Manual Pages  — CHOWN

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

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES ERRORS SEE ALSO STANDARDS HISTORY

Standard C Library (libc, -lc)

#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);

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.

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 translating 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 information.
[EROFS]
	The named file resides on a read-only file system.
[EFAULT]
	The path argument points outside the process's allocated address space.
[EIO]	An I/O error occurred while reading from or writing to the file system.
[EINTEGRITY]
	Corrupted data was detected while reading from 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.
[EINTEGRITY]
	Corrupted data was detected while reading from 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.
[ENOTCAPABLE]
	path is an absolute path, or contained a ".." component leading to a directory outside of the directory hierarchy specified by fd, and the process is in capability mode or the AT_RESOLVE_BENEATH flag was specified.

The chown() system call is expected to conform to IEEE Std 1003.1-90 ("POSIX.1"). The fchownat() system call follows The Open Group Extended API Set 2 specification.

The chown() function appeared in AT&T v1 . The fchown() system call appeared in BSD 4.2 .

The chown() system call was changed to follow symbolic links in BSD 4.4 . 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 .