How to login into mysql as a different user rather than root without entering password and username?

[Pratap Singh]

I want to know how to login into mysql without giving user name and password.
if i login into mysql it will be like this

[user@localhost ~]mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 48
Server version: 5.0.45 Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql>