contrib/tcsh-6/sh.sem.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.sem.c,v 3.86 2011/02/25 23:24:19 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 3.86 2011/02/25 23:24:19 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 = (unsigned char)getn(t->t_dcom[1]);
 236                             lshift(t->t_dcom, 2);
 237                             t->t_dflg |= F_NICE;
 238                         }
 239                         else
 240                             break;
 241                     }
 242                     else {
 243                         t->t_nice = 4;
 244                         lshift(t->t_dcom, 1);
 245                         t->t_dflg |= F_NICE;
 246                     }
 247                 }
 248                 else
 249                     break;
 250             }
 251             else if (eq(t->t_dcom[0], STRnohup)) {
 252                 if (t->t_dcom[1]) {
 253                     t->t_dflg |= F_NOHUP;
 254                     lshift(t->t_dcom, 1);
 255                 }
 256                 else
 257                     break;
 258             }
 259             else if (eq(t->t_dcom[0], STRhup)) {
 260                 if (t->t_dcom[1]) {
 261                     t->t_dflg |= F_HUP;
 262                     lshift(t->t_dcom, 1);
 263                 }
 264                 else
 265                     break;
 266             }
 267             else if (eq(t->t_dcom[0], STRtime)) {
 268                 if (t->t_dcom[1]) {
 269                     t->t_dflg |= F_TIME;
 270                     lshift(t->t_dcom, 1);
 271                 }
 272                 else
 273                     break;
 274             }
 275 #ifdef F_VER
 276             else if (eq(t->t_dcom[0], STRver))
 277                 if (t->t_dcom[1] && t->t_dcom[2]) {
 278                     setname("ver");
 279                     t->t_systype = getv(t->t_dcom[1]);
 280                     lshift(t->t_dcom, 2);
 281                     t->t_dflg |= F_VER;
 282                 }
 283                 else
 284                     break;
 285 #endif  /* F_VER */
 286             else
 287                 break;
 288
 289         /* is it a command */
 290         if (t->t_dtyp == NODE_COMMAND) {
 291             /*
 292              * Check if we have a builtin function and remember which one.
 293              */
 294             bifunc = isbfunc(t);
 295             if (noexec) {
 296                 /*
 297                  * Continue for builtins that are part of the scripting language
 298                  */
 299                 if (bifunc == NULL)
 300                     break;
 301                 if (bifunc->bfunct != (bfunc_t)dobreak  &&
 302                     bifunc->bfunct != (bfunc_t)docontin &&
 303                     bifunc->bfunct != (bfunc_t)doelse   &&
 304                     bifunc->bfunct != (bfunc_t)doend    &&
 305                     bifunc->bfunct != (bfunc_t)doforeach&&
 306                     bifunc->bfunct != (bfunc_t)dogoto   &&
 307                     bifunc->bfunct != (bfunc_t)doif     &&
 308                     bifunc->bfunct != (bfunc_t)dorepeat &&
 309                     bifunc->bfunct != (bfunc_t)doswbrk  &&
 310                     bifunc->bfunct != (bfunc_t)doswitch &&
 311                     bifunc->bfunct != (bfunc_t)dowhile  &&
 312                     bifunc->bfunct != (bfunc_t)dozip)
 313                     break;
 314             }
 315         }
 316         else {                  /* not a command */
 317             bifunc = NULL;
 318             if (noexec)
 319                 break;
 320         }
 321
 322         /*
 323          * GrP Executing a command - run jobcmd hook
 324          * Don't run for builtins
 325          * Don't run if we're not in a tty
 326          * Don't run if we're not really executing
 327          */
 328         /*
 329          * CR  -  Charles Ross Aug 2005
 330          * added "isoutatty".
 331          * The new behavior is that the jobcmd won't be executed
 332          * if stdout (SHOUT) isnt attached to a tty.. IE when
 333          * redirecting, or using backquotes etc..
 334          */
 335         if (t->t_dtyp == NODE_COMMAND && !bifunc && !noexec && intty && isoutatty) {
 336             Char *cmd = unparse(t);
 337
 338             cleanup_push(cmd, xfree);
 339             job_cmd(cmd);
 340             cleanup_until(cmd);
 341         }
 342
 343         /*
 344          * We fork only if we are timed, or are not the end of a parenthesized
 345          * list and not a simple builtin function. Simple meaning one that is
 346          * not pipedout, niced, nohupped, or &'d. It would be nice(?) to not
 347          * fork in some of these cases.
