sh.sem.c revision 167466
1/* $Header: /p/tcsh/cvsroot/tcsh/sh.sem.c,v 3.78 2006/10/14 17:23:39 christos Exp $ */ 2/* 3 * sh.sem.c: I/O redirections and job forking. A touchy issue! 4 * Most stuff with builtins is incorrect 5 */ 6/*- 7 * Copyright (c) 1980, 1991 The Regents of the University of California. 8 * All rights reserved. 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#include "sh.h" 35 36RCSID("$tcsh: sh.sem.c,v 3.78 2006/10/14 17:23:39 christos Exp $") 37 38#include "tc.h" 39#include "tw.h" 40#ifdef WINNT_NATIVE 41#include "nt.const.h" 42#endif /*WINNT_NATIVE*/ 43 44#ifdef CLOSE_ON_EXEC 45# ifndef SUNOS4 46# ifndef CLEX_DUPS 47# define CLEX_DUPS 48# endif /* CLEX_DUPS */ 49# endif /* !SUNOS4 */ 50#endif /* CLOSE_ON_EXEC */ 51 52#if defined(__sparc__) || defined(sparc) 53# if !defined(MACH) && SYSVREL == 0 && !defined(Lynx) && !defined(BSD4_4) && !defined(linux) && !defined(__GNU__) && !defined(__GLIBC__) 54# include <vfork.h> 55# endif /* !MACH && SYSVREL == 0 && !Lynx && !BSD4_4 && !glibc */ 56#endif /* __sparc__ || sparc */ 57 58#ifdef VFORK 59static void vffree (int); 60#endif 61static Char *splicepipe (struct command *, Char *); 62static void doio (struct command *, int *, int *); 63static void chkclob (const char *); 64 65/* 66 * C shell 67 */ 68 69/* 70 * For SVR4, there are problems with pipelines having the first process as 71 * the group leader. The problem occurs when the first process exits before 72 * the others have a chance to setpgid(). This is because in SVR4 you can't 73 * have a zombie as a group leader. The solution I have used is to reverse 74 * the order in which pipelines are started, making the last process the 75 * group leader. (Note I am not using 'pipeline' in the generic sense -- I 76 * mean processes connected by '|'.) I don't know yet if this causes other 77 * problems. 78 * 79 * All the changes for this are in execute(), and are enclosed in 80 * '#ifdef BACKPIPE' 81 * 82 * David Dawes (dawes@physics.su.oz.au) Oct 1991 83 */ 84 85/*VARARGS 1*/ 86void 87execute(struct command *t, volatile int wanttty, int *pipein, int *pipeout, 88 int do_glob) 89{ 90 int forked = 0; 91 const struct biltins * volatile bifunc; 92 pid_t pid = 0; 93 int pv[2]; 94 sigset_t set; 95 static sigset_t csigset; 96#ifdef VFORK 97 static int onosigchld = 0; 98#endif /* VFORK */ 99 static int nosigchld = 0; 100 101 (void) &wanttty; 102 (void) &forked; 103 (void) &bifunc; 104 105 if (t == 0) 106 return; 107 108#ifdef WINNT_NATIVE 109 { 110 if ((varval(STRNTslowexec) == STRNULL) && 111 !t->t_dcdr && !t->t_dcar && !t->t_dflg && !didfds && 112 (intty || intact) && (t->t_dtyp == NODE_COMMAND) && 113 !isbfunc(t)) { 114 if ((t->t_dcom[0][0] & (QUOTE | TRIM)) == QUOTE) 115 (void) Strcpy(t->t_dcom[0], t->t_dcom[0] + 1); 116 Dfix(t); 117 if (nt_try_fast_exec(t) == 0) 118 return; 119 } 120 } 121#endif /* WINNT_NATIVE */ 122 123 /* 124 * Ed hutchins@sgi.com & Dominic dbg@sgi.com 125 * Sat Feb 25 03:13:11 PST 1995 126 * try implicit cd if we have a 1 word command 127 */ 128 