'\" t .\" Copyright (c) 2006 by Michael Kerrisk .\" .\" SPDX-License-Identifier: Linux-man-pages-copyleft .\" .TH fcloseall 3 2023-07-20 "Linux man-pages 6.05.01" .SH NAME fcloseall \- close all open streams .SH LIBRARY Standard C library .RI ( libc ", " \-lc ) .SH SYNOPSIS .nf .BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */" .B #include .PP .B int fcloseall(void); .fi .SH DESCRIPTION The .BR fcloseall () function closes all of the calling process's open streams. Buffered output for each stream is written before it is closed (as for .BR fflush (3)); buffered input is discarded. .PP The standard streams, .IR stdin , .IR stdout , and .I stderr are also closed. .SH RETURN VALUE This function returns 0 if all files were successfully closed; on error, .B EOF is returned. .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 fcloseall () T} Thread safety MT-Unsafe race:streams .TE .sp 1 .PP The .BR fcloseall () function does not lock the streams, so it is not thread-safe. .SH STANDARDS GNU. .SH SEE ALSO .BR close (2), .BR fclose (3), .BR fflush (3), .BR fopen (3), .BR setbuf (3)