CHOWN(2) BSD System Calls Manual CHOWN(2)NAME
chown, fchown — change owner and group of a file or link
SYNOPSIS
#include <sys/types.h>
#include <unistd.h>
int
chown(const char *path, uid_t owner, gid_t group);
int
fchown(int fd, uid_t owner, gid_t group);
DESCRIPTION
The owner ID and group ID of the file (or link) named by path or refer‐
enced 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.
Chown() clears the set-user-id and set-group-id bits on the file to pre‐
vent accidental or mischievous creation of set-user-id and set-group-id
programs.
Fchown() is particularly useful when used in conjunction with the file
locking primitives (see flock(2)).
One of the owner or group id's may be left unchanged by specifying it as
-1.
RETURN VALUES
Zero is returned if the operation was successful; -1 is returned if an
error occurs, with a more specific error code being placed in the global
variable errno.
ERRORSChown() will fail and the file or link will be unchanged if:
[ENOTDIR] A component of the path prefix is not a directory.
[ENAMETOOLONG] A component of a pathname exceeded {NAME_MAX} charac‐
ters, or an entire path name exceeded {PATH_MAX} char‐
acters.
[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 effective user ID is not the super-user.
[EROFS] The named file resides on a read-only file system.
[EFAULT] Path points outside the process's allocated address
space.
[EIO] An I/O error occurred while reading from or writing to
the file system.
Fchown() will fail if:
[EBADF] fd does not refer to a valid descriptor.
[EINVAL] fd 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.
SEE ALSOchown(8), chgrp(1), chmod(2), flock(2)STANDARDS
The chown() function is expected to conform to IEEE Std 1003.1-1988
(“POSIX.1”).
HISTORY
The fchown() function call appeared in 4.2BSD.
The chown() and fchown() functions were changed to follow symbolic links
in 4.4BSD.
BSD January 25, 1997 BSD