1 /* $NetBSD: eval.c,v 1.175 2019/05/04 02:52:55 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 1.175 2019/05/04 02:52:55 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 commmand. 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 if (n->type != NCMD && traps_invalid) 284 free_traps(); 285 switch (n->type) { 286 case NSEMI: 287 evaltree(n->nbinary.ch1, sflags); 288 if (nflag || evalskip) 289 goto out1; 290 next = n->nbinary.ch2; 291 break; 292 case NAND: 293 evaltree(n->nbinary.ch1, EV_TESTED); 294 if (nflag || evalskip || exitstatus != 0) 295 goto out1; 296 next = n->nbinary.ch2; 297 break; 298 case NOR: 299 evaltree(n->nbinary.ch1, EV_TESTED); 300 if (nflag || evalskip || exitstatus == 0) 301 goto out1; 302 next = n->nbinary.ch2; 303 break; 304 case NREDIR: 305 evalredir(n, flags); 306 break; 307 case NSUBSHELL: 308 evalsubshell(n, flags); 309 do_etest = !(flags & EV_TESTED); 310 break; 311 case NBACKGND: 312 evalsubshell(n, flags); 313 break; 314 case NIF: { 315 evaltree(n->nif.test, EV_TESTED); 316 if (nflag || evalskip) 317 goto out1; 318 if (exitstatus == 0) 319 next = n->nif.ifpart; 320 else if (n->nif.elsepart) 321 next = n->nif.elsepart; 322 else 323 exitstatus = 0; 324 break; 325 } 326 case NWHILE: 327 case NUNTIL: 328 evalloop(n, sflags); 329 break; 330 case NFOR: 331 evalfor(n, sflags); 332 break; 333 case NCASE: 334 evalcase(n, sflags); 335 break; 336 case NDEFUN: 337 CTRACE(DBG_EVAL, ("Defining fn %s @%d%s\n", 338 n->narg.text, n->narg.lineno, 339 fnline1 ? " LINENO=1" : "")); 340 defun(n->narg.text, n->narg.next, n->narg.lineno); 341 exitstatus = 0; 342 break; 343 case NNOT: 344 evaltree(n->nnot.com, EV_TESTED); 345 exitstatus = !exitstatus; 346 break; 347 case NDNOT: 348 evaltree(n->nnot.com, EV_TESTED); 349 if (exitstatus != 0) 350 exitstatus = 1; 351 break; 352 case NPIPE: 353 evalpipe(n); 354 do_etest = !(flags & EV_TESTED); 355 break; 356 case NCMD: 357 evalcommand(n, flags, NULL); 358 do_etest = !(flags & EV_TESTED); 359 break; 360 default: 361 #ifdef NODETYPENAME 362 out1fmt("Node type = %d(%s)\n", 363 n->type, NODETYPENAME(n->type)); 364 #else 365 out1fmt("Node type = %d\n", n->type); 366 #endif 367 flushout(&output); 368 break; 369 } 370 n = next; 371 rststackmark(&smark); 372 } while(n != NULL); 373 out1: 374 popstackmark(&smark); 375 out2: 376 if (pendingsigs) 377 dotrap(); 378 if (eflag && exitstatus != 0 && do_etest) 379 exitshell(exitstatus); 380 if (flags & EV_EXIT) 381 exraise(EXEXIT); 382 } 383 384 385 STATIC void 386 evalloop(union node *n, int flags) 387 { 388 int status; 389 390 loopnest++; 391 status = 0; 392 393 CTRACE(DBG_EVAL, ("evalloop %s:", NODETYPENAME(n->type))); 394 VXTRACE(DBG_EVAL, (" "), showtree(n->nbinary.ch1)); 395 VXTRACE(DBG_EVAL, ("evalloop do: "), showtree(n->nbinary.ch2)); 396 VTRACE(DBG_EVAL, ("evalloop done\n")); 397 CTRACE(DBG_EVAL, ("\n")); 398 399 for (;;) { 400 evaltree(n->nbinary.ch1, EV_TESTED); 401 if (nflag) 402 break; 403 if (evalskip) { 404 skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { 405 evalskip = SKIPNONE; 406 continue; 407 } 408 if (evalskip == SKIPBREAK && --skipcount <= 0) 409 evalskip = SKIPNONE; 410 if (evalskip == SKIPFUNC || evalskip == SKIPFILE) 411 status = exitstatus; 412 break; 413 } 414 if (n->type == NWHILE) { 415 if (exitstatus != 0) 416 break; 417 } else { 418 if (exitstatus == 0) 419 break; 420 } 421 evaltree(n->nbinary.ch2, flags & EV_TESTED); 422 status = exitstatus; 423 if (evalskip) 424 goto skipping; 425 } 426 loopnest--; 427 exitstatus = status; 428 } 429 430 431 432 STATIC void 433 evalfor(union node *n, int flags) 434 { 435 struct arglist arglist; 436 union node *argp; 437 struct strlist *sp; 438 struct stackmark smark; 439 int status; 440 441 status = nflag ? exitstatus : 0; 442 443 setstackmark(&smark); 444 arglist.lastp = &arglist.list; 445 for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { 446 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 447 if (evalskip) 448 goto out; 449 } 450 *arglist.lastp = NULL; 451 452 loopnest++; 453 for (sp = arglist.list ; sp ; sp = sp->next) { 454 if (xflag) { 455 outxstr(expandstr(ps4val(), line_number)); 456 outxstr("for "); 457 outxstr(n->nfor.var); 458 outxc('='); 459 outxshstr(sp->text); 460 outxc('\n'); 461 flushout(outx); 462 } 463 464 setvar(n->nfor.var, sp->text, 0); 465 evaltree(n->nfor.body, flags & EV_TESTED); 466 status = exitstatus; 467 if (nflag) 468 break; 469 if (evalskip) { 470 if (evalskip == SKIPCONT && --skipcount <= 0) { 471 evalskip = SKIPNONE; 472 continue; 473 } 474 if (evalskip == SKIPBREAK && --skipcount <= 0) 475 evalskip = SKIPNONE; 476 break; 477 } 478 } 479 loopnest--; 480 exitstatus = status; 481 out: 482 popstackmark(&smark); 483 } 484 485 486 487 STATIC void 488 evalcase(union node *n, int flags) 489 { 490 union node *cp, *ncp; 491 union node *patp; 492 struct arglist arglist; 493 struct stackmark smark; 494 int status = 0; 495 496 setstackmark(&smark); 497 arglist.lastp = &arglist.list; 498 line_number = n->ncase.lineno; 499 expandarg(n->ncase.expr, &arglist, EXP_TILDE); 500 for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) { 501 for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) { 502 line_number = patp->narg.lineno; 503 if (casematch(patp, arglist.list->text)) { 504 while (cp != NULL && evalskip == 0 && 505 nflag == 0) { 506 if (cp->type == NCLISTCONT) 507 ncp = cp->nclist.next; 508 else 509 ncp = NULL; 510 line_number = cp->nclist.lineno; 511 evaltree(cp->nclist.body, flags); 512 status = exitstatus; 513 cp = ncp; 514 } 515 goto out; 516 } 517 } 518 } 519 out: 520 exitstatus = status; 521 popstackmark(&smark); 522 } 523 524 525 526 /* 527 * Kick off a subshell to evaluate a tree. 528 */ 529 530 STATIC void 531 evalsubshell(union node *n, int flags) 532 { 533 struct job *jp= NULL; 534 int backgnd = (n->type == NBACKGND); 535 536 expredir(n->nredir.redirect); 537 if (xflag && n->nredir.redirect) { 538 union node *rn; 539 540 outxstr(expandstr(ps4val(), line_number)); 541 outxstr("using redirections:"); 542 for (rn = n->nredir.redirect; rn; rn = rn->nfile.next) 543 (void) outredir(outx, rn, ' '); 544 outxstr(" do subshell ("/*)*/); 545 if (backgnd) 546 outxstr(/*(*/") &"); 547 outxc('\n'); 548 flushout(outx); 549 } 550 INTOFF; 551 if ((!backgnd && flags & EV_EXIT && !have_traps()) || 552 forkshell(jp = makejob(n, 1), n, backgnd?FORK_BG:FORK_FG) == 0) { 553 if (backgnd) 554 flags &=~ EV_TESTED; 555 redirect(n->nredir.redirect, REDIR_KEEP); 556 INTON; 557 evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ 558 } else if (backgnd) 559 exitstatus = 0; 560 else 561 exitstatus = waitforjob(jp); 562 INTON; 563 564 if (!backgnd && xflag && n->nredir.redirect) { 565 outxstr(expandstr(ps4val(), line_number)); 566 outxstr(/*(*/") done subshell\n"); 567 flushout(outx); 568 } 569 } 570 571 572 573 /* 574 * Compute the names of the files in a redirection list. 575 */ 576 577 STATIC void 578 expredir(union node *n) 579 { 580 union node *redir; 581 582 for (redir = n ; redir ; redir = redir->nfile.next) { 583 struct arglist fn; 584 585 fn.lastp = &fn.list; 586 switch (redir->type) { 587 case NFROMTO: 588 case NFROM: 589 case NTO: 590 case NCLOBBER: 591 case NAPPEND: 592 expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); 593 redir->nfile.expfname = fn.list->text; 594 break; 595 case NFROMFD: 596 case NTOFD: 597 if (redir->ndup.vname) { 598 expandarg(redir->ndup.vname, &fn, EXP_TILDE | EXP_REDIR); 599 fixredir(redir, fn.list->text, 1); 600 } 601 break; 602 } 603 } 604 } 605 606 /* 607 * Perform redirections for a compound command, and then do it (and restore) 608 */ 609 STATIC void 610 evalredir(union node *n, int flags) 611 { 612 struct jmploc jmploc; 613 struct jmploc * const savehandler = handler; 614 volatile int in_redirect = 1; 615 const char * volatile PS4 = NULL; 616 617 expredir(n->nredir.redirect); 618 619 if (xflag && n->nredir.redirect) { 620 union node *rn; 621 622 outxstr(PS4 = expandstr(ps4val(), line_number)); 623 outxstr("using redirections:"); 624 for (rn = n->nredir.redirect; rn != NULL; rn = rn->nfile.next) 625 (void) outredir(outx, rn, ' '); 626 outxstr(" do {\n"); /* } */ 627 flushout(outx); 628 } 629 630 if (setjmp(jmploc.loc)) { 631 int e; 632 633 handler = savehandler; 634 e = exception; 635 popredir(); 636 if (PS4 != NULL) { 637 outxstr(PS4); 638 /* { */ outxstr("} failed\n"); 639 flushout(outx); 640 } 641 if (e == EXERROR || e == EXEXEC) { 642 if (in_redirect) { 643 exitstatus = 2; 644 return; 645 } 646 } 647 longjmp(handler->loc, 1); 648 } else { 649 INTOFF; 650 handler = &jmploc; 651 redirect(n->nredir.redirect, REDIR_PUSH | REDIR_KEEP); 652 in_redirect = 0; 653 INTON; 654 evaltree(n->nredir.n, flags); 655 } 656 INTOFF; 657 handler = savehandler; 658 popredir(); 659 INTON; 660 661 if (PS4 != NULL) { 662 outxstr(PS4); 663 /* { */ outxstr("} done\n"); 664 flushout(outx); 665 } 666 } 667 668 669 /* 670 * Evaluate a pipeline. All the processes in the pipeline are children 671 * of the process creating the