Greetings patient Monks.
I am parsing and converting a real-time binary data stream that is coming in on the serial port (COM port). This is working fine, but every 4th byte is a 'sample delimiter' that I need to check and confirm. Currently I am using a reg exp in the ARE_MATCH function of the serialport module to grab the first 3 bytes: 
$ob->are_match("-re", '\x{0a}');

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The problem with this is that if one of the first 3 bytes is a 0x0a, the match will return too few bytes and mess the whole thing up. Also, if the fourth byte is anything other than 0x0a, we have a problem that we need to know about. So what I need to do is count the number of bytes as they stream in, and check every fourth byte to confirm that it is indeed a 0x0a. This would be easily done if I were reading a file using the READ function. But since I am reading a real-time datastream from the COM port instead, I am puzzled about how to do this. I have tried assigning the COM port a filehandle (with OPEN) and READing that, but of course the COM port is locked by then by the serialport module.
My apologies for the rambling explanation, but I hope that the explanation was sufficient enough to convey the issue.
Many Humble Thanks for reading this query

In reply to Counting bytes in an input stream instead of a file by sawtooth

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