chmod(1)							   User Commands							  chmod(1)

NAME

       chmod - change the permissions mode of a file

SYNOPSIS

       chmod [-fR] absolute-mode file...

       chmod [-fR] symbolic-mode-list file...

DESCRIPTION

       The chmod utility changes or assigns the mode of a file. The mode of a file specifies its permissions and other attributes. The mode may be
       absolute or symbolic.

   Absolute mode
       An absolute mode specification has the following format:

	      chmod [options] absolute-mode file . . .

       where absolute-mode is specified using octal numbers nnnn defined as follows:

       n	a number from 0 to 7. An absolute mode is constructed from the OR of any of the following modes:

		4000	 Set user ID on execution.

		20#0	 Set group ID on execution if # is 7, 5, 3, or 1.

			 Enable mandatory locking if # is 6, 4, 2, or 0.

			 For directories, files are created with BSD semantics for propagation of the group ID. With this option, files and subdi-
			 rectories  created in the directory inherit the group ID of the directory, rather than of the current process. For direc-
			 tories, the set-gid bit may only be set or cleared by using symbolic mode.

		1000	 Turn on sticky bit. See chmod(2).

		0400	 Allow read by owner.

		0200	 Allow write by owner.

		0100	 Allow execute (search in directory) by owner.

		0700	 Allow read, write, and execute (search) by owner.

		0040	 Allow read by group.

		0020	 Allow write by group.

		0010	 Allow execute (search in directory) by group.

		0070	 Allow read, write, and execute (search) by group.

		0004	 Allow read by others.

		0002	 Allow write by others.

		0001	 Allow execute (search in directory) by others.

		0007	 Allow read, write, and execute (search) by others.

       For directories, the setgid bit cannot be set (or cleared) in absolute mode; it must be set (or cleared) in symbolic mode using g+s (or	g-
       s).

   Symbolic mode
       A symbolic mode specification has the following format:

	      chmod [options] symbolic-mode-list file . . .

       where symbolic-mode-list is a comma-separated list (with no intervening whitespace) of symbolic mode expressions of the form:

	      [who] operator [permissions]

       Operations are performed in the order given. Multiple permissions letters following a single operator cause the corresponding operations to
       be performed simultaneously.

       who	       zero or more of the characters u, g, o, and a specifying whose permissions are to be changed or assigned:

		       u	user's permissions

		       g	group's permissions

		       o	others' permissions

		       a	all permissions (user, group, and other)

		       If who is omitted, it defaults to a, but the setting of the file mode creation mask (see umask in sh(1) or csh(1) for  more
		       information) is taken into account.  When who is omitted, chmod will not override the restrictions of your user mask.

       operator        either +, -, or =, signifying how permissions are to be changed:

		       +	Add permissions.

				If permissions is omitted, nothing is added.

				If who is omitted, add the file mode bits represented by permissions, except for the those with corresponding bits
				in the file mode creation mask.

				If who is present, add the file mode bits represented by the permissions.

		       -	Take away permissions.

				If permissions is omitted, do nothing.

				If who is omitted, clear the file mode bits represented by permissions, except for those with  corresponding  bits
				in the file mode creation mask.

				If who is present, clear the file mode bits represented by permissions.

		       =	Assign permissions absolutely.

				If who is omitted, clear all file mode bits; if who is present, clear the file mode bits represented by who.

				If permissions is omitted, do nothing else.

				If who is omitted, add the file mode bits represented by permissions, except for the those with corresponding bits
				in the file mode creation mask.

				If who is present, add the file mode bits represented by permissions.

		       Unlike other symbolic operations, = has an absolute effect in that it resets all other bits represented	by  who.  Omitting
		       permissions is useful only with = to take away all permissions.

       permission      any compatible combination of the following letters:

		       l	mandatory locking

		       r	read permission

		       s	user or group set-ID

		       t	sticky bit

		       w	write permission

		       x	execute permission

		       X	execute permission if the file is a directory or if there is execute permission for one of the other user classes

		       u,g,o	indicate that permission is to be taken from the current user, group or other mode respectively.