if (implicit_cd && (intty || intact) && t->t_dcom && t->t_dcom[0] && 129 t->t_dcom[0][0] && (blklen(t->t_dcom) == 1) && !noexec) { 130 Char *sCName; 131 struct stat stbuf; 132 char *pathname; 133 134 sCName = dollar(t->t_dcom[0]); 135 if (sCName != NULL && sCName[0] == '~') { 136 struct Strbuf buf = Strbuf_INIT; 137 const Char *name_end; 138 139 for (name_end = sCName + 1; *name_end != '\0' && *name_end != '/'; 140 name_end++) 141 continue; 142 if (name_end != sCName + 1) { 143 Char *name, *home; 144 145 name = Strnsave(sCName + 1, name_end - (sCName + 1)); 146 home = gethdir(name); 147 if (home != NULL) { 148 Strbuf_append(&buf, home); 149 xfree(home); 150 } else 151 Strbuf_append(&buf, name); 152 xfree(name); 153 } else 154 Strbuf_append(&buf, varval(STRhome)); 155 Strbuf_append(&buf, name_end); 156 xfree(sCName); 157 sCName = Strbuf_finish(&buf); 158 } 159 160 pathname = short2str(sCName); 161 xfree(sCName); 162 /* if this is a dir, tack a "cd" on as the first arg */ 163 if (pathname != NULL && 164 ((stat(pathname, &stbuf) != -1 && S_ISDIR(stbuf.st_mode)) 165#ifdef WINNT_NATIVE 166 || (pathname[0] && pathname[1] == ':' && pathname[2] == '\0') 167#endif /* WINNT_NATIVE */ 168 )) { 169 Char *vCD[2]; 170 Char **ot_dcom = t->t_dcom; 171 172 vCD[0] = Strsave(STRcd); 173 vCD[1] = NULL; 174 t->t_dcom = blkspl(vCD, ot_dcom); 175 xfree(ot_dcom); 176 if (implicit_cd > 1) { 177 blkpr(t->t_dcom); 178 xputchar( '\n' ); 179 } 180 } 181 } 182 183 /* 184 * From: Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de> 185 * Don't check for wantty > 0... 186 */ 187 if (t->t_dflg & F_AMPERSAND) 188 wanttty = 0; 189 switch (t->t_dtyp) { 190 191 case NODE_COMMAND: 192 if ((t->t_dcom[0][0] & (QUOTE | TRIM)) == QUOTE) 193 memmove(t->t_dcom[0], t->t_dcom[0] + 1, 194 (Strlen(t->t_dcom[0] + 1) + 1) * sizeof (*t->t_dcom[0])); 195 if ((t->t_dflg & F_REPEAT) == 0) 196 Dfix(t); /* $ " ' \ */ 197 if (t->t_dcom[0] == 0) { 198 return; 199 } 200 /*FALLTHROUGH*/ 201 202 case NODE_PAREN: 203#ifdef BACKPIPE 204 if (t->t_dflg & F_PIPEIN) 205 mypipe(pipein); 206#else /* !BACKPIPE */ 207 if (t->t_dflg & F_PIPEOUT) 208 mypipe(pipeout); 209#endif /* BACKPIPE */ 210 /* 211 * Must do << early so parent will know where input pointer should be. 212 * If noexec then this is all we do. 213 */ 214 if (t->t_dflg & F_READ) { 215 xclose(0); 216 heredoc(t->t_dlef); 217 if (noexec) 218 xclose(0); 219 } 220 221 setcopy(STRstatus, STR0, VAR_READWRITE); 222 223 /* 224 * This mess is the necessary kludge to handle the prefix builtins: 225 * nice, nohup, time. These commands can also be used by themselves, 226 * and this is not handled here. This will also work when loops are 227 * parsed. 