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 (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 cor‐
responding long value. If the string pointed to by s contains more than
six characters, a64l() shall use the first six. If the first six char‐
acters 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 result‐
ing 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 representa‐
tion. 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 ALSOstrtoul()
The Base Definitions volume of POSIX.1‐2008, <stdlib.h>
The Shell and Utilities volume of POSIX.1‐2008, uuencode
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/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.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 A64L(3P)
