Differences between current version and revision by previous author of close(2).
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Newer page: | version 2 | Last edited on Thursday, October 31, 2002 5:24:50 pm | by PerryLorier | |
Older page: | version 1 | Last edited on Tuesday, June 4, 2002 12:23:40 am | by perry | Revert |
@@ -1,94 +1,36 @@
-CLOSE
-!!!CLOSE
-NAME
-SYNOPSIS
-DESCRIPTION
-RETURN VALUE
-ERRORS
-CONFORMING TO
-NOTES
-SEE ALSO
-----
!!NAME
-
close - close a file descriptor
!!SYNOPSIS
-__#include
-__ ''fd''__);
-
__
+
__#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 locks 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).
-__close__ closes a file descriptor, so that it no longer
-refers to any file and may be reused. Any locks 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.
+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, or -1 if an error
-
occurred.
+__close__ returns zero on success, or -1 if an error occurred.
!!ERRORS
+;[EBADF]: ''fd'' isn't a valid open file descriptor, probably was never opened, or has been previously closed
+;[EINTR]: The __close__() call was interrupted by a signal.
+;[EIO]: An I/O error occurred.
-__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, SVID, POSIX, X/OPEN, BSD 4.3. SVr4 documents an additional [ENOLINK] error condition.
-SVr4, SVID, POSIX, X/OPEN, BSD 4.3. SVr4 documents an
-additional ENOLINK error condition.
!!NOTES
+Not checking the return value of close is a common but nevertheless serious programming error. File system implementations which use techniques as ``write-behind'' to increase performance may lead to write(2) succeeding, although the data has not been written yet. The error status
+may be reported at a later write operation, but it is guaranteed to be reported on closing the file. Not checking the return value when closing the file may lead to silent loss of data. This can especially be observed with NFS and disk quotas.
-Not checking the return value of
close is a common but
-nevertheless serious programming error. File system
-implementations which use techniques as ``write-behind'' to
-increase performance may lead to write(2) succeeding,
-although
the data has not
been written yet. The error status
-may be reported at a later write operation
, but it
is
-guaranteed
to be reported on closing
the file. Not checking
-the return value
when closing
the file may lead to silent
-loss of data
. This can especially
be observed with NFS and
-
disk quotas
.
+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) or sync(2), they will get you closer to that goal (it will depend on the
disk hardware at this point)
.
-
-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) or sync(2),
-they will get you closer to that goal (it will depend on the
-disk hardware at this point).
!!SEE ALSO
-
-
open(2), fcntl(2), shutdown(2),
-
unlink(2), fclose(3)
-----
+open(2), fcntl(2), shutdown(2), unlink(2), fclose(3)