fpurge, __fpurge — purge a stream


/* unsupported */
#include <stdio.h>

int fpurge(FILE *stream);

/* supported */
#include <stdio.h>
#include <stdio_ext.h>

void  __fpurge(FILE *stream);


The function fpurge() clears the buffers of 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). See also fflush(3).

The function __fpurge() does precisely the same, but without returning a value.

Return Value

Upon successful completion fpurge() returns 0. On error, it returns -1 and sets errno appropriately.



stream is not an open stream.


For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
__fpurge() Thread safety MT-Safe race:stream

Conforming to

These functions are nonstandard and not portable. The function fpurge() was introduced in 4.4BSD and is not available under Linux. The function __fpurge() was introduced in Solaris, and is present in glibc 2.1.95 and later.


Usually it is a mistake to want to discard input buffers.

See Also

fflush(3), setbuf(3), stdio_ext(3)


This page is part of release 5.04 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/.

Referenced By

stdio(3), stdio_ext(3).

The man page __fpurge(3) is an alias of fpurge(3).

2017-09-15 Linux Programmer's Manual