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| author | Guillem Jover | 2015-06-06 06:19:05 +0200 |
|---|---|---|
| committer | Karel Zak | 2015-06-08 12:10:02 +0200 |
| commit | 8e86d93d1e3f0c11b3fdca3246c4f3a267acf8eb (patch) | |
| tree | 50db242d8bde7b5c63807a6bac6a3b36360d9be3 /lib/fileutils.c | |
| parent | man: fix nolazytime typo in mount(8) (diff) | |
| download | kernel-qcow2-util-linux-8e86d93d1e3f0c11b3fdca3246c4f3a267acf8eb.tar.gz kernel-qcow2-util-linux-8e86d93d1e3f0c11b3fdca3246c4f3a267acf8eb.tar.xz kernel-qcow2-util-linux-8e86d93d1e3f0c11b3fdca3246c4f3a267acf8eb.zip | |
lib/fileutils: Add new dup_fd_cloexec function
This function duplicates and marks a file descriptor as close-on-exec.
Takes care of build and run-time support for the fcntl F_DUPFD_CLOEXEC
command, and other errors.
Signed-off-by: Guillem Jover <guillem@hadrons.org>
Diffstat (limited to 'lib/fileutils.c')
| -rw-r--r-- | lib/fileutils.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/lib/fileutils.c b/lib/fileutils.c index bffa8ff34..81b38ad3a 100644 --- a/lib/fileutils.c +++ b/lib/fileutils.c @@ -50,6 +50,36 @@ int xmkstemp(char **tmpname, char *dir) return fd; } +int dup_fd_cloexec(int oldfd, int lowfd) +{ + int fd, flags, errno_save; + +#ifdef F_DUPFD_CLOEXEC + fd = fcntl(oldfd, F_DUPFD_CLOEXEC, lowfd); + if (fd >= 0) + return fd; +#endif + + fd = dup(oldfd); + if (fd < 0) + return fd; + + flags = fcntl(fd, F_GETFD); + if (flags < 0) + goto unwind; + if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) + goto unwind; + + return fd; + +unwind: + errno_save = errno; + close(fd); + errno = errno_save; + + return -1; +} + /* * portable getdtablesize() */ |