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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 

.TH "LCHOWN" P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"

.\" lchown 

.SH NAME

lchown \- change the owner and group of a symbolic link

.SH SYNOPSIS

.LP

\fB#include <unistd.h>

.br

.sp

int lchown(const char *\fP\fIpath\fP\fB, uid_t\fP \fIowner\fP\fB,

gid_t\fP \fIgroup\fP\fB); \fP

\fB

.br

\fP

.SH DESCRIPTION

.LP

The \fIlchown\fP() function shall be equivalent to \fIchown\fP(),

except in the case

where the named file is a symbolic link. In this case, \fIlchown\fP()

shall change the ownership of the symbolic link file itself,

while \fIchown\fP() changes the ownership of the file or directory

to which the symbolic

link refers.

.SH RETURN VALUE

.LP

Upon successful completion, \fIlchown\fP() shall return 0. Otherwise,

it shall return -1 and set \fIerrno\fP to indicate an

error.

.SH ERRORS

.LP

The \fIlchown\fP() function shall fail if:

.TP 7

.B EACCES

Search permission is denied on a component of the path prefix of \fIpath\fP.

.TP 7

.B EINVAL

The owner or group ID is not a value supported by the implementation.

.TP 7

.B ELOOP

A loop exists in symbolic links encountered during resolution of the

\fIpath\fP argument.

.TP 7

.B ENAMETOOLONG

The length of a pathname exceeds {PATH_MAX} or a pathname component

is longer than {NAME_MAX}.

.TP 7

.B ENOENT

A component of \fIpath\fP does not name an existing file or \fIpath\fP

is an empty string.

.TP 7

.B ENOTDIR

A component of the path prefix of \fIpath\fP is not a directory.

.TP 7

.B EOPNOTSUPP

The \fIpath\fP argument names a symbolic link and the implementation

does not support setting the owner or group of a symbolic

link.

.TP 7

.B EPERM

The effective user ID does not match the owner of the file and the

process does not have appropriate privileges.

.TP 7

.B EROFS

The file resides on a read-only file system.

.sp

.LP

The \fIlchown\fP() function may fail if:

.TP 7

.B EIO

An I/O error occurred while reading or writing to the file system.

.TP 7

.B EINTR

A signal was caught during execution of the function.

.TP 7

.B ELOOP

More than {SYMLOOP_MAX} symbolic links were encountered during resolution

of the \fIpath\fP argument.

.TP 7

.B ENAMETOOLONG

Pathname resolution of a symbolic link produced an intermediate result

whose length exceeds {PATH_MAX}.

.sp

.LP

\fIThe following sections are informative.\fP

.SH EXAMPLES

.SS Changing the Current Owner of a File

.LP

The following example shows how to change the ownership of the symbolic

link named \fB/modules/pass1\fP to the user ID

associated with "jones" and the group ID associated with "cnd".

.LP

The numeric value for the user ID is obtained by using the \fIgetpwnam\fP()

function.

The numeric value for the group ID is obtained by using the \fIgetgrnam\fP()

function.

.sp

.RS

.nf

\fB#include <sys/types.h>

#include <unistd.h>

#include <pwd.h>

#include <grp.h>

.sp

struct passwd *pwd;

struct group  *grp;

char          *path = "/modules/pass1";

\&...

pwd = getpwnam("jones");

grp = getgrnam("cnd");

lchown(path, pwd->pw_uid, grp->gr_gid);

\fP

.fi

.RE

.SH APPLICATION USAGE

.LP

On implementations which support symbolic links as directory entries

rather than files, \fIlchown\fP() may fail.

.SH RATIONALE

.LP

None.

.SH FUTURE DIRECTIONS

.LP

None.

.SH SEE ALSO

.LP

\fIchown\fP() , \fIsymlink\fP() , the Base Definitions volume of

IEEE\ Std\ 1003.1-2001, \fI<unistd.h>\fP

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology

-- Portable Operating System Interface (POSIX), The Open Group Base

Specifications Issue 6, Copyright (C) 2001-2003 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 .