• NAME
  
  close - close a file descriptor
• SYNOPSIS
  

  
   #include <unistd.h>
  
   int close(int  fd );
  

• DESCRIPTION
  
  close ()
  closes a file descriptor, so that it no longer refers to any file and
  may be reused.
  Any record locks (see
  fcntl(2) )
  held on the file it was associated with,
  and owned by the process, are removed (regardless of the file
  descriptor that was used to obtain the lock).
  
  
  
  If
  fd
  is the last file descriptor referring to the underlying
  open file description (see
  open(2) ),
  the resources associated with the open file description are freed;
  if the descriptor was the last reference to a file which has been
  removed using
  unlink(2)
  the file is deleted.
  
• RETURN VALUE
  
  close ()
  returns zero on success.
  On error, -1 is returned, and
  errno
  is set appropriately.
  
• ERRORS
  

  EBADF

  fd
  isn't a valid open file descriptor.
  

  EINTR

  The
  close ()
  call was interrupted by a signal; see
  signal(7) .
  

  EIO

  An I/O error occurred.
  

• CONFORMING TO
  
  SVr4, 4.3BSD, POSIX.1-2001.
  
  
• NOTES
  
  Not checking the return value of
  close ()
  is a common but nevertheless
  serious programming error.
  It is quite possible that errors on a
  previous
  write(2)
  operation are first reported at the final
  close ().
  Not checking the return value when closing the file may lead to
  silent loss of data.
  This can especially be observed with NFS
  and with disk quota.
  
  
  
  A successful close does not guarantee that the data has been successfully
  saved to disk, as the kernel defers writes.
  It is not common for a file system
  to flush the buffers when the stream is closed.
  If you need to be sure that
  the data is physically stored use
  fsync(2) .
  (It will depend on the disk hardware at this point.)
  
  
  
  It is probably unwise to close file descriptors while
  they may be in use by system calls in
  other threads in the same process.
  Since a file descriptor may be re-used,
  there are some obscure race conditions
  that may cause unintended side effects.
  
  
  
  
  
  
  
  
  
• SEE ALSO
  
  fcntl(2) ,
  fsync(2) ,
  open(2) ,
  shutdown(2) ,
  unlink(2) ,
  fclose(3)
  
• COLOPHON
  
  This page is part of release 3.19 of the Linux
  man-pages
  project.
  A description of the project,
  and information about reporting bugs,
  can be found at
  http://www.kernel.org/doc/man-pages/.
  

Current Users: 85 © 1999-2009 PenguinSoft. All trademarks and copyrights on this page are owned by their respective companies. Linux is a trademark of Linus Torvalds.