/* $Header: /home/hyperion/mu/christos/src/sys/tcsh-6.00/RCS/sh.sem.c,v 3.0 1991/07/04 23:34:26 christos Exp $ */ /* * sh.sem.c: I/O redirections and job forking. A touchy issue! * Most stuff with builtins is incorrect */ /*- * Copyright (c) 1980, 1991 The Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include "config.h" #if !defined(lint) && !defined(pdp11) static char *rcsid() { return "$Id: sh.sem.c,v 3.0 1991/07/04 23:34:26 christos Exp $"; } #endif #include "sh.h" #ifdef FIOCLEX #ifndef sun #ifndef CLEX_DUPS #define CLEX_DUPS #endif /* CLEX_DUPS */ #endif /* sun */ #endif /* FIOCLEX */ #ifdef sparc #include #endif /* sparc */ #ifdef VFORK static sigret_t vffree __P((int)); #endif static void doio __P((struct command *t, int *, int *)); static void chkclob __P((char *)); /* * C shell */ /*VARARGS 1*/ void execute(t, wanttty, pipein, pipeout) register struct command *t; int wanttty, *pipein, *pipeout; { #if defined(convex) || defined(__convex__) extern bool use_fork; /* use fork() instead of vfork()? */ #endif bool forked = 0; struct biltins *bifunc; int pid = 0; int pv[2]; #ifdef BSDSIGS static sigmask_t csigmask; # ifdef VFORK static sigmask_t ocsigmask; # endif /* VFORK */ #endif /* BSDSIGS */ #ifdef VFORK static int onosigchld = 0; #endif /* VFORK */ static int nosigchld = 0; if (t == 0) return; /* * From: Michael Schroeder * Don't check for wantty > 0... */ if (t->t_dflg & F_AMPERSAND) wanttty = 0; switch (t->t_dtyp) { case NODE_COMMAND: if ((t->t_dcom[0][0] & (QUOTE | TRIM)) == QUOTE) (void) Strcpy(t->t_dcom[0], t->t_dcom[0] + 1); if ((t->t_dflg & F_REPEAT) == 0) Dfix(t); /* $ " ' \ */ if (t->t_dcom[0] == 0) return; /* fall into... */ case NODE_PAREN: if (t->t_dflg & F_PIPEOUT) mypipe(pipeout); /* * Must do << early so parent will know where input pointer should be. * If noexec then this is all we do. */ if (t->t_dflg & F_READ) { (void) close(0); heredoc(t->t_dlef); if (noexec) (void) close(0); } if (noexec) break; set(STRstatus, Strsave(STR0)); /* * This mess is the necessary kludge to handle the prefix builtins: * nice, nohup, time. These commands can also be used by themselves, * and this is not handled here. This will also work when loops are * parsed. */ while (t->t_dtyp == NODE_COMMAND) if (eq(t->t_dcom[0], STRnice)) if (t->t_dcom[1]) if (strchr("+-", t->t_dcom[1][0])) if (t->t_dcom[2]) { setname("nice"); t->t_nice = getn(t->t_dcom[1]); lshift(t->t_dcom, 2); t->t_dflg |= F_NICE; } else break; else { t->t_nice = 4; lshift(t->t_dcom, 1); t->t_dflg |= F_NICE; } else break; else if (eq(t->t_dcom[0], STRnohup)) if (t->t_dcom[1]) { t->t_dflg |= F_NOHUP; lshift(t->t_dcom, 1); } else break; else if (eq(t->t_dcom[0], STRtime)) if (t->t_dcom[1]) { t->t_dflg |= F_TIME; lshift(t->t_dcom, 1); } else break; #ifdef F_VER else if (eq(t->t_dcom[0], STRver)) if (t->t_dcom[1] && t->t_dcom[2]) { setname("ver"); t->t_systype = getv(t->t_dcom[1]); lshift(t->t_dcom, 2); t->t_dflg |= F_VER; } else break; #endif else break; /* is t a command */ if (t->t_dtyp == NODE_COMMAND) { /* * Check if we have a builtin function and remember which one. */ bifunc = isbfunc(t); } else { /* not a command */ bifunc = NULL; } /* * We fork only if we are timed, or are not the end of a parenthesized * list and not a simple builtin function. Simple meaning one that is * not pipedout, niced, nohupped, or &'d. It would be nice(?) to not * fork in some of these cases. */ /* * Prevent forking cd, pushd, popd, chdir cause this will cause the * shell not to change dir! */ if (bifunc && (bifunc->bfunct == dochngd || bifunc->bfunct == dopushd || bifunc->bfunct == dopopd)) t->t_dflg &= ~(F_NICE); if (((t->t_dflg & F_TIME) || (t->t_dflg & F_NOFORK) == 0 && (!bifunc || t->t_dflg & (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP))) || /* * We have to fork for eval too. */ (bifunc && (t->t_dflg & F_PIPEIN) != 0 && bifunc->bfunct == doeval)) #ifdef VFORK if (t->t_dtyp == NODE_PAREN || t->t_dflg & (F_REPEAT | F_AMPERSAND) || bifunc) #endif { forked++; /* * We need to block SIGCHLD here, so that if the process does * not die before we can set the process group */ if (wanttty >= 0 && !nosigchld) { #ifdef BSDSIGS csigmask = sigblock(sigmask(SIGCHLD)); #else sighold(SIGCHLD); #endif /* BSDSIGS */ nosigchld = 1; } pid = pfork(t, wanttty); if (pid == 0 && nosigchld) { #ifdef BSDSIGS (void) sigsetmask(csigmask); #else (void) sigrelse(SIGCHLD); #endif /* BSDSIGS */ nosigchld = 0; } } #ifdef VFORK else { int ochild, osetintr, ohaderr, odidfds; int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp; int oisoutatty, oisdiagatty; #ifndef FIOCLEX int odidcch; #endif #ifdef BSDSIGS sigmask_t omask; #endif /* BSDSIGS */ /* * Prepare for the vfork by saving everything that the child * corrupts before it exec's. Note that in some signal * implementations which keep the signal info in user space * (e.g. Sun's) it will also be necessary to save and restore * the current sigvec's for the signals the child touches * before it exec's. */ #ifdef BSDSIGS /* * Sooooo true... If this is a Sun, save the sigvec's. (Skip * Gilbrech - 11/22/87) */ #ifdef SAVESIGVEC sigvec_t savesv[NSIGSAVED]; sigmask_t savesm; #endif /* SAVESIGVEC */ if (wanttty >= 0 && !nosigchld && !noexec) { #ifdef BSDSIGS csigmask = sigblock(sigmask(SIGCHLD)); #else sighold(SIGCHLD); #endif /* BSDSIGS */ nosigchld = 1; } omask = sigblock(sigmask(SIGCHLD) | sigmask(SIGINT)); #else (void) sighold(SIGCHLD); (void) sighold(SIGINT); #endif ochild = child; osetintr = setintr; ohaderr = haderr; odidfds = didfds; #ifndef FIOCLEX odidcch = didcch; #endif oSHIN = SHIN; oSHOUT = SHOUT; oSHDIAG = SHDIAG; oOLDSTD = OLDSTD; otpgrp = tpgrp; oisoutatty = isoutatty; oisdiagatty = isdiagatty; #ifdef BSDSIGS ocsigmask = csigmask; #endif /* BSDSIGS */ onosigchld = nosigchld; Vsav = Vdp = 0; Vexpath = 0; Vt = 0; #ifdef SAVESIGVEC savesm = savesigvec(savesv); #endif /* SAVESIGVEC */ #if defined(convex) || defined(__convex__) if (use_fork) pid = fork(); else pid = vfork(); #else pid = vfork(); #endif if (pid < 0) { #ifdef BSDSIGS #ifdef SAVESIGVEC restoresigvec(savesv, savesm); #endif /* SAVESIGVEC */ (void) sigsetmask(omask); #else (void) sigrelse(SIGCHLD); (void) sigrelse(SIGINT); #endif stderror(ERR_NOPROC); } forked++; if (pid) { /* parent */ #ifdef pdp11 register char **v; #endif #ifdef BSDSIGS #ifdef SAVESIGVEC restoresigvec(savesv, savesm); #endif /* SAVESIGVEC */ #endif /* BSDSIGS */ child = ochild; setintr = osetintr; haderr = ohaderr; didfds = odidfds; SHIN = oSHIN; #ifndef FIOCLEX didcch = odidcch; #endif SHOUT = oSHOUT; SHDIAG = oSHDIAG; OLDSTD = oOLDSTD; tpgrp = otpgrp; isoutatty = oisoutatty; isdiagatty = oisdiagatty; #ifdef BSDSIGS csigmask = ocsigmask; #endif /* BSDSIGS */ nosigchld = onosigchld; xfree((ptr_t) Vsav); Vsav = 0; xfree((ptr_t) Vdp); Vdp = 0; xfree((ptr_t) Vexpath); Vexpath = 0; blkfree((Char **) Vt); Vt = 0; #ifdef pdp11 if (v = gargv) gargv = 0, blkfree(v); if (v = pargv) pargv = 0, blkfree(v); #endif /* this is from pfork() */ palloc(pid, t); #ifdef BSDSIGS (void) sigsetmask(omask); #else (void) sigrelse(SIGCHLD); (void) sigrelse(SIGINT); #endif } else { /* child */ /* this is from pfork() */ int pgrp; bool ignint = 0; if (nosigchld) { #ifdef BSDSIGS (void) sigsetmask(csigmask); #else (void) sigrelse(SIGCHLD); #endif /* BSDSIGS */ nosigchld = 0; } if (setintr) ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) || gointr && eq(gointr, STRminus); pgrp = pcurrjob ? pcurrjob->p_jobid : getpid(); child++; if (setintr) { setintr = 0; #ifdef notdef (void) signal(SIGCHLD, SIG_DFL); #endif /* * casts made right for SunOS 4.0 by Douglas C. Schmidt * * (thanks! -- PWP) * * ignint ifs cleaned by Johan Widen * (thanks again) */ if (ignint) { (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); } else { (void) signal(SIGINT, vffree); (void) signal(SIGQUIT, SIG_DFL); } if (wanttty >= 0) { (void) signal(SIGTSTP, SIG_DFL); (void) signal(SIGTTIN, SIG_DFL); (void) signal(SIGTTOU, SIG_DFL); } (void) signal(SIGTERM, parterm); } else if (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) { (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); } #ifdef _SEQUENT_ pgetty(wanttty ? wanttty : 1, pgrp); #else /* _SEQUENT_ */ pgetty(wanttty, pgrp); #endif /* _SEQUENT_ */ if (t->t_dflg & F_NOHUP) (void) signal(SIGHUP, SIG_IGN); if (t->t_dflg & F_NICE) #ifdef BSDNICE (void) setpriority(PRIO_PROCESS, 0, t->t_nice); #else /* BSDNICE */ (void) nice(t->t_nice); #endif /* BSDNICE */ #ifdef F_VER if (t->t_dflg & F_VER) { Setenv(STRSYSTYPE, t->t_systype ? STRbsd43 : STRsys53); dohash(); } #endif } } #endif /* VFORK */ if (pid != 0) { /* * It would be better if we could wait for the whole job when we * knew the last process had been started. Pwait, in fact, does * wait for the whole job anyway, but this test doesn't really * express our intentions. */ if (didfds == 0 && t->t_dflg & F_PIPEIN) { (void) close(pipein[0]); (void) close(pipein[1]); } if ((t->t_dflg & F_PIPEOUT) == 0) { if (nosigchld) { #ifdef BSDSIGS (void) sigsetmask(csigmask); #else (void) sigrelse(SIGCHLD); #endif /* BSDSIGS */ nosigchld = 0; } if ((t->t_dflg & F_AMPERSAND) == 0) pwait(); } break; } doio(t, pipein, pipeout); if (t->t_dflg & F_PIPEOUT) { (void) close(pipeout[0]); (void) close(pipeout[1]); } /* * Perform a builtin function. If we are not forked, arrange for * possible stopping */ if (bifunc) { func(t, bifunc); if (forked) exitstat(); break; } if (t->t_dtyp != NODE_PAREN) { doexec(t); /* NOTREACHED */ } /* * For () commands must put new 0,1,2 in FSH* and recurse */ OLDSTD = dcopy(0, FOLDSTD); SHOUT = dcopy(1, FSHOUT); isoutatty = isatty(SHOUT); SHDIAG = dcopy(2, FSHDIAG); isdiagatty = isatty(SHDIAG); (void) close(SHIN); SHIN = -1; #ifndef FIOCLEX didcch = 0; #endif didfds = 0; wanttty = -1; t->t_dspr->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dspr, wanttty, NULL, NULL); exitstat(); case NODE_PIPE: t->t_dcar->t_dflg |= F_PIPEOUT | (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT)); execute(t->t_dcar, wanttty, pipein, pv); t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg & (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT)); if (wanttty > 0) wanttty = 0; /* got tty already */ execute(t->t_dcdr, wanttty, pv, pipeout); break; case NODE_LIST: if (t->t_dcar) { t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dcar, wanttty, NULL, NULL); /* * In strange case of A&B make a new job after A */ if (t->t_dcar->t_dflg & F_AMPERSAND && t->t_dcdr && (t->t_dcdr->t_dflg & F_AMPERSAND) == 0) pendjob(); } if (t->t_dcdr) { t->t_dcdr->t_dflg |= t->t_dflg & (F_NOFORK | F_NOINTERRUPT); execute(t->t_dcdr, wanttty, NULL, NULL); } break; case NODE_OR: case NODE_AND: if (t->t_dcar) { t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dcar, wanttty, NULL, NULL); if ((getn(value(STRstatus)) == 0) != (t->t_dtyp == NODE_AND)) return; } if (t->t_dcdr) { t->t_dcdr->t_dflg |= t->t_dflg & (F_NOFORK | F_NOINTERRUPT); execute(t->t_dcdr, wanttty, NULL, NULL); } break; } /* * Fall through for all breaks from switch * * If there will be no more executions of this command, flush all file * descriptors. Places that turn on the F_REPEAT bit are responsible for * doing donefds after the last re-execution */ if (didfds && !