Binary replace in files

Of course, find is case sensitive and fixed, not a regex, so it's not very flexible. It wouldn't be that hard to expand to a list of old,new pairs as a change spec though. Of course that would slow it down some. Except you run the risk of not having a unique search result, unless you have a really guaranteed unique pattern. I think you misunderstand Python strings. There is no need to "convert" the result of open filename, 'rb'. Re-read the example below ;- [ The old thing to find was 'out', to be changed to 'OUT', and the 20 was a silly small return chunks size for the sreplace Alll these chunks were simply passed to I guess I should have made sreplace.

The files are no worry, but what is the source of your old and new binary patterns that you want use for find and replace? You can't enter them in unescaped format on a command line, so you may want to specify them in separate binary files, or you could specify them as Python strings in a module that could be imported.

Do so at your own risk!! And, if you know where to seek to, that seems like the best way ;- Regards, Bengt Richter. John Lenton. On Wed, Jan 12, at PM , yaipa wrote: What would be the common sense way of finding a binary pattern in a.

It's not that I'm any kind of mmap expert, that I twirl mmaps for a living; in fact I barely have cause to use it in my work, but give me a break! Let's say m is your mmap handle, a is the pattern you want to find, b is the pattern you want to replace, and n is the size of both a and b.

I've never used it with something other than the file size as its second argument, and with its access argument in sync with open 's second arg. John, Thanks for reminding me of the mmap module. The following worked as expected. Thanks Francois, It worked as expected. Bengt, Thanks for the input, sorry, your diff threw me the first time I looked at it, but then I went back and tried it later. Yes it works fine and I've tucked it away for later use.

For this particular Use Case String. But, I image I will use this bit of code when I need a finer grained tool. Thanks again. Cheers, --Alan.

This discussion thread is closed Start new discussion. Asked 2 years, 9 months ago. Active 2 years, 9 months ago. Viewed 1k times. Improve this question. Can you make your question clearer. It will depend on the file format. Add a comment. Active Oldest Votes. Improve this answer. Sign up or log in Sign up using Google. Sign up using Facebook.

Sign up using Email and Password. Search related threads. Remove From My Forums. Answered by:. Archived Forums. Visual Basic. Not for VB6 questions. Sign in to vote. Hi , I need some help here with reading binary files. I am using VB. NET and I need to read a binary file , convert it somehow and replace a text value that is stored inside.

For eg. If I am viewing normally the file and not the binary I am seeing that format. But when it comes to the binary I cannot view it. Does anyone have a working example written in VB. NET which do these things? Any sample code? I would be mostly appreciated with any help you can give me. Thank you zkar. Tuesday, October 2, PM. You can also take a look at the following article on the issue: How to: Read and Write to a Newly Created Data File The BinaryWriter and BinaryReader classes are used for writing and reading data, rather than character strings.

Code Block. Friday, October 5, AM. You need to open the file and load it into an array if it is not such a big file as follows: Code Block. Saturday, October 6, AM. Should you be searching for X'x? Or an actual date and time? Thursday, October 11, AM. HI Mike and thank you for your answer. The only problem is that I don't Know the structure of the file. I have to search all the binary file.

Do you have any example with binaryreader and binarywriter? Wednesday, October 3, AM.