228 */ 229 while (t->t_dtyp == NODE_COMMAND) 230 if (eq(t->t_dcom[0], STRnice)) { 231 if (t->t_dcom[1]) { 232 if (strchr("+-", t->t_dcom[1][0])) { 233 if (t->t_dcom[2]) { 234 setname("nice"); 235 t->t_nice = 236 getn(t->t_dcom[1]); 237 lshift(t->t_dcom, 2); 238 t->t_dflg |= F_NICE; 239 } 240 else 241 break; 242 } 243 else { 244 t->t_nice = 4; 245 lshift(t->t_dcom, 1); 246 t->t_dflg |= F_NICE; 247 } 248 } 249 else 250 break; 251 } 252 else if (eq(t->t_dcom[0], STRnohup)) { 253 if (t->t_dcom[1]) { 254 t->t_dflg |= F_NOHUP; 255 lshift(t->t_dcom, 1); 256 } 257 else 258 break; 259 } 260 else if (eq(t->t_dcom[0], STRhup)) { 261 if (t->t_dcom[1]) { 262 t->t_dflg |= F_HUP; 263 lshift(t->t_dcom, 1); 264 } 265 else 266 break; 267 } 268 else if (eq(t->t_dcom[0], STRtime)) { 269 if (t->t_dcom[1]) { 270 t->t_dflg |= F_TIME; 271 lshift(t->t_dcom, 1); 272 } 273 else 274 break; 275 } 276#ifdef F_VER 277 else if (eq(t->t_dcom[0], STRver)) 278 if (t->t_dcom[1] && t->t_dcom[2]) { 279 setname("ver"); 280 t->t_systype = getv(t->t_dcom[1]); 281 lshift(t->t_dcom, 2); 282 t->t_dflg |= F_VER; 283 } 284 else 285 break; 286#endif /* F_VER */ 287 else 288 break; 289 290 /* is it a command */ 291 if (t->t_dtyp == NODE_COMMAND) { 292 /* 293 * Check if we have a builtin function and remember which one. 294 */ 295 bifunc = isbfunc(t); 296 if (noexec) { 297 /* 298 * Continue for builtins that are part of the scripting language 299 */ 300 if (bifunc == NULL) 301 break; 302 if (bifunc->bfunct != (bfunc_t)dobreak && 303 bifunc->bfunct != (bfunc_t)docontin && 304 bifunc->bfunct != (bfunc_t)doelse && 305 bifunc->bfunct != (bfunc_t)doend && 306 bifunc->bfunct != (bfunc_t)doforeach&& 307 bifunc->bfunct != (bfunc_t)dogoto && 308 bifunc->bfunct != (bfunc_t)doif && 309 bifunc->bfunct != (bfunc_t)dorepeat && 310 bifunc->bfunct != (bfunc_t)doswbrk && 311 bifunc->bfunct != (bfunc_t)doswitch && 312 bifunc->bfunct != (bfunc_t)dowhile && 313 bifunc->bfunct != (bfunc_t)dozip) 314 break; 315 } 316 } 317 else { /* not a command */ 318 bifunc = NULL; 319 if (noexec) 320 break; 321 } 322 323 /* 324 * GrP Executing a command - run jobcmd hook 325 * Don't run for builtins 326 * Don't run if we're not in a tty 327 * Don't run if we're not really executing 328 */ 329 if (t->t_dtyp == NODE_COMMAND && !bifunc && !noexec && intty) { 330 Char *cmd = unparse(t); 331 332 cleanup_push(cmd, xfree); 333 job_cmd(cmd); 334 cleanup_until(cmd); 335 } 336 337 /* 338 * We fork only if we are timed, or are not the end of a parenthesized 339 * list and not a simple builtin function. Simple meaning one that is 340 * not pipedout, niced, nohupped, or &'d. It would be nice(?) to not 341 * fork in some of these cases. 342 */ 343 /* 344 * Prevent forking cd, pushd, popd, chdir cause this will cause the 345 * shell not to change dir! 346 */ 347#ifdef BACKPIPE 348 /* 349 * Can't have NOFORK for the tail of a pipe - because it is not the 350 * last command spawned (even if it is at the end of a parenthesised 351 * list). 