FFLUSH Section: Linux Programmer's Manual (3) Updated: 29 November 2025 Index   NAME fflush - flush a stream   SYNOPSIS #include <stdio.h> int fflush(FILE *stream);   DESCRIPTION The function fflush forces a write of all buffered data for the given output or update stream via the stream's underlying write function. The open status of the stream is unaffected. If the stream argument is NULL, fflush flushes all open output streams.   RETURN VALUES Upon successful completion 0 is returned. Otherwise, EOF is returned and the global variable 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 the routine   SEE ALSO   CONFORMING TO The fflush function conforms to ANSI C3.159-1989 (``ANSI C'').   Index NAME SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO CONFORMING TO This document was created by using the manual pages. Time: 11:58:03 GMT, March 24, 2025