PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult 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 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 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 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 POSIX.1‐2017, <stdlib.h>

       The Shell and Utilities volume of POSIX.1‐2017, uuencode

COPYRIGHT

       Portions  of  this  text  are  reprinted  and  reproduced in electronic form from IEEE Std
       1003.1-2017, Standard for Information Technology -- Portable  Operating  System  Interface
       (POSIX),  The  Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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.opengroup.org/unix/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .