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CHOWN(2)		  FreeBSD System Calls Manual		      CHOWN(2)

NAME
     chown, fchown, lchown, fchownat --	change owner and group of a file

LIBRARY
     Standard C	Library	(libc, -lc)

SYNOPSIS
     #include <unistd.h>

     int
     chown(const char *path, uid_t owner, gid_t	group);

     int
     fchown(int	fd, uid_t owner, gid_t group);

     int
     lchown(const char *path, uid_t owner, gid_t group);

     int
     fchownat(int fd, const char *path,	uid_t owner, gid_t group, int flag);

DESCRIPTION
     The owner ID and group ID of the file named by path or referenced by fd
     is	changed	as specified by	the arguments owner and	group.	The owner of a
     file may change the group to a group of which he or she is	a member, but
     the change	owner capability is restricted to the super-user.

     The chown() system	call clears the	set-user-id and	set-group-id bits on
     the file to prevent accidental or mischievous creation of set-user-id and
     set-group-id programs if not executed by the super-user.  The chown()
     system call follows symbolic links	to operate on the target of the	link
     rather than the link itself.

     The fchown() system call is particularly useful when used in conjunction
     with the file locking primitives (see flock(2)).

     The lchown() system call is similar to chown() but	does not follow	sym-
     bolic links.

     The fchownat() system call	is equivalent to the chown() and lchown()
     except in the case	where path specifies a relative	path.  In this case
     the file to be changed is determined relative to the directory associated
     with the file descriptor fd instead of the	current	working	directory.

     Values for	flag are constructed by	a bitwise-inclusive OR of flags	from
     the following list, defined in <fcntl.h>:

     AT_SYMLINK_NOFOLLOW
	     If	path names a symbolic link, ownership of the symbolic link is
	     changed.

     If	fchownat() is passed the special value AT_FDCWD	in the fd parameter,
     the current working directory is used and the behavior is identical to a
     call to chown() or	lchown() respectively, depending on whether or not the
     AT_SYMLINK_NOFOLLOW bit is	set in the flag	argument.

     One of the	owner or group id's may	be left	unchanged by specifying	it as
     -1.

RETURN VALUES
     Upon successful completion, the value 0 is	returned; otherwise the
     value -1 is returned and the global variable errno	is set to indicate the
     error.

ERRORS
     The chown() and lchown() will fail	and the	file will be unchanged if:

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded 255 characters, or
			an entire path name exceeded 1023 characters.

     [ENOENT]		The named file does not	exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EPERM]		The operation would change the ownership, but the
			effective user ID is not the super-user.

     [EPERM]		The named file has its immutable or append-only	flag
			set, see the chflags(2)	manual page for	more informa-
			tion.

     [EROFS]		The named file resides on a read-only file system.

     [EFAULT]		The path argument points outside the process's allo-
			cated address space.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     The fchown() system call will fail	if:

     [EBADF]		The fd argument	does not refer to a valid descriptor.

     [EINVAL]		The fd argument	refers to a socket, not	a file.

     [EPERM]		The effective user ID is not the super-user.

     [EROFS]		The named file resides on a read-only file system.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     In	addition to the	errors specified for chown() and lchown(), the
     fchownat()	system call may	fail if:

     [EBADF]		The path argument does not specify an absolute path
			and the	fd argument is neither AT_FDCWD	nor a valid
			file descriptor	open for searching.

     [EINVAL]		The value of the flag argument is not valid.

     [ENOTDIR]		The path argument is not an absolute path and fd is
			neither	AT_FDCWD nor a file descriptor associated with
			a directory.

SEE ALSO
     chgrp(1), chflags(2), chmod(2), flock(2), chown(8)

STANDARDS
     The chown() system	call is	expected to conform to ISO/IEC 9945-1:1990
     (``POSIX.1'').  The fchownat() system call	follows	The Open Group
     Extended API Set 2	specification.

HISTORY
     The chown() function appeared in Version 7	AT&T UNIX.  The	fchown() sys-
     tem call appeared in 4.2BSD.

     The chown() system	call was changed to follow symbolic links in 4.4BSD.
     The lchown() system call was added	in FreeBSD 3.0 to compensate for the
     loss of functionality.

     The fchownat() system call	appeared in FreeBSD 8.0.

FreeBSD	10.1			April 10, 2008			  FreeBSD 10.1

NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS | HISTORY

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