chmod(1)						      General Commands Manual							  chmod(1)

NAME

       chmod - change file mode access permissions

SYNOPSIS

       symbolic_mode_list file ...

   Obsolescent form
       numeric_mode file ...

DESCRIPTION

       The command changes the permissions of one or more files according to the value of symbolic_mode_list or numeric_mode.  You can display the
       current permissions for a file with the command (see ls(1)).

       Only the owner of a file, or a user with appropriate privileges, can change its mode.

       Only a user having appropriate privileges can set (or retain, if previously set) the sticky bit of a regular file.

       If the sticky bit is set on a directory, files inside the directory may be renamed or removed only by the owner of the file, the  owner	of
       the directory, or the superuser (even if the modes of the directory would otherwise allow such an operation).

       In order to set the set-group-ID bit, the group of the file must correspond to your current group ID.

       If is used on a symbolic link, the mode of the file referred to by the link is changed.

   Options
       The command recognizes the following options:

	      Preserve any optional access control list (ACL) entries
		     associated  with  the  file  (HFS	file  systems only).  By default, in conformance with the IEEE Standard POSIX 1003.1-1988,
		     optional HFS ACL entries are deleted.  For JFS ACLs, this option has no effect, because optional JFS ACL entries  are  always
		     preserved.  For information about access control lists, see acl(5) and aclv(5).

	      Recursively change the file mode bits.
		     For  each file operand that names a directory, alters the file mode bits of the named directory and all files and subdirecto-
		     ries in the file hierarchy below it.

   Operands
       The command recognizes the following operands:

	      file   Targe file for which the permissions are changes.

	      numeric-mode
		     Numeric value used to determine permission on a specified file.  See the section for more information.

	      symbolic-mode-list
		     List of operations used to determine permissions on a specified file.  See the section for more information.

   Symbolic Mode List
       A symbolic_mode_list is a comma-separated list of operations in the following form.  Whitespace is not permitted.

	      [who]op[permission

       The variable fields can have the following values:

	      who	  One or more of the following letters:

			       Modify permissions for user (owner).
			       Modify permissions for group.
			       Modify permissions for others.
			       Modify permissions for all users
				      is equivalent to

	      op	  Required; one of the following symbols:

			       Add    permission to the existing file mode bits of who.
			       Delete permission from the existing file mode bits of who.
			       Replace the existing mode bits of
				      who with permission.

	      permission  One or more of the following letters:

			       Add or delete the read permission for
				      who.
			       Add or delete the write permission for
				      who.
			       Add or delete the execute file (search directory) permission for
				      who.
			       Add or delete the set-owner-ID-on-file-execution
				      or set-group-ID-on-file-execution permission for who.  Useful only if or is expressed or implied in who.
			       Add or delete the sticky bit permission.
				      Useful only if is expressed or implied in who.  See chmod(2).
			       Conditionally add or delete the execute/search permission as follows:
				      o  If file is a directory, add or delete the search permission to the existing file mode for who.  (Same as
				      o  If file is not a directory, and the current file permissions include the execute permission  displays	an
					 or an for at least one of user, group, or other, then add or delete the execute file permission for who.
				      o  If  file  is  not  a  directory, and no execute permissions are set in the current file mode, then do not
					 change any execute permission.

			  Or one only of the following letters:

			       Copy the current user permissions to
				      who.
			       Copy the current group permissions to
				      who.
			       Copy the current other permissions to
				      who.

       The operations are performed in the order specified, and can override preceding operations specified in the same command line.

       If who is omitted, the and permissions are changed for all users if the changes are permitted by the current file mode creation	mask  (see
       umask(1)).  The and permissions are changed as if was specified in who.

       Omitting permission is useful only when used with to delete all permissions.

   Numeric Mode (Obsolescent)
       Absolute  permissions  can be set by specifying a numeric_mode, an octal number constructed from the logical OR (sum) of the following mode
       bits:

       Miscellaneous mode bits:

       Permission mode bits:

EXTERNAL INFLUENCES

   Environment Variables
       determines the language in which messages are displayed.

       If is not specified or is null, it defaults to the value of If is not specified or is null, it defaults to (see lang(5)).

       If any internationalization variable contains an invalid setting, all internationalization variables default to See environ(5).

   International Code Set Support
       Single- and multibyte character code sets are supported.

RETURN VALUE

       Upon completion, returns one of the following values:

	      Successful completion.
	      An error condition occurred.

EXAMPLES

       Deny write permission to others:

       Make a file executable by everybody:

       Assign read and execute permission to everybody, and set the set-user-ID bit:

       Assign read and write permission to the file owner, and read permission to everybody else:

       or the obsolescent form:

       Traverse a directory subtree making all regular files readable by user and group only,  and  all  executables  and  directories	executable
       (searchable) by everyone:

       If the current value of is displays do not change write permission for group) and the current permissions for file are displayed by as then
       the command

       sets the permissions to displayed by as

       If the current value of is displays do not change write permission for group) and the current permissions for file are displayed by as then
       the command

       sets the permissions to displayed by as

DEPENDENCIES

       The option causes to fail on file systems that do not support ACLs.

AUTHOR

       was developed by AT&T and HP.

SEE ALSO

       chacl(1), ls(1), umask(1), chmod(2), acl(5), aclv(5).

STANDARDS CONFORMANCE

																	  chmod(1)