 1055 path = syspath() + 5; 1056 } while (argc != 0); 1057 if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC) 1058 /* posix mandates that 'command <splbltin>' act as if 1059 <splbltin> was a normal builtin */ 1060 cmdentry.cmdtype = CMDBUILTIN; 1061 } 1062 1063 /* 1064 * When traps are invalid, we permit the following: 1065 * trap 1066 * command trap 1067 * eval trap 1068 * command eval trap 1069 * eval command trap 1070 * without zapping the traps completely, in all other cases we do. 1071 * Function calls also do not zap the traps (but commands they execute 1072 * probably will) - this allows a function like 1073 * trapstate() { trap -p; } 1074 * called as save_traps=$(trapstate). 1075 * 1076 * The test here permits eval "anything" but when evalstring() comes 1077 * back here again, the "anything" will be validated. 1078 * This means we can actually do: 1079 * eval eval eval command eval eval command trap 1080 * as long as we end up with just "trap" 1081 * 1082 * We permit "command" by allowing CMDBUILTIN as well as CMDSPLBLTIN 1083 * 1084 * trapcmd() takes care of doing free_traps() if it is needed there. 1085 */ 1086 if (traps_invalid && 1087 cmdentry.cmdtype != CMDFUNCTION && 1088 ((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) || 1089 (cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd))) 1090 free_traps(); 1091 1092 /* Fork off a child process if necessary. */ 1093 if (cmd->ncmd.backgnd 1094 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 1095 && (have_traps() || (flags & EV_EXIT) == 0)) 1096 #ifdef notyet /* EV_BACKCMD is never set currently */ 1097 /* this will need more work if/when it gets used */ 1098 || ((flags & EV_BACKCMD) != 0 1099 && (cmdentry.cmdtype != CMDBUILTIN 1100 && cmdentry.cmdtype != CMDSPLBLTIN) 1101 || cmdentry.u.bltin == dotcmd 1102 || cmdentry.u.bltin == evalcmd) 1103 #endif 1104 ) { 1105 INTOFF; 1106 jp = makejob(cmd, 1); 1107 mode = cmd->ncmd.backgnd; 1108 if (flags & EV_BACKCMD) { 1109 mode = FORK_NOJOB; 1110 if (sh_pipe(pip) < 0) 1111 error("Pipe call failed"); 1112 } 1113 #ifdef DO_SHAREDVFORK 1114 /* It is essential that if DO_SHAREDVFORK is defined that the 1115 * child's address space is actually shared with the parent as 1116 * we rely on this. 1117 */ 1118 if (usefork == 0 && cmdentry.cmdtype == CMDNORMAL && 1119 (!cmd->ncmd.backgnd || cmd->ncmd.redirect == NULL)) { 1120 pid_t pid; 1121 int serrno; 1122 1123 savelocalvars = localvars; 1124 localvars = NULL; 1125 vforked = 1; 1126 VFORK_BLOCK 1127 switch (pid = vfork()) { 1128 case -1: 1129 serrno = errno; 1130 VTRACE(DBG_EVAL, ("vfork() failed, errno=%d\n", 1131 serrno)); 1132 INTON; 1133 error("Cannot vfork (%s)", strerror(serrno)); 1134 break; 1135 case 0: 1136 /* Make sure that exceptions only unwind to 1137 * after the vfork(2) 1138 */ 1139 SHELL_FORKED(); 1140 if (setjmp(jmploc.loc)) { 1141 VTRACE(DBG_EVAL|DBG_ERRS| 1142 DBG_PROCS|DBG_CMDS|DBG_TRAP, 1143 ("vfork child exit exception:%d " 1144 "exitstatus:%d exerrno:%d\n", 1145 exception, exitstatus, exerrno)); 1146 1147 if (exception == EXSHELLPROC) { 1148 /* 1149 * We can't progress with the 1150 * vfork, so, set vforked = 2 1151 * so the parent knows, 1152 * and _exit(); 1153 */ 1154 vforked = 2; 1155 _exit(0); 1156 } else { 1157 _exit(exception == EXEXIT ? 