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PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
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LCHOWN(3P) POSIX Programmer's Manual LCHOWN(3P)
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.
lchown — change the owner and group of a symbolic link
#include <unistd.h>
int lchown(const char *path, uid_t owner, gid_t group);
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.
Upon successful completion, lchown() shall return 0. Otherwise,
it shall return -1 and set errno to indicate an error.
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.
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);
On implementations which support symbolic links as directory
entries rather than files, lchown() may fail.
None.
None.
chown(3p), symlink(3p)
The Base Definitions volume of POSIX.1‐2017, unistd.h(0p)
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 .
IEEE/The Open Group 2017 LCHOWN(3P)
Pages that refer to this page: unistd.h(0p), chown(3p), symlink(3p)
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HTML rendering created 2023-12-22 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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