a64l(3) Library Functions Manual a64l(3)
NAME
a64l, l64a - convert between long and base-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 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 │
└────────────────────────────────┴───────────────┴─────────────────────┘
STANDARDS
POSIX.1-2008.
HISTORY
POSIX.1-2001.
NOTES
The value returned by l64a() may be a pointer to a static buffer, possi-
bly 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)
Linux man-pages 6.9.1 2024-05-02 a64l(3)
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