pipeline. (This differs from some versions 672 * of the shell, which make the last process in a pipeline the parent 673 * of all the rest.) 674 */ 675 676 STATIC void 677 evalpipe(union node *n) 678 { 679 struct job *jp; 680 struct nodelist *lp; 681 int pipelen; 682 int prevfd; 683 int pip[2]; 684 685 CTRACE(DBG_EVAL, ("evalpipe(%p) called\n", n)); 686 pipelen = 0; 687 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) 688 pipelen++; 689 INTOFF; 690 jp = makejob(n, pipelen); 691 prevfd = -1; 692 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 693 prehash(lp->n); 694 pip[1] = -1; 695 if (lp->next) { 696 if (sh_pipe(pip) < 0) { 697 if (prevfd >= 0) 698 close(prevfd); 699 error("Pipe call failed: %s", strerror(errno)); 700 } 701 } 702 if (forkshell(jp, lp->n, 703 n->npipe.backgnd ? FORK_BG : FORK_FG) == 0) { 704 INTON; 705 if (prevfd > 0) 706 movefd(prevfd, 0); 707 if (pip[1] >= 0) { 708 close(pip[0]); 709 movefd(pip[1], 1); 710 } 711 evaltree(lp->n, EV_EXIT); 712 } 713 if (prevfd >= 0) 714 close(prevfd); 715 prevfd = pip[0]; 716 close(pip[1]); 717 } 718 if (n->npipe.backgnd == 0) { 719 exitstatus = waitforjob(jp); 720 CTRACE(DBG_EVAL, ("evalpipe: job done exit status %d\n", 721 exitstatus)); 722 } else 723 exitstatus = 0; 724 INTON; 725 } 726 727 728 729 /* 730 * Execute a command inside back quotes. If it's a builtin command, we 731 * want to save its output in a block obtained from malloc. Otherwise 732 * we fork off a subprocess and get the output of the command via a pipe. 733 * Should be called with interrupts off. 734 */ 735 736 void 737 evalbackcmd(union node *n, struct backcmd *result) 738 { 739 int pip[2]; 740 struct job *jp; 741 struct stackmark smark; /* unnecessary (because we fork) */ 742 743 result->fd = -1; 744 result->buf = NULL; 745 result->nleft = 0; 746 result->jp = NULL; 747 748 if (nflag || n == NULL) 749 goto out; 750 751 setstackmark(&smark); 752 753 #ifdef notyet 754 /* 755 * For now we disable executing builtins in the same 756 * context as the shell, because we are not keeping 757 * enough state to recover from changes that are 758 * supposed only to affect subshells. eg. echo "`cd /`" 759 */ 760 if (n->type == NCMD) { 761 exitstatus = oexitstatus; /* XXX o... no longer exists */ 762 evalcommand(n, EV_BACKCMD, result); 763 } else 764 #endif 765 { 766 INTOFF; 767 if (sh_pipe(pip) < 0) 768 error("Pipe call failed"); 769 jp = makejob(n, 1); 770 if (forkshell(jp, n, FORK_NOJOB) == 0) { 771 FORCEINTON; 772 close(pip[0]); 773 movefd(pip[1], 1); 774 eflag = 0; 775 evaltree(n, EV_EXIT); 776 /* NOTREACHED */ 777 } 778 close(pip[1]); 779 result->fd = pip[0]; 780 result->jp = jp; 781 INTON; 782 } 783 popstackmark(&smark); 784 out: 785 CTRACE(DBG_EVAL, ("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", 786 result->fd, result->buf, result->nleft, result->jp)); 787 } 788 789 const char * 790 syspath(void) 791 { 792 static char *sys_path = NULL; 793 static int mib[] = {CTL_USER, USER_CS_PATH}; 794 static char def_path[] = "PATH=/usr/bin:/bin:/usr/sbin:/sbin"; 795 size_t len; 796 797 if (sys_path == NULL) { 798 if (sysctl(mib, 2, 0, &len, 0, 0) != -1 && 799 (sys_path = ckmalloc(len + 5)) != NULL && 800 sysctl(mib, 2, sys_path + 5, &len, 0, 0) != -1) { 801 memcpy(sys_path, "PATH=", 5); 802 } else { 803 ckfree(sys_path); 804 /* something to keep things happy */ 805 sys_path = def_path; 806 } 807 } 808 return sys_path; 809 } 810 811 static int 812 parse_command_args(int argc, char **argv, int *use_syspath) 813 { 814 int sv_argc = argc; 815 char *cp, c; 816 817 *use_syspath = 0; 818 819 for (;;) { 820 argv++; 821 if (--argc == 0) 822 break; 823 cp = *argv; 824 if (*cp++ != '-') 825 break; 826 if (*cp == '-' && cp[1] == 0) { 827 argv++; 828 argc--; 829 break; 830 } 831 while ((c = *cp++)) { 832 switch (c) { 833 case 'p': 834 *use_syspath = 1; 835 break; 836 default: 837 /* run 'typecmd' for other options */ 838 return 0; 839 } 840 } 841 } 842 return sv_argc - argc; 843 } 844 845 int vforked = 0; 846 847 /* 848 * Execute a simple command. 