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 _SVID_SOURCE || _XOPEN_SOURCE\ >=\ 500 ||
  31 _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
  32 .RE
  33 .ad
  34 .SH DESCRIPTION
  35 These functions provide a conversion between 32-bit long integers
  36 and little-endian base-64 ASCII strings (of length zero to six).
  37 If the string used as argument for
  38 .BR a64l ()
  39 has length greater than six, only the first six bytes are used.
  40 If the type
  41 .I long
  42 has more than 32 bits, then
  43 .BR l64a ()
  44 uses only the low order 32 bits of
  45 .IR value ,
  46 and
  47 .BR a64l ()
  48 sign-extends its 32-bit result.
  49 .LP
  50 The 64 digits in the base-64 system are:
  51 .RS
  52 .nf
  53
  54 \&\(aq.\(aq     represents a 0
  55 \&\(aq/\(aq     represents a 1
  56 0-9     represent  2-11
  57 A-Z     represent 12-37
  58 a-z     represent 38-63
  59
  60 .fi
  61 .RE
  62 So 123 = 59*64^0 + 1*64^1 = "v/".
  63 .SH ATTRIBUTES
  64 For an explanation of the terms used in this section, see
  65 .BR attributes (7).
  66 .TS
  67 allbox;
  68 lb lb lb
  69 l l l.
  70 Interface       Attribute       Value
  71 T{
  72 .BR l64a ()
  73 T}      Thread safety   MT-Unsafe race:l64a
  74 T{
  75 .BR a64l ()
  76 T}      Thread safety   MT-Safe
  77 .TE
  78 .SH CONFORMING TO
  79 POSIX.1-2001, POSIX.1-2008.
  80 .SH NOTES
  81 The value returned by
  82 .BR l64a ()
  83 may be a pointer to a static buffer, possibly overwritten
  84 by later calls.
  85 .LP
  86 The behavior of
  87 .BR l64a ()
  88 is undefined when
  89 .I value
  90 is negative.
  91 If
  92 .I value
  93 is zero, it returns an empty string.
  94 .LP
  95 These functions are broken in glibc before 2.2.5
  96 (puts most significant digit first).
  97 .LP
  98 This is not the encoding used by
  99 .BR uuencode (1).
 100 .SH SEE ALSO
 101 .BR uuencode (1),
 102 .\" .BR itoa (3),
 103 .BR strtoul (3)