 348          */
 349         /*
 350          * Prevent forking cd, pushd, popd, chdir cause this will cause the
 351          * shell not to change dir!
 352          */
 353 #ifdef BACKPIPE
 354         /*
 355          * Can't have NOFORK for the tail of a pipe - because it is not the
 356          * last command spawned (even if it is at the end of a parenthesised
 357          * list).
 358          */
 359         if (t->t_dflg & F_PIPEIN)
 360             t->t_dflg &= ~(F_NOFORK);
 361 #endif /* BACKPIPE */
 362         if (bifunc && (bifunc->bfunct == (bfunc_t)dochngd ||
 363                        bifunc->bfunct == (bfunc_t)dopushd ||
 364                        bifunc->bfunct == (bfunc_t)dopopd))
 365             t->t_dflg &= ~(F_NICE);
 366         if (((t->t_dflg & F_TIME) || ((t->t_dflg & F_NOFORK) == 0 &&
 367              (!bifunc || t->t_dflg &
 368               (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP | F_HUP)))) ||
 369         /*
 370          * We have to fork for eval too.
 371          */
 372             (bifunc && (t->t_dflg & F_PIPEIN) != 0 &&
 373              bifunc->bfunct == (bfunc_t)doeval)) {
 374 #ifdef VFORK
 375             if (t->t_dtyp == NODE_PAREN ||
 376                 t->t_dflg & (F_REPEAT | F_AMPERSAND) || bifunc)
 377 #endif /* VFORK */
 378             {
 379                 forked++;
 380                 /*
 381                  * We need to block SIGCHLD here, so that if the process does
 382                  * not die before we can set the process group
 383                  */
 384                 if (wanttty >= 0 && !nosigchld) {
 385                     sigemptyset(&set);
 386                     sigaddset(&set, SIGCHLD);
 387                     (void)sigprocmask(SIG_BLOCK, &set, &csigset);
 388
 389                     nosigchld = 1;
 390                 }
 391
 392                 pid = pfork(t, wanttty);
 393                 if (pid == 0 && nosigchld) {
 394                     sigprocmask(SIG_SETMASK, &csigset, NULL);
 395                     nosigchld = 0;
 396                 }
 397                 else if (pid != 0 && (t->t_dflg & F_AMPERSAND))
 398                     backpid = pid;
 399             }
 400
 401 #ifdef VFORK
 402             else {
 403                 int     ochild, osetintr, ohaderr, odidfds;
 404                 int     oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp;
 405                 int     oisoutatty, oisdiagatty;
 406                 sigset_t oset, ocsigset;
 407 # ifndef CLOSE_ON_EXEC
 408                 int     odidcch;
 409 # endif  /* !CLOSE_ON_EXEC */
 410
 411                 /*
 412                  * Prepare for the vfork by saving everything that the child
 413                  * corrupts before it exec's. Note that in some signal
 414                  * implementations which keep the signal info in user space
 415                  * (e.g. Sun's) it will also be necessary to save and restore
 416                  * the current sigvec's for the signals the child touches
 417                  * before it exec's.
 418                  */
 419
 420                 /*
 421                  * Sooooo true... If this is a Sun, save the sigvec's. (Skip
 422                  * Gilbrech - 11/22/87)
 423                  */
 424 # ifdef SAVESIGVEC
 425                 struct sigaction savesv[NSIGSAVED];
 426                 sigset_t savesm;
 427
 428 # endif /* SAVESIGVEC */
 429                 if (wanttty >= 0 && !nosigchld && !noexec) {
 430                     sigemptyset(&set);
 431                     sigaddset(&set, SIGCHLD);
 432                     (void)sigprocmask(SIG_BLOCK, &set, &csigset);
 433                     nosigchld = 1;
 434                 }
 435                 sigemptyset(&set);
 436                 sigaddset(&set, SIGCHLD);
 437                 sigaddset(&set, SIGINT);
 438                 (void)sigprocmask(SIG_BLOCK, &set, &oset);
 439                 ochild = child;
 440                 osetintr = setintr;
 441                 ohaderr = haderr;
 442                 odidfds = didfds;
 443 # ifndef CLOSE_ON_EXEC
 444                 odidcch = didcch;
 445 # endif /* !CLOSE_ON_EXEC */
 446                 oSHIN = SHIN;
 447                 oSHOUT = SHOUT;
 448                 oSHDIAG = SHDIAG;
 449                 oOLDSTD = OLDSTD;
 450                 otpgrp = tpgrp;
 451                 oisoutatty = isoutatty;
 452                 oisdiagatty = isdiagatty;
 453                 ocsigset = csigset;
 454                 onosigchld = nosigchld;
 455                 Vsav = Vdp = 0;
 456                 Vexpath = 0;
 457                 Vt = 0;
 458 # ifdef SAVESIGVEC
 459                 savesigvec(savesv, savesm);
 460 # endif /* SAVESIGVEC */
 461                 if (use_fork)
 462                     pid = fork();
 463                 else
 464                     pid = vfork();
 465
 466                 if (pid < 0) {
 467 # ifdef SAVESIGVEC
 468                     restoresigvec(savesv, savesm);
 469 # endif /* SAVESIGVEC */
 470                     sigprocmask(SIG_SETMASK, &oset, NULL);
 471                     stderror(ERR_NOPROC);
 472                 }
 473                 forked++;
 474                 if (pid) {      /* parent */
 475 # ifdef SAVESIGVEC
 476                     restoresigvec(savesv, savesm);
 477 # endif /* SAVESIGVEC */
 478                     child = ochild;
 479                     setintr = osetintr;
 480                     haderr = ohaderr;
 481                     didfds = odidfds;
 482                     SHIN = oSHIN;
 483 # ifndef CLOSE_ON_EXEC
 484                     didcch = odidcch;
 485 # endif /* !CLOSE_ON_EXEC */
 486                     SHOUT = oSHOUT;
 487                     SHDIAG = oSHDIAG;
 488                     OLDSTD = oOLDSTD;
 489                     tpgrp = otpgrp;
 490                     isoutatty = oisoutatty;
 491                     isdiagatty = oisdiagatty;
 492                     csigset = ocsigset;
 493                     nosigchld = onosigchld;
 494
 495                     xfree(Vsav);
 496                     Vsav = 0;
 497                     xfree(Vdp);
 498                     Vdp = 0;
 499                     xfree(Vexpath);
 500                     Vexpath = 0;
 501                     blk_cleanup(Vt);
 502                     Vt = 0;
 503                     /* this is from pfork() */
 504                     palloc(pid, t);
 505                     sigprocmask(SIG_SETMASK, &oset, NULL);
 506                 }
 507                 else {          /* child */
 508                     /* this is from pfork() */
 509                     pid_t pgrp;
 510                     int    ignint = 0;
 511                     if (nosigchld) {
 512                         sigprocmask(SIG_SETMASK, &csigset, NULL);
 513                         nosigchld = 0;
 514                     }
 515
 516                     if (setintr)
 517                         ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT))
 518                                 || (gointr && eq(gointr, STRminus));
 519                     pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
 520                     child++;
 521                     if (setintr) {
 522                         setintr = 0;
 523 /*
 524  * casts made right for SunOS 4.0 by Douglas C. Schmidt
 525  * <schmidt%sunshine.ics.uci.edu@ROME.ICS.UCI.EDU>
 526  * (thanks! -- PWP)
 527  *
 528  * ignint ifs cleaned by Johan Widen <mcvax!osiris.sics.se!jw@uunet.UU.NET>
