contrib/tcsh-6/sh.sem.c

   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
  36 RCSID("$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
  59 static  void            vffree          (int);
  60 #endif
  61 static  Char            *splicepipe     (struct command *, Char *);
  62 static  void             doio           (struct command *, int *, int *);
  63 static  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*/
  86 void
  87 execute(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
 732 static void
 733 /*ARGSUSED*/
 734 vffree(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  */
 757 static Char *
 758 splicepipe(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  */
 802 static void
 803 doio(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
 926 void
 927 mypipe(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]);
 940 oops:
 941     stderror(ERR_PIPE);
 942 }
 943
 944 static void
 945 chkclob(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 }