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chown(2) [ultrix man page]

chown(2)							System Calls Manual							  chown(2)

Name
       chown, fchown - change owner and group of a file

Syntax
       #include <sys/types.h>

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

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

Description
       The and system calls change the owner and group of the file named by path or referenced by fd .	Only the superuser can change the owner of
       a file.	Other users can change the group-id of a file that they own to another group to which they belong.

       If you specify -1 in owner or group, the corresponding owner-id or group-id of the file is unchanged.

       The system call clears the set-user-id and set-group-id bits on the file when it returns successfully, unless the call is made by the supe-
       ruser.  Clearing  these	bits when a file's owner is changed protects the file from remaining set-user-id or set-group-id after being modi-
       fied.  If a file, specifically a program, remained set-user-id or set-group-id after being modified, that  file	could  allow  unauthorized
       access to other files or accounts.

       You  should  use the system call with the file locking primitives because preserves any locks you previously obtained with the system call.
       For more information about file locking, see the reference page.

Return Values
       The and calls return zero if the operation is successful; if an error occurs they return -1 and store a more specific  error  code  in  the
       global variable errno.

Environment
   System Five
       Differs from the System V definition in that only the superuser can change the ownership of a file.  In addition, ELOOP is a possible error
       condition.

   POSIX
       When your program is compiled in the POSIX environment, the owner argument is of type uid_t, and the group argument is of type gid_t.

Diagnostics
       The system call fails and the file is unchanged under the following conditions:

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

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

       [ENOENT]       The named file does not exist.

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

       [EPERM]	      The effective user-id is not the superuser.

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

       [EFAULT]       The pathname points outside the process's allocated address space.

       [ELOOP]	      Too many symbolic links are encountered in translating the pathname.

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

       [ESTALE]       The fd argument is invalid because the file referred to by that file handle no longer exists or has been revoked.

       The system call fails 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 superuser.

       [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.

       [ETIMEDOUT]    A connect request or remote file operation fails because the connected party does not properly respond  after  a	period	of
		      time that is dependent on the communications protocol.

See Also
       chmod(2), flock(2)

																	  chown(2)

Check Out this Related Man Page

CHOWN(2)						      BSD System Calls Manual							  CHOWN(2)

NAME
chown, fchown, lchown -- change owner and group of a file SYNOPSIS
#include <unistd.h> int chown(const char *path, uid_t owner, gid_t group); int fchown(int fildes, uid_t owner, gid_t group); int lchown(const char *path, uid_t owner, gid_t group); DESCRIPTION
The owner ID and group ID of the file named by path or referenced by fildes 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 symbolic links. 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() system calls will fail if: [EACCES] Search permission is denied for a component of the path prefix. [EFAULT] The path argument points outside the process's allocated address space. [ELOOP] Too many symbolic links are encountered in translating the pathname. This is taken to be indicative of a looping symbolic link. [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an entire path name exceeded 1023 characters. [ENOENT] A component of path does not exist. [ENOTDIR] A component of the path prefix is not a directory. The fchown() system call will fail if: [EBADF] The fildes argument does not refer to a valid descriptor. [EINVAL] The fildes argument refers to a socket, not a file. Any of these calls will fail if: [EINTR] Its execution is interrupted by a signal. [EIO] An I/O error occurs while reading from or writing to the file system. [EPERM] The effective user ID does not match the owner of the file and the calling process does not have appropriate (i.e., root) privileges. [EROFS] The named file resides on a read-only file system. SEE ALSO
chgrp(1), chmod(2), flock(2), chown(8) STANDARDS
The chown() system call is expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1''). HISTORY
The chown() function appeared in Version 7 AT&T UNIX. The fchown() system call appeared in 4.2BSD. The chown() and fchown() system calls were 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. BSD
April 19, 1994 BSD
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