1158 exitstatus : exerrno); 1159 } 1160 } 1161 savehandler = handler; 1162 handler = &jmploc; 1163 listmklocal(varlist.list, 1164 VDOEXPORT | VEXPORT | VNOFUNC); 1165 forkchild(jp, cmd, mode, vforked); 1166 break; 1167 default: 1168 VFORK_UNDO(); 1169 /* restore from vfork(2) */ 1170 CTRACE(DBG_PROCS|DBG_CMDS, 1171 ("parent after vfork - vforked=%d\n", 1172 vforked)); 1173 handler = savehandler; 1174 poplocalvars(); 1175 localvars = savelocalvars; 1176 if (vforked == 2) { 1177 vforked = 0; 1178 1179 (void)waitpid(pid, NULL, 0); 1180 /* 1181 * We need to progress in a 1182 * normal fork fashion 1183 */ 1184 goto normal_fork; 1185 } 1186 /* 1187 * Here the child has left home, 1188 * getting on with its life, so 1189 * so must we... 1190 */ 1191 vforked = 0; 1192 forkparent(jp, cmd, mode, pid); 1193 goto parent; 1194 } 1195 VFORK_END 1196 } else { 1197 normal_fork: 1198 #endif 1199 if (forkshell(jp, cmd, mode) != 0) 1200 goto parent; /* at end of routine */ 1201 CTRACE(DBG_PROCS|DBG_CMDS, ("Child sets EV_EXIT\n")); 1202 flags |= EV_EXIT; 1203 FORCEINTON; 1204 #ifdef DO_SHAREDVFORK 1205 } 1206 #endif 1207 if (flags & EV_BACKCMD) { 1208 if (!vforked) { 1209 FORCEINTON; 1210 } 1211 close(pip[0]); 1212 movefd(pip[1], 1); 1213 } 1214 flags |= EV_EXIT; 1215 } 1216 1217 /* This is the child process if a fork occurred. */ 1218 /* Execute the command. */ 1219 switch (cmdentry.cmdtype) { 1220 volatile int saved; 1221 struct funcdef * volatile savefunc; 1222 1223 case CMDFUNCTION: 1224 VXTRACE(DBG_EVAL, ("Shell function%s: ",vforked?" VF":""), 1225 trargs(argv)); 1226 redirect(cmd->ncmd.redirect, saved = 1227 !(flags & EV_EXIT) || have_traps() ? REDIR_PUSH : 0); 1228 saveparam = shellparam; 1229 shellparam.malloc = 0; 1230 shellparam.reset = 1; 1231 shellparam.nparam = argc - 1; 1232 shellparam.p = argv + 1; 1233 shellparam.optnext = NULL; 1234 INTOFF; 1235 savelocalvars = localvars; 1236 localvars = NULL; 1237 reffunc(savefunc = cmdentry.u.func); 1238 INTON; 1239 if (setjmp(jmploc.loc)) { 1240 if (exception == EXSHELLPROC) { 1241 freeparam((volatile struct shparam *) 1242 &saveparam); 1243 } else { 1244 freeparam(&shellparam); 1245 shellparam = saveparam; 1246 } 1247 if (saved) 1248 popredir(); 1249 unreffunc(savefunc); 1250 poplocalvars(); 1251 localvars = savelocalvars; 1252 funclinebase = savefuncline; 1253 funclineabs = savefuncabs; 1254 handler = savehandler; 1255 longjmp(handler->loc, 1); 1256 } 1257 savehandler = handler; 1258 handler = &jmploc; 1259 if (cmdentry.u.func) { 1260 if (cmdentry.lno_frel) 1261 funclinebase = cmdentry.lineno - 1; 1262 else 1263 funclinebase = 0; 1264 funclineabs = cmdentry.lineno; 1265 1266 VTRACE(DBG_EVAL, 1267 ("function: node: %d '%s' # %d%s; funclinebase=%d\n", 1268 getfuncnode(cmdentry.u.func)->type, 1269 NODETYPENAME(getfuncnode(cmdentry.u.func)->type), 1270 cmdentry.lineno, cmdentry.lno_frel?" (=1)":"", 1271 funclinebase)); 1272 } 1273 listmklocal(varlist.list, VDOEXPORT | VEXPORT); 1274 /* stop shell