 529  * (thanks again)
 530  */
 531                         if (ignint) {
 532                             (void) signal(SIGINT, SIG_IGN);
 533                             (void) signal(SIGQUIT, SIG_IGN);
 534                         }
 535                         else {
 536                             (void) signal(SIGINT, vffree);
 537                             (void) signal(SIGQUIT, SIG_DFL);
 538                         }
 539 # ifdef BSDJOBS
 540                         if (wanttty >= 0) {
 541                             (void) signal(SIGTSTP, SIG_DFL);
 542                             (void) signal(SIGTTIN, SIG_DFL);
 543                             (void) signal(SIGTTOU, SIG_DFL);
 544                         }
 545 # endif /* BSDJOBS */
 546
 547                         sigaction(SIGTERM, &parterm, NULL);
 548                     }
 549                     else if (tpgrp == -1 &&
 550                              (t->t_dflg & F_NOINTERRUPT)) {
 551                         (void) signal(SIGINT, SIG_IGN);
 552                         (void) signal(SIGQUIT, SIG_IGN);
 553                     }
 554
 555                     pgetty(wanttty, pgrp);
 556
 557                     if (t->t_dflg & F_NOHUP)
 558                         (void) signal(SIGHUP, SIG_IGN);
 559                     if (t->t_dflg & F_HUP)
 560                         (void) signal(SIGHUP, SIG_DFL);
 561                     if (t->t_dflg & F_NICE) {
 562                         int nval = SIGN_EXTEND_CHAR(t->t_nice);
 563 # ifdef HAVE_SETPRIORITY
 564                         if (setpriority(PRIO_PROCESS, 0, nval) == -1 && errno)
 565                                 stderror(ERR_SYSTEM, "setpriority",
 566                                     strerror(errno));
 567 # else /* !HAVE_SETPRIORITY */
 568                         (void) nice(nval);
 569 # endif /* HAVE_SETPRIORITY */
 570                     }
 571 # ifdef F_VER
 572                     if (t->t_dflg & F_VER) {
 573                         tsetenv(STRSYSTYPE, t->t_systype ? STRbsd43 : STRsys53);
 574                         dohash(NULL, NULL);
 575                     }
 576 # endif /* F_VER */
 577                 }
 578
 579             }
 580 #endif /* VFORK */
 581         }
 582         if (pid != 0) {
 583             /*
 584              * It would be better if we could wait for the whole job when we
 585              * knew the last process had been started.  Pwait, in fact, does
 586              * wait for the whole job anyway, but this test doesn't really
 587              * express our intentions.
 588              */
 589 #ifdef BACKPIPE
 590             if (didfds == 0 && t->t_dflg & F_PIPEOUT) {
 591                 xclose(pipeout[0]);
 592                 xclose(pipeout[1]);
 593             }
 594             if ((t->t_dflg & F_PIPEIN) != 0)
 595                 break;
 596 #else /* !BACKPIPE */
 597             if (didfds == 0 && t->t_dflg & F_PIPEIN) {
 598                 xclose(pipein[0]);
 599                 xclose(pipein[1]);
 600             }
 601             if ((t->t_dflg & F_PIPEOUT) != 0)
 602                 break;
 603 #endif /* BACKPIPE */
 604
 605             if (nosigchld) {
 606                 sigprocmask(SIG_SETMASK, &csigset, NULL);
 607                 nosigchld = 0;
 608             }
 609             if ((t->t_dflg & F_AMPERSAND) == 0)
 610                 pwait();
 611             break;
 612         }
 613
 614         doio(t, pipein, pipeout);
 615 #ifdef BACKPIPE
 616         if (t->t_dflg & F_PIPEIN) {
 617             xclose(pipein[0]);
 618             xclose(pipein[1]);
 619         }
 620 #else /* !BACKPIPE */
 621         if (t->t_dflg & F_PIPEOUT) {
 622             xclose(pipeout[0]);
 623             xclose(pipeout[1]);
 624         }
 625 #endif /* BACKPIPE */
 626         /*
 627          * Perform a builtin function. If we are not forked, arrange for
 628          * possible stopping
 629          */
 630         if (bifunc) {
 631             if (forked) {
 632                 func(t, bifunc);
 633                 exitstat();
 634             } else {
 635                 jmp_buf_t oldexit;
 636                 int ohaderr = haderr;
 637
 638                 getexit(oldexit);
 639                 if (setexit() == 0)
 640                     func(t, bifunc);
 641                 resexit(oldexit);
 642                 haderr = ohaderr;
 643
