contrib/tcsh-6/sh.sem.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.sem.c,v 3.80 2009/06/25 21:27:38 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 3.80 2009/06/25 21:27:38 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         /*
 330          * CR  -  Charles Ross Aug 2005
 331          * added "isoutatty".
 332          * The new behavior is that the jobcmd won't be executed
 333          * if stdout (SHOUT) isnt attached to a tty.. IE when
 334          * redirecting, or using backquotes etc..
 335          */
 336         if (t->t_dtyp == NODE_COMMAND && !bifunc && !noexec && intty && isoutatty) {
 337             Char *cmd = unparse(t);
 338
 339             cleanup_push(cmd, xfree);
 340             job_cmd(cmd);
 341             cleanup_until(cmd);
 342         }
 343
 344         /*
 345          * We fork only if we are timed, or are not the end of a parenthesized
 346          * list and not a simple builtin function. Simple meaning one that is
 347          * not pipedout, niced, nohupped, or &'d. It would be nice(?) to not
 348          * fork in some of these cases.
 349          */
 350         /*
 351          * Prevent forking cd, pushd, popd, chdir cause this will cause the
 352          * shell not to change dir!
 353          */
 354 #ifdef BACKPIPE
 355         /*
 356          * Can't have NOFORK for the tail of a pipe - because it is not the
 357          * last command spawned (even if it is at the end of a parenthesised
 358          * list).
 359          */
 360         if (t->t_dflg & F_PIPEIN)
 361             t->t_dflg &= ~(F_NOFORK);
 362 #endif /* BACKPIPE */
 363         if (bifunc && (bifunc->bfunct == (bfunc_t)dochngd ||
 364                        bifunc->bfunct == (bfunc_t)dopushd ||
 365                        bifunc->bfunct == (bfunc_t)dopopd))
 366             t->t_dflg &= ~(F_NICE);
 367         if (((t->t_dflg & F_TIME) || ((t->t_dflg & F_NOFORK) == 0 &&
 368              (!bifunc || t->t_dflg &
 369               (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP | F_HUP)))) ||
 370         /*
 371          * We have to fork for eval too.
 372          */
 373             (bifunc && (t->t_dflg & F_PIPEIN) != 0 &&
 374              bifunc->bfunct == (bfunc_t)doeval)) {
 375 #ifdef VFORK
 376             if (t->t_dtyp == NODE_PAREN ||
 377                 t->t_dflg & (F_REPEAT | F_AMPERSAND) || bifunc)
 378 #endif /* VFORK */
 379             {
 380                 forked++;
 381                 /*
 382                  * We need to block SIGCHLD here, so that if the process does
 383                  * not die before we can set the process group
 384                  */
 385                 if (wanttty >= 0 && !nosigchld) {
 386                     sigemptyset(&set);
 387                     sigaddset(&set, SIGCHLD);
 388                     (void)sigprocmask(SIG_BLOCK, &set, &csigset);
 389
 390                     nosigchld = 1;
 391                 }
 392
 393                 pid = pfork(t, wanttty);
 394                 if (pid == 0 && nosigchld) {
 395                     sigprocmask(SIG_SETMASK, &csigset, NULL);
 396                     nosigchld = 0;
 397                 }
 398                 else if (pid != 0 && (t->t_dflg & F_AMPERSAND))
 399                     backpid = pid;
 400             }
 401
 402 #ifdef VFORK
 403             else {
 404                 int     ochild, osetintr, ohaderr, odidfds;
 405                 int     oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp;
 406                 int     oisoutatty, oisdiagatty;
 407                 sigset_t oset, ocsigset;
 408 # ifndef CLOSE_ON_EXEC
 409                 int     odidcch;
 410 # endif  /* !CLOSE_ON_EXEC */
 411
 412                 /*
 413                  * Prepare for the vfork by saving everything that the child
 414                  * corrupts before it exec's. Note that in some signal
 415                  * implementations which keep the signal info in user space
 416                  * (e.g. Sun's) it will also be necessary to save and restore
 417                  * the current sigvec's for the signals the child touches
 418                  * before it exec's.
