LCHOWN
Section: POSIX Programmer's Manual (3P)
Updated: 2017
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PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
lchown
--- change the owner and group of a symbolic link
SYNOPSIS
#include <unistd.h>
int lchown(const char *path, uid_t owner, gid_t group);
DESCRIPTION
The
lchown()
function shall be equivalent to
chown(),
except in the case where the named file is a symbolic link. In this
case,
lchown()
shall change the ownership of the symbolic link file itself, while
chown()
changes the ownership of the file or directory to which the symbolic
link refers.
RETURN VALUE
Upon successful completion,
lchown()
shall return 0. Otherwise, it shall return -1 and set
errno
to indicate an error.
ERRORS
The
lchown()
function shall fail if:
- EACCES
-
Search permission is denied on a component of the path prefix of
path.
- EINVAL
-
The owner or group ID is not a value supported by the implementation.
- ELOOP
-
A loop exists in symbolic links encountered during resolution of the
path
argument.
- ENAMETOOLONG
-
The length of a component of a pathname is longer than
{NAME_MAX}.
- ENOENT
-
A component of
path
does not name an existing file or
path
is an empty string.
- ENOTDIR
-
A component of the path prefix names an existing file that is neither
a directory nor a symbolic link to a directory, or the
path
argument contains at least one non-<slash>
character and ends with one or more trailing
<slash>
characters and the last pathname component names an existing file
that is neither a directory nor a symbolic link to a directory.
- EPERM
-
The effective user ID does not match the owner of the file and the
process does not have appropriate privileges.
- EROFS
-
The file resides on a read-only file system.
The
lchown()
function may fail if:
- EIO
-
An I/O error occurred while reading or writing to the file system.
- EINTR
-
A signal was caught during execution of the function.
- ELOOP
-
More than
{SYMLOOP_MAX}
symbolic links were encountered during resolution of the
path
argument.
- ENAMETOOLONG
-
The length of a pathname exceeds
{PATH_MAX},
or pathname resolution of a symbolic link produced an intermediate
result with a length that exceeds
{PATH_MAX}.
The following sections are informative.
EXAMPLES
Changing the Current Owner of a File
The following example shows how to change the ownership of the symbolic
link named
/modules/pass1
to the user ID associated with ``jones'' and the group ID associated
with ``cnd''.
The numeric value for the user ID is obtained by using the
getpwnam()
function. The numeric value for the group ID is obtained by using the
getgrnam()
function.
-
#include <sys/types.h>
#include <unistd.h>
#include <pwd.h>
#include <grp.h>
struct passwd *pwd;
struct group *grp;
char *path = "/modules/pass1";
...
pwd = getpwnam("jones");
grp = getgrnam("cnd");
lchown(path, pwd->pw_uid, grp->gr_gid);
APPLICATION USAGE
On implementations which support symbolic links as directory entries
rather than files,
lchown()
may fail.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
chown(),
symlink()
The Base Definitions volume of POSIX.1-2017,
<unistd.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
Index
- PROLOG
-
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- EXAMPLES
-
- Changing the Current Owner of a File
-
- APPLICATION USAGE
-
- RATIONALE
-
- FUTURE DIRECTIONS
-
- SEE ALSO
-
- COPYRIGHT
-
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