849 */ 850 851 STATIC void 852 evalcommand(union node *cmd, int flgs, struct backcmd *backcmd) 853 { 854 struct stackmark smark; 855 union node *argp; 856 struct arglist arglist; 857 struct arglist varlist; 858 volatile int flags = flgs; 859 char ** volatile argv; 860 volatile int argc; 861 char **envp; 862 int varflag; 863 struct strlist *sp; 864 volatile int mode; 865 int pip[2]; 866 struct cmdentry cmdentry; 867 struct job * volatile jp; 868 struct jmploc jmploc; 869 struct jmploc *volatile savehandler = NULL; 870 const char *volatile savecmdname; 871 volatile struct shparam saveparam; 872 struct localvar *volatile savelocalvars; 873 struct parsefile *volatile savetopfile; 874 volatile int e; 875 char * volatile lastarg; 876 const char * volatile path = pathval(); 877 volatile int temp_path; 878 const int savefuncline = funclinebase; 879 const int savefuncabs = funclineabs; 880 volatile int cmd_flags = 0; 881 882 vforked = 0; 883 /* First expand the arguments. */ 884 CTRACE(DBG_EVAL, ("evalcommand(%p, %d) called [%s]\n", cmd, flags, 885 cmd->ncmd.args ? cmd->ncmd.args->narg.text : "")); 886 setstackmark(&smark); 887 back_exitstatus = 0; 888 889 line_number = cmd->ncmd.lineno; 890 891 arglist.lastp = &arglist.list; 892 varflag = 1; 893 /* Expand arguments, ignoring the initial 'name=value' ones */ 894 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 895 if (varflag && isassignment(argp->narg.text)) 896 continue; 897 varflag = 0; 898 line_number = argp->narg.lineno; 899 expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); 900 } 901 *arglist.lastp = NULL; 902 903 expredir(cmd->ncmd.redirect); 904 905 /* Now do the initial 'name=value' ones we skipped above */ 906 varlist.lastp = &varlist.list; 907 for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { 908 line_number = argp->narg.lineno; 909 if (!isassignment(argp->narg.text)) 910 break; 911 expandarg(argp, &varlist, EXP_VARTILDE); 912 } 913 *varlist.lastp = NULL; 914 915 argc = 0; 916 for (sp = arglist.list ; sp ; sp = sp->next) 917 argc++; 918 argv = stalloc(sizeof (char *) * (argc + 1)); 919 920 for (sp = arglist.list ; sp ; sp = sp->next) { 921 VTRACE(DBG_EVAL, ("evalcommand arg: %s\n", sp->text)); 922 *argv++ = sp->text; 923 } 924 *argv = NULL; 925 lastarg = NULL; 926 if (iflag && funcnest == 0 && argc > 0) 927 lastarg = argv[-1]; 928 argv -= argc; 929 930 /* Print the command if xflag is set. */ 931 if (xflag) { 932 char sep = 0; 933 union node *rn; 934 935 outxstr(expandstr(ps4val(), line_number)); 936 for (sp = varlist.list ; sp ; sp = sp->next) { 937 char *p; 938 939 if (sep != 0) 940 outxc(sep); 941 942 /* 943 * The "var=" part should not be quoted, regardless 944 * of the value, or it would not represent an 945 * assignment, but rather a command 946 */ 947 p = strchr(sp->text, '='); 948 if (p != NULL) { 949 *p = '\0'; /*XXX*/ 950 outxshstr(sp->text); 951 outxc('='); 952 *p++ = '='; /*XXX*/ 953 } else 954 p = sp->text; 955 outxshstr(p); 956 sep = ' '; 957 } 958 for (sp = arglist.list ; sp ; sp = sp->next) { 959 if (sep != 0) 960 outxc(sep); 961 outxshstr(sp->text); 962 sep = ' '; 963 } 964 for (rn = cmd->ncmd.redirect; rn; rn = rn->nfile.next) 965 if (outredir(outx, rn, sep)) 966 sep = ' '; 967 outxc('\n'); 968 flushout(outx); 969 } 970 971 /* Now locate the command. */ 972 if (argc == 0) { 973 /* 974 * the empty command begins as a normal builtin, and 975 * remains that way while redirects are processed, then 976 * will become special before we get to doing the 977 * var assigns. 978 */ 979 cmdentry.cmdtype = CMDBUILTIN; 980 cmdentry.u.bltin = bltincmd; 981 VTRACE(DBG_CMDS, ("No command name, assume \"comamnd\"\n")); 982 } else { 983 static const char PATH[] = "PATH="; 984 985 /* 986 * Modify the command lookup path, if a PATH= assignment 987 * is present 988 */ 989 for (sp = varlist.list; sp; sp = sp->next) 990 if (strncmp(sp->text, PATH, sizeof(PATH) - 1) == 0) 991 path = sp->text + sizeof(PATH) - 1; 992 993 do { 994 int argsused, use_syspath; 995 996 find_command(argv[0], &cmdentry, cmd_flags, path); 997 VTRACE(DBG_CMDS, ("Command %s type %d\n", argv[0], 998 cmdentry.cmdtype)); 999 #if 0 1000 /* 1001 * This short circuits all of the processing that 1002 * should be done (including processing the 1003 * redirects), so just don't ... 1004 * 1005 * (eventually this whole #if'd block will vanish) 1006 */ 1007 if (cmdentry.cmdtype == CMDUNKNOWN) { 1008 exitstatus = 127; 1009 flushout(&errout); 1010 goto out; 1011 } 1012 #endif 1013 1014 /* implement the 'command' builtin here */ 1015 if (cmdentry.cmdtype != CMDBUILTIN || 1016 cmdentry.u.bltin != bltincmd) 1017 break; 1018 VTRACE(DBG_CMDS, ("Command \"command\"\n")); 1019 cmd_flags |= DO_NOFUNC; 1020 argsused = parse_command_args(argc, argv, &use_syspath); 1021 if (argsused == 0) { 1022 /* use 'type' builtin to display info */ 1023 VTRACE(DBG_CMDS, 1024 ("Command \"command\" -> \"type\"\n")); 1025 cmdentry.u.bltin = typecmd; 1026 break; 1027 } 1028 argc -= argsused; 1029 