Perl版NetCat(NC)

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1. #!/usr/bin/perl
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3. use strict;
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4. use IO::Socket;
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5. use IO::Select;
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6. use Getopt::Std;
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8. my %option;
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9. getopts('lp:', %option);
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11. # listen on local port
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12. if( defined $option{'l'} )
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13. {
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14. if( !defined $option{'p'} )
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15. {
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16. &Usage( );
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17. exit( -1 );
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18. }
87 collapsed lines
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20. my $port = $option{'p'};
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21. my $listen = IO::Socket::INET->new(Proto => 'tcp',
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22. LocalPort => $port,
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23. Listen => 1,
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24. Reuse => 1) or die "Listen on port $port error: $!n";
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26. while( my $client_sock = $listen->accept() )
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27. {
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28. &ProcessData( $client_sock );
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29. }
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30. }
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32. # if has no -l argument, maybe want to connect to other host
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33. if( @ARGV != 2 )
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34. {
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35. &Usage( );
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36. exit( -1 );
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37. }
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39. my $client_sock = IO::Socket::INET->new(Proto => 'tcp', PeerHost => $ARGV[0], PeerPort => $ARGV[1] ) || die "Connect to $ARGV[0]:$ARGV[1] error:$!n";
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40. &ProcessData( $client_sock );
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42. sub ProcessData
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43. {
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44. my $client_sock = shift;
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46. my $select = IO::Select->new( );
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48. $select->add( *STDIN );
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49. $select->add( $client_sock );
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51. my $buffer;
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52. while( 1 )
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53. {
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54. if( ! $select->exists( $client_sock ) )
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55. {
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56. print "waiting connection....n";
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57. last;
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58. }
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60. my @ready = $select->can_read;
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62. for my $tmp_sock(@ready)
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63. {
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64. if( $tmp_sock eq *STDIN )
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65. {
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66. if( my $recv_len = sysread( *STDIN, $buffer, 1024 )  )
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67. {
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68. if( ! syswrite($client_sock, $buffer) )
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69. {
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70. $select->remove( $client_sock );
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71. $select->remove( *STDIN );
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72. close( $client_sock );
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74. last;
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75. }
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76. }
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77. else
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78. {
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79. $select->remove( $client_sock );
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80. $select->remove( *STDIN );
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81. close( $client_sock );
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83. last;
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84. }
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85. }
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87. elsif( $tmp_sock eq $client_sock )
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88. {
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89. if( my $recv_len = sysread( $client_sock, $buffer, 1024*5 ) )
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90. {
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91. if( ! syswrite( *STDOUT, $buffer) )
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92. {
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93. $select->remove( $client_sock );
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94. $select->remove( *STDIN );
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95. close( $client_sock );
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97. last;
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98. }
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99. }
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100. else
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101. {
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102. print "socket disconnected.n";
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103. $select->remove( $client_sock );
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104. $select->remove( *STDIN );
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105. close( $client_sock );
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107. last;
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108. }
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109. }
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110. }
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111. }
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112. }
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114. sub Usage
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115. {
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116. print "simple nc.pl, code by wustyunshu@hotmail.comn";
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117. print "this script don't support -e cmd.exe, ^_^n";
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118. print "Usage:n";
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119. print "t  -l -p 99n";
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120. print "t 192.168.0.1 80n";
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121. }