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fclose(3)
NAME
  fclose, fflush, fclose_unlocked, fflush_unlocked - Closes or flushes a
  stream

LIBRARY
  Standard C Library (libc.so, libc.a)

SYNOPSIS
  #include <stdio.h>

  int fclose (
	  FILE *stream);

  int fclose_unlocked(
	  FILE *stream);

  int fflush(
	  FILE *stream);

  int fflush_unlocked(
	  FILE *stream);

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  fclose(), fflush():  XPG4, XPG4-UNIX

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

PARAMETERS
  stream    Specifies the output or update stream.

DESCRIPTION
  The fclose() function writes buffered data to the stream specified by the
  stream parameter, and then closes the associated file.  The function is
  automatically called for all open files when the exit() 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 the close() function on the file descriptor
  associated with the stream parameter.	 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.

  The fflush() function writes any buffered data for the stream specified by
  the stream parameter and leaves the stream open.  If stream is a null
  pointer, the fflush() function performs this flushing action on all streams
  for which the behavior was previously defined.  The st_ctime and st_mtime
  fields of the underlying file are marked for update.

  [Digital]  The fclose_unlocked() and fflush_unlocked() functions are
  functionally identical to the fclose() and fflush() functions, except that
  fclose_unlocked() and fflush_unlocked() may be safely used only within a
  scope that is protected by the flockfile() and funlockfile() functions used
  as a pair. The caller must ensure that the stream is locked before these
  functions are used.

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

ERRORS
  The fclose(), fflush(), fclose_unlocked(), and fflush_unlocked() functions
  set errno to the specified value for following conditions:

  [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.

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

  [EFBIG]   An attempt was made to write a file that exceeds the process's
	    file size limit or the maximum file size.  (See the ulimit(3)
	    reference page).

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

  [EIO]	    The TOSTOP tty local mode causes a background process to get a
	    SIGTTOU signal if it attempts to write to the controlling
	    terminal.  The SIGTTOU signal, if it is not caught or ignored,
	    will cause the process to block in a stopped state.	 A process in
	    an orphaned process group is not allowed to become stopped, since
	    there is no unprivileged process to unblock it.  This condition
	    only applies to operations on stdio streams associated with ttys.

	    [EIO] is also associated with driver errors.

  [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.

RELATED INFORMATION
  Functions: close(2), exit(2), fopen(3), setbuf(3)

  Standards: standards(5)