argv += argsused; 1030 if (use_syspath) 1031 path = syspath() + 5; 1032 } while (argc != 0); 1033 if (cmdentry.cmdtype == CMDSPLBLTIN && cmd_flags & DO_NOFUNC) 1034 /* posix mandates that 'command <splbltin>' act as if 1035 <splbltin> was a normal builtin */ 1036 cmdentry.cmdtype = CMDBUILTIN; 1037 } 1038 1039 /* 1040 * When traps are invalid, we permit the following: 1041 * trap 1042 * command trap 1043 * eval trap 1044 * command eval trap 1045 * eval command trap 1046 * without zapping the traps completely, in all other cases we do. 1047 * 1048 * The test here permits eval "anything" but when evalstring() comes 1049 * back here again, the "anything" will be validated. 1050 * This means we can actually do: 1051 * eval eval eval command eval eval command trap 1052 * as long as we end up with just "trap" 1053 * 1054 * We permit "command" by allowing CMDBUILTIN as well as CMDSPLBLTIN 1055 * 1056 * trapcmd() takes care of doing free_traps() if it is needed there. 1057 */ 1058 if (traps_invalid && 1059 ((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) || 1060 (cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd))) 1061 free_traps(); 1062 1063 /* Fork off a child process if necessary. */ 1064 if (cmd->ncmd.backgnd || (have_traps() && (flags & EV_EXIT) != 0) 1065 || ((cmdentry.cmdtype == CMDNORMAL || cmdentry.cmdtype == CMDUNKNOWN) 1066 && (flags & EV_EXIT) == 0) 1067 || ((flags & EV_BACKCMD) != 0 && 1068 ((cmdentry.cmdtype != CMDBUILTIN && cmdentry.cmdtype != CMDSPLBLTIN) 1069 || cmdentry.u.bltin == dotcmd 1070 || cmdentry.u.bltin == evalcmd))) { 1071 INTOFF; 1072 jp = makejob(cmd, 1); 1073 mode = cmd->ncmd.backgnd; 1074 if (flags & EV_BACKCMD) { 1075 mode = FORK_NOJOB; 1076 if (sh_pipe(pip) < 0) 1077 error("Pipe call failed"); 1078 } 1079 #ifdef DO_SHAREDVFORK 1080 /* It is essential that if DO_SHAREDVFORK is defined that the 1081 * child's address space is actually shared with the parent as 1082 * we rely on this. 1083 */ 1084 if (usefork == 0 && cmdentry.cmdtype == CMDNORMAL) { 1085 pid_t pid; 1086 int serrno; 1087 1088 savelocalvars = localvars; 1089 localvars = NULL; 1090 vforked = 1; 1091 VFORK_BLOCK 1092 switch (pid = vfork()) { 1093 case -1: 1094 serrno = errno; 1095 VTRACE(DBG_EVAL, ("vfork() failed, errno=%d\n", 1096 serrno)); 1097 INTON; 1098 error("Cannot vfork (%s)", strerror(serrno)); 1099 break; 1100 case 0: 1101 /* Make sure that exceptions only unwind to 1102 * after the vfork(2) 1103 */ 1104 SHELL_FORKED(); 1105 if (setjmp(jmploc.loc)) { 1106 if (exception == EXSHELLPROC) { 1107 /* 1108 * We can't progress with the 1109 * vfork, so, set vforked = 2 1110 * so the parent knows, 1111 * and _exit(); 1112 */ 1113 vforked = 2; 1114 _exit(0); 1115 } else { 1116 _exit(exception == EXEXIT ? 1117 exitstatus : exerrno); 1118 } 1119 } 1120 savehandler = handler; 1121 handler = &jmploc; 1122 listmklocal(varlist.list, 1123 VDOEXPORT | VEXPORT | VNOFUNC); 1124 forkchild(jp, cmd, mode, vforked); 1125 break; 1126 default: 1127 VFORK_UNDO(); 1128 /* restore from vfork(2) */ 1129 CTRACE(DBG_PROCS|DBG_CMDS, 1130 ("parent after vfork - vforked=%d\n", 1131 vforked)); 1132 handler = savehandler; 1133 poplocalvars(); 1134 localvars = savelocalvars; 1135 if (vforked == 2) { 1136 vforked = 0; 1137 1138 (void)waitpid(pid, NULL, 0); 1139 /* 1140 * We need to progress in a 1141 * normal fork fashion 1142 */ 1143 goto normal_fork; 1144 } 1145 /* 1146 * Here the child has left home, 1147 * getting on with its life, so 1148 * so must we... 1149 */ 1150 vforked = 0; 1151 forkparent(jp, cmd, mode, pid); 1152 goto parent; 1153 } 1154 VFORK_END 1155 } else { 1156 normal_fork: 1157 #endif 1158 if (forkshell(jp, cmd, mode) != 0) 1159 goto parent; /* at end of routine */ 1160 CTRACE(DBG_PROCS|DBG_CMDS, ("Child sets EV_EXIT\n")); 1161 flags |= EV_EXIT; 1162 FORCEINTON; 1163 #ifdef DO_SHAREDVFORK 1164 } 1165 #endif 1166 if (flags & EV_BACKCMD) { 1167 if (!vforked) { 1168 FORCEINTON; 1169 } 1170 close(pip[0]); 1171 movefd(pip[1], 1); 1172 } 1173 flags |= EV_EXIT; 1174 } 1175 1176 /* This is the child process if a fork occurred. */ 1177 /* Execute the command. */ 1178 switch (cmdentry.cmdtype) { 1179 volatile int saved; 1180 1181 case CMDFUNCTION: 1182 VXTRACE(DBG_EVAL, ("Shell function%s: ",vforked?" VF":""), 1183 trargs(argv)); 1184 redirect(cmd->ncmd.redirect, saved = 1185 !