NAME
close — close a file descriptor
SYNOPSIS
#include <unistd.h>
int close(int fildes);
DESCRIPTION
close()
closes the file descriptor indicated by
fildes.
fildes
is a file descriptor obtained from a
creat(),
open(),
dup(),
fcntl(),
or
pipe()
system call.
All associated file segments which have been locked by this process with the
lockf()
function are released (i.e., unlocked).
RETURN VALUE
Upon successful completion,
close()
returns a value of 0; otherwise, it returns -1 and sets
errno
to indicate the error.
ERRORS
close()
fails if the any of following conditions are encountered:
- [EBADF]
fildes
is not a valid open file descriptor.
- [EINTR]
An attempt to close a slow device or connection
was interrupted by a signal.
The file descriptor still points to an open device or connection.
- [ENOSPC]
Not enough space on the file system.
This error can occur when closing a file on an
NFS
file system.
[When a
write()
system call is executed on a local file system
and if a new buffer needs to be allocated to hold the data,
the buffer is mapped onto the disk at that time.
A full disk is detected at this time and
write()
returns an error.
When the
write()
system call is executed on an
NFS
file system,
the new buffer is allocated without communicating with the
NFS
server to see if there is space for the buffer
(to improve
NFS
performance).
It is only when the buffer is written to the server
(at file close or the buffer is full)
that the disk-full condition is detected.]
STANDARDS CONFORMANCE
close(): AES, SVID2, SVID3, XPG2, XPG3, XPG4, FIPS 151-2, POSIX.1
