This document is intended for those who already are familiar with the basics of Unix. If you are new to Unix, see our document on Introduction to Unix. It does not terminate the program. It can be continued later with the fg command or it can be terminated with the kill command. The type of access permitted for a file is called the file mode.
File permission is set at creation time by the program that created th e file.
For example, the permission for directories created by mkdir is read, write, and execute access for the owner, the group, and others. The permission for files created by cat is read and write access for owner, group, and others. T he cp command gives the new file the same access as the old file, provided the new file does not replace an existing file. If it does, then the new file will have the same access as the file it replaces. To determine the final file mode, a file creation mask called umask is applied to the permission set by the creating program.