(flags & EV_EXIT) || have_traps() ? REDIR_PUSH : 0); 1186 saveparam = shellparam; 1187 shellparam.malloc = 0; 1188 shellparam.reset = 1; 1189 shellparam.nparam = argc - 1; 1190 shellparam.p = argv + 1; 1191 shellparam.optnext = NULL; 1192 INTOFF; 1193 savelocalvars = localvars; 1194 localvars = NULL; 1195 reffunc(cmdentry.u.func); 1196 INTON; 1197 if (setjmp(jmploc.loc)) { 1198 if (exception == EXSHELLPROC) { 1199 freeparam((volatile struct shparam *) 1200 &saveparam); 1201 } else { 1202 freeparam(&shellparam); 1203 shellparam = saveparam; 1204 } 1205 if (saved) 1206 popredir();; 1207 unreffunc(cmdentry.u.func); 1208 poplocalvars(); 1209 localvars = savelocalvars; 1210 funclinebase = savefuncline; 1211 funclineabs = savefuncabs; 1212 handler = savehandler; 1213 longjmp(handler->loc, 1); 1214 } 1215 savehandler = handler; 1216 handler = &jmploc; 1217 if (cmdentry.u.func) { 1218 if (cmdentry.lno_frel) 1219 funclinebase = cmdentry.lineno - 1; 1220 else 1221 funclinebase = 0; 1222 funclineabs = cmdentry.lineno; 1223 1224 VTRACE(DBG_EVAL, 1225 ("function: node: %d '%s' # %d%s; funclinebase=%d\n", 1226 getfuncnode(cmdentry.u.func)->type, 1227 NODETYPENAME(getfuncnode(cmdentry.u.func)->type), 1228 cmdentry.lineno, cmdentry.lno_frel?" (=1)":"", 1229 funclinebase)); 1230 } 1231 listmklocal(varlist.list, VDOEXPORT | VEXPORT); 1232 /* stop shell blowing its stack */ 1233 if (++funcnest > 1000) 1234 error("too many nested function calls"); 1235 evaltree(getfuncnode(cmdentry.u.func), 1236 flags & (EV_TESTED|EV_EXIT)); 1237 funcnest--; 1238 INTOFF; 1239 unreffunc(cmdentry.u.func); 1240 poplocalvars(); 1241 localvars = savelocalvars; 1242 funclinebase = savefuncline; 1243 funclineabs = savefuncabs; 1244 freeparam(&shellparam); 1245 shellparam = saveparam; 1246 handler = savehandler; 1247 if (saved) 1248 popredir(); 1249 INTON; 1250 if (evalskip == SKIPFUNC) { 1251 evalskip = SKIPNONE; 1252 skipcount = 0; 1253 } 1254 if (flags & EV_EXIT) 1255 exitshell(exitstatus); 1256 break; 1257 1258 case CMDSPLBLTIN: 1259 VTRACE(DBG_EVAL, ("special ")); 1260 case CMDBUILTIN: 1261 VXTRACE(DBG_EVAL, ("builtin command [%d]%s: ", argc, 1262 vforked ? " VF" : ""), trargs(argv)); 1263 mode = (cmdentry.u.bltin == execcmd) ? 0 : REDIR_PUSH; 1264 if (flags == EV_BACKCMD) { 1265 memout.nleft = 0; 1266 memout.nextc = memout.buf; 1267 memout.bufsize = 64; 1268 mode |= REDIR_BACKQ; 1269 } 1270 e = -1; 1271 savecmdname = commandname; 1272 savetopfile = getcurrentfile(); 1273 savehandler = handler; 1274 temp_path = 0; 1275 if (!setjmp(jmploc.loc)) { 1276 handler = &jmploc; 1277 1278 /* 1279 * We need to ensure the command hash table isn't 1280 * corrupted by temporary PATH assignments. 1281 * However we must ensure the 'local' command works! 1282 */ 1283 if (path != pathval() && (cmdentry.u.bltin == hashcmd || 1284 cmdentry.u.bltin == typecmd)) { 1285 savelocalvars = localvars; 1286 localvars = 0; 1287 temp_path = 1; 1288 mklocal(path - 5 /* PATH= */, 0); 1289 } 1290 redirect(cmd->ncmd.redirect, mode); 1291 1292 /* 1293 * the empty command is regarded as a normal 1294 * builtin for the purposes of redirects, but 1295 * is a special builtin for var assigns. 1296 * (unless we are the "command" command.) 1297 */ 1298 if (argc == 0 && !(cmd_flags & DO_NOFUNC)) 1299 cmdentry.cmdtype = CMDSPLBLTIN; 1300 1301 /* exec is a special builtin, but needs this list... */ 1302 cmdenviron = varlist.list; 1303 /* we must check 'readonly' flag for all builtins */ 1304 listsetvar(varlist.list, 1305 cmdentry.cmdtype == CMDSPLBLTIN ? 0 : VNOSET); 1306 commandname = argv[0]; 1307 /* initialize nextopt */ 1308 argptr = argv + 1; 1309 optptr = NULL; 1310 /* and getopt */ 1311 optreset = 1; 1312 optind = 1; 1313 builtin_flags = flags; 1314 exitstatus = cmdentry.u.bltin(argc, argv); 1315 } else { 1316 e = exception; 1317 if (e == EXINT) 1318 exitstatus = SIGINT + 128; 1319 else if (e == EXEXEC) 1320 exitstatus = exerrno; 1321 else if (e != EXEXIT) 1322 exitstatus = 2; 1323 } 1324 handler = savehandler; 1325 flushall(); 1326 out1 = &output; 1327 out2 = &errout; 1328 freestdout(); 1329 if (temp_path) { 1330 poplocalvars(); 1331 localvars = savelocalvars; 1332 } 1333 cmdenviron = NULL; 1334 if (e != EXSHELLPROC) { 1335 commandname = savecmdname; 1336 if (flags & EV_EXIT) 1337 exitshell(exitstatus); 1338 } 1339 if (e != -1) { 1340 if ((e != EXERROR && e != EXEXEC) 1341 || cmdentry.cmdtype == CMDSPLBLTIN) 1342 exraise(e); 1343 popfilesupto(savetopfile); 1344 FORCEINTON; 1345 } 1346 if (cmdentry.u.bltin != execcmd) 1347 popredir(); 1348 if (flags == EV_BACKCMD) { 1349 backcmd->buf = memout.buf; 1350 backcmd->nleft = memout.nextc - memout.buf; 1351 memout.buf = NULL; 