Crunch can be used to create password lists to any length, pattern or character set you define. This tool is useful for creating password lists for cracking passwords if you know some of the characteristics of the target password.
crunch <min> <max> <charset> <options> -t <pattern>
For the pattern the following symbols are used:
@ = Lowe case characters only
, = Upper case characters only
% = Numbers only
^ = Symbols only
crunch 8 8 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ -t ,@@@@%%^ -o /root/pass.lst