util-linux/include/closestream.h

111 lines
2.1 KiB
C

#ifndef UTIL_LINUX_CLOSESTREAM_H
#define UTIL_LINUX_CLOSESTREAM_H
#include <stdio.h>
#ifdef HAVE_STDIO_EXT_H
#include <stdio_ext.h>
#endif
#include <unistd.h>
#include "c.h"
#include "nls.h"
#ifndef CLOSE_EXIT_CODE
# define CLOSE_EXIT_CODE EXIT_FAILURE
#endif
static inline int
close_stream(FILE * stream)
{
#ifdef HAVE___FPENDING
const int some_pending = (__fpending(stream) != 0);
#endif
const int prev_fail = (ferror(stream) != 0);
const int fclose_fail = (fclose(stream) != 0);
if (prev_fail || (fclose_fail && (
#ifdef HAVE___FPENDING
some_pending ||
#endif
errno != EBADF))) {
if (!fclose_fail && !(errno == EPIPE))
errno = 0;
return EOF;
}
return 0;
}
static inline int
flush_standard_stream(FILE *stream)
{
int fd;
errno = 0;
if (ferror(stream) != 0 || fflush(stream) != 0)
goto error;
/*
* Calling fflush is not sufficient on some filesystems
* like e.g. NFS, which may defer the actual flush until
* close. Calling fsync would help solve this, but would
* probably result in a performance hit. Thus, we work
* around this issue by calling close on a dup'd file
* descriptor from the stream.
*/
if ((fd = fileno(stream)) < 0 || (fd = dup(fd)) < 0 || close(fd) != 0)
goto error;
return 0;
error:
return (errno == EBADF) ? 0 : EOF;
}
/* Meant to be used atexit(close_stdout); */
static inline void
close_stdout(void)
{
if (flush_standard_stream(stdout) != 0 && !(errno == EPIPE)) {
if (errno)
warn(_("write error"));
else
warnx(_("write error"));
_exit(CLOSE_EXIT_CODE);
}
if (flush_standard_stream(stderr) != 0)
_exit(CLOSE_EXIT_CODE);
}
static inline void
close_stdout_atexit(void)
{
/*
* Note that close stdout at exit disables ASAN to report memory leaks
*/
#if !HAS_FEATURE_ADDRESS_SANITIZER
atexit(close_stdout);
#endif
}
#ifndef HAVE_FSYNC
static inline int
fsync(int fd __attribute__((__unused__)))
{
return 0;
}
#endif
static inline int
close_fd(int fd)
{
const int fsync_fail = (fsync(fd) != 0);
const int close_fail = (close(fd) != 0);
if (fsync_fail || close_fail)
return EOF;
return 0;
}
#endif /* UTIL_LINUX_CLOSESTREAM_H */