Updated CONFORMING TO section

[thirdparty/man-pages.git] / man2 / unlink.2

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.\" This manpage is Copyright (C) 1992 Drew Eckhardt;
.\"                               1993 Ian Jackson.
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.\" Modified 1993-07-24 by Rik Faith <faith@cs.unc.edu>
.\" Modified 1996-09-08 by Arnt Gulbrandsen <agulbra@troll.no>
.\" Modified 1997-01-31 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 2001-05-17 by aeb
.\" Modified 2004-06-23 by Michael Kerrisk <mtk-manpages@gmx.net>
.\"
.TH UNLINK 2 2004-06-23 "Linux 2.6.7" "Linux Programmer's Manual"
.SH NAME
unlink \- delete a name and possibly the file it refers to
.SH SYNOPSIS
.B #include <unistd.h>
.sp
.BI "int unlink(const char *" pathname );
.SH DESCRIPTION
.BR unlink ()
deletes a name from the filesystem. If that name was the
last link to a file and no processes have the file open the file is
deleted and the space it was using is made available for reuse.

If the name was the last link to a file but any processes still have
the file open the file will remain in existence until the last file
descriptor referring to it is closed.

If the name referred to a symbolic link the link is removed.

If the name referred to a socket, fifo or device the name for it is
removed but processes which have the object open may continue to use
it.
.SH "RETURN VALUE"
On success, zero is returned.  On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EACCES
Write access to the directory containing
.I pathname
is not allowed for the process's effective UID, or one of the
directories in
.IR pathname
did not allow search permission.
(See also
.BR path_resolution (2).)
.TP
.BR EBUSY " (not on Linux)"
The file
.I pathname
cannot be unlinked because it is being used by the system
or another process and the implementation considers this an error.
.TP
.B EFAULT
.I pathname
points outside your accessible address space.
.TP
.B EIO
An I/O error occurred.
.TP
.B EISDIR
.I pathname
refers to a directory.
(This is the non-POSIX value returned by Linux since 2.1.132.)
.TP
.B ELOOP
Too many symbolic links were encountered in translating
.IR pathname .
.TP
.B ENAMETOOLONG
.IR pathname " was too long."
.TP
.B ENOENT
A component in
.I pathname
does not exist or is a dangling symbolic link, or
.I pathname
is empty.
.TP
.B ENOMEM
Insufficient kernel memory was available.
.TP
.B ENOTDIR
A component used as a directory in
.I pathname
is not, in fact, a directory.
.TP
.B EPERM
The system does not allow unlinking of directories,
or unlinking of directories requires privileges that the
current process doesn't have.
(This is the POSIX prescribed error return;
as noted above, Linux returns
.B EISDIR
for this case.)
.TP
.BR EPERM " (Linux only)"
The filesystem does not allow unlinking of files.
.TP
.BR EPERM " or " EACCES
The directory containing
.I pathname
has the sticky bit
.RB ( S_ISVTX )
set and the process's effective UID is neither the UID of the file to
be deleted nor that of the directory containing it, and
the process is not privileged (Linux: does not have the
.B CAP_FOWNER
capability).
.TP
.B EROFS
.I pathname
refers to a file on a read-only filesystem.
.SH "CONFORMING TO"
SVr4, SVID, POSIX, X/OPEN, 4.3BSD.  SVr4 documents additional error
conditions EINTR, EMULTIHOP, ETXTBSY, ENOLINK.
.SH BUGS
Infelicities in the protocol underlying NFS can cause the unexpected
disappearance of files which are still being used.
.SH "SEE ALSO"
.BR rm (1),
.BR chmod (2),
.BR link (2),
.BR mknod (2),
.BR open (2),
.BR path_resolution (2),
.BR rename (2),
.BR rmdir (2),
.BR unlinkat (2),
.BR mkfifo (3),
.BR remove (3)