long a64l (s) char*s;
char *l64a (l) long l;
The characters used to represent ``digits'' are ``.'' for 0, ``/'' for 1, ``0'' through ``9'' for 2-11, ``A'' through ``Z'' for 12-37, and ``a'' through ``z'' for 38-63.
The a64l function takes a pointer to a null-terminated base-64 representation and returns a corresponding long value. If the string pointed to by s contains more than six characters, a64l will use the first six.
The a64l function scans the character string from left to right, decoding each character as a 6-bit Radix 64 number.
The l64a function takes a long argument and returns a pointer to the corresponding base-64 representation. If the argument is 0, l64a returns a pointer to a null string.