in reply to Re: Regex String
in thread Regex String

Hi,

I am searching a hexdump. Just want to make sure it is not all zeroes, before i split it to bytes.

Looks like 00000FFEDFF67FFB8FF96FFE200BBFF240020FFBAFF360132FF6500FCFED30079

Thanks a lot for your reply.

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Re^3: Regex String
by AppleFritter (Vicar) on Jul 04, 2014 at 09:54 UTC

    You're welcome! And in that case, I'd change those checks to the following: 

    die "Not a valid file, Check output!" if $dumpbuf =~ m/[^0-9A-F]/; #ma
+tch one
die "File contains only zeros, Check output!" if $dumpbuf !~ m/[1-9A-F
+]/; #match two

    [download]

    (In particular, note that the second regex should include A-F, since otherwise some valid files will be rejected.)

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[d/l]

      You could also try the following, as an alternative solution:

      die "Invalid file, check output!" unless $dumpbuf =~ /^(?!0*$)[0-9A-F]+$/; # Ensure file contains a hex string other than all 0
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[d/l]
Re^3: Regex String
by AnomalousMonk (Archbishop) on Jul 04, 2014 at 14:52 UTC
    ... split it to bytes.

    If this means you want to end up with an array (or string) of byte values for each pair of hex digits, consider pack: 

    c:\@Work\Perl>perl -wMstrict -MData::Dump -le
"my $s = '00000FFEDFF6';
 print qq{'$s'};
 ;;
 my @bytes = split '', pack 'H*', $s;
 dd \@bytes;
"
'00000FFEDFF6'
["\0", "\0", "\17", "\xFE", "\xDF", "\xF6"]

    [download]

    Update: Another validation test to make sure you have an even number of hex digits in the source string might also be a good idea.

[reply]
[d/l]

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