mbrehin/msoffice_ooffice_pdf_diffs_with_git.md

## msoffice_ooffice_pdf_diffs_with_git.md

      
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              msoffice_ooffice_pdf_diffs_with_git.md
            
          
    Sometimes when working with Git you'd like to commit binary files.

But those files won't have clean comparisons with Git standard diff command.

Fortunately Git is a great tool that comes with a lot of possibilities…
MS Office

If, as a developer, you are under company constraints and must use MS Office,

you'll encounter some issues when trying to diff MS Office files.
Maybe you're asking yourself: what's the problem with that?
Here it is: MS Office will produce binary files which Git won't be able to compare.

Luckily there are great tools that will convert your files in order to get nice diffs:

catdoc (for Word)
xls2csv (for Excel)
catppt (for Powerpoint)

You can download them here: http://www.wagner.pp.ru/~vitus/software/catdoc/

Verify that each one works on your operating system, there is no guarantee that it works with Git Bash, for instance.
Now, how do you configure Git in order to use these tools?

First, add the following lines into your $HOME/.config/git/attributes file.  If on Windows, $HOME is your user's root directory, such as C:\Users\<your-user>.
*.doc diff=doc
*.xls diff=xls
*.ppt diff=ppt

If you don’t want this to be global, you can configure it in your project:

in .gitattributes
in .git/info/attributes if you don’t want it to be committed with your project

Then, in your global configuration file $HOME/.gitconfig (or $HOME/.config/git/config) add these:
[diff "word"]
  textconv = catdoc
  binary = true
[diff "xls"]
  textconv = xls2csv
  binary = true
[diff "ppt"]
  textconv = catppt
  binary = true

You can do the same without opening that file writing in your console:
git config --global diff.doc.textconv catdoc
git config --global diff.xls.textconv xls2csv
git config --global diff.ppt.textconv catppt

Again, if you only want these locally in your project, either use the .git/config local configuration file, or just strip the --global flags in the commands above.
Here you are, ready to diff on MS Office files! 😎
Open Office

If you are using Open Office, you'd probably like to do the same. The procedure is described in the French edition of the Git Book. Here is a summary:
In your attributes file:
*.odt diff=odt

In your config file:
[diff "odt"]
    textconv = odt2txt
    binary = true

.odt files are compressed directories, the contents is XML.
In the French edition of the Git Book, the author writes his own PERL scripts, which didn't work for me.

I recommend you use odt2txt. You can find packages for Linux and MacOS (brew install odt2txt).
And there you go!
PDF

There is a nice tool that extracts PDFs as text, written in Python: PDF miner.

If you don't already have it, you can download it here: https://github.com/euske/pdfminer/
Configuration is as simple as the previous ones:
In your attributes file:
*.pdf diff=pdf

In your config file:
[diff "pdf"]
  textconv = pdf2txt.py
  binary = true

Here you are, ready to diff all these binary file types!
A word about performance

Because converting binary files into text could take a while, you would probably like to enable caching.  In your config, you can expand the diff driver definitions like so:
[diff "DIFF_DRIVER_NAME"]
  textconv = …
  cachetextconv = true

If you need to manually expire a cache:
git update-ref -d refs/notes/textconv/DIFF_DRIVER_NAME

You can read more in the French edition of the Git Book, which seems to slightly differ from the English-language one:

French: https://git-scm.com/book/fr/v1/Personnalisation-de-Git-Attributs-Git
English: https://git-scm.com/book/en/v2/Customizing-Git-Git-Attributes

As I said before, Git is a great tool. You can customize it in many ways and save a lot of time.