Summary

In this chapter, we gave you a brief introduction to special file permission flags in Linux. The setuid flag works only on commands and not on scripts, and lets a program execute as the user defined as the file owner instead of the user who is running that program. The setgid flag has two special meanings. The first is for commands and the other for folders. If you set it on a command, it will work like the setuid flag, but will run it as the group ownership of that file instead of the file owner of that file. The second meaning is if you set it on a folder, the group owner of the folder where you set setgid will automatically be assigned to every new file you created within that folder. Within a directory where sticky bit has been set, only the file owner can delete his own files