A64L(3) BSD Programmer's Manual A64L(3)
a64l, l64a - convert between 32-bit integer and radix-64 ASCII string
#include <stdlib.h>
long
a64l(const char *s);
char *
l64a(long l);
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 NUL-terminated radix-64
representation 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, decoding
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
corresponding radix-64 representation.
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 glo-
bal variable errno to EINVAL.
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.
The a64l() and l64a() functions conform to X/Open Portability Guide Issue
4, Version 2 ("XPG4.2").
MirBSD #10-current August 17, 1997 1