How do I implement a pre-commit hook script in SVN that calls dos2unix to validate checked-in file

I was wondering if anyone here had some experience writing this type of script and if they could give me some pointers.

I would like to modify this script to validate that the check-in file does not have a Carriage Return in the EOL formatting. The EOL format is CR LF in Windows and LF in Unix. When a User checks-in code with the Windows format. It does not compile in Unix anymore. I know this can be done on the client side but I need to have this validation done on the server side. To achieve this, I need to do the following:

1) Make sure the file I check is not a binary, I dont know how to do this with svnlook, should I check the mime:type of the file? The Red Book does not indicate this clearly or I must have not seen it.

2) I would like to run the dos2unix command to validate that the file has the correct EOL format. I would compare the output of the dos2unix command against the original file. If there is a diff between both, I give an error message to the client and cancel the check-in.

I would like your comments/feedback on this approach.