 419                  */
 420
 421                 /*
 422                  * Sooooo true... If this is a Sun, save the sigvec's. (Skip
 423                  * Gilbrech - 11/22/87)
 424                  */
 425 # ifdef SAVESIGVEC
 426                 struct sigaction savesv[NSIGSAVED];
 427                 sigset_t savesm;
 428
 429 # endif /* SAVESIGVEC */
 430                 if (wanttty >= 0 && !nosigchld && !noexec) {
 431                     sigemptyset(&set);
 432                     sigaddset(&set, SIGCHLD);
 433                     (void)sigprocmask(SIG_BLOCK, &set, &csigset);
 434                     nosigchld = 1;
 435                 }
 436                 sigemptyset(&set);
 437                 sigaddset(&set, SIGCHLD);
 438                 sigaddset(&set, SIGINT);
 439                 (void)sigprocmask(SIG_BLOCK, &set, &oset);
 440                 ochild = child;
 441                 osetintr = setintr;
 442                 ohaderr = haderr;
 443                 odidfds = didfds;
 444 # ifndef CLOSE_ON_EXEC
 445                 odidcch = didcch;
 446 # endif /* !CLOSE_ON_EXEC */
 447                 oSHIN = SHIN;
 448                 oSHOUT = SHOUT;
 449                 oSHDIAG = SHDIAG;
 450                 oOLDSTD = OLDSTD;
 451                 otpgrp = tpgrp;
 452                 oisoutatty = isoutatty;
 453                 oisdiagatty = isdiagatty;
 454                 ocsigset = csigset;
 455                 onosigchld = nosigchld;
 456                 Vsav = Vdp = 0;
 457                 Vexpath = 0;
 458                 Vt = 0;
 459 # ifdef SAVESIGVEC
 460                 savesigvec(savesv, savesm);
 461 # endif /* SAVESIGVEC */
 462                 if (use_fork)
 463                     pid = fork();
 464                 else
 465                     pid = vfork();
 466
 467                 if (pid < 0) {
 468 # ifdef SAVESIGVEC
 469                     restoresigvec(savesv, savesm);
 470 # endif /* SAVESIGVEC */
 471                     sigprocmask(SIG_SETMASK, &oset, NULL);
 472                     stderror(ERR_NOPROC);
 473                 }
 474                 forked++;
 475                 if (pid) {      /* parent */
 476 # ifdef SAVESIGVEC
 477                     restoresigvec(savesv, savesm);
 478 # endif /* SAVESIGVEC */
 479                     child = ochild;
 480                     setintr = osetintr;
 481                     haderr = ohaderr;
 482                     didfds = odidfds;
 483                     SHIN = oSHIN;
 484 # ifndef CLOSE_ON_EXEC
 485                     didcch = odidcch;
 486 # endif /* !CLOSE_ON_EXEC */
 487                     SHOUT = oSHOUT;
 488                     SHDIAG = oSHDIAG;
 489                     OLDSTD = oOLDSTD;
 490                     tpgrp = otpgrp;
 491                     isoutatty = oisoutatty;
 492                     isdiagatty = oisdiagatty;
 493                     csigset = ocsigset;
 494                     nosigchld = onosigchld;
 495
 496                     xfree(Vsav);
 497                     Vsav = 0;
 498                     xfree(Vdp);
 499                     Vdp = 0;
 500                     xfree(Vexpath);
 501                     Vexpath = 0;
 502                     blk_cleanup(Vt);
 503                     Vt = 0;
 504                     /* this is from pfork() */
 505                     palloc(pid, t);
 506                     sigprocmask(SIG_SETMASK, &oset, NULL);
 507                 }
 508                 else {          /* child */
 509                     /* this is from pfork() */
 510                     pid_t pgrp;
 511                     int    ignint = 0;
 512                     if (nosigchld) {
 513                         sigprocmask(SIG_SETMASK, &csigset, NULL);
 514                         nosigchld = 0;
 515                     }
 516
 517                     if (setintr)
 518                         ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT))
 519                                 || (gointr && eq(gointr, STRminus));
 520                     pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
 521                     child++;
 522                     if (setintr) {
 523                         setintr = 0;
 524 /*
 525  * casts made right for SunOS 4.0 by Douglas C. Schmidt
