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authorJörg Frings-Fürst <debian@jff.email>2022-02-07 06:57:44 +0100
committerJörg Frings-Fürst <debian@jff.email>2022-02-07 06:57:44 +0100
commit6ffaa52cf732a84c0f8259dbc9b8183960ec5c33 (patch)
treed3136c22e3e805cfc0efe78412cce905a17e0c8d /tests/cloexec.c
parent591cbf5878b7d4105b275585b9db1324c9dfce56 (diff)
parentaf151c593704a40e10efb28d1e3dd59a23a661f3 (diff)
Merge branch 'release/debian/1.0-1'debian/1.0-1
Diffstat (limited to 'tests/cloexec.c')
-rw-r--r--tests/cloexec.c83
1 files changed, 83 insertions, 0 deletions
diff --git a/tests/cloexec.c b/tests/cloexec.c
new file mode 100644
index 00000000..812be01a
--- /dev/null
+++ b/tests/cloexec.c
@@ -0,0 +1,83 @@
+/* cloexec.c - set or clear the close-on-exec descriptor flag
+
+ Copyright (C) 1991, 2004-2006, 2009-2022 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file 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 Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser 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);
+}