.SQL into MySQL

In a shell prompt how do I import a .SQL file into MySQL? I need to restore a test database that has gone bad.

[Jordan]

I've had to do this a lot for the users on my server. Once you have the dump it is always easiest to go through phpMyAdmin if possible but here is the shell command:

mysql -u USER -p DBNAME < dump.sql

That works. How do I get it out in the .SQL file from shell?

[Jordan]

mysqldump -u <username> -p <database_name> > sqlfile.sql