in reply to Re^2: hexdump -C
in thread hexdump -C

That is so cool! I modified it slightly so it also runs on TinyPerl 5.8: 

sub hexdump
{
  my $s;
  $_[0] =~ s/\G([\0-\xff]{1,16})/ $s = $1; $s =~ y|\x20-\x7e|.|c; spri
+ntf("%08X  %-50s|%s|\n", $-[0], "@{[unpack q{(H2)8a0(H2)8}, $1]}", $s
+);/ge;
  return $_[0];
}

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I don't understand why I had to do this: ([\0-\xff]{1,16}) instead of (.{16}) This latter one won't capture anything, which is weird. The second thing I don't understand is why this works: 

"@{[unpack q{(H2)8a0(H2)8}, $1]}"

[download]

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Re^4: hexdump -C
by ikegami (Patriarch) on Oct 15, 2025 at 14:15 UTC

    Maybe cause you were missing the /s? (It was also missing in the original code.)

    a0 returns a zero-length string. [ ] creates an anon array and returns a reference to is. @{ ... } is the referenced array. Interpolating an array in a string joins elements with spaces by default.

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[d/l]
[select]
      Hmm... interesting! oh yes yes yes, I forgot the /s

      So, once again, here is the working code: 

      #!/usr/bin/perl -w

use strict;
use warnings;

@ARGV = ($0);

print hexdump( join('', <>) );

sub hexdump
{
  my $s;
  $_[0] =~ s/\G(.{1,16})/ $s = $1; $s =~ y|\x20-\x7e|.|c; sprintf("%08
+X  %-50s|%s|\n", $-[0], "@{[unpack q{(H2)8a0(H2)8}, $1]}", $s);/ges;
  return $_[0];
}

      [download]
[reply]
[d/l]

        Since we're golfing, 

        $s = $1; $s =~ y|\x20-\x7e|.|c;

        [download]

        can be replaced with 

        ( $s = $1 ) =~ y|\x20-\x7e|.|c;

        [download]

        It's one character shorter with spaces removed.

        Or 

        $s = $1 =~ y|\x20-\x7e|.|cr;

        [download]

        It's yet another character shorter with spaces removed.

[reply]
[d/l]
[select]
        Beware that you are modifying the scalar passed as $_[0]. You probably want to do: 
        sub hexdump {
  (my $x= shift) =~ s/\G(.{1,16})/
    (my $s= $1) =~ y|\x20-\x7e|.|c;
    sprintf "%08x  %-50|%s|\n", $-[0],
      "@{[unpack q{(H2)8a0(H2)8},$1]}", $s
  /ges;
  $x
}

        [download]
[reply]
[d/l]

In Section Obfuscated Code