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Diffstat (limited to 'src/stdio/freopen.c')
-rw-r--r--src/stdio/freopen.c17
1 files changed, 10 insertions, 7 deletions
diff --git a/src/stdio/freopen.c b/src/stdio/freopen.c
index 5b4f126d..c80ce3b4 100644
--- a/src/stdio/freopen.c
+++ b/src/stdio/freopen.c
@@ -7,24 +7,27 @@
/* Locking is not necessary because, in the event of failure, the stream
* passed to freopen is invalid as soon as freopen is called. */
+int __dup3(int, int, int);
+
FILE *freopen(const char *restrict filename, const char *restrict mode, FILE *restrict f)
{
- int fl;
+ int fl = __fmodeflags(mode);
FILE *f2;
fflush(f);
if (!filename) {
- f2 = fopen("/dev/null", mode);
- if (!f2) goto fail;
- fl = __syscall(SYS_fcntl, f2->fd, F_GETFL, 0);
+ if (fl&O_CLOEXEC)
+ __syscall(SYS_fcntl, f->fd, F_SETFD, FD_CLOEXEC);
+ fl &= ~(O_CREAT|O_EXCL|O_CLOEXEC);
if (syscall(SYS_fcntl, f->fd, F_SETFL, fl) < 0)
- goto fail2;
+ goto fail;
+ return f;
} else {
f2 = fopen(filename, mode);
if (!f2) goto fail;
- if (syscall(SYS_dup2, f2->fd, f->fd) < 0)
- goto fail2;
+ if (f2->fd == f->fd) f2->fd = -1; /* avoid closing in fclose */
+ else if (__dup3(f2->fd, f->fd, fl&O_CLOEXEC)<0) goto fail2;
}
f->flags = (f->flags & F_PERM) | f2->flags;