* Copyright (c) 1988 The Regents of the University of California.
* This code is derived from software written by Ken Arnold and
* published in UNIX Review, Vol. 6, No. 8.
* %sccs.include.redist.c%
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid
[] = "@(#)popen.c 5.15 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */
if (*type
!= 'r' && *type
!= 'w' || type
[1])
if ((fds
= getdtablesize()) <= 0)
if ((pids
= (pid_t
*)malloc((u_int
)(fds
* sizeof(int)))) == NULL
)
bzero((char *)pids
, fds
* sizeof(pid_t
));
if (pdes
[1] != STDOUT_FILENO
) {
(void) dup2(pdes
[1], STDOUT_FILENO
);
if (pdes
[0] != STDIN_FILENO
) {
(void) dup2(pdes
[0], STDIN_FILENO
);
execl(_PATH_BSHELL
, "sh", "-c", program
, NULL
);
/* parent; assume fdopen can't fail... */
iop
= fdopen(pdes
[0], type
);
iop
= fdopen(pdes
[1], type
);
* pclose returns -1 if stream is not associated with a
* `popened' command, if already `pclosed', or waitpid
if (pids
== NULL
|| pids
[fdes
= fileno(iop
)] == 0)
omask
= sigblock(sigmask(SIGINT
)|sigmask(SIGQUIT
)|sigmask(SIGHUP
));
pid
= waitpid(pids
[fdes
], (int *) &pstat
, 0);
} while (pid
== -1 && errno
== EINTR
);
(void) sigsetmask(omask
);
return (pid
== -1 ? -1 : pstat
.w_status
);