1A64L(3P) POSIX Programmer's Manual A64L(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 a64l, l64a — convert between a 32-bit integer and a radix-64 ASCII
13 string
14
16 #include <stdlib.h>
17 long a64l(const char *s);
19 char *l64a(long value);
20
22 These functions maintain numbers stored in radix-64 ASCII characters.
23 This is a notation by which 32-bit integers can be represented by up to
24 six characters; each character represents a digit in radix-64 notation.
25 If the type long contains more than 32 bits, only the low-order 32 bits
26 shall be used for these operations.
27 The characters used to represent digits are '.' (dot) for 0, '/' for
29 1, '0' through '9' for [2,11], 'A' through 'Z' for [12,37], and 'a'
30 through 'z' for [38,63].
31 The a64l() function shall take a pointer to a radix-64 representation,
33 in which the first digit is the least significant, and return the cor‐
34 responding long value. If the string pointed to by s contains more than
35 six characters, a64l() shall use the first six. If the first six char‐
36 acters of the string contain a null terminator, a64l() shall use only
37 characters preceding the null terminator. The a64l() function shall
38 scan the character string from left to right with the least significant
39 digit on the left, decoding each character as a 6-bit radix-64 number.
40 If the type long contains more than 32 bits, the resulting value is
41 sign-extended. The behavior of a64l() is unspecified if s is a null
42 pointer or the string pointed to by s was not generated by a previous
43 call to l64a().
44 The l64a() function shall take a long argument and return a pointer to
46 the corresponding radix-64 representation. The behavior of l64a() is
47 unspecified if value is negative.
48 The value returned by l64a() may be a pointer into a static buffer.
50 Subsequent calls to l64a() may overwrite the buffer.
51 The l64a() function need not be thread-safe.
53
55 Upon successful completion, a64l() shall return the long value result‐
56 ing from conversion of the input string. If a string pointed to by s is
57 an empty string, a64l() shall return 0L.
58 The l64a() function shall return a pointer to the radix-64 representa‐
60 tion. If value is 0L, l64a() shall return a pointer to an empty string.
61
63 No errors are defined.
64 The following sections are informative.
66
68 None.
69
71 If the type long contains more than 32 bits, the result of
72 a64l(l64a(x)) is x in the low-order 32 bits.
73
75 This is not the same encoding as used by either encoding variant of the
76 uuencode utility.
77
79 None.
80
82 strtoul()
83 The Base Definitions volume of POSIX.1‐2017, <stdlib.h>
85 The Shell and Utilities volume of POSIX.1‐2017, uuencode
87
89 Portions of this text are reprinted and reproduced in electronic form
90 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
91 table Operating System Interface (POSIX), The Open Group Base Specifi‐
92 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
93 Electrical and Electronics Engineers, Inc and The Open Group. In the
94 event of any discrepancy between this version and the original IEEE and
95 The Open Group Standard, the original IEEE and The Open Group Standard
96 is the referee document. The original Standard can be obtained online
97 at http://www.opengroup.org/unix/online.html .
98 Any typographical or formatting errors that appear in this page are
100 most likely to have been introduced during the conversion of the source
101 files to man page format. To report such errors, see https://www.ker‐
102 nel.org/doc/man-pages/reporting_bugs.html .
103IEEE/The Open Group 2017 A64L(3P)