4.3BSD-Reno/src/bin/csh/sh.sem.c
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley Software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char *sccsid = "@(#)sh.sem.c 5.8 (Berkeley) 4/14/90";
#endif
#include "sh.h"
#include "sh.proc.h"
#include <sys/file.h>
#include <sys/ioctl.h>
#include "pathnames.h"
/*
* C shell
*/
static int nosigchld = 0, osigmask;
static int onosigchld = 0, oosigmask;
/*VARARGS 1*/
execute(t, wanttty, pipein, pipeout)
register struct command *t;
int wanttty, *pipein, *pipeout;
{
bool forked = 0;
struct biltins *bifunc;
int pid = 0;
int pv[2];
if (t == 0)
return;
if ((t->t_dflg & FAND) && wanttty > 0)
wanttty = 0;
switch (t->t_dtyp) {
case TCOM:
if ((t->t_dcom[0][0] & (QUOTE|TRIM)) == QUOTE)
(void) strcpy(t->t_dcom[0], t->t_dcom[0] + 1);
if ((t->t_dflg & FREDO) == 0)
Dfix(t); /* $ " ' \ */
if (t->t_dcom[0] == 0)
return;
/* fall into... */
case TPAR:
if (t->t_dflg & FPOU)
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 & FHERE) {
(void) close(0);
heredoc(t->t_dlef);
if (noexec)
(void) close(0);
}
if (noexec)
break;
set("status", "0");
/*
* 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 == TCOM)
if (eq(t->t_dcom[0], "nice"))
if (t->t_dcom[1])
if (any(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 |= FNICE;
} else
break;
else {
t->t_nice = 4;
lshift(t->t_dcom, 1);
t->t_dflg |= FNICE;
}
else
break;
else if (eq(t->t_dcom[0], "nohup"))
if (t->t_dcom[1]) {
t->t_dflg |= FNOHUP;
lshift(t->t_dcom, 1);
} else
break;
else if (eq(t->t_dcom[0], "time"))
if (t->t_dcom[1]) {
t->t_dflg |= FTIME;
lshift(t->t_dcom, 1);
} else
break;
else
break;
/*
* Check if we have a builtin function and remember which one.
*/
bifunc = t->t_dtyp == TCOM ? isbfunc(t) : (struct biltins *) 0;
/*
* 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.
*/
if (((t->t_dflg & FTIME) || (t->t_dflg & FPAR) == 0 &&
(!bifunc || t->t_dflg & (FPOU|FAND|FNICE|FNOHUP))))
#ifdef VFORK
if (t->t_dtyp == TPAR || t->t_dflg&(FREDO|FAND) || bifunc)
#endif
{ forked++;
if (wanttty >= 0 && !nosigchld) {
osigmask = sigblock(sigmask(SIGCHLD));
nosigchld = 1;
}
pid = pfork(t, wanttty);
if (pid == 0 && nosigchld) {
sigsetmask(osigmask);
nosigchld = 0;
}
}
#ifdef VFORK
else {
sig_t vffree;
int ochild, osetintr, ohaderr, odidfds;
int oSHIN, oSHOUT, oSHDIAG, oOLDSTD, otpgrp;
long omask;
/*
* 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.
*/
if (wanttty >= 0 && !nosigchld && !noexec) {
osigmask = sigblock(sigmask(SIGCHLD));
nosigchld = 1;
}
omask = sigblock(sigmask(SIGCHLD));
ochild = child; osetintr = setintr;
ohaderr = haderr; odidfds = didfds;
oSHIN = SHIN; oSHOUT = SHOUT;
oSHDIAG = SHDIAG; oOLDSTD = OLDSTD; otpgrp = tpgrp;
oosigmask = osigmask; onosigchld = nosigchld;
Vsav = Vdp = 0; Vav = 0;
pid = vfork();
if (pid < 0) {
(void) sigsetmask(omask);
error("No more processes");
}
forked++;
if (pid) { /* parent */
child = ochild; setintr = osetintr;
haderr = ohaderr; didfds = odidfds;
SHIN = oSHIN;
SHOUT = oSHOUT; SHDIAG = oSHDIAG;
OLDSTD = oOLDSTD; tpgrp = otpgrp;
osigmask = oosigmask; nosigchld = onosigchld;
xfree(Vsav); Vsav = 0;
xfree(Vdp); Vdp = 0;
xfree((char *)Vav); Vav = 0;
/* this is from pfork() */
palloc(pid, t);
(void) sigsetmask(omask);
} else { /* child */
/* this is from pfork() */
int pgrp;
bool ignint = 0;
if (nosigchld) {
sigsetmask(osigmask);
nosigchld = 0;
}
if (setintr)
ignint =
(tpgrp == -1 && (t->t_dflg&FINT))
|| gointr && eq(gointr, "-");
pgrp = pcurrjob ? pcurrjob->p_jobid : getpid();
child++;
if (setintr) {
setintr = 0;
#ifdef notdef
(void) signal(SIGCHLD, SIG_DFL);
#endif
(void) signal(SIGINT, ignint ?
SIG_IGN : vffree);
(void) signal(SIGQUIT, ignint ?
