Zentara wrote: > > On Thu, 20 Jun 2002 17:43:29 -0700, [EMAIL PROTECTED] (John W. Krahn) > wrote: > >>Zentara wrote: > >>I'm starting work on my own virus scanner. > >> I'm especially looking for ways to convert to hex more > >> efficiently, > > >my $hexstring = '58354f2150254041505b345c505a'; > >my $hexlen = length( $hexstring ) / 2; > > > >my $hex = pack 'C*', unpack 'H' x $hexlen, $hexstring; > > Wow, John, I can't figure what this does. $hexstring already > is hex. I'm guessing that you meant
Sorry, it was late and I didn't test it. :-( The correct code should be my $bin = pack 'H*', $hextest; > my $filestring; # slurped binary file > my $hexlen = length($filestring) / 2; > my $hexfilestring = pack 'C*', unpack 'H' x $hexlen, $filestring > > ????? You have me totally lost, as usual. :-) Are you toying with me? > What does this do? > Unless I'm confusing 'hex' with the 'hex representation' using > 0-9, a-f and A-F. > > >> rather than using =~ m/ $hextest /i > > > >If you are going to use a regular expression you should quotemeta > >$hextest and you don't want to use /i or it might not match correctly. > > > >/\Q$hextest\E/ > > Hmmmm, my idea with m/$hextest/i was to make sure that > the hex would match either a-f or A-F ; since sometimes the > hexstrings are like 5e4d3a or 5E4D3A which I would want to > be treated as equivalent. Why might not this match properly. > > I have to read up on Quotemeta, but since all the files and strings are > converted to hex representation before the regex, there shouldn't > be any non-alphanumeric characters to backslash. ??? I know you have > far superior perl skills, so why? Sorry, my understanding is that the hex string is just an ASCII representation of the binary data to search for. Virus files don't have actual "hex strings" in them but are compiled executables. John -- use Perl; program fulfillment -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
