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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:49:50 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:49:50 +0000
commit74b60c5712f2a84904b95d008953c140a9bd5dd2 (patch)
treedd12cc58c6d4cfb5e2c1183f47757295ce3b5662 /gl/lib/cloexec.c
parentInitial commit. (diff)
downloadman-db-74b60c5712f2a84904b95d008953c140a9bd5dd2.tar.xz
man-db-74b60c5712f2a84904b95d008953c140a9bd5dd2.zip
Adding upstream version 2.9.4.upstream/2.9.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gl/lib/cloexec.c')
-rw-r--r--gl/lib/cloexec.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/gl/lib/cloexec.c b/gl/lib/cloexec.c
new file mode 100644
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--- /dev/null
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+/* cloexec.c - set or clear the close-on-exec descriptor flag
+
+ Copyright (C) 1991, 2004-2006, 2009-2020 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
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+ The code is taken from glibc/manual/llio.texi */
+
+#include <config.h>
+
+#include "cloexec.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+/* Set the 'FD_CLOEXEC' flag of DESC if VALUE is true,
+ or clear the flag if VALUE is false.
+ Return 0 on success, or -1 on error with 'errno' set.
+
+ Note that on MingW, this function does NOT protect DESC from being
+ inherited into spawned children. Instead, either use dup_cloexec
+ followed by closing the original DESC, or use interfaces such as
+ open or pipe2 that accept flags like O_CLOEXEC to create DESC
+ non-inheritable in the first place. */
+
+int
+set_cloexec_flag (int desc, bool value)
+{
+#ifdef F_SETFD
+
+ int flags = fcntl (desc, F_GETFD, 0);
+
+ if (0 <= flags)
+ {
+ int newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC);
+
+ if (flags == newflags
+ || fcntl (desc, F_SETFD, newflags) != -1)
+ return 0;
+ }
+
+ return -1;
+
+#else /* !F_SETFD */
+
+ /* Use dup2 to reject invalid file descriptors; the cloexec flag
+ will be unaffected. */
+ if (desc < 0)
+ {
+ errno = EBADF;
+ return -1;
+ }
+ if (dup2 (desc, desc) < 0)
+ /* errno is EBADF here. */
+ return -1;
+
+ /* There is nothing we can do on this kind of platform. Punt. */
+ return 0;
+#endif /* !F_SETFD */
+}
+
+
+/* Duplicates a file handle FD, while marking the copy to be closed
+ prior to exec or spawn. Returns -1 and sets errno if FD could not
+ be duplicated. */
+
+int
+dup_cloexec (int fd)
+{
+ return fcntl (fd, F_DUPFD_CLOEXEC, 0);
+}