RegEx on Binary data

rdaniels_77 has asked for the wisdom of the Perl Monks concerning the following question:

I've not been successful in finding a lot of info using Perl RegEx for binary data. Think of a high level C structure:

typedef struct {
  int ID;
  int otherInt;
  unsigned char data[10];
} MYSTRUCT;
[download]

Let's say I have an array of MYSTRUCTs in a binary file. I want to look for a pattern, say 0xaa, 0xbb, 0xcc in each 'data' field. If I find it, return true.

For this example let's just say I have 1 structure, so the regex should skip 8 bytes (jump over the 2-32bit integers), then look for the 3 byte pattern 0xaa, 0xbb, 0xcc across the 10 bytes of the data field.

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Re: RegEx on Binary data by dave_the_m (Monsignor) on Oct 02, 2012 at 19:37 UTC
Like runrig said, you probably want to unpack the individual fields first, but in answer to your question, perhaps something like: `$packed_record =~ /^[\x00-\xff]{8,15}\xaa\xbb\xcc/;` [download] Dave.	[reply] [d/l]
Re^2: RegEx on Binary data by rdaniels_77 (Initiate) on Oct 02, 2012 at 19:59 UTC
Thanks... The library approach doesn't actually work for me. I should have prefaced that I am not using raw Perl, but compiled PCRE in C language, so I needed the raw RegEx. I'll play with that expression...	[reply]
Re: RegEx on Binary data by runrig (Abbot) on Oct 02, 2012 at 19:31 UTC
It seems like you want unpack, or maybe an unpack helper library like Parse::Binary.	[reply]