in reply to decimal -> hex

my $address = "127.0.0.1";

  # from decimal to hex:
my ($a,$b,$c,$d) = $address =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/;
my $hex_addr = sprintf "%02x.%02x.%02x.%02x", $a, $b, $c, $d;

print "[$hex_addr]\n";  #prints "[7f.00.00.01]";

  # from hex to decimal:
my ($a, $b, $c, $d) = $hex_addr =~ /(\w+)\.(\w+)\.(\w+)\.(\w+)/;
my $addr = hex($a). "." . hex($b) . "." . hex($c) . "." . hex($d);

print "[$addr]\n";      #prints "[127.0.0.1]"

[download]

Hope it helps.

jarich

Update: Added the second part once I worked it out, but kabel beat me anyway.

Replies are listed 'Best First'.
Re: Re: decimal -> hex
by grantm (Parson) on Oct 11, 2002 at 07:18 UTC 
    my ($a,$b,$c,$d) = $address =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/;
my $hex_addr = sprintf "%02x.%02x.%02x.%02x", $a, $b, $c, $d;

    Save yourself some typing and use an array :-)

    my @bytes = $address =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/;
my $hex_addr = sprintf "%02x.%02x.%02x.%02x", @bytes;
[reply]
      Save yourself some typing and use an array :-) 
      my @bytes = $address =~ /(\d+)\.(\d+)\.(\d+)\.(\d+)/;
my $hex_addr = sprintf "%02x.%02x.%02x.%02x", @bytes;

      [download]
      Save yourself even more typing and make one expression of it. 
      my $hex_addr = sprintf "%02x.%02x.%02x.%02x", $address =~ /(\d+)\.(\d+
+)\.(\d+)\.(\d+)/;

      [download]
      As you seem to be absolutely sure on the address format, split() will do: 
      my $hex_addr = sprintf "%02x.%02x.%02x.%02x", split /\./, $address;

      [download]
      I'm sure others would recommend use of inet_aton(), from Socket.pm, because it's more flexible in what it accepts for an IP address. Unfortunately for us, if produces a string of 4 packed bytes, but it's nothing unpack() can't easily handle. 
      use Socket;
my $address = '127.1';
my $hex_addr = sprintf "%02x.%02x.%02x.%02x", unpack 'C*', inet_aton($
+address);

      [download]
      And if you prefer uppercase hex instead of lowercase, use '%02X' instead of '%02x' in the sprintf() template.
[reply]
[d/l]
[select]

        ...and slightly shorter|more extensible (if perhaps less efficient) way:

        my $hex_addr=join '.',map {sprintf "%02x",$_} split /\./,$address;

        Or even:

        (my $hex_addr=$address)=~s/(\d+)/sprintf("%02x",$1)/gx;

        ...although of course the results could be a bit funny if it's not an IP address.

[reply]
[d/l]
[select]
      Ok, thanks all!
[reply]

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