very incomplete and likely buggy ansi decoder

README.md

In order to investigate a bug, I needed an ansi escape code decoder.

This is it.

I just wrote exactly what was required for the bug analysis, so it is bad.

parseAnsiEscape.pl

#!/usr/bin/perl -w

use strict;
use 5.010;

my %modes = (
    0 => 'reset all modes',
);

my $escape = chr(0x1b);
while (my $line = <>) {
    chomp $line;
    # printf qq(Line: "%s"\n), quotemeta($line);
    while ($line ne '') {
        if ($line =~ s/^([\x20-\xFF]+)//) {
            printf qq(Normal chars: "%s"\n), $1;
        } elsif ($line =~ s/^$escape\[(\d+)([ABGm])//) {
            my ($n, $command) =  ($1, $2);
            if ($command eq 'A') {
                print "Move cursor up $n lines\n";
            } elsif ($command eq 'B') {
                print "Move cursor down $n lines\n";
            } elsif ($command eq 'G') {
                print "Move cursor to column $n\n";
            } elsif ($command eq 'm') {
                my $mode = $modes{$n} // "unknown mode: $n";
                printf "Mode: %s\n", $mode;
            } else {
            }
        } elsif ($line =~ s/^$escape\[K//) {
            print "Clear current line\n";
        } else {
            # $line =~ s/$escape/↑/g;
            $line =~ s/([^\x20-\x7F])/sprintf "0x%0x", ord($1)/ge;
            printf qq(Remainder: "%s"\n), $line;
            $line = '';
        }
    }
    printf "line done\n";
}