replace a byte in a binary file using perl

[subok]

I've been trying but no success. I want to replace byte in a binary file and save a backup file :

Where a byte sequence in the file is : EE 09 12 C3

will be replaced by : EE D9 12 C3
(09--> D9)

Is it possible?

Thanks for your help.

 

[PaulTEG]

you'll have to binmode the file before reading it ...

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)

 

[fishiface]

I've been trying...

If you show us the code you have so far, it will be easier for us to understand the level of help you require.


Yours,

fish

["]As soon as we started programming, we found to our surprise that it wasn't as easy to get programs right as we had thought. Debugging had to be discovered. I can remember the exact instant when I realized that a large part of my life was going to be spent in finding mistakes in my own programs.["]
--Maurice Wilkes, 1949

 

[TrojanWarBlade]

Try the following at the prompt:

perl -pi.bak -e 's{\xEE\x09\x12\xC3}{\xEE\xD9\x12\xC3}' file.bin


where "file.bin" is the name of the file(s) you want to change.



Trojan.

 

[PaulTEG]

Trojan's code will replace the first occurrence of this sequence, are you sure this is what you want? Also changing any bytes in a file may cause the CRC check to fail resulting in a useless file, unless of course you reverse the codes above and hope that a similar occurrence hasn't happened before.

Paul
------------------------------------
Spend an hour a week on CPAN, helps cure all known programming ailments ;-)