 526  * <schmidt%sunshine.ics.uci.edu@ROME.ICS.UCI.EDU>
 527  * (thanks! -- PWP)
 528  *
 529  * ignint ifs cleaned by Johan Widen <mcvax!osiris.sics.se!jw@uunet.UU.NET>
 530  * (thanks again)
 531  */
 532                         if (ignint) {
 533                             (void) signal(SIGINT, SIG_IGN);
 534                             (void) signal(SIGQUIT, SIG_IGN);
 535                         }
 536                         else {
 537                             (void) signal(SIGINT, vffree);
 538                             (void) signal(SIGQUIT, SIG_DFL);
 539                         }
 540 # ifdef BSDJOBS
 541                         if (wanttty >= 0) {
 542                             (void) signal(SIGTSTP, SIG_DFL);
 543                             (void) signal(SIGTTIN, SIG_DFL);
 544                             (void) signal(SIGTTOU, SIG_DFL);
 545                         }
 546 # endif /* BSDJOBS */
 547
 548                         sigaction(SIGTERM, &parterm, NULL);
 549                     }
 550                     else if (tpgrp == -1 &&
 551                              (t->t_dflg & F_NOINTERRUPT)) {
 552                         (void) signal(SIGINT, SIG_IGN);
 553                         (void) signal(SIGQUIT, SIG_IGN);
 554                     }
 555
 556                     pgetty(wanttty, pgrp);
 557
 558                     if (t->t_dflg & F_NOHUP)
 559                         (void) signal(SIGHUP, SIG_IGN);
 560                     if (t->t_dflg & F_HUP)
 561                         (void) signal(SIGHUP, SIG_DFL);
 562                     if (t->t_dflg & F_NICE) {
 563                         int nval = SIGN_EXTEND_CHAR(t->t_nice);
 564 # ifdef HAVE_SETPRIORITY
 565                         if (setpriority(PRIO_PROCESS, 0, nval) == -1 && errno)
 566                                 stderror(ERR_SYSTEM, "setpriority",
 567                                     strerror(errno));
 568 # else /* !HAVE_SETPRIORITY */
 569                         (void) nice(nval);
 570 # endif /* HAVE_SETPRIORITY */
 571                     }
 572 # ifdef F_VER
 573                     if (t->t_dflg & F_VER) {
 574                         tsetenv(STRSYSTYPE, t->t_systype ? STRbsd43 : STRsys53);
 575                         dohash(NULL, NULL);
 576                     }
 577 # endif /* F_VER */
 578                 }
 579
 580             }
 581 #endif /* VFORK */
 582         }
 583         if (pid != 0) {
 584             /*
 585              * It would be better if we could wait for the whole job when we
 586              * knew the last process had been started.  Pwait, in fact, does
 587              * wait for the whole job anyway, but this test doesn't really
 588              * express our intentions.
 589              */
 590 #ifdef BACKPIPE
 591             if (didfds == 0 && t->t_dflg & F_PIPEOUT) {
 592                 xclose(pipeout[0]);
 593                 xclose(pipeout[1]);
 594             }
 595             if ((t->t_dflg & F_PIPEIN) != 0)
 596                 break;
 597 #else /* !BACKPIPE */
 598             if (didfds == 0 && t->t_dflg & F_PIPEIN) {
 599                 xclose(pipein[0]);
 600                 xclose(pipein[1]);
 601             }
 602             if ((t->t_dflg & F_PIPEOUT) != 0)
 603                 break;
 604 #endif /* BACKPIPE */
 605
 606             if (nosigchld) {
 607                 sigprocmask(SIG_SETMASK, &csigset, NULL);
 608                 nosigchld = 0;
 609             }
 610             if ((t->t_dflg & F_AMPERSAND) == 0)
 611                 pwait();
 612             break;
 613         }
 614
 615         doio(t, pipein, pipeout);
 616 #ifdef BACKPIPE
 617         if (t->t_dflg & F_PIPEIN) {
 618             xclose(pipein[0]);
 619             xclose(pipein[1]);
 620         }
 621 #else /* !BACKPIPE */
 622         if (t->t_dflg & F_PIPEOUT) {
 623             xclose(pipeout[0]);
 624             xclose(pipeout[1]);
 625         }
 626 #endif /* BACKPIPE */
 627         /*
 628          * Perform a builtin function. If we are not forked, arrange for
 629          * possible stopping
 630          */
 631         if (bifunc) {
 632             func(t, bifunc);
 633             if (forked)
 634                 exitstat();
