2.11BSD/src/bin/tcsh/sh.sem.c
/* $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 <vfork.h>
#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 <mlschroe@immd4.informatik.uni-erlangen.de>
* 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
* <schmidt%sunshine.ics.uci.edu@ROME.ICS.UCI.EDU>
* (thanks! -- PWP)
*
* ignint ifs cleaned by Johan Widen <mcvax!osiris.sics.se!jw@uunet.UU.NET>
* (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);
}