knu

/*
 *  call-seq:
 *     str.crypt(salt_str)   -> new_str
 *
 *  Applies a one-way cryptographic hash to <i>str</i> by invoking the
 *  standard library function <code>crypt(3)</code> with the given
 *  salt string.  While the format and the results are
 *  system/implementation dependent, using a salt matching the regular
 *  expression <code>\A[a-zA-Z0-9./]{2}</code> should be safe and valid
 *  on any platform, in which only the first two characters are