(t->t_dflg & F_REPEAT)) donefds(); } #ifdef VFORK static sigret_t /*ARGSUSED*/ vffree(snum) int snum; { register Char **v; if (v = gargv) { gargv = 0; #ifdef pdp11 blkfree(v); #else xfree((ptr_t) v); #endif } if (v = pargv) { pargv = 0; #ifdef pdp11 blkfree(v); #else xfree((ptr_t) v); #endif } _exit(1); } #endif /* * Perform io redirection. * We may or maynot be forked here. */ static void doio(t, pipein, pipeout) register struct command *t; int *pipein, *pipeout; { register int fd; register Char *cp, *dp; register int flags = t->t_dflg; if (didfds || (flags & F_REPEAT)) return; if ((flags & F_READ) == 0) {/* F_READ already done */ if (cp = t->t_dlef) { char tmp[MAXPATHLEN+1]; /* * so < /dev/std{in,out,err} work */ (void) dcopy(SHIN, 0); (void) dcopy(SHOUT, 1); (void) dcopy(SHDIAG, 2); cp = globone(dp = Dfix1(cp), G_IGNORE); (void) strncpy(tmp, short2str(cp), MAXPATHLEN); tmp[MAXPATHLEN] = '\0'; xfree((ptr_t) cp); xfree((ptr_t) dp); if ((fd = open(tmp, O_RDONLY)) < 0) stderror(ERR_SYSTEM, tmp, strerror(errno)); (void) dmove(fd, 0); } else if (flags & F_PIPEIN) { (void) close(0); (void) dup(pipein[0]); (void) close(pipein[0]); (void) close(pipein[1]); } else if ((flags & F_NOINTERRUPT) && tpgrp == -1) { (void) close(0); (void) open(_PATH_DEVNULL, O_RDONLY); } else { (void) close(0); (void) dup(OLDSTD); #ifdef FIOCLEX #ifdef CLEX_DUPS /* * PWP: Unlike Bezerkeley 4.3, FIONCLEX for Pyramid is preserved * across dup()s, so we have to UNSET it here or else we get a * command with NO stdin, stdout, or stderr at all (a bad thing * indeed) */ (void) ioctl(0, FIONCLEX, NULL); #endif /* CLEX_DUPS */ #endif /* FIONCLEX */ } } if (cp = t->t_drit) { char tmp[MAXPATHLEN+1]; cp = globone(dp = Dfix1(cp), G_IGNORE); (void) strncpy(tmp, short2str(cp), MAXPATHLEN); tmp[MAXPATHLEN] = '\0'; xfree((ptr_t) dp); xfree((ptr_t) cp); /* * so > /dev/std{out,err} work */ (void) dcopy(SHOUT, 1); (void) dcopy(SHDIAG, 2); if ((flags & F_APPEND) && #ifdef O_APPEND (fd = open(tmp, O_WRONLY | O_APPEND)) >= 0); #else (fd = open(tmp, O_WRONLY)) >= 0) (void) lseek(1, (off_t) 0, L_XTND); #endif else { if (!(flags & F_OVERWRITE) && adrof(STRnoclobber)) { if (flags & F_APPEND) stderror(ERR_SYSTEM, tmp, strerror(errno)); chkclob(tmp); } if ((fd = creat(tmp, 0666)) < 0) stderror(ERR_SYSTEM, tmp, strerror(errno)); } (void) dmove(fd, 1); is1atty = isatty(1); } else if (flags & F_PIPEOUT) { (void) close(1); (void) dup(pipeout[1]); is1atty = 0; } else { (void) close(1); (void) dup(SHOUT); is1atty = isoutatty; #ifdef FIOCLEX #ifdef CLEX_DUPS (void) ioctl(1, FIONCLEX, NULL); #endif /* CLEX_DUPS */ #endif /* FIONCLEX */ } (void) close(2); if (flags & F_STDERR) { (void) dup(1); is2atty = is1atty; } else { (void) dup(SHDIAG); is2atty = isdiagatty; #ifdef FIOCLEX #ifdef CLEX_DUPS (void) ioctl(2, FIONCLEX, NULL); #endif /* CLEX_DUPS */ #endif /* FIONCLEX */ } didfds = 1; } void mypipe(pv) register int *pv; { if (pipe(pv) < 0) goto oops; pv[0] = dmove(pv[0], -1); pv[1] = dmove(pv[1], -1); if (pv[0] >= 0 && pv[1] >= 0) return; oops: stderror(ERR_PIPE); } static void chkclob(cp) register char *cp; { struct stat stb; if (stat(cp, &stb) < 0) return; if ((stb.st_mode & S_IFMT) == S_IFCHR) return; stderror(ERR_EXISTS, cp); }