## File Permissions --- ## Linux File Permissions All files have permissions for different types of classifications The classifications are Owners, Groups, and Others ___ ### Available Permissions Read, Write, Execute, None Read: User, Group, and Other can Read the file Write: User, Group, and Other can Write to the file Execute: User, Group, and Other can execute the file None: None of the above permissions ___ ## Possible Permission Combinations Read only Write Only Execute only Read and Write Read and Execute Write and Execute Read, Write, and Execute None ___ ### View Permissions You can use the -l option with the ls command for a long listing format of files within a given directory You can expand even further and provide the -a option in addition to -l for all files (including hidden) --- ## Changing File Permissions The chmod command allows you to change file permissions for a file or directory chmod [OPTION] [file-name] Read is represented by the numeric value 4 Write is represented by the numeric value 2 Execute is represented by the numeric value 1 None is represented by the numberic value 0 ___ ### chmod Command Example chmod 444 example-file-name The above command would provide the Owner, Group, and all Other users with access to the "example-file-name" file with Read only permissions ___ ### Providing Multiple Permissions You are able to use the numeric values in addition to one another to provide multiple permissions for any given Owner, Group, and Other users Read + Execute = 5 Read + Write = 6 Read + Write + Execute = 7 --- ## Changing File Ownership The chown command allows you to change file ownership for a file or directory chown [OPTION] [OWNER][:[GROUP]] [file-name] ___ ### Change User Ownership chown new-user example-file The above command would change the ownership of the example-file from its current owner to "new-user" ___ ### Change Group Ownership chown :new-group example-file The above command would change the ownership of the example-file from its current group to "new-group" ___ ### Change User and Group Ownership chown new-user:new-group example-file The above command would change the ownership of the example-file from its current owner to "new-user" and group to "new-group"