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fflush(3) [v7 man page]

FFLUSH(3)                                                    Linux Programmer's Manual                                                   FFLUSH(3)

NAME
fflush - flush a stream SYNOPSIS
#include <stdio.h> int fflush(FILE *stream); DESCRIPTION
For output streams, fflush() forces a write of all user-space buffered data for the given output or update stream via the stream's underly- ing write function. For input streams associated with seekable files (e.g., disk files, but not pipes or terminals), fflush() discards any buffered data that has been fetched from the underlying file, but has not been consumed by the application. The open status of the stream is unaffected. If the stream argument is NULL, fflush() flushes all open output streams. For a nonlocking counterpart, see unlocked_stdio(3). RETURN VALUE
Upon successful completion 0 is returned. Otherwise, EOF is returned and errno is set to indicate the error. ERRORS
EBADF stream is not an open stream, or is not open for writing. The function fflush() may also fail and set errno for any of the errors specified for write(2). ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7). +----------+---------------+---------+ |Interface | Attribute | Value | +----------+---------------+---------+ |fflush() | Thread safety | MT-Safe | +----------+---------------+---------+ CONFORMING TO
C89, C99, POSIX.1-2001, POSIX.1-2008. POSIX.1-2001 did not specify the behavior for flushing of input streams, but the behavior is specified in POSIX.1-2008. NOTES
Note that fflush() 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
fsync(2), sync(2), write(2), fclose(3), fileno(3), fopen(3), setbuf(3), unlocked_stdio(3) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. GNU 2017-09-15 FFLUSH(3)

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FCLOSE(3)						     Linux Programmer's Manual							 FCLOSE(3)

NAME
fclose - close a stream 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 attributes(7). +----------+---------------+---------+ |Interface | Attribute | Value | +----------+---------------+---------+ |fclose() | Thread safety | MT-Safe | +----------+---------------+---------+ CONFORMING TO
POSIX.1-2001, POSIX.1-2008, C89, C99. 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) COLOPHON
This page is part of release 4.15 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/. GNU
2016-12-12 FCLOSE(3)
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