Commit: 9d3da6b9bd308bc7a9c55d38848b5cfddf900eb0 - addr2country (git)

Commit MetaInfo

• Revision: 9d3da6b9bd308bc7a9c55d38848b5cfddf900eb0 (tree)
• Zeit: 2022-04-10 03:35:49
• Autor: dyknon <dyknon@user...>
• Commiter: dyknon

Log Message

example perl

Ändern Zusammenfassung

• add: examples/perl.pl

Diff

--- /dev/null
+++ b/examples/perl.pl
@@ -0,0 +1,44 @@
+#!/usr/bin/perl
+
+use warnings;
+use strict;
+use feature qw(say);
+use List::Util qw(reduce);
+
+if(@ARGV != 2){
+    say "Usage: $0 ../ipv4.bin 192.0.2.0";
+    exit 1;
+}
+
+my $size = 2 + 4 + 4;
+my $file = $ARGV[0];
+my $addr = reduce{$a << 8 | $b}split(/\./, $ARGV[1]);
+
+open(my $fh, "<:raw", $file);
+my $fsize = (stat $fh)[7];
+die if(!$fsize || $fsize % $size);
+my $from = 0;
+my $to = $fsize / $size - 1;
+my $buf;
+my $cnt = 0;
+
+# Binary search
+while($from <= $to){
+    my $center = int(($from + $to) / 2);
+    $fh->seek($center * $size, 0);
+    $fh->read($buf, $size);
+    $cnt++;
+    my ($cc, $start, $end) = unpack("A2L>2", $buf);
+    if($start <= $addr && $addr <= $end){
+        say $cc, " (read $cnt times)";
+        exit;
+    }
+    if($start < $addr){
+        $from = $center + 1;
+    }else{
+        $to = $center - 1;
+    }
+}
+say "No Match (read $cnt times)";
+
+$fh->close;