SIG_IGN : 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&FINT)) {
(void) signal(SIGINT, SIG_IGN);
(void) signal(SIGQUIT, SIG_IGN);
}
if (wanttty >= 0 && tpgrp >= 0)
(void) setpgrp(0, pgrp);
if (wanttty > 0)
(void) ioctl(FSHTTY, TIOCSPGRP,
(char *)&pgrp);
if (tpgrp > 0)
tpgrp = 0;
if (t->t_dflg & FNOHUP)
(void) signal(SIGHUP, SIG_IGN);
if (t->t_dflg & FNICE)
(void) setpriority(PRIO_PROCESS,
0, t->t_nice);
}
}
#endif
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&FPIN) {
(void) close(pipein[0]);
(void) close(pipein[1]);
}
if ((t->t_dflg & FPOU) == 0) {
if (nosigchld) {
#ifdef foobarbaz
printf("DID\n");
#endif
sigsetmask(osigmask);
nosigchld = 0;
}
if ((t->t_dflg & FAND) == 0)
pwait();
}
break;
}
doio(t, pipein, pipeout);
if (t->t_dflg & FPOU) {
(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 != TPAR) {
doexec(t);
/*NOTREACHED*/
}
/*
* For () commands must put new 0,1,2 in FSH* and recurse
*/
OLDSTD = dcopy(0, FOLDSTD);
SHOUT = dcopy(1, FSHOUT);
SHDIAG = dcopy(2, FSHDIAG);
(void) close(SHIN);
SHIN = -1;
didfds = 0;
wanttty = -1;
t->t_dspr->t_dflg |= t->t_dflg & FINT;
execute(t->t_dspr, wanttty);
exitstat();
case TFIL:
t->t_dcar->t_dflg |= FPOU |
(t->t_dflg & (FPIN|FAND|FDIAG|FINT));
execute(t->t_dcar, wanttty, pipein, pv);
t->t_dcdr->t_dflg |= FPIN |
(t->t_dflg & (FPOU|FAND|FPAR|FINT));
if (wanttty > 0)
wanttty = 0; /* got tty already */
execute(t->t_dcdr, wanttty, pv, pipeout);
break;
case TLST:
if (t->t_dcar) {
t->t_dcar->t_dflg |= t->t_dflg & FINT;
execute(t->t_dcar, wanttty);
/*
* In strange case of A&B make a new job after A
*/
if (t->t_dcar->t_dflg&FAND && t->t_dcdr &&
(t->t_dcdr->t_dflg&FAND) == 0)
pendjob();
}
if (t->t_dcdr) {
t->t_dcdr->t_dflg |= t->t_dflg & (FPAR|FINT);
execute(t->t_dcdr, wanttty);
}
break;
case TOR:
case TAND:
if (t->t_dcar) {
t->t_dcar->t_dflg |= t->t_dflg & FINT;
execute(t->t_dcar, wanttty);
if ((getn(value("status")) == 0) != (t->t_dtyp == TAND))
return;
}
if (t->t_dcdr) {
t->t_dcdr->t_dflg |= t->t_dflg & (FPAR|FINT);
execute(t->t_dcdr, wanttty);
}
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 FREDO bit are responsible
* for doing donefds after the last re-execution
*/
if (didfds && !(t->t_dflg & FREDO))
donefds();
}
#ifdef VFORK
vffree()
{
register char **v;
if (v = gargv)
gargv = 0, xfree((char *)v);
if (v = pargv)
pargv = 0, xfree((char *)v);
_exit(1);
}
#endif
/*
* Perform io redirection.
* We may or maynot be forked here.
*/
doio(t, pipein, pipeout)
register struct command *t;
int *pipein, *pipeout;
{
register char *cp;
register int flags = t->t_dflg;
if (didfds || (flags & FREDO))
return;
if ((flags & FHERE) == 0) { /* FHERE already done */
(void) close(0);
if (cp = t->t_dlef) {
cp = globone(Dfix1(cp));
xfree(cp);
if (open(cp, 0) < 0)
Perror(cp);
} else if (flags & FPIN) {
(void) dup(pipein[0]);
(void) close(pipein[0]);
(void) close(pipein[1]);
} else if ((flags & FINT) && tpgrp == -1) {
(void) close(0);
(void) open(_PATH_DEVNULL, 0);
} else
(void) dup(OLDSTD);
}
(void) close(1);
if (cp = t->t_drit) {
cp = globone(Dfix1(cp));
xfree(cp);
if (!(flags & FCAT) || open(cp, O_WRONLY|O_APPEND, 0) < 0) {
if (!(flags & FANY) && adrof("noclobber")) {
if (flags & FCAT)
Perror(cp);
chkclob(cp);
}
if (creat(cp, 0666) < 0)
Perror(cp);
}
} else if (flags & FPOU)
(void) dup(pipeout[1]);
else
(void) dup(SHOUT);
(void) close(2);
if (flags & FDIAG)
(void) dup(1);
else
(void) dup(SHDIAG);
didfds = 1;
}
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:
error("Can't make pipe");
}
chkclob(cp)
register char *cp;
{
struct stat stb;
if (stat(cp, &stb) < 0)
return;
if ((stb.st_mode & S_IFMT) == S_IFCHR)
return;
error("%s: File exists", cp);
}