long
     a64l(const char *s);

     char *
     l64a(long l);

DESCRIPTION

     The a64l() and l64a() functions are used to maintain numbers stored in
     radix-64 ASCII characters.  This is a notation by which 32-bit integers
     can be represented by up to six characters; each character represents a
     ``digit'' in a radix-64 notation.

     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 radix-64 repre-
     sentation and returns a corresponding 32-bit value.  If the string
     pointed to by s contains more than six characters, a64l() will use the
     first six.  a64l() scans the character string from left to right, decod-
     ing each character as a 6-bit radix-64 number.  If a long integer is
     larger than 32 bits, the return value will be sign-extended.

     l64a() takes a long integer argument l and returns a pointer to the cor-
     responding radix-64 representation.

RETURN VALUES

     On success, a64l() returns a 32-bit representation of s.  If s is a null
     pointer or if it contains digits other than those described above.
     a64l() returns -1 and sets the global variable errno to EINVAL.

     On success, l64a() returns a pointer to a string containing the radix-64
     representation of l.  If l is 0, l64a() returns a pointer to the empty
     string.  If l is negative, l64a() returns a null pointer and sets the
     global variable errno to EINVAL.

WARNINGS

     The value returned by l64a() is a pointer into a static buffer, the con-
     tents of which will be overwritten by subsequent calls.

     The value returned by a64l() may be incorrect if the value is too large;
     for that reason, only strings that resulted from a call to l64a() should
     be used to call a64l().

     If a long integer is larger than 32 bits, only the low-order 32 bits are
     used.

STANDARDS

     The a64l() and l64a() functions conform to X/Open Portability Guide
     Issue 4, Version 2 (``XPG4.2'').