cap.pm

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.

package Term::Cap;

# Since the debugger uses Term::ReadLine which uses Term::Cap, we want
# to load as few modules as possible.  This includes Carp.pm.
sub carp
{
    require Carp;
    goto &Carp::carp;
}

sub croak
{
    require Carp;
    goto &Carp::croak;
}

use strict;

use vars qw($VERSION $VMS_TERMCAP);
use vars qw($termpat $state $first $entry);

$VERSION = '1.12';

# Version undef: Thu Dec 14 20:02:42 CST 1995 by [e-mail]
# Version 1.00:  Thu Nov 30 23:34:29 EST 2000 by [e-mail]
#	[PATCH] $VERSION crusade, strict, tests, etc... all over lib/
# Version 1.01:  Wed May 23 00:00:00 CST 2001 by [e-mail]
#	Avoid warnings in Tgetent and Tputs
# Version 1.02:  Sat Nov 17 13:50:39 GMT 2001 by [e-mail]
#       Altered layout of the POD
#       Added Test::More to PREREQ_PM in Makefile.PL
#       Fixed no argument Tgetent()
# Version 1.03:  Wed Nov 28 10:09:38 GMT 2001
#       VMS Support from Charles Lane <[e-mail]>
# Version 1.04:  Thu Nov 29 16:22:03 GMT 2001
#       Fixed warnings in test
# Version 1.05:  Mon Dec  3 15:33:49 GMT 2001
#       Don't try to fall back on infocmp if it's not there. From chromatic.
# Version 1.06:  Thu Dec  6 18:43:22 GMT 2001
#       Preload the default VMS termcap from Charles Lane
#       Don't carp at setting OSPEED unless warnings are on.
# Version 1.07:  Wed Jan  2 21:35:09 GMT 2002
#       Sanity check on infocmp output from Norton Allen
#       Repaired INSTALLDIRS thanks to Michael Schwern
# Version 1.08:  Sat Sep 28 11:33:15 BST 2002
#       Late loading of 'Carp' as per Michael Schwern
# Version 1.09:  Tue Apr 20 12:06:51 BST 2004
#       Merged in changes from and to Core
#       Core (Fri Aug 30 14:15:55 CEST 2002):
#       Cope with comments lines from 'infocmp' from Brendan O'Dea
#       Allow for EBCDIC in Tgoto magic test.
# Version 1.10: Thu Oct 18 16:52:20 BST 2007
#       Don't use try to use $ENV{HOME} if it doesn't exist
#       Give Win32 'dumb' if TERM isn't set
#       Provide fallback 'dumb' termcap entry as last resort
# Version 1.11: Thu Oct 25 09:33:07 BST 2007
#       EBDIC fixes from Chun Bing Ge <[e-mail]>
# Version 1.12: Sat Dec  8 00:10:21 GMT 2007
#       QNX test fix from Matt Kraai <[e-mail]>
#
# TODO:
# support Berkeley DB termcaps
# force $FH into callers package?
# keep $FH in object at Tgetent time?

=head1 NAME

Term::Cap - Perl termcap interface

=head1 SYNOPSIS

    require Term::Cap;
    $terminal = Tgetent Term::Cap { TERM => undef, OSPEED => $ospeed };
    $terminal->Trequire(qw/ce ku kd/);
    $terminal->Tgoto('cm', $col, $row, $FH);
    $terminal->Tputs('dl', $count, $FH);
    $terminal->Tpad($string, $count, $FH);

=head1 DESCRIPTION

These are low-level functions to extract and use capabilities from
a terminal capability (termcap) database.

More information on the terminal capabilities will be found in the
termcap manpage on most Unix-like systems.

=head2 METHODS

=over 4

The output strings for B<Tputs> are cached for counts of 1 for performance.
B<Tgoto> and B<Tpad> do not cache.  C<$self-E<gt>{_xx}> is the raw termcap
data and C<$self-E<gt>{xx}> is the cached version.

    print $terminal->Tpad($self->{_xx}, 1);

B<Tgoto>, B<Tputs>, and B<Tpad> return the string and will also
output the string to $FH if specified.


=cut

# Preload the default VMS termcap.
# If a different termcap is required then the text of one can be supplied
# in $Term::Cap::VMS_TERMCAP before Tgetent is called.

if ( $^O eq 'VMS' )
{
    chomp( my @entry = <DATA> );
    $VMS_TERMCAP = join '', @entry;
}

# Returns a list of termcap files to check.

sub termcap_path
{    ## private
    my @termcap_path;

    # $TERMCAP, if it's a filespec
    push( @termcap_path, $ENV{TERMCAP} )
      if (
        ( exists $ENV{TERMCAP} )
        && (
            ( $^O eq 'os2' || $^O eq 'MSWin32' || $^O eq 'dos' )
            ? $ENV{TERMCAP} =~ /^[a-z]:[\\\/]/is
            : $ENV{TERMCAP} =~ /^\//s
        )
      );
    if ( ( exists $ENV{TERMPATH} ) && ( $ENV{TERMPATH} ) )
    {

        # Add the users $TERMPATH
        push( @termcap_path, split( /(:|\s+)/, $ENV{TERMPATH} ) );
    }
    else
    {

        # Defaults
        push( @termcap_path,
            exists $ENV{'HOME'} ? $ENV{'HOME'} . '/.termcap' : undef,
            '/etc/termcap', '/usr/share/misc/termcap', );
    }

    # return the list of those termcaps that exist
    return grep { defined $_ && -f $_ } @termcap_path;
}

=item B<Tgetent>

Returns a blessed object reference which the user can
then use to send the control strings to the terminal using B<Tputs>
and B<Tgoto>.

The function extracts the entry of the specified terminal
type I<TERM> (defaults to the environment variable I<TERM>) from the
database.

It will look in the environment for a I<TERMCAP> variable.  If
found, and the value does not begin with a slash, and the terminal
type name is the same as the environment string I<TERM>, the
I<TERMCAP> string is used instead of reading a termcap file.  If
it does begin with a slash, the string is used as a path name of
the termcap file to search.  If I<TERMCAP> does not begin with a
slash and name is different from I<TERM>, B<Tgetent> searches the
files F<$HOME/.termcap>, F</etc/termcap>, and F</usr/share/misc/termcap>,
in that order, unless the environment variable I<TERMPATH> exists,
in which case it specifies a list of file pathnames (separated by
spaces or colons) to be searched B<instead>.  Whenever multiple
files are searched and a tc field occurs in the requested entry,
the entry it names must be found in the same file or one of the
succeeding files.  If there is a C<:tc=...:> in the I<TERMCAP>
environment variable string it will continue the search in the
files as above.

The extracted termcap entry is available in the object
as C<$self-E<gt>{TERMCAP}>.

It takes a hash reference as an argument with two optional keys:

=over 2

=item OSPEED

The terminal output bit rate (often mistakenly called the baud rate)
for this terminal - if not set a warning will be generated
and it will be defaulted to 9600.  I<OSPEED> can be be specified as
either a POSIX termios/SYSV termio speeds (where 9600 equals 9600) or
an old DSD-style speed ( where 13 equals 9600).


=item TERM

The terminal type whose termcap entry will be used - if not supplied it will
default to $ENV{TERM}: if that is not set then B<Tgetent> will croak.

=back

It calls C<croak> on failure.

=cut

sub Tgetent
{    ## public -- static method
    my $class = shift;
    my ($self) = @_;

    $self = {} unless defined $self;
    bless $self, $class;

    my ( $term, $cap, $search, $field, $max, $tmp_term, $TERMCAP );
    local ( $termpat, $state, $first, $entry );    # used inside eval
    local $_;

    # Compute PADDING factor from OSPEED (to be used by Tpad)
    if ( !$self->{OSPEED} )
    {
        if ($^W)
        {
            carp "OSPEED was not set, defaulting to 9600";
        }
        $self->{OSPEED} = 9600;
    }
    if ( $self->{OSPEED} < 16 )
    {

        # delays for old style speeds
        my @pad = (
            0,    200, 133.3, 90.9, 74.3, 66.7, 50, 33.3,
            16.7, 8.3, 5.5,   4.1,  2,    1,    .5, .2
        );
        $self->{PADDING} = $pad[ $self->{OSPEED} ];
    }
    else
    {
        $self->{PADDING} = 10000 / $self->{OSPEED};
    }

    unless ( $self->{TERM} )
    {
       if ( $ENV{TERM} )
       {
         $self->{TERM} =  $ENV{TERM} ;
       }
       else
       {
          if ( $^O eq 'Win32' )
          {
             $self->{TERM} =  'dumb';
          }
          else
          {
             croak "TERM not set";
          }
       }
    }