1352 } 1353 break; 1354 1355 default: 1356 VXTRACE(DBG_EVAL, ("normal command%s: ", vforked?" VF":""), 1357 trargs(argv)); 1358 redirect(cmd->ncmd.redirect, 1359 (vforked ? REDIR_VFORK : 0) | REDIR_KEEP); 1360 if (!vforked) 1361 for (sp = varlist.list ; sp ; sp = sp->next) 1362 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK); 1363 envp = environment(); 1364 shellexec(argv, envp, path, cmdentry.u.index, vforked); 1365 break; 1366 } 1367 goto out; 1368 1369 parent: /* parent process gets here (if we forked) */ 1370 1371 exitstatus = 0; /* if not altered just below */ 1372 if (mode == FORK_FG) { /* argument to fork */ 1373 exitstatus = waitforjob(jp); 1374 } else if (mode == FORK_NOJOB) { 1375 backcmd->fd = pip[0]; 1376 close(pip[1]); 1377 backcmd->jp = jp; 1378 } 1379 FORCEINTON; 1380 1381 out: 1382 if (lastarg) 1383 /* implement $_ for whatever use that really is */ 1384 (void) setvarsafe("_", lastarg, VNOERROR); 1385 popstackmark(&smark); 1386 } 1387 1388 1389 /* 1390 * Search for a command. This is called before we fork so that the 1391 * location of the command will be available in the parent as well as 1392 * the child. The check for "goodname" is an overly conservative 1393 * check that the name will not be subject to expansion. 1394 */ 1395 1396 STATIC void 1397 prehash(union node *n) 1398 { 1399 struct cmdentry entry; 1400 1401 if (n && n->type == NCMD && n->ncmd.args) 1402 if (goodname(n->ncmd.args->narg.text)) 1403 find_command(n->ncmd.args->narg.text, &entry, 0, 1404 pathval()); 1405 } 1406 1407 int 1408 in_function(void) 1409 { 1410 return funcnest; 1411 } 1412 1413 enum skipstate 1414 current_skipstate(void) 1415 { 1416 return evalskip; 1417 } 1418 1419 void 1420 save_skipstate(struct skipsave *p) 1421 { 1422 *p = s_k_i_p; 1423 } 1424 1425 void 1426 restore_skipstate(const struct skipsave *p) 1427 { 1428 s_k_i_p = *p; 1429 } 1430 1431 void 1432 stop_skipping(void) 1433 { 1434 evalskip = SKIPNONE; 1435 skipcount = 0; 1436 } 1437 1438 /* 1439 * Builtin commands. Builtin commands whose functions are closely 1440 * tied to evaluation are implemented here. 1441 */ 1442 1443 /* 1444 * No command given. 1445 */ 1446 1447 int 1448 bltincmd(int argc, char **argv) 1449 { 1450 /* 1451 * Preserve exitstatus of a previous possible redirection 1452 * as POSIX mandates 1453 */ 1454 return back_exitstatus; 1455 } 1456 1457 1458 /* 1459 * Handle break and continue commands. Break, continue, and return are 1460 * all handled by setting the evalskip flag. The evaluation routines 1461 * above all check this flag, and if it is set they start skipping 1462 * commands rather than executing them. The variable skipcount is 1463 * the number of loops to break/continue, or the number of function 1464 * levels to return. (The latter is always 1.) It should probably 1465 * be an error to break out of more loops than exist, but it isn't 1466 * in the standard shell so we don't make it one here. 1467 */ 1468 1469 int 1470 breakcmd(int argc, char **argv) 1471 { 1472 int n = argc > 1 ? number(argv[1]) : 1; 1473 1474 if (n <= 0) 1475 error("invalid count: %d", n); 1476 if (n > loopnest) 1477 n = loopnest; 1478 if (n > 0) { 1479 evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; 1480 skipcount = n; 1481 } 1482 return 0; 1483 } 1484 1485 int 1486 dotcmd(int argc, char **argv) 1487 { 1488 exitstatus = 0; 1489 1490 if (argc >= 2) { /* That's what SVR2 does */ 1491 char *fullname; 1492 /* 1493 * dot_funcnest needs to be 0 when not in a dotcmd, so it 1494 * cannot be restored with (funcnest + 1). 1495 */ 1496 int dot_funcnest_old; 1497 struct stackmark smark; 1498 1499 setstackmark(&smark); 1500 fullname = find_dot_file(argv[1]); 1501 setinputfile(fullname, 1); 1502 commandname = fullname; 1503 dot_funcnest_old = dot_funcnest; 1504 dot_funcnest = funcnest + 1; 1505 cmdloop(0); 1506 dot_funcnest = dot_funcnest_old; 1507 popfile(); 1508 popstackmark(&smark); 1509 } 1510 return exitstatus; 1511 } 1512 1513 /* 1514 * allow dotfile function nesting to be manipulated 1515 * (for read_profile). This allows profile files to 1516 * be treated as if they were used as '.' commands, 1517 * (approximately) and in particular, for "return" to work. 1518 */ 1519 int 1520 set_dot_funcnest(int new) 1521 { 1522 int rv = dot_funcnest; 1523 1524 if (new >= 0) 1525 dot_funcnest = new; 1526 1527 return rv; 1528 } 1529 1530 /* 1531 * Take commands from a file. To be compatible we should do a path 1532 * search for the file, which is necessary to find sub-commands. 