 635             else {
 636                 if (adrof(STRprintexitvalue)) {
 637                     int rv = getn(varval(STRstatus));
 638                     if (rv != 0)
 639                         xprintf(CGETS(17, 2, "Exit %d\n"), rv);
 640                 }
 641             }
 642             break;
 643         }
 644         if (t->t_dtyp != NODE_PAREN) {
 645             doexec(t, do_glob);
 646             /* NOTREACHED */
 647         }
 648         /*
 649          * For () commands must put new 0,1,2 in FSH* and recurse
 650          */
 651         (void)close_on_exec(OLDSTD = dcopy(0, FOLDSTD), 1);
 652         (void)close_on_exec(SHOUT = dcopy(1, FSHOUT), 1);
 653         isoutatty = isatty(SHOUT);
 654         (void)close_on_exec(SHDIAG = dcopy(2, FSHDIAG), 1);
 655         isdiagatty = isatty(SHDIAG);
 656         xclose(SHIN);
 657         SHIN = -1;
 658 #ifndef CLOSE_ON_EXEC
 659         didcch = 0;
 660 #else
 661         (void) close_on_exec(FSHOUT, 1);
 662         (void) close_on_exec(FSHDIAG, 1);
 663         (void) close_on_exec(FOLDSTD, 1);
 664 #endif /* !CLOSE_ON_EXEC */
 665         didfds = 0;
 666         wanttty = -1;
 667         t->t_dspr->t_dflg |= t->t_dflg & F_NOINTERRUPT;
 668         execute(t->t_dspr, wanttty, NULL, NULL, do_glob);
 669         exitstat();
 670
 671     case NODE_PIPE:
 672 #ifdef BACKPIPE
 673         t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg &
 674                         (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT));
 675         execute(t->t_dcdr, wanttty, pv, pipeout, do_glob);
 676         t->t_dcar->t_dflg |= F_PIPEOUT |
 677             (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT));
 678         execute(t->t_dcar, wanttty, pipein, pv, do_glob);
 679 #else /* !BACKPIPE */
 680         t->t_dcar->t_dflg |= F_PIPEOUT |
 681             (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT));
 682         execute(t->t_dcar, wanttty, pipein, pv, do_glob);
 683         t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg &
 684                         (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT));
 685         execute(t->t_dcdr, wanttty, pv, pipeout, do_glob);
 686 #endif /* BACKPIPE */
 687         break;
 688
 689     case NODE_LIST:
 690         if (t->t_dcar) {
 691             t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT;
 692             execute(t->t_dcar, wanttty, NULL, NULL, do_glob);
 693             /*
 694              * In strange case of A&B make a new job after A
 695              */
 696             if (t->t_dcar->t_dflg & F_AMPERSAND && t->t_dcdr &&
 697                 (t->t_dcdr->t_dflg & F_AMPERSAND) == 0)
 698                 pendjob();
 699         }
 700         if (t->t_dcdr) {
 701             t->t_dcdr->t_dflg |= t->t_dflg &
 702                 (F_NOFORK | F_NOINTERRUPT);
 703             execute(t->t_dcdr, wanttty, NULL, NULL, do_glob);
 704         }
 705         break;
 706
 707     case NODE_OR:
 708     case NODE_AND:
 709         if (t->t_dcar) {
 710             t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT;
 711             execute(t->t_dcar, wanttty, NULL, NULL, do_glob);
 712             if ((getn(varval(STRstatus)) == 0) !=
 713                 (t->t_dtyp == NODE_AND)) {
 714                 return;
 715             }
 716         }
 717         if (t->t_dcdr) {
 718             t->t_dcdr->t_dflg |= t->t_dflg &
 719                 (F_NOFORK | F_NOINTERRUPT);
 720             execute(t->t_dcdr, wanttty, NULL, NULL, do_glob);
 721         }
 722         break;
 723
 724     default:
 725         break;
 726     }
 727     /*
 728      * Fall through for all breaks from switch
 729      *
 730      * If there will be no more executions of this command, flush all file
 731      * descriptors. Places that turn on the F_REPEAT bit are responsible for
 732      * doing donefds after the last re-execution
 733      */
 734     if (didfds && !(t->t_dflg & F_REPEAT))
 735         donefds();
 736 }
 737
 738 #ifdef VFORK
 739 static void
 740 /*ARGSUSED*/
 741 vffree(int snum)
 742 {
 743     USE(snum);
 744
 745     _exit(1);
 746 }
 747 #endif /* VFORK */
 748
 749 /*
 750  * Expand and glob the words after an i/o redirection.
