a64l(3) - f38

1a64l(3)                    Library Functions Manual                    a64l(3)
2
3
4
5
6

NAME

8       a64l, l64a - convert between long and base-64
9

LIBRARY

11       Standard C library (libc, -lc)
12

SYNOPSIS

14       #include <stdlib.h>
15
16       long a64l(const char *str64);
17       char *l64a(long value);
18
19   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
20
21       a64l(), l64a():
22           _XOPEN_SOURCE >= 500
23               || /* glibc >= 2.19: */ _DEFAULT_SOURCE
24               || /* glibc <= 2.19: */ _SVID_SOURCE
25

DESCRIPTION

27       These  functions  provide a conversion between 32-bit long integers and
28       little-endian base-64 ASCII strings (of length zero to  six).   If  the
29       string  used  as  argument for a64l() has length greater than six, only
30       the first six bytes are used.  If the type long has more than 32  bits,
31       then  l64a() uses only the low order 32 bits of value, and a64l() sign-
32       extends its 32-bit result.
33
34       The 64 digits in the base-64 system are:
35
36              '.'  represents a 0
37              '/'  represents a 1
38              0-9  represent  2-11
39              A-Z  represent 12-37
40              a-z  represent 38-63
41
42       So 123 = 59*64^0 + 1*64^1 = "v/".
43

ATTRIBUTES

45       For an  explanation  of  the  terms  used  in  this  section,  see  at‐
46       tributes(7).
47
48       ┌────────────────────────────────┬───────────────┬─────────────────────┐
49       │Interface                       │ Attribute     │ Value               │
50       ├────────────────────────────────┼───────────────┼─────────────────────┤
51       │l64a()                          │ Thread safety │ MT-Unsafe race:l64a │
52       ├────────────────────────────────┼───────────────┼─────────────────────┤
53       │a64l()                          │ Thread safety │ MT-Safe             │
54       └────────────────────────────────┴───────────────┴─────────────────────┘
55

STANDARDS

57       POSIX.1-2008.
58

HISTORY

60       POSIX.1-2001.
61

NOTES

63       The  value returned by l64a() may be a pointer to a static buffer, pos‐
64       sibly overwritten by later calls.
65
66       The behavior of l64a() is undefined when value is negative.   If  value
67       is zero, it returns an empty string.
68
69       These  functions  are  broken before glibc 2.2.5 (puts most significant
70       digit first).
71
72       This is not the encoding used by uuencode(1).
73