perl pack equivalent in lua - Printable Version

perl pack equivalent in lua - Printable Version

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+--- Thread: perl pack equivalent in lua (/showthread.php?tid=3224)

perl pack equivalent in lua - baggins - 15.03.2021

Hi,

I am trying to convert a perl script to lua and ran into the pack command.
Simplified, this is what's in the script:

Code:
#!/usr/bin/perl -l

$data = "00990102";

$checksum = 49;

    my $command = pack("H*","07F0" . $data . $checksum . "070F");

print $command;

This results in :

Code:
./test.pl |od -x --endian big

0000000 07f0 0099 0102 4907 0f0a

How can I achieve this in lua?
The perl script also uses the unpack command...

Thanks for your help.

RE: perl pack equivalent in lua - admin - 15.03.2021

This should do the trick:

Code:
data = "00990102"

checksum = 49

chbyte = string.format("%02X", checksum)

command = lmcore.hextostr("07F0" .. data .. chbyte .. "070F", true)

RE: perl pack equivalent in lua - baggins - 15.03.2021

Thanks admin.

Now, I am developping this script not on LM but on a 'normal' Linux box, because I don't want to use the LM that is in production... Is there some standard lua equivalent for lmcore.hextostring?

Also the perl script converts the command to a readable string for logging purposes:

Code:
$commandhex =~ s/(.)/sprintf("0x%x ",ord($1))/eg;

How would that be done in lua?

Thanks!

RE: perl pack equivalent in lua - baggins - 15.03.2021

(15.03.2021, 14:21)baggins Wrote: Thanks admin.

Now, I am developping this script not on LM but on a 'normal' Linux box, because I don't want to use the LM that is in production... Is there some standard lua equivalent for lmcore.hextostring?

Also the perl script converts the command to a readable string for logging purposes:

Code:
$commandhex =~ s/(.)/sprintf("0x%x ",ord($1))/eg;

How would that be done in lua?

Thanks!

I've found a script and written another one that I can use on my Linux box.

Code:
function string.fromhex(str)

    return (str:gsub('..', function (cc)

        return string.char(tonumber(cc, 16))

    end))

end

function printhex (str)

    length = string.len(str)

    result = ""

    for i = 1, length,2 do

        result = result..'0x'..string.sub(str,i,i+1).." "

    end

    return result

end