 751  * If more than one word is generated, then update the command vector.
 752  *
 753  * This is done differently in all the shells:
 754  * 1. in the bourne shell and ksh globbing is not performed
 755  * 2. Bash/csh say ambiguous
 756  * 3. zsh does i/o to/from all the files
 757  * 4. itcsh concatenates the words.
 758  *
 759  * I don't know what is best to do. I think that Ambiguous is better
 760  * than restructuring the command vector, because the user can get
 761  * unexpected results. In any case, the command vector restructuring
 762  * code is present and the user can choose it by setting noambiguous
 763  */
 764 static Char *
 765 splicepipe(struct command *t, Char *cp)
 766 {
 767     Char *blk[2];
 768
 769     if (adrof(STRnoambiguous)) {
 770         Char **pv;
 771         int gflag;
 772
 773         blk[0] = Dfix1(cp); /* expand $ */
 774         blk[1] = NULL;
 775
 776         gflag = tglob(blk);
 777         if (gflag) {
 778             pv = globall(blk, gflag);
 779             if (pv == NULL) {
 780                 setname(short2str(blk[0]));
 781                 xfree(blk[0]);
 782                 stderror(ERR_NAME | ERR_NOMATCH);
 783             }
 784             if (pv[1] != NULL) { /* we need to fix the command vector */
 785                 Char **av = blkspl(t->t_dcom, &pv[1]);
 786                 xfree(t->t_dcom);
 787                 t->t_dcom = av;
 788             }
 789             xfree(blk[0]);
 790             blk[0] = pv[0];
 791             xfree(pv);
 792         }
 793     }
 794     else {
 795         Char *buf;
 796
 797         buf = Dfix1(cp);
 798         cleanup_push(buf, xfree);
 799         blk[0] = globone(buf, G_ERROR);
 800         cleanup_until(buf);
 801     }
 802     return(blk[0]);
 803 }
 804
 805 /*
 806  * Perform io redirection.
 807  * We may or maynot be forked here.
 808  */
 809 static void
 810 doio(struct command *t, int *pipein, int *pipeout)
 811 {
 812     int fd;
 813     Char *cp;
 814     unsigned long flags = t->t_dflg;
 815
 816     if (didfds || (flags & F_REPEAT))
 817         return;
 818     if ((flags & F_READ) == 0) {/* F_READ already done */
 819         if (t->t_dlef) {
 820             char *tmp;
 821
 822             /*
 823              * so < /dev/std{in,out,err} work
 824              */
 825             (void) dcopy(SHIN, 0);
 826             (void) dcopy(SHOUT, 1);
 827             (void) dcopy(SHDIAG, 2);
 828             cp = splicepipe(t, t->t_dlef);
 829             tmp = strsave(short2str(cp));
 830             xfree(cp);
 831             cleanup_push(tmp, xfree);
 832             if ((fd = xopen(tmp, O_RDONLY|O_LARGEFILE)) < 0)
 833                 stderror(ERR_SYSTEM, tmp, strerror(errno));
 834             cleanup_until(tmp);
 835             /* allow input files larger than 2Gb  */
 836 #ifndef WINNT_NATIVE
 837             (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE);
 838 #endif /*!WINNT_NATIVE*/
 839             (void) dmove(fd, 0);
 840         }
 841         else if (flags & F_PIPEIN) {
 842             xclose(0);
 843             IGNORE(dup(pipein[0]));
 844             xclose(pipein[0]);
 845             xclose(pipein[1]);
 846         }
 847         else if ((flags & F_NOINTERRUPT) && tpgrp == -1) {
 848             xclose(0);
 849             (void) xopen(_PATH_DEVNULL, O_RDONLY|O_LARGEFILE);
 850         }
 851         else {
 852             xclose(0);
 853             IGNORE(dup(OLDSTD));
