decrypt function in unix?

Hai Friends

We have a function called char * crypt(const char ps, const char key) to encrypt the password in the unix environment.. Do we have any decrypt function to decrypt it? If not then how can we verify the password through program?

Thanks in Advance
Collins

Not an expert (or even a user) with this but normally there is no decrypt - to check (verify) a password, you take it, encrypt it, and compare the encrypted password with the encrypted password in your 'password/shadow' file.