Change the access mode (permissions) of one or more files. Only the owner of a file or a privileged user may change the mode. mode can be numeric or an expression in the form of who opcode permission. who is optional (if omitted, default is a); choose only one opcode. Multiple modes are separated by commas.
Print information about files that are changed.
Do not notify user of files that chmod cannot change.
Print help message and then exit.
Traverse subdirectories recursively, applying changes.
Change permissions to match those associated with filename.
Print information about each file, whether changed or not.
Print version information and then exit.
Assign permission (and remove permission of the unspecified fields).
Set user (or group) ID.
Sticky bit; used on directories to prevent removal of files by non-owners.
User’s present permission.
Group’s present permission.
Other’s present permission.
Alternatively, specify permissions by a three-digit octal number. The first digit designates owner permission; the second, group permission; and the third, other’s permission. Permissions are calculated by adding the following octal values: