FILE *
popen(const char *cmd, const char *type)
{
struct pid *cur;
int pdes[2], serrno;
pid_t pid;
_DIAGASSERT(cmd != NULL);
_DIAGASSERT(type != NULL);
if ((cur = pdes_get(pdes, &type)) == NULL)
return NULL;
#ifdef _REENTRANT
(void)rwlock_rdlock(&pidlist_lock);
#endif
(void)__readlockenv();
switch (pid = vfork()) {
case -1: /* Error. */
serrno = errno;
(void)__unlockenv();
#ifdef _REENTRANT
(void)rwlock_unlock(&pidlist_lock);
#endif
pdes_error(pdes, cur);
errno = serrno;
return NULL;
/* NOTREACHED */
case 0: /* Child. */
pdes_child(pdes, type);
execl(_PATH_BSHELL, "sh", "-c", cmd, NULL);
_exit(127);
/* NOTREACHED */
}
(void)__unlockenv();
pdes_parent(pdes, cur, pid, type);
#ifdef _REENTRANT
(void)rwlock_unlock(&pidlist_lock);
#endif
return cur->fp;
}
FILE *
popen(const char *command, const char *type)
{
struct pid *cur, *old;
FILE *iop;
const char * volatile xtype = type;
int pdes[2], pid, serrno;
volatile int twoway;
int flags;
_DIAGASSERT(command != NULL);
_DIAGASSERT(xtype != NULL);
flags = strchr(xtype, 'e') ? O_CLOEXEC : 0;
if (strchr(xtype, '+')) {
int stype = flags ? (SOCK_STREAM | SOCK_CLOEXEC) : SOCK_STREAM;
twoway = 1;
xtype = "r+";
if (socketpair(AF_LOCAL, stype, 0, pdes) < 0)
return NULL;
} else {
twoway = 0;
xtype = strrchr(xtype, 'r') ? "r" : "w";
if (pipe2(pdes, flags) == -1)
return NULL;
}
if ((cur = malloc(sizeof(struct pid))) == NULL) {
(void)close(pdes[0]);
(void)close(pdes[1]);
errno = ENOMEM;
return (NULL);
}
#if defined(__minix)
rwlock_rdlock(&pidlist_lock);
#else
(void)rwlock_rdlock(&pidlist_lock);
#endif /* defined(__minix) */
(void)__readlockenv();
switch (pid = vfork()) {
case -1: /* Error. */
serrno = errno;
(void)__unlockenv();
#if defined(__minix)
rwlock_unlock(&pidlist_lock);
#else
(void)rwlock_unlock(&pidlist_lock);
#endif /* defined(__minix) */
free(cur);
(void)close(pdes[0]);
(void)close(pdes[1]);
errno = serrno;
return (NULL);
/* NOTREACHED */
case 0: /* Child. */
/* POSIX.2 B.3.2.2 "popen() shall ensure that any streams
from previous popen() calls that remain open in the
parent process are closed in the new child process. */
for (old = pidlist; old; old = old->next)
#ifdef _REENTRANT
close(old->fd); /* don't allow a flush */
#else
close(fileno(old->fp)); /* don't allow a flush */
#endif
if (*xtype == 'r') {
(void)close(pdes[0]);
if (pdes[1] != STDOUT_FILENO) {
(void)dup2(pdes[1], STDOUT_FILENO);
(void)close(pdes[1]);
}
if (twoway)
(void)dup2(STDOUT_FILENO, STDIN_FILENO);
} else {
(void)close(pdes[1]);
if (pdes[0] != STDIN_FILENO) {
(void)dup2(pdes[0], STDIN_FILENO);
(void)close(pdes[0]);
}
}
execl(_PATH_BSHELL, "sh", "-c", command, NULL);
_exit(127);
/* NOTREACHED */
}
(void)__unlockenv();
/* Parent; assume fdopen can't fail. */
if (*xtype == 'r') {
iop = fdopen(pdes[0], xtype);
#ifdef _REENTRANT
cur->fd = pdes[0];
#endif
(void)close(pdes[1]);
} else {
iop = fdopen(pdes[1], xtype);
#ifdef _REENTRANT
cur->fd = pdes[1];
#endif
(void)close(pdes[0]);
}
/* Link into list of file descriptors. */
cur->fp = iop;
cur->pid = pid;
cur->next = pidlist;
pidlist = cur;
#if defined(__minix)
rwlock_unlock(&pidlist_lock);
#else
(void)rwlock_unlock(&pidlist_lock);
#endif /* defined(__minix) */
return (iop);
}
int
system(const char *command)
{
pid_t pid;
struct sigaction intsa, quitsa, sa;
sigset_t nmask, omask;
int pstat;
const char *argp[] = {"sh", "-c", NULL, NULL};
argp[2] = command;
/*
* ISO/IEC 9899:1999 in 7.20.4.6 describes this special case.
* We need to check availability of a command interpreter.
*/
if (command == NULL) {
if (access(_PATH_BSHELL, X_OK) == 0)
return 1;
return 0;
}
sa.sa_handler = SIG_IGN;
sigemptyset(&sa.sa_mask);
sa.sa_flags = 0;
if (sigaction(SIGINT, &sa, &intsa) == -1)
return -1;
if (sigaction(SIGQUIT, &sa, &quitsa) == -1) {
sigaction(SIGINT, &intsa, NULL);
return -1;
}
sigemptyset(&nmask);
sigaddset(&nmask, SIGCHLD);
if (sigprocmask(SIG_BLOCK, &nmask, &omask) == -1) {
sigaction(SIGINT, &intsa, NULL);
sigaction(SIGQUIT, &quitsa, NULL);
return -1;
}
(void)__readlockenv();
switch(pid = vfork()) {
case -1: /* error */
(void)__unlockenv();
sigaction(SIGINT, &intsa, NULL);
sigaction(SIGQUIT, &quitsa, NULL);
(void)sigprocmask(SIG_SETMASK, &omask, NULL);
return -1;
case 0: /* child */
sigaction(SIGINT, &intsa, NULL);
sigaction(SIGQUIT, &quitsa, NULL);
(void)sigprocmask(SIG_SETMASK, &omask, NULL);
execve(_PATH_BSHELL, __UNCONST(argp), environ);
_exit(127);
}
(void)__unlockenv();
while (waitpid(pid, &pstat, 0) == -1) {
if (errno != EINTR) {
pstat = -1;
break;
}
}
sigaction(SIGINT, &intsa, NULL);
sigaction(SIGQUIT, &quitsa, NULL);
(void)sigprocmask(SIG_SETMASK, &omask, NULL);
return (pstat);
}
