crypt(3) on unix maximal length

When i have a password comparaison function using crypt(3) i really should remember that the comparaison stop at the 7 bytes, because that stuff is weird for me :

In 1: import crypt
In [2]: seed=‘foo!bar’
In [3]: crypt.crypt(‘abcdefghaa123456681’, seed)
Out[3]: ‘foEoVhbk7ad7A’
In [4]: crypt.crypt(‘abcdefghpax;lalx;al’, seed)
Out[4]: ‘foEoVhbk7ad7A’
In [5]:

any stuff after the 6 char will always get ignored by the hash algorithm.