fclose(3) Library Functions Manual fclose(3)
NAME
fclose - close a stream
LIBRARY
Standard C library (libc, -lc)
SYNOPSIS
#include <stdio.h>
int fclose(FILE *stream);
DESCRIPTION
The fclose() function flushes the stream pointed to by stream (writing
any buffered output data using fflush(3)) and closes the underlying
file descriptor.
The behaviour of fclose() is undefined if the stream parameter is an
illegal pointer, or is a descriptor already passed to a previous invo-
cation of fclose().
RETURN VALUE
Upon successful completion, 0 is returned. Otherwise, EOF is returned
and errno is set to indicate the error. In either case, any further
access (including another call to fclose()) to the stream results in
undefined behavior.
ERRORS
EBADF The file descriptor underlying stream is not valid.
The fclose() function may also fail and set errno for any of the errors
specified for the routines close(2), write(2), or fflush(3).
ATTRIBUTES
For an explanation of the terms used in this section, see attrib-
utes(7).
┌───────────────────────────────────────────┬───────────────┬─────────┐
│ Interface │ Attribute │ Value │
├───────────────────────────────────────────┼───────────────┼─────────┤
│ fclose() │ Thread safety │ MT-Safe │
└───────────────────────────────────────────┴───────────────┴─────────┘
STANDARDS
C11, POSIX.1-2008.
HISTORY
C89, POSIX.1-2001.
NOTES
Note that fclose() flushes only the user-space buffers provided by the
C library. To ensure that the data is physically stored on disk the
kernel buffers must be flushed too, for example, with sync(2) or
fsync(2).
SEE ALSO
close(2), fcloseall(3), fflush(3), fileno(3), fopen(3), setbuf(3)
Linux man-pages 6.7 2023-10-31 fclose(3)
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