FCLOSE(3S)                           SysV                           FCLOSE(3S)



NAME
     fclose, fflush - close or flush a stream

SYNOPSIS
     #include <stdio.h>

     int fclose (stream)
     FILE *stream;

     int fflush (stream)
     FILE *stream;

DESCRIPTION
     fclose causes any buffered data for the named stream to be written out,
     and the stream to be closed. It is automatically called for all open
     files when the exit(2) function is invoked.

     Any unwritten buffered data for the stream is delivered to the host
     environment to be written to the file; any unread buffered data is
     discarded.  The stream is disassociated from the file.  If the associated
     buffer was automatically allocated, it is deallocated.  Any further use
     of the stream specified by the stream parameter causes undefined
     behavior.

     The fclose function performs close(2) on the file descriptor associated
     with the stream parameter.

     The fflush call causes any buffered data for the named stream to be
     written to that file.  The stream remains open.

     If stream is a null pointer, the fflush function performs this flushing
     action on all streams for which the behavior is defined above.

     For fclose, If the stream was writable and buffered data was not yet
     written to the file, it marks the st_ctime and st_mtime fields of the
     underlying file for update.

     For fflush, the st_ctime and st_mtime fields of the underlying file are
     marked for update.  If the stream is open for reading, any unread data
     buffered in the stream is discarded.

     In an AES, POSIX, or XPG3 environment, the following is true for the
     fclose and fflush calls:

          if the file is not already at EOF, and is capable of seeking (or, in
          the case of fflush,
           is open for reading), the file pointer (or file offset) of the
          underlying open file description is adjusted so that the next
          operation on the open file description deals with the byte after the
          last one read from or written to the stream being closed.

DIAGNOSTICS
     Upon successful completion, both the fclose and fflush functions return a
     value of 0 (zero). Otherwise, EOF is returned and errno is set to
     indicate the error.

ERRORS
     If the fclose function fails, errno is set to one of the following
     values:

     [EBADF]        The file descriptor underlying the stream parameter is not

                    valid.

     [EINTR]        The fclose function was interrupted by a signal which was
                    caught.

     [EAGAIN]       The O_NONBLOCK flag is set for the file descriptor
                    underlying the stream parameter and the process would be
                    delayed in the write operation.

     [EFBIG]        An attempt was made to write a file that exceeds the
                    process' file size limit or the maximum file size.  See
                    the ulimit function.

     [EIO]          The process is a member of a background process group
                    attempting to write to its controlling terminal, TOSTOP is
                    set, the process is neither ignoring nor blocking SIGTTOU
                    and the process group of the process is orphaned.  This
                    error may also be returned under implementation-defined
                    conditions.

     [ENOSPC]       There was no free space remaining on the device containing
                    the file.

     [EPIPE]        An attempt was made to write to a pipe or FIFO that is not
                    open for reading by any process.  A SIGPIPE signal will
                    also be sent to the process.

     If the fflush function fails, errno is set to one of the following
     values:

     [EAGAIN]       The O_NONBLOCK flag is set for the file descriptor
                    underlying stream and the process would be delayed in the
                    write operation.

     [EBADF]        The file descriptor underlying the stream parameter is not
                    valid.

     [EFBIG]        An attempt was made to write a file that exceeds the
                    process' file size limit or the maximum file size.  See
                    the ulimit function.

     [EINTR]        The fflush function was interrupted by a signal which was
                    caught.

     [EIO]          The implementation supports job control, the process is a
                    member of a background process group attempting to write
                    to its controlling terminal, TOSTOP is set, the process is
                    neither ignoring nor blocking SIGTTOU and the process
                    group of the process is orphaned.  This error may also be
                    returned under implementation-defined conditions.

     [ENOSPC]       There was no free space remaining on the device containing
                    the file.

     [EPIPE]        An attempt is made to write to a pipe or FIFO that is not
                    open for reading by any process.  A SIGPIPE signal will
                    also be sent to the process.

SEE ALSO
     close(2), exit(2), fopen(3S), setbuf(3S), stdio.h.