blowing its stack */ 1275 if (++funcnest > 1000) 1276 error("too many nested function calls"); 1277 evaltree(getfuncnode(cmdentry.u.func), 1278 flags & (EV_TESTED|EV_EXIT)); 1279 funcnest--; 1280 INTOFF; 1281 unreffunc(cmdentry.u.func); 1282 poplocalvars(); 1283 localvars = savelocalvars; 1284 funclinebase = savefuncline; 1285 funclineabs = savefuncabs; 1286 freeparam(&shellparam); 1287 shellparam = saveparam; 1288 handler = savehandler; 1289 if (saved) 1290 popredir(); 1291 INTON; 1292 if (evalskip == SKIPFUNC) { 1293 evalskip = SKIPNONE; 1294 skipcount = 0; 1295 } 1296 if (flags & EV_EXIT) 1297 exitshell(exitstatus); 1298 break; 1299 1300 case CMDSPLBLTIN: 1301 VTRACE(DBG_EVAL, ("special ")); 1302 case CMDBUILTIN: 1303 VXTRACE(DBG_EVAL, ("builtin command [%d]%s: ", argc, 1304 vforked ? " VF" : ""), trargs(argv)); 1305 mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH; 1306 if (flags == EV_BACKCMD) { 1307 memout.nleft = 0; 1308 memout.nextc = memout.buf; 1309 memout.bufsize = 64; 1310 mode |= REDIR_BACKQ; 1311 } 1312 e = -1; 1313 savecmdname = commandname; 1314 savetopfile = getcurrentfile(); 1315 savehandler = handler; 1316 temp_path = 0; 1317 if (!setjmp(jmploc.loc)) { 1318 handler = &jmploc; 1319 1320 /* 1321 * We need to ensure the command hash table isn't 1322 * corrupted by temporary PATH assignments. 1323 * However we must ensure the 'local' command works! 1324 */ 1325 if (path != pathval() && (cmdentry.u.bltin == hashcmd || 1326 cmdentry.u.bltin == typecmd)) { 1327 savelocalvars = localvars; 1328 localvars = 0; 1329 temp_path = 1; 1330 mklocal(path - 5 /* PATH= */, 0); 1331 } 1332 redirect(cmd->ncmd.redirect, mode); 1333 1334 /* 1335 * the empty command is regarded as a normal 1336 * builtin for the purposes of redirects, but 1337 * is a special builtin for var assigns. 1338 * (unless we are the "command" command.) 1339 */ 1340 if (argc == 0 && !(cmd_flags & DO_NOFUNC)) 1341 cmdentry.cmdtype = CMDSPLBLTIN; 1342 1343 /* exec is a special builtin, but needs this list... */ 1344 cmdenviron = varlist.list; 1345 /* we must check 'readonly' flag for all builtins */ 1346 listsetvar(varlist.list, 1347 cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET); 1348 commandname = argv[0]; 1349 /* initialize nextopt */ 1350 argptr = argv + 1; 1351 optptr = NULL; 1352 /* and getopt */ 1353 optreset = 1; 1354 optind = 1; 1355 builtin_flags = flags; 1356 clr_err(out1); /* discard previous I/O errors */ 1357 exitstatus = cmdentry.u.bltin(argc, argv); 1358 } else { 1359 e = exception; 1360 if (e == EXINT) 1361 exitstatus = SIGINT + 128; 1362 else if (e == EXEXEC) 1363 exitstatus = exerrno; 1364 else if (e != EXEXIT) 1365 exitstatus = 2; 1366 } 1367 handler = savehandler; 1368 flushall(); 1369 out1 = &output; 1370 out2 = &errout; 1371 freestdout(); 1372 if (temp_path) { 1373 poplocalvars(); 1374 localvars = savelocalvars; 1375 } 1376 cmdenviron = NULL; 1377 if (e != EXSHELLPROC) { 1378 commandname = savecmdname; 1379 if (flags & EV_EXIT) 1380 exitshell(exitstatus); 1381 } 1382 if (e != -1) { 1383 if ((e != EXERROR && e != EXEXEC) 1384 || cmdentry.cmdtype == CMDSPLBLTIN) 1385 