man3/a64l.3

   1 \t
   2 .\" Copyright 2002 walter harms (walter.harms@informatik.uni-oldenburg.de)
   3 .\"
   4 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   5 .\" Distributed under GPL
   6 .\" %%%LICENSE_END
   7 .\"
   8 .\" Corrected, aeb, 2002-05-30
   9 .\"
  10 .TH A64L 3 2015-08-08 "" "Linux Programmer's Manual"
  11 .SH NAME
  12 a64l, l64a \- convert between long and base-64
  13 .SH SYNOPSIS
  14 .B #include <stdlib.h>
  15 .sp
  16 .BI "long a64l(const char *" str64 );
  17 .sp
  18 .BI "char *l64a(long " value );
  19 .sp
  20 .in -4n
  21 Feature Test Macro Requirements for glibc (see
  22 .BR feature_test_macros (7)):
  23 .in
  24 .sp
  25 .BR a64l (),
  26 .BR l64a ():
  27 .br
  28 .RS 4
  29 .ad l
  30 _XOPEN_SOURCE\ >=\ 500
  31 .\"    || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
  32     || /* Glibc since 2.19: */ _DEFAULT_SOURCE
  33     || /* Glibc versions <= 2.19: */ _SVID_SOURCE
  34 .RE
  35 .ad
  36 .SH DESCRIPTION
  37 These functions provide a conversion between 32-bit long integers
  38 and little-endian base-64 ASCII strings (of length zero to six).
  39 If the string used as argument for
  40 .BR a64l ()
  41 has length greater than six, only the first six bytes are used.
  42 If the type
  43 .I long
  44 has more than 32 bits, then
  45 .BR l64a ()
  46 uses only the low order 32 bits of
  47 .IR value ,
  48 and
  49 .BR a64l ()
  50 sign-extends its 32-bit result.
  51 .LP
  52 The 64 digits in the base-64 system are:
  53 .RS
  54 .nf
  55
  56 \&\(aq.\(aq     represents a 0
  57 \&\(aq/\(aq     represents a 1
  58 0-9     represent  2-11
  59 A-Z     represent 12-37
  60 a-z     represent 38-63
  61
  62 .fi
  63 .RE
  64 So 123 = 59*64^0 + 1*64^1 = "v/".
  65 .SH ATTRIBUTES
  66 For an explanation of the terms used in this section, see
  67 .BR attributes (7).
  68 .TS
  69 allbox;
  70 lb lb lb
  71 l l l.
  72 Interface       Attribute       Value
  73 T{
  74 .BR l64a ()
  75 T}      Thread safety   MT-Unsafe race:l64a
  76 T{
  77 .BR a64l ()
  78 T}      Thread safety   MT-Safe
  79 .TE
  80 .SH CONFORMING TO
  81 POSIX.1-2001, POSIX.1-2008.
  82 .SH NOTES
  83 The value returned by
  84 .BR l64a ()
  85 may be a pointer to a static buffer, possibly overwritten
  86 by later calls.
  87 .LP
  88 The behavior of
  89 .BR l64a ()
  90 is undefined when
  91 .I value
  92 is negative.
  93 If
  94 .I value
  95 is zero, it returns an empty string.
  96 .LP
  97 These functions are broken in glibc before 2.2.5
  98 (puts most significant digit first).
  99 .LP
 100 This is not the encoding used by
 101 .BR uuencode (1).
 102 .SH SEE ALSO
 103 .BR uuencode (1),
 104 .\" .BR itoa (3),
 105 .BR strtoul (3)