CPSC 1280 Lecture Notes - Lecture 12: Umask, File System Permissions, Chmod

• School: Langara College
• Department: Computer Science
• Course: CPSC 1280
• Professor: Wei Cai

Document Summary

Change permission: file and directory permissions can only be modified by their owners or by the supervisor chmod(change [file or directory] mode, $ chmodoptionsfiles/directory, options can be written in two forms, a sequence of 3 octal digits or symbols. Digit options: 3 digits represents the access permissions for owner, group and others, respectively, the mapping of permission onto their octal. $ chmod600 private. txt set the permissions on private. txt to rw------- only the owner can read and write to the file. Using the symbols to indicate permissions u g o a r w x user group other all read write execute add permission take away permission assign permission. R option: -r option for chmod, recursively modify file permissions, $ chmod-r go+rplay, grant group and other read rights to the directory play and all of the files and directories within play. The user mask: reassigns default file and directory permissions.