Linux Shell Scripting Cookbook - Third Edition

How it works...

The user_adm.sh script performs several common user management tasks. The usage() text explains how to use the script when the user provides incorrect parameters or includes the -usage parameter. A case statement parses command arguments and executes the appropriate commands.

The valid command options for the user_adm.sh script are: -adduser, -deluser, -shell, -disable, -enable, -expiry, -passwd, -newgroup, -delgroup, -addgroup, -details, and -usage. When the *) case is matched, it means no option was recognized; hence, usage() is invoked.

Run this script as the root. It confirms the user ID (the root's user ID is 0) before the arguments are examined.

When an argument is matched, the [ $# -ne 3 ] && test usage checks the number ...