1533 */ 1534 1535 STATIC char * 1536 find_dot_file(char *basename) 1537 { 1538 char *fullname; 1539 const char *path = pathval(); 1540 struct stat statb; 1541 1542 /* don't try this for absolute or relative paths */ 1543 if (strchr(basename, '/')) { 1544 if (stat(basename, &statb) == 0) { 1545 if (S_ISDIR(statb.st_mode)) 1546 error("%s: is a directory", basename); 1547 if (S_ISBLK(statb.st_mode)) 1548 error("%s: is a block device", basename); 1549 return basename; 1550 } 1551 } else while ((fullname = padvance(&path, basename, 1)) != NULL) { 1552 if ((stat(fullname, &statb) == 0)) { 1553 /* weird format is to ease future code... */ 1554 if (S_ISDIR(statb.st_mode) || S_ISBLK(statb.st_mode)) 1555 ; 1556 #if notyet 1557 else if (unreadable()) { 1558 /* 1559 * testing this via st_mode is ugly to get 1560 * correct (and would ignore ACLs). 1561 * better way is just to open the file. 1562 * But doing that here would (currently) 1563 * mean opening the file twice, which 1564 * might not be safe. So, defer this 1565 * test until code is restructures so 1566 * we can return a fd. Then we also 1567 * get to fix the mem leak just below... 1568 */ 1569 } 1570 #endif 1571 else { 1572 /* 1573 * Don't bother freeing here, since 1574 * it will be freed by the caller. 1575 * XXX no it won't - a bug for later. 1576 */ 1577 return fullname; 1578 } 1579 } 1580 stunalloc(fullname); 1581 } 1582 1583 /* not found in the PATH */ 1584 error("%s: not found", basename); 1585 /* NOTREACHED */ 1586 } 1587 1588 1589 1590 /* 1591 * The return command. 1592 * 1593 * Quoth the POSIX standard: 1594 * The return utility shall cause the shell to stop executing the current 1595 * function or dot script. If the shell is not currently executing 1596 * a function or dot script, the results are unspecified. 1597 * 1598 * As for the unspecified part, there seems to be no de-facto standard: bash 1599 * ignores the return with a warning, zsh ignores the return in interactive 1600 * mode but seems to liken it to exit in a script. (checked May 2014) 1601 * 1602 * We choose to silently ignore the return. Older versions of this shell 1603 * set evalskip to SKIPFILE causing the shell to (indirectly) exit. This 1604 * had at least the problem of circumventing the check for stopped jobs, 1605 * which would occur for exit or ^D. 1606 */ 1607 1608 int 1609 returncmd(int argc, char **argv) 1610 { 1611 int ret = argc > 1 ? number(argv[1]) : exitstatus; 1612 1613 if ((dot_funcnest == 0 && funcnest) 1614 || (dot_funcnest > 0 && funcnest - (dot_funcnest - 1) > 0)) { 1615 evalskip = SKIPFUNC; 1616 skipcount = 1; 1617 } else if (dot_funcnest > 0) { 1618 evalskip = SKIPFILE; 1619 skipcount = 1; 1620 } else { 1621 /* XXX: should a warning be issued? */ 1622 ret = 0; 1623 } 1624 1625 return ret; 1626 } 1627 1628 1629 int 1630 falsecmd(int argc, char **argv) 1631 { 1632 return 1; 1633 } 1634 1635 1636 int 1637 truecmd(int argc, char **argv) 1638 { 1639 return 0; 1640 } 1641 1642 1643 int 1644 execcmd(int argc, char **argv) 1645 { 1646 if (argc > 1) { 1647 struct strlist *sp; 1648 1649 iflag = 0; /* exit on error */ 1650 mflag = 0; 1651 optschanged(); 1652 for (sp = cmdenviron; sp; sp = sp->next) 1653 setvareq(sp->text, VDOEXPORT|VEXPORT|VSTACK); 1654 shellexec(argv + 1, environment(), pathval(), 0, 0); 1655 } 1656 return 0; 1657 } 1658 1659 static int 1660 conv_time(clock_t ticks, char *seconds, size_t l) 1661 { 1662 static clock_t tpm = 0; 1663 clock_t mins; 1664 int i; 1665 1666 if (!tpm) 1667 tpm = sysconf(_SC_CLK_TCK) * 60; 1668 1669 mins = ticks / tpm; 1670 snprintf(seconds, l, "%.4f", (ticks - mins * tpm) * 60.0 / tpm ); 1671 1672 if (seconds[0] == '6' && seconds[1] == '0') { 1673 /* 59.99995 got rounded up... */ 1674 mins++; 1675 strlcpy(seconds, "0.0", l); 1676 return mins; 1677 } 1678 1679 /* suppress trailing zeros */ 1680 i = strlen(seconds) - 1; 1681 for (; seconds[i] == '0' && seconds[i - 1] != '.'; i--) 1682 seconds[i] = 0; 1683 return mins; 1684 } 1685 1686 int 1687 timescmd(int argc, char **argv) 1688 { 1689 struct tms tms; 1690 int u, s, cu, cs; 1691 char us[8], ss[8], cus[8], css[8]; 1692 1693 nextopt(""); 1694 1695 times(&tms); 1696 1697 u = conv_time(tms.tms_utime, us, sizeof(us)); 1698 s = conv_time(tms.tms_stime, ss, sizeof(ss)); 1699 cu = conv_time(tms.tms_cutime, cus, sizeof(cus)); 1700 cs = conv_time(tms.tms_cstime, css, sizeof(css)); 1701 1702 outfmt(out1, "%dm%ss %dm%ss\n%dm%ss %dm%ss\n", 1703 u, us, s, ss, cu, cus, cs, css); 1704 1705 return 0; 1706 } 1707