    $term = $self->{TERM};    # $term is the term type we are looking for

    # $tmp_term is always the next term (possibly :tc=...:) we are looking for
    $tmp_term = $self->{TERM};

    # protect any pattern metacharacters in $tmp_term
    $termpat = $tmp_term;
    $termpat =~ s/(\W)/\\$1/g;

    my $foo = ( exists $ENV{TERMCAP} ? $ENV{TERMCAP} : '' );

    # $entry is the extracted termcap entry
    if ( ( $foo !~ m:^/:s ) && ( $foo =~ m/(^|\|)${termpat}[:|]/s ) )
    {
        $entry = $foo;
    }

    my @termcap_path = termcap_path();

    unless ( @termcap_path || $entry )
    {

        # last resort--fake up a termcap from terminfo
        local $ENV{TERM} = $term;

        if ( $^O eq 'VMS' )
        {
            $entry = $VMS_TERMCAP;
        }
        else
        {
            if ( grep { -x "$_/infocmp" } split /:/, $ENV{PATH} )
            {
                eval {
                    my $tmp = `infocmp -C 2>/dev/null`;
                    $tmp =~ s/^#.*\n//gm;    # remove comments
                    if (   ( $tmp !~ m%^/%s )
                        && ( $tmp =~ /(^|\|)${termpat}[:|]/s ) )
                    {
                        $entry = $tmp;
                    }
                };
            }
            else
            {
               # this is getting desperate now
               if ( $self->{TERM} eq 'dumb' )
               {
                  $entry = 'dumb|80-column dumb tty::am::co#80::bl=^G:cr=^M:do=^J:sf=^J:';
               }
            }
        }
    }

    croak "Can't find a valid termcap file" unless @termcap_path || $entry;

    $state = 1;    # 0 == finished
                   # 1 == next file
                   # 2 == search again

    $first = 0;    # first entry (keeps term name)

    $max = 32;     # max :tc=...:'s

    if ($entry)
    {

        # ok, we're starting with $TERMCAP
        $first++;    # we're the first entry
                     # do we need to continue?
        if ( $entry =~ s/:tc=([^:]+):/:/ )
        {
            $tmp_term = $1;

            # protect any pattern metacharacters in $tmp_term
            $termpat = $tmp_term;
            $termpat =~ s/(\W)/\\$1/g;
        }
        else
        {
            $state = 0;    # we're already finished
        }
    }

    # This is eval'ed inside the while loop for each file
    $search = q{
	while (<TERMCAP>) {
	    next if /^\\t/ || /^#/;
	    if ($_ =~ m/(^|\\|)${termpat}[:|]/o) {
		chomp;
		s/^[^:]*:// if $first++;
		$state = 0;
		while ($_ =~ s/\\\\$//) {
		    defined(my $x = <TERMCAP>) or last;
		    $_ .= $x; chomp;
		}
		last;
	    }
	}
	defined $entry or $entry = '';
	$entry .= $_ if $_;
    };

    while ( $state != 0 )
    {
        if ( $state == 1 )
        {

            # get the next TERMCAP
            $TERMCAP = shift @termcap_path
              || croak "failed termcap lookup on $tmp_term";
        }
        else
        {

            # do the same file again
            # prevent endless recursion
            $max-- || croak "failed termcap loop at $tmp_term";
            $state = 1;    # ok, maybe do a new file next time
        }

        open( TERMCAP, "< $TERMCAP\0" ) || croak "open $TERMCAP: $!";
        eval $search;
        die $@ if $@;
        close TERMCAP;

        # If :tc=...: found then search this file again
        $entry =~ s/:tc=([^:]+):/:/ && ( $tmp_term = $1, $state = 2 );

        # protect any pattern metacharacters in $tmp_term
        $termpat = $tmp_term;
        $termpat =~ s/(\W)/\\$1/g;
    }

    croak "Can't find $term" if $entry eq '';
    $entry =~ s/:+\s*:+/:/g;    # cleanup $entry
    $entry =~ s/:+/:/g;         # cleanup $entry
    $self->{TERMCAP} = $entry;  # save it
                                # print STDERR "DEBUG: $entry = ", $entry, "\n";

    # Precompile $entry into the object
    $entry =~ s/^[^:]*://;
    foreach $field ( split( /:[\s:\\]*/, $entry ) )
    {