bigint.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

.\" Automatically generated by Pod::Man 2.16 (Pod::Simple 3.05)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sh \" Subsection heading
.br
.if t .Sp
.ne 5
.PP
\fB\\$1\fR
.PP
..
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.ie \nF \{\
.    de IX
.    tm Index:\\$1\t\\n%\t"\\$2"
..
.    nr % 0
.    rr F
.\}
.el \{\
.    de IX
..
.\}
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "bigint 3"
.TH bigint 3 "2007-12-18" "perl v5.10.0" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
bigint \- Transparent BigInteger support for Perl
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&  use bigint;
\&
\&  $x = 2 + 4.5,"\en";                    # BigInt 6
\&  print 2 ** 512,"\en";                  # really is what you think it is
\&  print inf + 42,"\en";                  # inf
\&  print NaN * 7,"\en";                   # NaN
\&  print hex("0x1234567890123490"),"\en"; # Perl v5.9.4 or later
\&
\&  {
\&    no bigint;
\&    print 2 ** 256,"\en";                # a normal Perl scalar now
\&  }
\&
\&  # Note that this will be global:
\&  use bigint qw/hex oct/;
\&  print hex("0x1234567890123490"),"\en";
\&  print oct("01234567890123490"),"\en";
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
All operators (including basic math operations) are overloaded. Integer
constants are created as proper BigInts.
.PP
Floating point constants are truncated to integer. All parts and results of
expressions are also truncated.
.PP
Unlike integer, this pragma creates integer constants that are only
limited in their size by the available memory and \s-1CPU\s0 time.
.Sh "use integer vs. use bigint"
.IX Subsection "use integer vs. use bigint"
There is one small difference between \f(CW\*(C`use integer\*(C'\fR and \f(CW\*(C`use bigint\*(C'\fR: the
former will not affect assignments to variables and the return value of
some functions. \f(CW\*(C`bigint\*(C'\fR truncates these results to integer too:
.PP
.Vb 8
\&        # perl \-Minteger \-wle \*(Aqprint 3.2\*(Aq
\&        3.2
\&        # perl \-Minteger \-wle \*(Aqprint 3.2 + 0\*(Aq
\&        3
\&        # perl \-Mbigint \-wle \*(Aqprint 3.2\*(Aq
\&        3
\&        # perl \-Mbigint \-wle \*(Aqprint 3.2 + 0\*(Aq
\&        3
\&
\&        # perl \-Mbigint \-wle \*(Aqprint exp(1) + 0\*(Aq
\&        2
\&        # perl \-Mbigint \-wle \*(Aqprint exp(1)\*(Aq
\&        2
\&        # perl \-Minteger \-wle \*(Aqprint exp(1)\*(Aq
\&        2.71828182845905
\&        # perl \-Minteger \-wle \*(Aqprint exp(1) + 0\*(Aq
\&        2
.Ve
.PP
In practice this makes seldom a difference as \fBparts and results\fR of
expressions will be truncated anyway, but this can, for instance, affect the
return value of subroutines:
.PP
.Vb 2
\&        sub three_integer { use integer; return 3.2; } 
\&        sub three_bigint { use bigint; return 3.2; }
\& 
\&        print three_integer(), " ", three_bigint(),"\en";        # prints "3.2 3"
.Ve
.Sh "Options"
.IX Subsection "Options"
bigint recognizes some options that can be passed while loading it via use.
The options can (currently) be either a single letter form, or the long form.
The following options exist:
.IP "a or accuracy" 2
.IX Item "a or accuracy"
This sets the accuracy for all math operations. The argument must be greater
than or equal to zero. See Math::BigInt's \fIbround()\fR function for details.
.Sp
.Vb 1
\&        perl \-Mbigint=a,2 \-le \*(Aqprint 12345+1\*(Aq
.Ve
.Sp
Note that setting precision and accurary at the same time is not possible.
.IP "p or precision" 2
.IX Item "p or precision"
This sets the precision for all math operations. The argument can be any
integer. Negative values mean a fixed number of digits after the dot, and
are <B>ignored</B> since all operations happen in integer space.
A positive value rounds to this digit left from the dot. 0 or 1 mean round to
integer and are ignore like negative values.
.Sp
See Math::BigInt's \fIbfround()\fR function for details.
.Sp
.Vb 1
\&        perl \-Mbignum=p,5 \-le \*(Aqprint 123456789+123\*(Aq
.Ve
.Sp
Note that setting precision and accurary at the same time is not possible.
.IP "t or trace" 2
.IX Item "t or trace"
This enables a trace mode and is primarily for debugging bigint or
Math::BigInt.
.IP "hex" 2
.IX Item "hex"
Override the built-in \fIhex()\fR method with a version that can handle big
integers. Note that under Perl v5.9.4 or ealier, this will be global
and cannot be disabled with \*(L"no bigint;\*(R".
.IP "oct" 2
.IX Item "oct"
Override the built-in \fIoct()\fR method with a version that can handle big
integers. Note that under Perl v5.9.4 or ealier, this will be global
and cannot be disabled with \*(L"no bigint;\*(R".
.IP "l, lib, try or only" 2
.IX Item "l, lib, try or only"
Load a different math lib, see \*(L"Math Library\*(R".
.Sp
.Vb 3
\&        perl \-Mbigint=lib,GMP \-e \*(Aqprint 2 ** 512\*(Aq
\&        perl \-Mbigint=try,GMP \-e \*(Aqprint 2 ** 512\*(Aq
\&        perl \-Mbigint=only,GMP \-e \*(Aqprint 2 ** 512\*(Aq
.Ve
.Sp
Currently there is no way to specify more than one library on the command
line. This means the following does not work:
.Sp
.Vb 1