'\" et

.TH LCHOWN "3P" 2013 "IEEE/The Open Group" "POSIX Programmer's Manual"

.SH 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.

.SH NAME

lchown

\(em change the owner and group of a symbolic link

.SH SYNOPSIS

.LP

.nf

#include <unistd.h>

.P

int lchown(const char *\fIpath\fP, uid_t \fIowner\fP, gid_t \fIgroup\fP);

.fi

.SH DESCRIPTION

The

\fIlchown\fR()

function shall be equivalent to

\fIchown\fR(),

except in the case where the named file is a symbolic link. In this

case,

\fIlchown\fR()

shall change the ownership of the symbolic link file itself, while

\fIchown\fR()

changes the ownership of the file or directory to which the symbolic

link refers.

.SH "RETURN VALUE"

Upon successful completion,

\fIlchown\fR()

shall return 0. Otherwise, it shall return \(mi1 and set

.IR errno

to indicate an error.

.SH ERRORS

The

\fIlchown\fR()

function shall fail if:

.TP

.BR EACCES

Search permission is denied on a component of the path prefix of

.IR path .

.TP

.BR EINVAL

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

.TP

.BR ELOOP

A loop exists in symbolic links encountered during resolution of the

.IR path

argument.

.TP

.BR ENAMETOOLONG

.br

The length of a component of a pathname is longer than

{NAME_MAX}.

.TP

.BR ENOENT

A component of

.IR path

does not name an existing file or

.IR path

is an empty string.

.TP

.BR 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

.IR path

argument contains at least one non-\c

<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.

.TP

.BR EPERM

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

process does not have appropriate privileges.

.TP

.BR EROFS

The file resides on a read-only file system.

.P

The

\fIlchown\fR()

function may fail if:

.TP

.BR EIO

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

.TP

.BR EINTR

A signal was caught during execution of the function.

.TP

.BR ELOOP

More than

{SYMLOOP_MAX}

symbolic links were encountered during resolution of the

.IR path

argument.

.TP

.BR ENAMETOOLONG

.br

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}.

.LP

.IR "The following sections are informative."

.SH EXAMPLES

.SS "Changing the Current Owner of a File"

.P

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

link named

.BR /modules/pass1

to the user ID associated with ``jones'' and the group ID associated

with ``cnd''.

.P

The numeric value for the user ID is obtained by using the

\fIgetpwnam\fR()

function. The numeric value for the group ID is obtained by using the

\fIgetgrnam\fR()

function.

.sp

.RS 4

.nf

\fB

#include <sys/types.h>

#include <unistd.h>

#include <pwd.h>

#include <grp.h>

.P

struct passwd *pwd;

struct group  *grp;

char          *path = "/modules/pass1";

\&...

pwd = getpwnam("jones");

grp = getgrnam("cnd");

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

.fi \fR

.P

.RE

.SH "APPLICATION USAGE"

On implementations which support symbolic links as directory entries

rather than files,

\fIlchown\fR()

may fail.

.SH RATIONALE

None.

.SH "FUTURE DIRECTIONS"

None.

.SH "SEE ALSO"

.IR "\fIchown\fR\^(\|)",

.IR "\fIsymlink\fR\^(\|)"

.P

The Base Definitions volume of POSIX.1\(hy2008,

.IR "\fB<unistd.h>\fP"

.SH COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form

from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology

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

Specifications Issue 7, Copyright (C) 2013 by the Institute of

Electrical and Electronics Engineers, Inc and The Open Group.

(This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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 .