352 */ 353 if (t->t_dflg & F_PIPEIN) 354 t->t_dflg &= ~(F_NOFORK); 355#endif /* BACKPIPE */ 356 if (bifunc && (bifunc->bfunct == (bfunc_t)dochngd || 357 bifunc->bfunct == (bfunc_t)dopushd || 358 bifunc->bfunct == (bfunc_t)dopopd)) 359 t->t_dflg &= ~(F_NICE); 360 if (((t->t_dflg & F_TIME) || ((t->t_dflg & F_NOFORK) == 0 && 361 (!bifunc || t->t_dflg & 362 (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP | F_HUP)))) || 363 /* 364 * We have to fork for eval too. 365 */ 366 (bifunc && (t->t_dflg & F_PIPEIN) != 0 && 367 bifunc->bfunct == (bfunc_t)doeval)) { 368#ifdef VFORK 369 if (t->t_dtyp == NODE_PAREN || 370 t->t_dflg & (F_REPEAT | F_AMPERSAND) || bifunc) 371#endif /* VFORK */ 372 { 373 forked++; 374 /* 375 * We need to block SIGCHLD here, so that if the process does 376 * not die before we can set the process group 377 */ 378 if (wanttty >= 0 && !nosigchld) { 379 sigemptyset(&set); 380 sigaddset(&set, SIGCHLD); 381 (void)sigprocmask(SIG_BLOCK, &set, &csigset); 382 383 nosigchld = 1; 384 } 385 386 pid = pfork(t, wanttty); 387 if (pid == 0 && nosigchld) { 388 sigprocmask(SIG_SETMASK, &csigset, NULL); 389 nosigchld = 0; 390 } 391 else if (pid != 0 && (t->t_dflg & F_AMPERSAND)) 392 backpid = pid; 393 } 394 395#ifdef VFORK 396 else { 397 int ochild, osetintr, ohaderr, odidfds; 398 int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp; 399 int oisoutatty, oisdiagatty; 400 sigset_t oset, ocsigset; 401# ifndef CLOSE_ON_EXEC 402 int odidcch; 403# endif /* !CLOSE_ON_EXEC */ 404 405 /* 406 * Prepare for the vfork by saving everything that the child 407 * corrupts before it exec's. Note that in some signal 408 * implementations which keep the signal info in user space 409 * (e.g. Sun's) it will also be necessary to save and restore 410 * the current sigvec's for the signals the child touches 411 * before it exec's. 412 */ 413 414 /* 415 * Sooooo true... If this is a Sun, save the sigvec's. (Skip 416 * Gilbrech - 11/22/87) 417 */ 418# ifdef SAVESIGVEC 419 struct sigaction savesv[NSIGSAVED]; 420 sigset_t savesm; 421 422# endif /* SAVESIGVEC */ 423 if (wanttty >= 0 && !nosigchld && !noexec) { 424 sigemptyset(&set); 425 sigaddset(&set, SIGCHLD); 426 (void)sigprocmask(SIG_BLOCK, &set, &csigset); 427 nosigchld = 1; 428 } 429 sigemptyset(&set); 430 sigaddset(&set, SIGCHLD); 431 sigaddset(&set, SIGINT); 432 (void)sigprocmask(SIG_BLOCK, &set, &oset); 433 ochild = child; 434 osetintr = setintr; 435 ohaderr = haderr; 436 odidfds = didfds; 437# ifndef CLOSE_ON_EXEC 438 odidcch = didcch; 439# endif /* !CLOSE_ON_EXEC */ 440 oSHIN = SHIN; 441 oSHOUT = SHOUT; 442 oSHDIAG = SHDIAG; 443 oOLDSTD = OLDSTD; 444 otpgrp = tpgrp; 445 oisoutatty = isoutatty; 446 oisdiagatty = isdiagatty; 447 ocsigset = csigset; 448 onosigchld = nosigchld; 449 Vsav = Vdp = 0; 450 Vexpath = 0; 451 Vt = 0; 452# ifdef SAVESIGVEC 453 savesigvec(savesv, savesm); 454# endif /* SAVESIGVEC */ 455 if (use_fork) 456 pid = fork(); 457 else 458 pid = vfork(); 459 460 if (pid < 0) { 461# ifdef SAVESIGVEC 462 restoresigvec(savesv, savesm); 463# endif /* SAVESIGVEC */ 464 sigprocmask(SIG_SETMASK, &oset, NULL); 465 stderror(ERR_NOPROC); 466 } 467 forked++; 468 if (pid) { /* parent */ 469# ifdef SAVESIGVEC 470 restoresigvec(savesv, savesm); 471# endif /* SAVESIGVEC */ 472 child = ochild; 473 setintr = osetintr; 474 haderr = ohaderr; 475 didfds = odidfds; 476 SHIN = oSHIN; 477# ifndef CLOSE_ON_EXEC 478 didcch = odidcch; 479# endif /* !CLOSE_ON_EXEC */ 480 SHOUT = oSHOUT; 481 SHDIAG = oSHDIAG; 482 OLDSTD = oOLDSTD; 483 tpgrp = otpgrp; 484 isoutatty = oisoutatty; 485 isdiagatty = oisdiagatty; 486 csigset = ocsigset; 487 nosigchld = onosigchld; 488 489 xfree(Vsav); 490 Vsav = 0; 491 xfree(Vdp); 492 Vdp = 0; 493 xfree(Vexpath); 494 Vexpath = 0; 495 blk_cleanup(Vt); 496 Vt = 0; 497 /* this is from pfork() */ 498 palloc(pid, t); 499 sigprocmask(SIG_SETMASK, &oset, NULL); 500 } 501 else { /* child */ 502 /* this is from pfork() */ 503 pid_t pgrp; 504 int ignint = 0; 505 if (nosigchld) { 506 sigprocmask(SIG_SETMASK, &csigset, NULL); 507 nosigchld = 0; 508 } 509 510 if (setintr) 511 ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) 512 || (gointr && eq(gointr, STRminus)); 513 pgrp = pcurrjob ? pcurrjob->p_jobid : getpid(); 514 child++; 515 if (setintr) { 516 setintr = 0; 517/* 518 * casts made right for SunOS 4.0 by Douglas C. Schmidt 519 * <schmidt%sunshine.ics.uci.edu@ROME.ICS.UCI.EDU> 520 * (thanks! -- PWP) 521 * 522 * ignint ifs cleaned by Johan Widen <mcvax!osiris.sics.se!jw@uunet.UU.NET> 523 * (thanks again) 524 */ 525 if (ignint) { 526 (void) signal(SIGINT, SIG_IGN); 527 (void) signal(SIGQUIT, SIG_IGN); 528 } 529 else { 530 (void) signal(SIGINT, vffree); 531 (void) signal(SIGQUIT, SIG_DFL); 532 } 533# ifdef BSDJOBS 534 if (wanttty >= 0) { 535 (void) signal(SIGTSTP, SIG_DFL); 536 (void) signal(SIGTTIN, SIG_DFL); 537 (void) signal(SIGTTOU, SIG_DFL); 538 } 539# endif /* BSDJOBS */ 540 541 sigaction(SIGTERM, &parterm, NULL); 542 } 543 else if (tpgrp == -1 && 544 (t->t_dflg & F_NOINTERRUPT)) { 545 (void) signal(SIGINT, SIG_IGN); 546 (void) signal(SIGQUIT, SIG_IGN); 547 } 548 549 pgetty(wanttty, pgrp); 550 551 if (t->t_dflg & F_NOHUP) 552 (void) signal(SIGHUP, SIG_IGN); 553 if (t->t_dflg & F_HUP) 554 (void) signal(SIGHUP, SIG_DFL); 555 if (t->t_dflg & F_NICE) { 556 int nval = SIGN_EXTEND_CHAR(t->t_nice); 557# ifdef HAVE_SETPRIORITY 558 if (setpriority(PRIO_PROCESS, 0, nval) == -1 && errno) 559 stderror(ERR_SYSTEM, "setpriority", 560 strerror(errno)); 561# else /* !HAVE_SETPRIORITY */ 562 (void) nice(nval); 563# endif /* HAVE_SETPRIORITY */ 564 } 565# ifdef F_VER 566 if (t->t_dflg & F_VER) { 567 tsetenv(STRSYSTYPE, t->t_systype ? STRbsd43 : STRsys53); 568 dohash(NULL, NULL); 569 } 570# endif /* F_VER */ 571 } 572 573 } 574#endif /* VFORK */ 575 } 576 if (pid != 0) { 577 /* 578 * It would be better if we could wait for the whole job when we 579 * knew the last process had been started. Pwait, in fact, does 580 * wait for the whole job anyway, but this test doesn't really 581 * express our intentions. 