26.5. Editing File Permissions

Each file or directory on a UNIX filesystem is owned by a single user and group and have a set of permissions that determines who can access it. Normally these are changed by the chown and chmod commands, but you can edit them in the file manager as well. To do this, select a single file from the right-hand pane and click the Info button on the toolbar. This will bring up the permissions window shown in Figure 26.2.

The File section of the window displays its full path, size, type, and last modification date. The Permissions section contains checkboxes that control which users can read, write, and execute the file. These are the same permissions that you can change at the command line with the chmod command. As they are selected and deselected, the octal permissions that would normally be used with chmod are shown in the Octal field below.

To change the file's owners, enter new user and group names or IDs into the User and Group fields in the Ownership section of the window. For executables, you can also control which user the program runs as using the Execute as user and Execute as group fields. Because these options correspond to chmod permissions, changing them will update the Octal field as well.

When editing a directory, the checkboxes available are slightly different. The execute permission is replaced with list, an Only owners can edit files box is added, and the Execute as checkboxes are replaced with Files inherit group. These all correspond to standard UNIX file permissions that any system administrator should already be familiar with.

If changing the permissions and ownership of a directory, you can also choose to change those of any subdirectories and files that it contains. The Apply changes to menu determines to which files and directories the permissions are applied, and has three options:

This directory only The ownership and permissions chosen will be set on the selected directory only.

This directory and its files The ownership and permissions will be set on the chosen directory and all files that it contains. Subdirectories and their files will not be effected.

This directory and all subdirectories Ownership and permissions will be set on the chosen directory and all files and subdirectories that it contains.

If the file that was selected when the Info button was clicked is actually a symbolic link, the window will contain an additional Link to field that can be changed if you want to edit the link destination. Changing the permission and ownership fields is pointless, as they cannot be edited for symbolic links on UNIX systems.