/* Invoke popen, but avoid some glitches.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2009-2014 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "cloexec.h"
-#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-# define O_CLOEXEC O_NOINHERIT
-#elif !defined O_CLOEXEC
-# define O_CLOEXEC 0
-#endif
-
/* Like open (name, flags | O_CLOEXEC), although not necessarily
atomic. FLAGS must not include O_CREAT. */
static int
open_noinherit (char const *name, int flags)
{
- int fd = open (name, flags | O_CLOEXEC);
- if (0 <= fd && !O_CLOEXEC && set_cloexec_flag (fd, true) != 0)
+ int fd;
+#if O_CLOEXEC
+ /* 0 = unknown, 1 = yes, -1 = no. */
+ static int have_cloexec;
+ if (have_cloexec >= 0)
+ {
+ fd = open (name, flags | O_CLOEXEC);
+ if (have_cloexec == 0 && (0 <= fd || errno == EINVAL))
+ have_cloexec = (0 <= fd ? 1 : -1);
+ if (have_cloexec == 1)
+ return fd;
+ }
+#endif
+
+ fd = open (name, flags);
+ if (0 <= fd && set_cloexec_flag (fd, true) != 0)
{
int saved_errno = errno;
close (fd);
else
{
/* Either all fd's are tied up, or fd is safe and the real popen
- will reuse it. */
+ will reuse it. */
close (fd);
fp = popen (cmd, mode);
}