582 */ 583#ifdef BACKPIPE 584 if (didfds == 0 && t->t_dflg & F_PIPEOUT) { 585 xclose(pipeout[0]); 586 xclose(pipeout[1]); 587 } 588 if ((t->t_dflg & F_PIPEIN) != 0) 589 break; 590#else /* !BACKPIPE */ 591 if (didfds == 0 && t->t_dflg & F_PIPEIN) { 592 xclose(pipein[0]); 593 xclose(pipein[1]); 594 } 595 if ((t->t_dflg & F_PIPEOUT) != 0) 596 break; 597#endif /* BACKPIPE */ 598 599 if (nosigchld) { 600 sigprocmask(SIG_SETMASK, &csigset, NULL); 601 nosigchld = 0; 602 } 603 if ((t->t_dflg & F_AMPERSAND) == 0) 604 pwait(); 605 break; 606 } 607 608 doio(t, pipein, pipeout); 609#ifdef BACKPIPE 610 if (t->t_dflg & F_PIPEIN) { 611 xclose(pipein[0]); 612 xclose(pipein[1]); 613 } 614#else /* !BACKPIPE */ 615 if (t->t_dflg & F_PIPEOUT) { 616 xclose(pipeout[0]); 617 xclose(pipeout[1]); 618 } 619#endif /* BACKPIPE */ 620 /* 621 * Perform a builtin function. If we are not forked, arrange for 622 * possible stopping 623 */ 624 if (bifunc) { 625 func(t, bifunc); 626 if (forked) 627 exitstat(); 628 else { 629 if (adrof(STRprintexitvalue)) { 630 int rv = getn(varval(STRstatus)); 631 if (rv != 0) 632 xprintf(CGETS(17, 2, "Exit %d\n"), rv); 633 } 634 } 635 break; 636 } 637 if (t->t_dtyp != NODE_PAREN) { 638 doexec(t, do_glob); 639 /* NOTREACHED */ 640 } 641 /* 642 * For () commands must put new 0,1,2 in FSH* and recurse 643 */ 644 (void)close_on_exec(OLDSTD = dcopy(0, FOLDSTD), 1); 645 (void)close_on_exec(SHOUT = dcopy(1, FSHOUT), 1); 646 isoutatty = isatty(SHOUT); 647 (void)close_on_exec(SHDIAG = dcopy(2, FSHDIAG), 1); 648 isdiagatty = isatty(SHDIAG); 649 xclose(SHIN); 650 SHIN = -1; 651#ifndef CLOSE_ON_EXEC 652 didcch = 0; 653#else 654 (void) close_on_exec(FSHOUT, 1); 655 (void) close_on_exec(FSHDIAG, 1); 656 (void) close_on_exec(FOLDSTD, 1); 657#endif /* !CLOSE_ON_EXEC */ 658 didfds = 0; 659 wanttty = -1; 660 t->t_dspr->t_dflg |= t->t_dflg & F_NOINTERRUPT; 661 execute(t->t_dspr, wanttty, NULL, NULL, do_glob); 662 exitstat(); 663 664 case NODE_PIPE: 665#ifdef BACKPIPE 666 t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg & 667 (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT)); 668 execute(t->t_dcdr, wanttty, pv, pipeout, do_glob); 669 t->t_dcar->t_dflg |= F_PIPEOUT | 670 (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT)); 671 execute(t->t_dcar, wanttty, pipein, pv, do_glob); 672#else /* !BACKPIPE */ 673 t->t_dcar->t_dflg |= F_PIPEOUT | 674 (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT)); 675 execute(t->t_dcar, wanttty, pipein, pv, do_glob); 676 t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg & 677 (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT)); 678 execute(t->t_dcdr, wanttty, pv, pipeout, do_glob); 679#endif /* BACKPIPE */ 680 break; 681 682 case NODE_LIST: 683 if (t->t_dcar) { 684 t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; 685 execute(t->t_dcar, wanttty, NULL, NULL, do_glob); 686 /* 687 * In strange case of A&B make a new job after A 688 */ 689 if (t->t_dcar->t_dflg & F_AMPERSAND && t->t_dcdr && 690 (t->t_dcdr->t_dflg & F_AMPERSAND) == 0) 691 pendjob(); 692 } 693 if (t->t_dcdr) { 694 t->t_dcdr->t_dflg |= t->t_dflg & 695 (F_NOFORK | F_NOINTERRUPT); 696 execute(t->t_dcdr, wanttty, NULL, NULL, do_glob); 697 } 698 break; 699 700 case NODE_OR: 701 case NODE_AND: 702 if (t->t_dcar) { 703 t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; 704 execute(t->t_dcar, wanttty, NULL, NULL, do_glob); 705 if ((getn(varval(STRstatus)) == 