fclose(3) -- Linux man page
NAMEfclose - close a stream
DESCRIPTIONThe fclose function dissociates the named stream from its underlying file or set of functions. If the stream was being used for output, any buffered data is written first, using fflush(3).
RETURN VALUEUpon successful completion 0 is returned. Otherwise, EOF is returned and the global variable errno is set to indicate the error. In either case any further access (including another call to fclose()) to the stream results in undefined behaviour.
- The filedescriptor underlying stream is not valid.
NOTESNote that fclose only flushes the user space buffers provided by the C library. To ensure that the data is physically stored on disk the kernel buffers must be flushed too, e.g. with sync(2) or fsync(2).
CONFORMING TOThe fclose function conforms to ANSI X3.159-1989 (``ANSI C'').
SEE ALSOclose(2), fcloseall(3), fflush(3), fopen(3), setbuf(3)