Hi brian,

I modified your script to match my local config ("eth0" instead of "en1", removed "or src port 80" since I don't need that, and ran it as root directly, so no need for sudoing before). However, I got no output when using it. Here's what I have:
#!/usr/bin/perl
use strict;


my( $header, $packet ) = ('', '');

open STDIN, "/usr/sbin/tcpdump -lx -s 1024 dst port 80  |";
#die "Could not open tcpdump" unless $?;

 while( <> )
        {
        chomp;

        if( /^\S+/ )
                {
                print_packet( $header, $packet );
                $header = $_;
                $packet = undef;
                next;
                }

    $packet .= $_;
 }

sub print_packet {
        my( $header, $packet ) = @_;

        $packet =~ s/\s//g;

        $packet =~ s/.{104}//; # remove protocol info
        return unless length $packet > 0;

        $packet =~ s/0d0a0d0a.*/0d0/i; # Just keep the HTTP header

        my $pretty = '';

        BYTE: while( $packet =~ m/\G([0-9a-f]{2})\s*/ig )
                {
                my $hex = hex $1;

                if( $hex == 0x0D ) { $pretty .= "\n"; next BYTE }
                if( $hex == 0x0A ) { next BYTE }

                $pretty .= do {
                        if( $hex < 0x20 or $hex > 0x7f ) { '.' }
                        else                             { chr $hex }
                        };
                }

        if( $pretty =~ m/^(?:HTTP|GET|POST)/ )
                {
                print_header( $header );
                print $pretty;
                }

        return length $packet;
}

sub print_header {
        my $header = shift;
        my ( $time, $src, undef, $dst, ) = split /\s+/, $header;
        $time =~ s/\..*//;
        $dst =~ s/:$//;
        print "-" x 73, "\n";
        print "Time: $time Src: $src Dst: $dst\n";
}

[download]

Cheers.

In reply to Re^2: converting tcpdump output by RnC
in thread converting tcpdump output by RnC

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