0) != 706 (t->t_dtyp == NODE_AND)) { 707 return; 708 } 709 } 710 if (t->t_dcdr) { 711 t->t_dcdr->t_dflg |= t->t_dflg & 712 (F_NOFORK | F_NOINTERRUPT); 713 execute(t->t_dcdr, wanttty, NULL, NULL, do_glob); 714 } 715 break; 716 717 default: 718 break; 719 } 720 /* 721 * Fall through for all breaks from switch 722 * 723 * If there will be no more executions of this command, flush all file 724 * descriptors. Places that turn on the F_REPEAT bit are responsible for 725 * doing donefds after the last re-execution 726 */ 727 if (didfds && !(t->t_dflg & F_REPEAT)) 728 donefds(); 729} 730 731#ifdef VFORK 732static void 733/*ARGSUSED*/ 734vffree(int snum) 735{ 736 USE(snum); 737 738 _exit(1); 739} 740#endif /* VFORK */ 741 742/* 743 * Expand and glob the words after an i/o redirection. 744 * If more than one word is generated, then update the command vector. 745 * 746 * This is done differently in all the shells: 747 * 1. in the bourne shell and ksh globbing is not performed 748 * 2. Bash/csh say ambiguous 749 * 3. zsh does i/o to/from all the files 750 * 4. itcsh concatenates the words. 751 * 752 * I don't know what is best to do. I think that Ambiguous is better 753 * than restructuring the command vector, because the user can get 754 * unexpected results. In any case, the command vector restructuring 755 * code is present and the user can choose it by setting noambiguous 756 */ 757static Char * 758splicepipe(struct command *t, Char *cp) 759{ 760 Char *blk[2]; 761 762 if (adrof(STRnoambiguous)) { 763 Char **pv; 764 int gflag; 765 766 blk[0] = Dfix1(cp); /* expand $ */ 767 blk[1] = NULL; 768 769 gflag = tglob(blk); 770 if (gflag) { 771 pv = globall(blk, gflag); 772 if (pv == NULL) { 773 setname(short2str(blk[0])); 774 xfree(blk[0]); 775 stderror(ERR_NAME | ERR_NOMATCH); 776 } 777 if (pv[1] != NULL) { /* we need to fix the command vector */ 778 Char **av = blkspl(t->t_dcom, &pv[1]); 779 xfree(t->t_dcom); 780 t->t_dcom = av; 781 } 782 xfree(blk[0]); 783 blk[0] = pv[0]; 784 xfree(pv); 785 } 786 } 787 else { 788 Char *buf; 789 790 buf = Dfix1(cp); 791 cleanup_push(buf, xfree); 792 blk[0] = globone(buf, G_ERROR); 793 cleanup_until(buf); 794 } 795 return(blk[0]); 796} 797 798/* 799 * Perform io redirection. 800 * We may or maynot be forked here. 801 */ 802static void 803doio(struct command *t, int *pipein, int *pipeout) 804{ 805 int fd; 806 Char *cp; 807 unsigned long flags = t->t_dflg; 808 809 if (didfds || (flags & F_REPEAT)) 810 return; 811 if ((flags & F_READ) == 0) {/* F_READ already done */ 812 if (t->t_dlef) { 813 char *tmp; 814 815 /* 816 * so < /dev/std{in,out,err} work 817 */ 818 (void) dcopy(SHIN, 0); 819 (void) dcopy(SHOUT, 1); 820 (void) dcopy(SHDIAG, 2); 821 cp = splicepipe(t, t->t_dlef); 822 tmp = strsave(short2str(cp)); 823 xfree(cp); 824 cleanup_push(tmp, xfree); 825 if ((fd = xopen(tmp, O_RDONLY|O_LARGEFILE)) < 0) 826 stderror(ERR_SYSTEM, tmp, strerror(errno)); 827 cleanup_until(tmp); 828 /* allow input files larger than 2Gb */ 829#ifndef WINNT_NATIVE 830 (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE); 831#endif /*!WINNT_NATIVE*/ 832 (void) dmove(fd, 0); 833 } 834 else if (flags & F_PIPEIN) { 835 xclose(0); 836 (void) dup(pipein[0]); 837 xclose(pipein[0]); 838 xclose(pipein[1]); 839 } 840 else if ((flags & F_NOINTERRUPT) && tpgrp == -1) { 841 xclose(0); 842 (void) xopen(_PATH_DEVNULL, O_RDONLY|O_LARGEFILE); 843 } 844 else { 845 xclose(0); 846 (void) dup(OLDSTD); 847#if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS) 848 /* 849 * PWP: Unlike Bezerkeley 4.3, FIONCLEX for Pyramid is preserved 850 * across dup()s, so we have to UNSET it here or else we get a 851 * command with NO stdin, stdout, or stderr at all (a bad thing 852 * indeed) 853 */ 854 (void) close_on_exec(0, 0); 855#endif /* CLOSE_ON_EXEC && CLEX_DUPS */ 856 } 857 } 858 if (t->t_drit) { 859 char *tmp; 860 861 cp = splicepipe(t, t->t_drit); 862 tmp = strsave(short2str(cp)); 863 xfree(cp); 864 cleanup_push(tmp, xfree); 865 /* 866 * so > /dev/std{out,err} work 867 */ 868 (void) dcopy(SHOUT, 1); 869 (void) dcopy(SHDIAG, 2); 870 if ((flags & F_APPEND) != 0) { 871#ifdef O_APPEND 872 fd = xopen(tmp, O_WRONLY|O_APPEND|O_LARGEFILE); 873#else /* !O_APPEND */ 874 fd = xopen(tmp, O_WRONLY|O_LARGEFILE); 875 (void) lseek(fd, (off_t) 0, L_XTND); 876#endif /* O_APPEND */ 877 } 878 else 879 fd = 0; 880 if ((flags & F_APPEND) == 0 || fd == -1) { 881 if (!(flags & F_OVERWRITE) && adrof(STRnoclobber)) { 882 if (flags & F_APPEND) 883 stderror(ERR_SYSTEM, tmp, strerror(errno)); 884 chkclob(tmp); 885 } 886 if ((fd = xcreat(tmp, 0666)) < 0) 887 stderror(ERR_SYSTEM, tmp, strerror(errno)); 888 /* allow input files larger than 2Gb */ 889#ifndef WINNT_NATIVE 890 (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE); 891#endif /*!WINNT_NATIVE*/ 892 } 893 cleanup_until(tmp); 894 (void) dmove(fd, 1); 895 is1atty = isatty(1); 896 } 897 else if (flags & F_PIPEOUT) { 898 xclose(1); 899 (void) dup(pipeout[1]); 900 is1atty = 0; 901 } 902 else { 903 xclose(1); 904 (void) dup(SHOUT); 905 is1atty = isoutatty; 906# if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS) 907 (void) close_on_exec(1, 0); 908# endif /* CLOSE_ON_EXEC && CLEX_DUPS */ 909 } 910 911 xclose(2); 912 if (flags & F_STDERR) { 913 (void) dup(1); 914 is2atty = is1atty; 915 } 916 else { 917 (void) dup(SHDIAG); 918 is2atty = isdiagatty; 919# if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS) 920 (void) close_on_exec(2, 0); 921# endif /* CLOSE_ON_EXEC && CLEX_DUPS */ 922 } 923 didfds = 1; 924} 925 926void 927mypipe(int *pv) 928{ 929 930 if (pipe(pv) < 0) 931 goto oops; 932 (void)close_on_exec(pv[0] = dmove(pv[0], -1), 1); 933 (void)close_on_exec(pv[1] = dmove(pv[1], -1), 1); 934 if (pv[0] >= 0 && pv[1] >= 0) 935 return; 936 if (pv[0] >= 0) 937 xclose(pv[0]); 938 if (pv[1] >= 0) 939 xclose(pv[1]); 940oops: 941 stderror(ERR_PIPE); 942} 943 944static void 945chkclob(const char *cp) 946{ 947 struct stat stb; 948 949 if (stat(cp, &stb) < 0) 950 return; 951 if (S_ISCHR(stb.st_mode)) 952 return; 953 stderror(ERR_EXISTS, cp); 954} 955