 644                 if (adrof(STRprintexitvalue)) {
 645                     int rv = getn(varval(STRstatus));
 646                     if (rv != 0)
 647                         xprintf(CGETS(17, 2, "Exit %d\n"), rv);
 648                 }
 649             }
 650             break;
 651         }
 652         if (t->t_dtyp != NODE_PAREN) {
 653             doexec(t, do_glob);
 654             /* NOTREACHED */
 655         }
 656         /*
 657          * For () commands must put new 0,1,2 in FSH* and recurse
 658          */
 659         if ((OLDSTD = dcopy(0, FOLDSTD)) >= 0)
 660             (void)close_on_exec(OLDSTD, 1);
 661         if ((SHOUT = dcopy(1, FSHOUT)) >= 0) {
 662             (void)close_on_exec(SHOUT, 1);
 663             isoutatty = isatty(SHOUT);
 664         }
 665         if ((SHDIAG = dcopy(2, FSHDIAG)) >= 0) {
 666             (void)close_on_exec(SHDIAG, 1);
 667             isdiagatty = isatty(SHDIAG);
 668         }
 669         xclose(SHIN);
 670         SHIN = -1;
 671 #ifndef CLOSE_ON_EXEC
 672         didcch = 0;
 673 #else
 674         (void) close_on_exec(FSHOUT, 1);
 675         (void) close_on_exec(FSHDIAG, 1);
 676         (void) close_on_exec(FOLDSTD, 1);
 677 #endif /* !CLOSE_ON_EXEC */
 678         didfds = 0;
 679         wanttty = -1;
 680         t->t_dspr->t_dflg |= t->t_dflg & (F_NOINTERRUPT | F_BACKQ);
 681         execute(t->t_dspr, wanttty, NULL, NULL, do_glob);
 682         exitstat();
 683
 684     case NODE_PIPE:
 685 #ifdef BACKPIPE
 686         t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg &
 687             (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT | F_BACKQ));
 688         execute(t->t_dcdr, wanttty, pv, pipeout, do_glob);
 689         t->t_dcar->t_dflg |= F_PIPEOUT | (t->t_dflg &
 690             (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT | F_BACKQ));
 691         execute(t->t_dcar, wanttty, pipein, pv, do_glob);
 692 #else /* !BACKPIPE */
 693         t->t_dcar->t_dflg |= F_PIPEOUT | (t->t_dflg &
 694             (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT | F_BACKQ));
 695         execute(t->t_dcar, wanttty, pipein, pv, do_glob);
 696         t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg &
 697             (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT | F_BACKQ));
 698         execute(t->t_dcdr, wanttty, pv, pipeout, do_glob);
 699 #endif /* BACKPIPE */
 700         break;
 701
 702     case NODE_LIST:
 703         if (t->t_dcar) {
 704             t->t_dcar->t_dflg |= t->t_dflg & (F_NOINTERRUPT | F_BACKQ);
 705             execute(t->t_dcar, wanttty, NULL, NULL, do_glob);
 706             /*
 707              * In strange case of A&B make a new job after A
 708              */
 709             if (t->t_dcar->t_dflg & F_AMPERSAND && t->t_dcdr &&
 710                 (t->t_dcdr->t_dflg & F_AMPERSAND) == 0)
 711                 pendjob();
 712         }
 713         if (t->t_dcdr) {
 714             t->t_dcdr->t_dflg |= t->t_dflg &
 715                 (F_NOFORK | F_NOINTERRUPT | F_BACKQ);
 716             execute(t->t_dcdr, wanttty, NULL, NULL, do_glob);
 717         }
 718         break;
 719
 720     case NODE_OR:
 721     case NODE_AND:
 722         if (t->t_dcar) {
 723             t->t_dcar->t_dflg |= t->t_dflg & (F_NOINTERRUPT | F_BACKQ);
 724             execute(t->t_dcar, wanttty, NULL, NULL, do_glob);
 725             if ((getn(varval(STRstatus)) == 0) !=
 726                 (t->t_dtyp == NODE_AND)) {
 727                 return;
 728             }
 729         }
 730         if (t->t_dcdr) {
 731             t->t_dcdr->t_dflg |= t->t_dflg &
 732                 (F_NOFORK | F_NOINTERRUPT | F_BACKQ);
 733             execute(t->t_dcdr, wanttty, NULL, NULL, do_glob);
 734         }
 735         break;
 736
 737     default:
 738         break;
 739     }
 740     /*
 741      * Fall through for all breaks from switch
 742      *
 743      * If there will be no more executions of this command, flush all file
 744      * descriptors. Places that turn on the F_REPEAT bit are responsible for
 745      * doing donefds after the last re-execution
 746      */
 747     if (didfds && !(t->t_dflg & F_REPEAT))
 748         donefds();
 749 }
 750
 751 #ifdef VFORK
 752 static void
 753 /*ARGSUSED*/
 754 vffree(int snum)
 755 {
 756     USE(snum);
 757
 758     _exit(1);
 759 }
 760 #endif /* VFORK */
 761
 762 /*
 763  * Expand and glob the words after an i/o redirection.
