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A64L(3) Linux Programmer's Manual A64L(3)

NAME

     a64l, l64a - convert between long and base-64

SYNOPSIS

     #include <stdlib.h>

     long a64l(const char *str64);

     char *l64a(long value);

 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

     a64l(), l64a():
         _XOPEN_SOURCE >= 500
             || /* Glibc since 2.19: */ _DEFAULT_SOURCE
             || /* Glibc versions <= 2.19: */ _SVID_SOURCE

DESCRIPTION

     These  functions  provide a conversion between 32-bit long integers and
     little-endian base-64 ASCII strings (of length zero to  six).   If  the
     string  used  as  argument for a64l() has length greater than six, only
     the first six bytes are used.  If the type long has more than 32  bits,
     then  l64a() uses only the low order 32 bits of value, and a64l() sign-
     extends its 32-bit result.

     The 64 digits in the base-64 system are:

            '.'  represents a 0
            '/'  represents a 1
            0-9  represent  2-11
            A-Z  represent 12-37
            a-z  represent 38-63

     So 123 = 59*64^0 + 1*64^1 = "v/".

ATTRIBUTES

     For  an  explanation  of  the  terms  used   in   this   section,   see
     attributes(7).

     +----------+---------------+---------------------+
     |Interface | Attribute     | Value               |
     +----------+---------------+---------------------+
     |l64a()    | Thread safety | MT-Unsafe race:l64a |
     +----------+---------------+---------------------+
     |a64l()    | Thread safety | MT-Safe             |
     +----------+---------------+---------------------+

CONFORMING TO

     POSIX.1-2001, POSIX.1-2008.

NOTES

     The  value returned by l64a() may be a pointer to a static buffer, pos-
     sibly overwritten by later calls.

     The behavior of l64a() is undefined when value is negative.   If  value
     is zero, it returns an empty string.

     These functions are broken in glibc before 2.2.5 (puts most significant
     digit first).

     This is not the encoding used by uuencode(1).