a64l(3)

NAME

a64l, l64a, l64a_r - convert between a long integer and a

base-64 ASCII
string

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <stdlib.h>
long
a64l(const char *s);
char *
l64a(long int l);
int
l64a_r(long int l, char *buffer, int buflen);

DESCRIPTION

These 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
radix-64 notation. If the type long contains more than 32

bits, only the
low-order 32 bits are used for these operations.

The characters used to represent ``digits'' are `.' for 0,

`/' for 1, `0'
- `9' for 2 - 11, `A' - `Z' for 12 - 37, and `a' - `z' for

38 - 63.

The a64l() function takes a pointer to a radix-64 represen

tation, in
which the first digit is the least significant, and returns

a corresponding long value. If the string pointed to by s contains more

than six
characters, a64l() uses the first six. If the first six

characters of
the string contain a null terminator, a64l() uses only char

acters preceding the null terminator. The a64l() function scans the

character string
from left to right with the least significant digit on the

left, decoding
each character as a 6-bit radix-64 number. If the type long

contains
more than 32 bits, the resulting value is sign-extended.

The behavior of
a64l() is unspecified if s is a null pointer or the string

pointed to by
s was not generated by a previous call to l64a().

The l64a() function takes a long argument and returns a

pointer to the
corresponding radix-64 representation. The behavior of

l64a() is unspecified if value is negative.

The value returned by l64a() is a pointer into a static

buffer. Subsequent calls to l64a() may overwrite the buffer.

The l64a_r() function performs a conversion identical to

that of l64a()
and stores the resulting representation in the memory area

pointed to by
buffer, consuming at most buflen characters including the

terminating NUL
character.

RETURN VALUES

On successful completion, a64l() returns the long value re

sulting from
conversion of the input string. If a string pointed to by s

is an empty
string, a64l() returns 0.

The l64a function returns a pointer to the radix-64 repre

sentation. If
value is 0, l64a() returns a pointer to an empty string.

SEE ALSO

stroul(3)

HISTORY

The a64l(), l64a(), and l64a_r() functions are derived from

NetBSD with
modifications. They were added to FreeBSD 6.1.

AUTHORS

The a64l(), l64a(), and l64a_r() were added to FreeBSD by

Tom Rhodes
<trhodes@FreeBSD.org>. Almost all of this manual page came

from the
POSIX standard.

BSD November 20, 2005

BSD