musl/src/stdio/fopen.c
Rich Felker 7765706c05 add O_CLOEXEC fallback for open and related functions
since there is no easy way to detect whether open honored or ignored
the O_CLOEXEC flag, the optimal solution to providing a fallback is
simply to make the fcntl syscall to set the close-on-exec flag
immediately after open returns.
2014-06-06 15:42:42 -04:00

33 lines
608 B
C

#include "stdio_impl.h"
#include <fcntl.h>
#include <string.h>
#include <errno.h>
FILE *fopen(const char *restrict filename, const char *restrict mode)
{
FILE *f;
int fd;
int flags;
/* Check for valid initial mode character */
if (!strchr("rwa", *mode)) {
errno = EINVAL;
return 0;
}
/* Compute the flags to pass to open() */
flags = __fmodeflags(mode);
fd = sys_open_cp(filename, flags, 0666);
if (fd < 0) return 0;
if (flags & O_CLOEXEC)
__syscall(SYS_fcntl, fd, F_SETFD, FD_CLOEXEC);
f = __fdopen(fd, mode);
if (f) return f;
__syscall(SYS_close, fd);
return 0;
}
LFS64(fopen);