fclose(3S)

fclose, fflush -- close or flush a stream

Synopsis

   #include <stdio.h>
   
   int fclose(FILE stream);
   

   int fflush(FILE stream);

Description

fclose causes any buffered data waiting to be written for the named stream (see intro(3)) to be written out, and the stream to be closed. If the underlying file pointer is not already at end of file, and the file is one capable of seeking, the file pointer is adjusted so that the next operation on the open file pointer deals with the byte after the last one read from or written to the file being closed.

fclose is performed automatically for all open files on calling exit.

If stream points to an output stream or an update stream on which the most recent operation was not input, fflush causes any buffered data waiting to be written for the named stream to be written to that file. Any unread data buffered in stream is discarded. The stream remains open.

When calling fflush, if stream is a null pointer, all files open for writing are flushed.

Return values

On successful completion these functions return a value of zero. Otherwise EOF is returned.

fclose and fflush fail when the file is a regular file and an attempt is made to write at or beyond the offset maximum associated with the corresponding stream.

References

close(2), exit(2), intro(3), fopen(3S), setbuf(3S), Intro(3S)