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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 invocation 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

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 attributes(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)

2023-07-20 Linux man-pages 6.05.01