exraise(e); 1386 popfilesupto(savetopfile); 1387 FORCEINTON; 1388 } 1389 if (cmdentry.u.bltin != execcmd) 1390 popredir(); 1391 if (flags == EV_BACKCMD) { 1392 backcmd->buf = memout.buf; 1393 backcmd->nleft = memout.nextc - memout.buf; 1394 memout.buf = NULL; 1395 } 1396 break; 1397 1398 default: 1399 VXTRACE(DBG_EVAL, ("normal command%s: ", vforked?" VF":""), 1400 trargs(argv)); 1401 redirect(cmd->ncmd.redirect, 1402 (vforked ? REDIR_VFORK : 0) | REDIR_KEEP); 1403 if (!vforked) 1404 for (sp = varlist.list ; sp ; sp = sp->next) 1405 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK); 1406 envp = environment(); 1407 shellexec(argv, envp, path, cmdentry.u.index, vforked); 1408 break; 1409 } 1410 goto out; 1411 1412 parent: /* parent process gets here (if we forked) */ 1413 1414 exitstatus = 0; /* if not altered just below */ 1415 if (mode == FORK_FG) { /* argument to fork */ 1416 exitstatus = waitforjob(jp); 1417 } else if (mode == FORK_NOJOB) { 1418 backcmd->fd = pip[0]; 1419 close(pip[1]); 1420 backcmd->jp = jp; 1421 } 1422 FORCEINTON; 1423 1424 out: 1425 if (lastarg) 1426 /* implement $_ for whatever use that really is */ 1427 (void) setvarsafe("_", lastarg, VNOERROR); 1428 popstackmark(&smark); 1429 } 1430 1431 1432 /* 1433 * Search for a command. This is called before we fork so that the 1434 * location of the command will be available in the parent as well as 1435 * the child. The check for "goodname" is an overly conservative 1436 * check that the name will not be subject to expansion. 1437 */ 1438 1439 STATIC void 1440 prehash(union node *n) 1441 { 1442 struct cmdentry entry; 1443 1444 if (n && n->type == NCMD && n->ncmd.args) 1445 if (goodname(n->ncmd.args->narg.text)) 1446 find_command(n->ncmd.args->narg.text, &entry, 0, 1447 pathval()); 1448 } 1449 1450 int 1451 in_function(void) 1452 { 1453 return funcnest; 1454 } 1455 1456 enum skipstate 1457 current_skipstate(void) 1458 { 1459 return evalskip; 1460 } 1461 1462 void 1463 save_skipstate(struct skipsave *p) 1464 { 1465 *p = s_k_i_p; 1466 } 1467 1468 void 1469 restore_skipstate(const struct skipsave *p) 1470 { 1471 s_k_i_p = *p; 1472 } 1473 1474 void 1475 stop_skipping(void) 1476 { 1477 evalskip = SKIPNONE; 1478 skipcount = 0; 1479 } 1480 1481 /* 1482 * Builtin commands. Builtin commands whose functions are closely 1483 * tied to evaluation are implemented here. 1484 */ 1485 1486 /* 1487 * No command given. 1488 */ 1489 1490 int 1491 bltincmd(int argc, char **argv) 1492 { 1493 /* 1494 * Preserve exitstatus of a previous possible redirection 1495 * as POSIX mandates 1496 */ 1497 return back_exitstatus; 1498 } 1499 1500 1501 /* 1502 * Handle break and continue commands. Break, continue, and return are 1503 * all handled by setting the evalskip flag. The evaluation routines 1504 * above all check this flag, and if it is set they start skipping 1505 * commands rather than executing them. The variable skipcount is 1506 * the number of loops to break/continue, or the number of function 1507 * levels to return. (The latter is always 1.) It should probably 1508 * be an error to break out of more loops than exist, but it isn't 1509 * in the standard shell so we don't make it one here. 1510 */ 1511 1512 int 1513 breakcmd(int argc, char **argv) 1514 { 1515 int n = argc > 1 ? number(argv[1]) : 1; 1516 1517 if (n <= 0) 1518 error("invalid count: %d", n); 1519 if (n > loopnest) 1520 n = loopnest; 1521 if (n > 0) { 1522 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1523 skipcount = n; 1524 } 1525 return 0; 1526 } 1527 1528 int 1529 dotcmd(int argc, char **argv) 1530 { 1531 exitstatus = 0; 1532 1533 (void) nextopt(NULL); /* ignore a leading "--" */ 1534 1535 if (*argptr != NULL) { /* That's what SVR2 does */ 1536 char *fullname; 1537 /* 1538 * dot_funcnest needs to be 0 when not in a dotcmd, so it 1539 * cannot be restored with (funcnest + 1). 1540 */ 1541 int dot_funcnest_old; 1542 struct stackmark smark; 1543 1544 setstackmark(&smark); 1545 fullname = find_dot_file(*argptr); 1546 setinputfile(fullname, 1); 1547 commandname = fullname; 1548 dot_funcnest_old = dot_funcnest; 1549 dot_funcnest = funcnest + 1; 1550 cmdloop(0); 1551 dot_funcnest = dot_funcnest_old; 1552 popfile(); 1553 popstackmark(&smark); 1554 } 1555 return exitstatus; 1556 } 1557 1558 /* 1559 * allow dotfile function nesting to be manipulated 1560 * (for read_profile). This allows profile files to 1561 * be treated as if they were used as '.' commands, 1562 * (approximately) and in particular, for "return" to work. 1563 */ 1564 int 1565 set_dot_funcnest(int new) 1566 { 1567 int rv = dot_funcnest; 1568 1569 if (new >= 0) 1570 dot_funcnest = new; 1571 1572 return rv; 1573 } 1574 1575 /* 1576 * Take commands from a file. To be compatible we should do a path 1577 * search for the file, which is necessary to find sub-commands. 1578 */ 1579 1580 STATIC char * 1581 find_dot_file(char *basename) 1582 { 1583 char *fullname; 1584 const char *path = pathval(); 1585 struct stat statb; 1586 1587 /* don't try this for absolute or relative paths */ 1588 if (strchr(basename, '/')) { 1589 if (stat(basename, &statb) == 0) { 1590 if (S_ISDIR(statb.st_mode)) 1591 error("%s: is a directory", basename); 1592 if (S_ISBLK(statb.st_mode)) 1593 error("%s: is a block device", basename); 1594 return basename; 1595 } 1596 } else while ((fullname = padvance(&path, basename, 1)) != NULL) { 1597 if ((stat(fullname, &statb) == 0)) { 1598 /* weird format is to ease future code... */ 1599 if (S_ISDIR(statb.st_mode) || S_ISBLK(statb.st_mode)) 1600 ; 1601 #if notyet 1602 else if (unreadable()) { 1603 /* 1604 * testing this via st_mode is ugly to get 1605 * correct (and would ignore ACLs). 1606 * better way is just to open the file. 1607 * But doing that here would (currently) 1608 * mean opening the file twice, which 1609 * might not be safe. So, defer this 1610 * test until code is restructures so 1611 * we can return a fd. Then we also 1612 * get to fix the mem leak just below... 1613 */ 1614 } 1615 #endif 1616 else { 1617 /* 1618 * Don't bother freeing here, since 1619 * it will be freed by the caller. 1620 * XXX no it won't - a bug for later. 1621 */ 1622 return fullname; 1623 } 1624 } 1625 stunalloc(fullname); 1626 } 1627 1628 /* not found in the PATH */ 1629 error("%s: not found", basename); 1630 /* NOTREACHED */ 1631 } 1632 1633 1634 1635 /* 1636 * The return command. 