 854 #if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 855             /*
 856              * PWP: Unlike Bezerkeley 4.3, FIONCLEX for Pyramid is preserved
 857              * across dup()s, so we have to UNSET it here or else we get a
 858              * command with NO stdin, stdout, or stderr at all (a bad thing
 859              * indeed)
 860              */
 861             (void) close_on_exec(0, 0);
 862 #endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 863         }
 864     }
 865     if (t->t_drit) {
 866         char *tmp;
 867
 868         cp = splicepipe(t, t->t_drit);
 869         tmp = strsave(short2str(cp));
 870         xfree(cp);
 871         cleanup_push(tmp, xfree);
 872         /*
 873          * so > /dev/std{out,err} work
 874          */
 875         (void) dcopy(SHOUT, 1);
 876         (void) dcopy(SHDIAG, 2);
 877         if ((flags & F_APPEND) != 0) {
 878 #ifdef O_APPEND
 879             fd = xopen(tmp, O_WRONLY|O_APPEND|O_LARGEFILE);
 880 #else /* !O_APPEND */
 881             fd = xopen(tmp, O_WRONLY|O_LARGEFILE);
 882             (void) lseek(fd, (off_t) 0, L_XTND);
 883 #endif /* O_APPEND */
 884         }
 885         else
 886             fd = 0;
 887         if ((flags & F_APPEND) == 0 || fd == -1) {
 888             if (!(flags & F_OVERWRITE) && adrof(STRnoclobber)) {
 889                 if (flags & F_APPEND)
 890                     stderror(ERR_SYSTEM, tmp, strerror(errno));
 891                 chkclob(tmp);
 892             }
 893             if ((fd = xcreat(tmp, 0666)) < 0)
 894                 stderror(ERR_SYSTEM, tmp, strerror(errno));
 895             /* allow input files larger than 2Gb  */
 896 #ifndef WINNT_NATIVE
 897             (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE);
 898 #endif /*!WINNT_NATIVE*/
 899         }
 900         cleanup_until(tmp);
 901         (void) dmove(fd, 1);
 902         is1atty = isatty(1);
 903     }
 904     else if (flags & F_PIPEOUT) {
 905         xclose(1);
 906         IGNORE(dup(pipeout[1]));
 907         is1atty = 0;
 908     }
 909     else {
 910         xclose(1);
 911         IGNORE(dup(SHOUT));
 912         is1atty = isoutatty;
 913 # if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 914         (void) close_on_exec(1, 0);
 915 # endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 916     }
 917
 918     xclose(2);
 919     if (flags & F_STDERR) {
 920         IGNORE(dup(1));
 921         is2atty = is1atty;
 922     }
 923     else {
 924         IGNORE(dup(SHDIAG));
 925         is2atty = isdiagatty;
 926 # if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 927         (void) close_on_exec(2, 0);
 928 # endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 929     }
 930     didfds = 1;
 931 }
 932
 933 void
 934 mypipe(int *pv)
 935 {
 936
 937     if (pipe(pv) < 0)
 938         goto oops;
 939     (void)close_on_exec(pv[0] = dmove(pv[0], -1), 1);
 940     (void)close_on_exec(pv[1] = dmove(pv[1], -1), 1);
 941     if (pv[0] >= 0 && pv[1] >= 0)
 942         return;
 943     if (pv[0] >= 0)
 944         xclose(pv[0]);
 945     if (pv[1] >= 0)
 946         xclose(pv[1]);
 947 oops:
 948     stderror(ERR_PIPE);
 949 }
 950
 951 static void
 952 chkclob(const char *cp)
 953 {
 954     struct stat stb;
 955
 956     if (stat(cp, &stb) < 0)
 957         return;
 958     if (S_ISCHR(stb.st_mode))
 959         return;
 960     stderror(ERR_EXISTS, cp);
 961 }