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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:40:15 +0000 |
commit | 399644e47874bff147afb19c89228901ac39340e (patch) | |
tree | 1c4c0b733f4c16b5783b41bebb19194a9ef62ad1 /man3/fflush.3 | |
parent | Initial commit. (diff) | |
download | manpages-upstream/6.05.01.tar.xz manpages-upstream/6.05.01.zip |
Adding upstream version 6.05.01.upstream/6.05.01
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'man3/fflush.3')
-rw-r--r-- | man3/fflush.3 | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/man3/fflush.3 b/man3/fflush.3 new file mode 100644 index 0000000..a26c3e8 --- /dev/null +++ b/man3/fflush.3 @@ -0,0 +1,116 @@ +'\" t +.\" Copyright (c) 1990, 1991 The Regents of the University of California. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to Berkeley by +.\" Chris Torek and the American National Standards Committee X3, +.\" on Information Processing Systems. +.\" +.\" SPDX-License-Identifier: BSD-4-Clause-UC +.\" +.\" @(#)fflush.3 5.4 (Berkeley) 6/29/91 +.\" +.\" Converted for Linux, Mon Nov 29 15:22:01 1993, faith@cs.unc.edu +.\" +.\" Modified 2000-07-22 by Nicolás Lichtmaier <nick@debian.org> +.\" Modified 2001-10-16 by John Levon <moz@compsoc.man.ac.uk> +.\" +.TH fflush 3 2023-07-20 "Linux man-pages 6.05.01" +.SH NAME +fflush \- flush a stream +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <stdio.h> +.PP +.BI "int fflush(FILE *_Nullable " stream ); +.fi +.SH DESCRIPTION +For output streams, +.BR fflush () +forces a write of all user-space buffered data for the given output or update +.I stream +via the stream's underlying write function. +.PP +For input streams associated with seekable files +(e.g., disk files, but not pipes or terminals), +.BR fflush () +discards any buffered data that has been fetched from the underlying file, +but has not been consumed by the application. +.PP +The open status of the stream is unaffected. +.PP +If the +.I stream +argument is NULL, +.BR fflush () +flushes +.I all +open output streams. +.\" mtk: POSIX specifies that only output streams are flushed for this case. +.\" Also verified for glibc by experiment. +.PP +For a nonlocking counterpart, see +.BR unlocked_stdio (3). +.SH RETURN VALUE +Upon successful completion 0 is returned. +Otherwise, +.B EOF +is returned and +.I errno +is set to indicate the error. +.SH ERRORS +.TP +.B EBADF +.I stream +is not an open stream, or is not open for writing. +.PP +The function +.BR fflush () +may also fail and set +.I errno +for any of the errors specified for +.BR write (2). +.SH ATTRIBUTES +For an explanation of the terms used in this section, see +.BR attributes (7). +.TS +allbox; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR fflush () +T} Thread safety MT-Safe +.TE +.sp 1 +.SH STANDARDS +C11, POSIX.1-2008. +.SH HISTORY +C89, POSIX.1-2001, POSIX.1-2008. +.PP +POSIX.1-2001 did not specify the behavior for flushing of input streams, +but the behavior is specified in POSIX.1-2008. +.SH NOTES +Note that +.BR 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 +.BR sync (2) +or +.BR fsync (2). +.SH SEE ALSO +.BR fsync (2), +.BR sync (2), +.BR write (2), +.BR fclose (3), +.BR fileno (3), +.BR fopen (3), +.BR fpurge (3), +.BR setbuf (3), +.BR unlocked_stdio (3) |