Komodo Edit has a compare files tool, but it is diff format with highlighting, not side by side.

You could use Meld or Kdiff/Kompare. You can add it to the Geany build options, and other editors offer various ways of calling external tools on the current file (you will still have to open the file to be compared).

If you are not using version control, that may be the real solution.

Hi ya, graeme;

Thanks for the reply. I will have to look into doing some of the things you suggested. Unfortunately, I don't really know what "build options" are.

I have a few wordpress sites where the changes to the style.css were written into the main theme instead of the child theme, so I am interested in comparing the modified theme with a copy of the UN-modified theme so I can extract the changes and put them in the child theme. (I know you aren't a big fan of wordpress, but if the client wants to use it, who am I to tell them otherwise?)

For that, I would use Meld or Kdiff/Kompare. Komodo Edit will do what you want as well but I prefer the way the others present it (side by side and very clear).

Komodo is good but rather heavy and less than rock-solid reliable. It is a good editor other than that and there is also a proprietary (expensive!) IDE version.

Are you working on something someone else did? Then check whether whoever worked on this previously has not used version control. Hidden or mysterious files/folders are an indicator (.git, .hg, __fossil__ ,.flckout are the ones I know). If so the changes have already been recorded.

*IF* you decide to give Geany a serious try: [wiki.geany.org...] You can do the same trick with Kate, and probably more easily with Gedit (it may have a run external script option - not sure). It is really intended for compiling code, but all it actually does is run a command against a file. I (used to) use it for running Python and HTML linters/checkers.

Of course you can always do it with vim - You can do ANYTHING with vim provided you are prepared to memorize a million key combinations...

If you expect to spend a lot of time on this, then I would put it in version control. Check in the unmodified theme in first, overwrite with the modified theme, check that in, then diff the checkins and you can see what you want AND you are set up to track future changes.

I just came across this: [askubuntu.com...]

Also, to clarify about Geany, instead of make or gcc you launch a file comparison tool: e.g. a build command like:

kdiff3 "%f"

I just tried this and it works fine. It opens with the current file already chosen, and a dialog box open to let you open a file chooser for the other.

Geany is very nice. I ought to find some time to write an extension to fill in the one bit of missing functionality and go back to using it.

Just to note that Dolphin has a KDiff3 menu plugin.. Dolphin is the best file manager I have used on any OS and a good reason to use KDE.