1637 * 1638 * Quoth the POSIX standard: 1639 * The return utility shall cause the shell to stop executing the current 1640 * function or dot script. If the shell is not currently executing 1641 * a function or dot script, the results are unspecified. 1642 * 1643 * As for the unspecified part, there seems to be no de-facto standard: bash 1644 * ignores the return with a warning, zsh ignores the return in interactive 1645 * mode but seems to liken it to exit in a script. (checked May 2014) 1646 * 1647 * We choose to silently ignore the return. Older versions of this shell 1648 * set evalskip to SKIPFILE causing the shell to (indirectly) exit. This 1649 * had at least the problem of circumventing the check for stopped jobs, 1650 * which would occur for exit or ^D. 1651 */ 1652 1653 int 1654 returncmd(int argc, char **argv) 1655 { 1656 int ret = argc > 1 ? number(argv[1]) : exitstatus; 1657 1658 if ((dot_funcnest == 0 && funcnest) 1659 || (dot_funcnest > 0 && funcnest - (dot_funcnest - 1) > 0)) { 1660 evalskip = SKIPFUNC; 1661 skipcount = 1; 1662 } else if (dot_funcnest > 0) { 1663 evalskip = SKIPFILE; 1664 skipcount = 1; 1665 } else { 1666 /* XXX: should a warning be issued? */ 1667 ret = 0; 1668 } 1669 1670 return ret; 1671 } 1672 1673 1674 int 1675 falsecmd(int argc, char **argv) 1676 { 1677 return 1; 1678 } 1679 1680 1681 int 1682 truecmd(int argc, char **argv) 1683 { 1684 return 0; 1685 } 1686 1687 1688 int 1689 execcmd(int argc, char **argv) 1690 { 1691 (void) nextopt(NULL); /* ignore a leading "--" */ 1692 1693 if (*argptr) { 1694 struct strlist *sp; 1695 1696 iflag = 0; /* exit on error */ 1697 mflag = 0; 1698 optschanged(); 1699 for (sp = cmdenviron; sp; sp = sp->next) 1700 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK); 1701 shellexec(argptr, environment(), pathval(), 0, 0); 1702 } 1703 return 0; 1704 } 1705 1706 static int 1707 conv_time(clock_t ticks, char *seconds, size_t l) 1708 { 1709 static clock_t tpm = 0; 1710 clock_t mins; 1711 int i; 1712 1713 if (!tpm) 1714 tpm = sysconf(_SC_CLK_TCK) * 60; 1715 1716 mins = ticks / tpm; 1717 snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm ); 1718 1719 if (seconds[0] == '6' && seconds[1] == '0') { 1720 /* 59.99995 got rounded up... */ 1721 mins++; 1722 strlcpy(seconds, "0.0", l); 1723 return mins; 1724 } 1725 1726 /* suppress trailing zeros */ 1727 i = strlen(seconds) - 1; 1728 for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--) 1729 seconds[i] = 0; 1730 return mins; 1731 } 1732 1733 int 1734 timescmd(int argc, char **argv) 1735 { 1736 struct tms tms; 1737 int u, s, cu, cs; 1738 char us[8], ss[8], cus[8], css[8]; 1739 1740 nextopt(""); 1741 1742 times(&tms); 1743 1744 u = conv_time(tms.tms_utime, us, sizeof(us)); 1745 s = conv_time(tms.tms_stime, ss, sizeof(ss)); 1746 cu = conv_time(tms.tms_cutime, cus, sizeof(cus)); 1747 cs = conv_time(tms.tms_cstime, css, sizeof(css)); 1748 1749 outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n", 1750 u, us, s, ss, cu, cus, cs, css); 1751 1752 return 0; 1753 } 1754