DANGER Geek Alert
So you would like to display an IPv4 address in its binary form. Don’t ask us why but some of us have a a habit, lets just leave it at that 🙂
Using PERL 5.6 and higher it is easy using the function sprintf. You can always check the version of perl you are using with:
To start with we will work with just one number to convert and then we can move to the full 4 octets of a dotted decimal address:
#!/usr/bin/perl my $dec = sprintf("%b",$ARGV); print "$decn";
The shebang tells the system to run the script with perl. We sent up a local variable $dec from the output of sprintf. The %b tells us to convert the first argument passed through to the script to binary. The 3rd and final line prints the the binary output, $dec, with a new line n. Running the script as follow:
And we should have 11111111 as the output.
If we run a smaller number though lets take 33, so
We have only 6 numbers 100001. If we want to keep the 8 bits of each octet including the leading zeros we modify the sprintf statement a little. We change from “%b” to “%08b”
my $dec = sprintf("%08b",$ARGV);
Now we can see that we do not strip the leading zeros and will allow the full 8 bits in the octet. Now we have the script working for one number we can pass 4 numbers representing the IP Address through to a modified script.
#!/usr/bin/perl my $octet1 = sprintf("%08b",$ARGV); my $octet2 = sprintf("%08b",$ARGV); my $octet3 = sprintf("%08b",$ARGV); my $octet4 = sprintf("%08b",$ARGV); print "$octet1.$octet2.$octet3.$octet4n";
We now have 4 variables to represent each octet and then we print the converted octets separated with dots as per the IPv4 standard.