 764  * If more than one word is generated, then update the command vector.
 765  *
 766  * This is done differently in all the shells:
 767  * 1. in the bourne shell and ksh globbing is not performed
 768  * 2. Bash/csh say ambiguous
 769  * 3. zsh does i/o to/from all the files
 770  * 4. itcsh concatenates the words.
 771  *
 772  * I don't know what is best to do. I think that Ambiguous is better
 773  * than restructuring the command vector, because the user can get
 774  * unexpected results. In any case, the command vector restructuring
 775  * code is present and the user can choose it by setting noambiguous
 776  */
 777 static Char *
 778 splicepipe(struct command *t, Char *cp)
 779 {
 780     Char *blk[2];
 781
 782     if (adrof(STRnoambiguous)) {
 783         Char **pv;
 784         int gflag;
 785
 786         blk[0] = Dfix1(cp); /* expand $ */
 787         blk[1] = NULL;
 788
 789         gflag = tglob(blk);
 790         if (gflag) {
 791             pv = globall(blk, gflag);
 792             if (pv == NULL) {
 793                 setname(short2str(blk[0]));
 794                 xfree(blk[0]);
 795                 stderror(ERR_NAME | ERR_NOMATCH);
 796             }
 797             if (pv[1] != NULL) { /* we need to fix the command vector */
 798                 Char **av = blkspl(t->t_dcom, &pv[1]);
 799                 xfree(t->t_dcom);
 800                 t->t_dcom = av;
 801             }
 802             xfree(blk[0]);
 803             blk[0] = pv[0];
 804             xfree(pv);
 805         }
 806     }
 807     else {
 808         Char *buf;
 809
 810         buf = Dfix1(cp);
 811         cleanup_push(buf, xfree);
 812         blk[0] = globone(buf, G_ERROR);
 813         cleanup_until(buf);
 814     }
 815     return(blk[0]);
 816 }
 817
 818 /*
 819  * Perform io redirection.
 820  * We may or maynot be forked here.
 821  */
 822 static void
 823 doio(struct command *t, int *pipein, int *pipeout)
 824 {
 825     int fd;
 826     Char *cp;
 827     unsigned long flags = t->t_dflg;
 828
 829     if (didfds || (flags & F_REPEAT))
 830         return;
 831     if ((flags & F_READ) == 0) {/* F_READ already done */
 832         if (t->t_dlef) {
 833             char *tmp;
 834
 835             /*
 836              * so < /dev/std{in,out,err} work
 837              */
 838             (void) dcopy(SHIN, 0);
 839             (void) dcopy(SHOUT, 1);
 840             (void) dcopy(SHDIAG, 2);
 841             cp = splicepipe(t, t->t_dlef);
 842             tmp = strsave(short2str(cp));
 843             xfree(cp);
 844             cleanup_push(tmp, xfree);
 845             if ((fd = xopen(tmp, O_RDONLY|O_LARGEFILE)) < 0)
 846                 stderror(ERR_SYSTEM, tmp, strerror(errno));
 847             cleanup_until(tmp);
 848             /* allow input files larger than 2Gb  */
 849 #ifndef WINNT_NATIVE
 850             (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE);
 851 #endif /*!WINNT_NATIVE*/
 852             (void) dmove(fd, 0);
 853         }
 854         else if (flags & F_PIPEIN) {
 855             xclose(0);
 856             TCSH_IGNORE(dup(pipein[0]));
 857             xclose(pipein[0]);
 858             xclose(pipein[1]);
 859         }
 860         else if ((flags & F_NOINTERRUPT) && tpgrp == -1) {
 861             xclose(0);
 862             (void) xopen(_PATH_DEVNULL, O_RDONLY|O_LARGEFILE);
 863         }
 864         else {
 865             xclose(0);
 866             TCSH_IGNORE(dup(OLDSTD));