		       Permissions  to	a  file  may vary depending on your user identification number (UID) or group identification number (GID).
		       Permissions are described in three sequences each having three characters:

		       User		    Group		  Other
		       rwx		    rwx 		  rwx

		       This example (user, group, and others all have permission to read, write, and execute a given file) demonstrates two  cate-
		       gories for granting permissions: the access class and the permissions themselves.

		       The letter s is only meaningful with u or g, and t only works with u.

		       Mandatory  file and record locking (l) refers to a file's ability to have its reading or writing permissions locked while a
		       program is accessing that file.

		       In a directory which has the set-group-ID bit set (reflected as either -----s--- or -----l--- in the output of  'ls  -ld'),
		       files and subdirectories are created with the group-ID of the parent directory--not that of current process.

		       It  is not possible to permit group execution and enable a file to be locked on execution at the same time. In addition, it
		       is not possible to turn on the set-group-ID bit and enable a file to be locked on execution at the same time. The following
		       examples, therefore, are invalid and elicit error messages:

		       chmod g+x,+l file
		       chmod g+s,+l file

		       Only  the  owner of a file or directory (or the super-user) may change that file's or directory's mode. Only the super-user
		       may set the sticky bit on a non-directory file. If you are not super-user, chmod will mask  the	sticky-bit  but  will  not
		       return  an  error. In order to turn on a file's set-group-ID bit, your own group ID must correspond to the file's and group
		       execution must be set.

OPTIONS

       The following options are supported:

       -f	Force. chmod will not complain if it fails to change the mode of a file.

       -R	Recursively descends through directory arguments, setting the mode for each file as  described	above.	When  symbolic	links  are
		encountered, the mode of the target file is changed, but no recursion takes place.

OPERANDS

       The following operands are supported:

       absolute-mode   Represents  the	change	to be made to the file mode bits of each file named by one of the file operands. See Absolute Mode
       symbolic-mode-liand Symbolic Mode above in the DESCRIPTION section for more information.

       file	       A path name of a file whose file mode bits are to be modified.

USAGE

       See largefile(5) for the description of the behavior of chmod when encountering files greater than or equal to 2 Gbyte ( 2**31 bytes).

EXAMPLES

       Example 1: Denying execute permission to everyone

       example% chmod a-x file

       Example 2: Allowing only read permission to everyone

       example% chmod 444 file

       Example 3: Making a file readable and writable by the group and others

       example% chmod go+rw file
       example% chmod 066 file

       Example 4: Causing a file to be locked during access

       example% chmod +l file

       Example 5: Allowing everyone to read, write, and execute the file and turn on the set group-ID

       example% chmod a=rwx,g+s file
       example% chmod 2777 file

ENVIRONMENT VARIABLES

       See environ(5) for descriptions of the following environment variables that affect the execution of chmod: LANG, LC_ALL, LC_CTYPE,  LC_MES-
       SAGES, and NLSPATH.

EXIT STATUS

       The following exit values are returned:

       0	Successful completion.

       >0	An error occurred.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+
       |CSI			     |enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       getfacl(1), ls(1), setfacl(1), chmod(2), attributes(5), environ(5), largefile(5), standards(5)

NOTES

       Absolute changes do not work for the set-group-ID bit of a directory. You must use g+s or g-s.

       chmod  permits  you  to produce useless modes so long as they are not illegal (for instance, making a text file executable). chmod does not
       check the file type to see if mandatory locking is meaningful.

       If the filesystem is mounted with the nosuid option, setuid execution is not allowed.

       If you use chmod to change the file group owner permissions on a file with ACL entries, both the file group owner permissions and  the  ACL
       mask  are  changed  to  the new permissions. Be aware that the new ACL mask permissions may change the effective permissions for additional
       users and groups who have ACL entries on the file. Use the getfacl(1) command to make sure the appropriate permissions are set for all  ACL
       entries.

SunOS 5.10							    4 Dec 2000								  chmod(1)