/*
* Copyright (c) 1995, by Sun Microsystems, Inc.
* All rights reserved.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/* from UCB 5.2 85/06/05 */
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#include <stdio.h>
#include <signal.h>
#include <vfork.h>
#define tst(a,b) (*mode == 'r'? (b) : (a))
#define RDR 0
#define WTR 1
extern char *malloc();
extern int execl(), vfork(), pipe(), close(), fcntl();
static int *popen_pid;
static int nfiles;
FILE *
popen(cmd,mode)
char *cmd;
char *mode;
{
int p[2];
register int *poptr;
register int myside, hisside, pid;
if (nfiles <= 0)
nfiles = getdtablesize();
if (popen_pid == NULL) {
popen_pid = (int *)malloc(nfiles * sizeof *popen_pid);
if (popen_pid == NULL)
return (NULL);
for (pid = 0; pid < nfiles; pid++)
popen_pid[pid] = -1;
}
if (pipe(p) < 0)
return (NULL);
myside = tst(p[WTR], p[RDR]);
hisside = tst(p[RDR], p[WTR]);
if ((pid = vfork()) == 0) {
/* myside and hisside reverse roles in child */
int stdio;
/* close all pipes from other popen's */
for (poptr = popen_pid; poptr < popen_pid+nfiles; poptr++) {
if(*poptr >= 0)
close(poptr - popen_pid);
}
stdio = tst(0, 1);
(void) close(myside);
if (hisside != stdio) {
(void) dup2(hisside, stdio);
(void) close(hisside);
}
(void) execl("/bin/sh", "sh", "-c", cmd, (char *)NULL);
_exit(127);
}
if (pid == -1) {
close(myside);
close(hisside);
return (NULL);
}
popen_pid[myside] = pid;
close(hisside);
return (fdopen(myside, mode));
}
int
pclose(ptr)
FILE *ptr;
{
int child = -1;
int pid, status, omask;
if (popen_pid != NULL) {
child = popen_pid[fileno(ptr)];
popen_pid[fileno(ptr)] = -1;
}
fclose(ptr);
if (child == -1)
return (-1);
omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
while ((pid = waitpid(child, &status, 0)) != child && pid != -1)
;
(void) sigsetmask(omask);
return (pid == -1 ? -1 : status);
}