A64L(3P)                                            POSIX Programmer's Manual                                           A64L(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       a64l, l64a - convert between a 32-bit integer and a radix-64 ASCII string

SYNOPSIS
       #include <stdlib.h>

       long a64l(const char *s);
       char *l64a(long value);


DESCRIPTION
       These functions 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 shall be used for these operations.

       The  characters  used to represent digits are '.' (dot) 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 shall take a pointer to a radix-64 representation, in which the first digit is the least significant,
       and  return  the  corresponding long value. If the string pointed to by s contains more than six characters, a64l() shall
       use the first six. If the first six characters of the string contain a null terminator, a64l() shall use only  characters
       preceding the null terminator. The a64l() function shall scan the character string from left to right with the least sig-
       nificant 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 shall take a long argument and return a pointer to the corresponding  radix-64  representation.   The
       behavior of l64a() is unspecified if value is negative.

       The value returned by l64a() may be a pointer into a static buffer. Subsequent calls to l64a() may overwrite the buffer.

       The  l64a() function need not be reentrant. A function that is not required to be reentrant is not required to be thread-
       safe.

RETURN VALUE
       Upon successful completion, a64l() shall return the long value resulting from conversion of the input string. If a string
       pointed to by s is an empty string, a64l() shall return 0L.

       The l64a() function shall return a pointer to the radix-64 representation.  If value is 0L, l64a() shall return a pointer
       to an empty string.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       If the type long contains more than 32 bits, the result of a64l(l64a(x)) is x in the low-order 32 bits.

RATIONALE
       This is not the same encoding as used by either encoding variant of the uuencode utility.

FUTURE DIRECTIONS
       None.

SEE ALSO
       strtoul(), the  Base  Definitions  volume  of  IEEE Std 1003.1-2001,  <stdlib.h>,  the  Shell  and  Utilities  volume  of
       IEEE Std 1003.1-2001, uuencode

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                      A64L(3P)