#include <fcntl.h>
#include <sys/ioctl.h>
#include <unistd.h>
-
+#include <sys/wait.h>
#include <sys/ioctl.h>
#include <termios.h>
+#include <errno.h>
#ifdef LISP_FEATURE_OPENBSD
/* FIXME: there has to be a better way to avoid ./util.h here */
int spawn(char *program, char *argv[], int sin, int sout, int serr,
int search, char *envp[], char *pty_name, int wait)
{
- int pid = fork();
+ pid_t pid;
int fd;
+ int channel[2];
sigset_t sset;
- if (pid != 0)
+ channel[0] = -1;
+ channel[1] = -1;
+ if (!pipe(channel)) {
+ if (-1==fcntl(channel[1], F_SETFD, FD_CLOEXEC)) {
+ close(channel[1]);
+ channel[1] = -1;
+ }
+ }
+
+ pid = fork();
+ if (pid) {
+ if ((-1 != pid) && (-1 != channel[1])) {
+ int child_errno = 0;
+ int bytes = sizeof(int);
+ int n;
+ char *p = (char*)&child_errno;
+ close(channel[1]);
+ /* Try to read child errno from channel. */
+ while ((bytes > 0) &&
+ (n = read(channel[0], p, bytes))) {
+ if (-1 == n) {
+ if (EINTR == errno) {
+ continue;
+ } else {
+ break;
+ }
+ } else {
+ bytes -= n;
+ p += n;
+ }
+ }
+ close(channel[0]);
+ if (child_errno) {
+ waitpid(pid, NULL, 0);
+ /* Our convention to tell Lisp that it was the exec that
+ * failed, not the fork. */
+ pid = -2;
+ errno = child_errno;
+ }
+ }
return pid;
+ }
+ close (channel[0]);
/* Put us in our own process group, but only if we need not
* share stdin with our parent. In the latter case we claim
/* Close all other fds. */
#ifdef SVR4
for (fd = sysconf(_SC_OPEN_MAX)-1; fd >= 3; fd--)
- close(fd);
+ if (fd != channel[1]) close(fd);
#else
for (fd = getdtablesize()-1; fd >= 3; fd--)
- close(fd);
+ if (fd != channel[1]) close(fd);
#endif
- environ = envp;
+ if (envp) {
+ environ = envp;
+ }
/* Exec the program. */
if (search)
execvp(program, argv);
else
execv(program, argv);
- exit (1);
+ /* When exec fails and channel is available, send the errno value. */
+ if (-1 != channel[1]) {
+ int our_errno = errno;
+ int bytes = sizeof(int);
+ int n;
+ char *p = (char*)&our_errno;
+ while ((bytes > 0) &&
+ (n = write(channel[1], p, bytes))) {
+ if (-1 == n) {
+ if (EINTR == errno) {
+ continue;
+ } else {
+ break;
+ }
+ } else {
+ bytes -= n;
+ p += n;
+ }
+ }
+ close(channel[1]);
+ }
+ _exit(1);
}
#else /* !LISP_FEATURE_WIN32 */