path: root/src
diff options
authorRich Felker <>2014-02-07 01:16:53 -0500
committerRich Felker <>2014-02-07 01:16:53 -0500
commit758ab35a167ac17a4e3102cee5d16b75053842a7 (patch)
treef6e052426088b5c7a894a9d3a1213ffa1847f766 /src
parent3af2edee150484940916eba1984f78c3b965dd05 (diff)
in fdopen, avoid setting O_APPEND flag if it's already set
this saves a syscall in the case where the underlying open already took place with O_APPEND, which is common because fopen with append modes sets O_APPEND at the time of open before passing the file descriptor to __fdopen.
Diffstat (limited to 'src')
1 files changed, 2 insertions, 1 deletions
diff --git a/src/stdio/__fdopen.c b/src/stdio/__fdopen.c
index a2ca62b1..a6ae73a2 100644
--- a/src/stdio/__fdopen.c
+++ b/src/stdio/__fdopen.c
@@ -32,7 +32,8 @@ FILE *__fdopen(int fd, const char *mode)
/* Set append mode on fd if opened for append */
if (*mode == 'a') {
int flags = __syscall(SYS_fcntl, fd, F_GETFL);
- __syscall(SYS_fcntl, fd, F_SETFL, flags | O_APPEND);
+ if (!(flags & O_APPEND))
+ __syscall(SYS_fcntl, fd, F_SETFL, flags | O_APPEND);
f->flags |= F_APP;