Limiting the number of charachters in a string/variable

[DoD]

Which fucntion will "cut" a string/variable down into size?

Such as i have 123456789

And i want the first 6 charachters so i get 123456?

Ive tried looking all over php.net but havent found it 🙁

[Xoid]

<?php
print substr("123456789",0,6);

?>