NAME
fflush, fpurge
— flush a stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<stdio.h>
int
fflush(FILE
*stream);
int
fpurge(FILE
*stream);
DESCRIPTION
The function
fflush()
synchronizes the state of the given stream in light of
buffered I/O. For output or update streams it writes all buffered data via
the stream's underlying write function. For input streams it seeks to the
current file position indicator via the stream's underlying seek function.
The open status of the stream is unaffected.
If the stream argument is
NULL,
fflush()
flushes all
open streams.
The function
fpurge()
erases any input or output buffered in the given
stream. For output streams this discards any unwritten
output. For input streams this discards any input read from the underlying
object but not yet obtained via
getc(3); this
includes any text pushed back via
ungetc(3).
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] - The stream argument is not an open stream.
The function fflush() may also fail and
set errno for any of the errors specified for the
routines write(2) and lseek(2).
SEE ALSO
STANDARDS
The fflush() function conforms to
ISO/IEC 9899:1990 (“ISO C90”)
and Version 3 of the Single UNIX Specification
(“SUSv3”).