Clearing an array of characters

[parksie]

char buf[90];
memset(buf, 0, 90);

[Yonatan]

Remember that if you want to just make a string empty, you don't have to zero out all the characters, but only the first.
This will make the string pretend it's empty - even strlen will return zero.
(The string won't really be empty, but most string functions usually think that the string ends at the first zero character)

buf[0] = 0;