Name
close — close a file descriptor
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
copy of a particular file descriptor the resources associated
with it 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.
- 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 filesystem 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.)
SEE ALSO
fcntl(2), fsync(2), open(2), shutdown(2), unlink(2), fclose(3)
This manpage is Copyright (C) 1992 Drew Eckhardt;
1993 Michael Haardt, Ian Jackson.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of this
manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Since the Linux kernel and libraries are constantly changing, this
manual page may be incorrect or out-of-date. The author(s) assume no
responsibility for errors or omissions, or for damages resulting from
the use of the information contained herein. The author(s) may not
have taken the same level of care in the production of this manual,
which is licensed free of charge, as they might when working
professionally.
Formatted or processed versions of this manual, if unaccompanied by
the source, must acknowledge the copyright and authors of this work.
Modified Wed Jul 21 22:40:25 1993 by Rik Faith <faith@cs.unc.edu>
Modified Sat Feb 18 15:27:48 1995 by Michael Haardt
Modified Sun Apr 14 11:40:50 1996 by Andries Brouwer <aeb@cwi.nl>:
corrected description of effect on locks (thanks to
Tigran Aivazian <tigran@sco.com>).
Modified Fri Jan 31 16:21:46 1997 by Eric S. Raymond <esr@thyrsus.com>
Modified 2000-07-22 by Nicolás Lichtmaier <nick@debian.org>
added note about close(2) not guaranteeing that data is safe on close.
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