Binary buffer - substr

highland7 has asked for the wisdom of the Perl Monks concerning the following question:

Hello PerlMonks

I read/create IP packets using Net::Frame::Layer.
I already have raw packet dump in $packet_dump.
I need to search for 4 consecutive bytes with values 0x16 0x3 0x1 0x1 and make a new binary buffer which will be send.
That new binary buffer will start from that 4 bytes (to the end of $packet_dump).
How can i do it ?
I have tried it with qq, pack, unpack but without suceess :(
Thanks,

Comment on Binary buffer - substr

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Re: Binary buffer - substr by dave_the_m (Monsignor) on Jan 13, 2013 at 22:53 UTC
`(my $out_packet = $packet_dump) =~ s/^.?(?=\x16\x03\x01\x01)//s;` [download] edit:* added /s modifier as pointed out by 7stud Dave.	[reply] [d/l]
Re^2: Binary buffer - substr by highland7 (Novice) on Jan 13, 2013 at 23:08 UTC
Thanks, it's working !!!	[reply]
Re^2: Binary buffer - substr by highland7 (Novice) on Jan 14, 2013 at 00:03 UTC
One more question: How can i find index number for specific binary string ? I would like to find out from which byte that specific 4 bytes appear (/x16/x03/0x1/0x0) Thanks	[reply]
Re^3: Binary buffer - substr by dave_the_m (Monsignor) on Jan 14, 2013 at 00:06 UTC
`index($packet_dump, "\x16\x03\x01\x01")` [download] Dave.	[reply] [d/l]
Re: Binary buffer - substr by 7stud (Deacon) on Jan 14, 2013 at 06:21 UTC
Binary data can contain newline characters, which cannot be matched by the default dot in a regex. `use strict; use warnings; use 5.012; my $str = "\x16-\x03\x01\x01-\x16\x03\x01\x01PAY\nLOAD"; if ($str =~ /(\x16\x03\x01\x01 .*)/xms) { say $1; printf "%vd \n", $1; say length($str) - length($1); } --output:-- PAY LOAD 22.3.1.1.80.65.89.10.76.79.65.68 6` [download]	[reply] [d/l]
Re^2: Binary buffer - substr by dave_the_m (Monsignor) on Jan 14, 2013 at 08:26 UTC
Binary data can contain newline characters, which cannot be matched by the default dot in a regex Good point. I've updated my original post to include /s Dave.	[reply]