 867 #if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 868             /*
 869              * PWP: Unlike Bezerkeley 4.3, FIONCLEX for Pyramid is preserved
 870              * across dup()s, so we have to UNSET it here or else we get a
 871              * command with NO stdin, stdout, or stderr at all (a bad thing
 872              * indeed)
 873              */
 874             (void) close_on_exec(0, 0);
 875 #endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 876         }
 877     }
 878     if (t->t_drit) {
 879         char *tmp;
 880
 881         cp = splicepipe(t, t->t_drit);
 882         tmp = strsave(short2str(cp));
 883         xfree(cp);
 884         cleanup_push(tmp, xfree);
 885         /*
 886          * so > /dev/std{out,err} work
 887          */
 888         (void) dcopy(SHOUT, 1);
 889         (void) dcopy(SHDIAG, 2);
 890         if ((flags & F_APPEND) != 0) {
 891 #ifdef O_APPEND
 892             fd = xopen(tmp, O_WRONLY|O_APPEND|O_LARGEFILE);
 893 #else /* !O_APPEND */
 894             fd = xopen(tmp, O_WRONLY|O_LARGEFILE);
 895             (void) lseek(fd, (off_t) 0, L_XTND);
 896 #endif /* O_APPEND */
 897         }
 898         else
 899             fd = 0;
 900         if ((flags & F_APPEND) == 0 || fd == -1) {
 901             if (!(flags & F_OVERWRITE) && adrof(STRnoclobber)) {
 902                 if (flags & F_APPEND)
 903                     stderror(ERR_SYSTEM, tmp, strerror(errno));
 904                 chkclob(tmp);
 905             }
 906             if ((fd = xcreat(tmp, 0666)) < 0)
 907                 stderror(ERR_SYSTEM, tmp, strerror(errno));
 908             /* allow input files larger than 2Gb  */
 909 #ifndef WINNT_NATIVE
 910             (void) fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) | O_LARGEFILE);
 911 #endif /*!WINNT_NATIVE*/
 912         }
 913         cleanup_until(tmp);
 914         (void) dmove(fd, 1);
 915         is1atty = isatty(1);
 916     }
 917     else if (flags & F_PIPEOUT) {
 918         xclose(1);
 919         TCSH_IGNORE(dup(pipeout[1]));
 920         is1atty = 0;
 921     }
 922     else {
 923         xclose(1);
 924         TCSH_IGNORE(dup(SHOUT));
 925         is1atty = isoutatty;
 926 # if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 927         (void) close_on_exec(1, 0);
 928 # endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 929     }
 930
 931     xclose(2);
 932     if (flags & F_STDERR) {
 933         TCSH_IGNORE(dup(1));
 934         is2atty = is1atty;
 935     }
 936     else {
 937         TCSH_IGNORE(dup(SHDIAG));
 938         is2atty = isdiagatty;
 939 # if defined(CLOSE_ON_EXEC) && defined(CLEX_DUPS)
 940         (void) close_on_exec(2, 0);
 941 # endif /* CLOSE_ON_EXEC && CLEX_DUPS */
 942     }
 943     didfds = 1;
 944 }
 945
 946 void
 947 mypipe(int *pv)
 948 {
 949
 950     if (pipe(pv) < 0)
 951         goto oops;
 952     (void)close_on_exec(pv[0] = dmove(pv[0], -1), 1);
 953     (void)close_on_exec(pv[1] = dmove(pv[1], -1), 1);
 954     if (pv[0] >= 0 && pv[1] >= 0)
 955         return;
 956     if (pv[0] >= 0)
 957         xclose(pv[0]);
 958     if (pv[1] >= 0)
 959         xclose(pv[1]);
 960 oops:
 961     stderror(ERR_PIPE);
 962 }
 963
 964 static void
 965 chkclob(const char *cp)
 966 {
 967     struct stat stb;
 968
 969     if (stat(cp, &stb) < 0)
 970         return;
 971     if (S_ISCHR(stb.st_mode))
 972         return;
 973     stderror(ERR_EXISTS, cp);
 974 }