#include <assert.h>
#include <pty.h>
#include <poll.h>
+#include <sys/stat.h>
#define LENGTH(x) (sizeof (x) / sizeof (*(x)))
static const char *progname;
-static volatile int signal_chld_hit = 0;
+static volatile pid_t child;
static void signal_chld (int signo)
{
- signal_chld_hit = 1;
}
static volatile int signal_alrm_hit = 0;
}
static char childptyname[LINE_MAX];
-static pid_t child;
static void print_child_error (const char *reason, char **argv)
{
/* Weird but at least after POLLHUP we get EIO instead of just EOF. */
if (buf_got == -1 && errno == EIO)
return 0;
+ if (buf_got == -1 && errno == EAGAIN)
+ return 0;
if (buf_got < 0)
{
perror ("read (amaster)");
return 1;
}
+/* kill (child, 0) ==0 sometimes even when CHILD's state is already Z. */
+
+static int child_exited (void)
+{
+ char buf[200];
+ int fd, i, retval;
+ ssize_t got;
+ char *state;
+
+ snprintf (buf, sizeof (buf), "/proc/%ld/stat", (long) child);
+ fd = open (buf, O_RDONLY);
+ if (fd == -1)
+ {
+ perror ("open (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ got = read (fd, buf, sizeof(buf));
+ if (got <= 0)
+ {
+ perror ("read (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ if (close (fd) != 0)
+ {
+ perror ("close (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ i = sscanf (buf, "%*d%*s%ms", &state);
+ if (i != 1)
+ {
+ perror ("sscanf (/proc/CHILD/stat)");
+ exit (EXIT_FAILURE);
+ }
+ retval = strcmp (state, "Z") == 0;
+ free (state);
+ return retval;
+}
+
static int spawn (char **argv, int timeout)
{
pid_t child_got;
assert (i == STDIN_FILENO);
#endif
+ i = sigemptyset (&set);
+ assert (i == 0);
+ i = sigprocmask (SIG_SETMASK, &set, NULL);
+ assert (i == 0);
+
/* Do not setpgrp(2) in the parent process as the process-group
is shared for the whole sh(1) pipeline we could be a part
of. The process-group is set according to PID of the first
pollfd.fd = amaster;
pollfd.events = POLLIN;
i = ppoll (&pollfd, 1, NULL, &set);
- if (i == -1 && errno == EINTR && signal_chld_hit)
- break;
+ if (i == -1 && errno == EINTR)
+ {
+ if (child_exited ())
+ break;
+ /* Non-CHILD child may have exited. */
+ continue;
+ }
assert (i == 1);
/* Data available? Process it first. */
if (pollfd.revents & POLLIN)
exit (EXIT_FAILURE);
}
/* Child exited? */
- if (signal_chld_hit)
+ if (child_exited ())
break;
}
exit (EXIT_FAILURE);
}
- /* In the POLLHUP case we may not have seen SIGCHLD so far. */
+ /* Not used in fact. */
i = sigprocmask (SIG_SETMASK, &set, NULL);
assert (i == 0);
- assert (signal_chld_hit != 0);
-
/* Do not unset O_NONBLOCK as a stale child (the whole purpose of this
program) having open its output pty would block us in read_out. */
#if 0