CLOSE (2)
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 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.
RETURN VALUE
close
returns zero on success, or -1 if an error occurred.
ERRORS
EBADF
fd
isn't a valid open file descriptor.
CONFORMING TO
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.
SEE ALSO
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