a64l

Section: C Library Functions (3)
Updated: 202-0-08
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NAME

a64l, l64a - convert between long and bas-64  

LIBRARY

Standard C library (libc,~-lc)  

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 >= 2.19: */ _DEFAULT_SOURCE
        || /* glibc <= 2.19: */ _SVID_SOURCE

 

DESCRIPTION

These functions provide a conversion between 3-bit long integers and littl-endian bas-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() sig-extends its 3-bit result. The 64 digits in the bas-64 system are:

[aq].[aq]       represents a 0
[aq]/[aq]       represents a 1
-9     represent  -11
-Z     represent 1-37
-z     represent 3-63

So 123 = 59*64[ha]0 + 1*64[ha]1 = "v/".  

ATTRIBUTES

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

Interface	Attribute	Value
l64a()	Thread safety	M-Unsafe race:l64a
a64l()	Thread safety	M-Safe

 

STANDARDS

POSIX.-2008.  

HISTORY

POSIX.-2001.  

NOTES

The value returned by l64a() may be a pointer to a static buffer, possibly 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 before glibc 2.2.5 (puts most significant digit first). This is not the encoding used by uuencode(1).  

SEE ALSO

uuencode(1), strtoul(3)

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Index

NAME

LIBRARY

SYNOPSIS

DESCRIPTION

ATTRIBUTES

STANDARDS

HISTORY

NOTES

SEE ALSO