Tracking changes in text files


20 August 2008


A common issue that arises with text files (e.g., R code) is to identify changes that have been made between versions. I usually number my R files as file1.R, file2.R, etc. (with “file” replaced by something more meaningful),with the number indicating the version of the file. Version numbers change whenever I send the file to someone else to modify, or whenever I make major changes myself.

I often need to know what changes have been made between successive versions. The best solution I’ve found is Compare It!. All I need to do is highlight the two files in Windows Explorer, right click and choose “Compare 2 files”. Then a screen showing the differences appears. An example is given below.

The bar on the left shows the parts of the file that have been changed. White background denotes unchanged lines.

The software enables me to:

I frequently use this software for R files and other text file. I sometimes use it for LaTeX files, but here there is often a problem with changes causing subsequent lines to re-wrap, thus producing apparent changes that have no effect on the final result.

For LaTeX files, there is a better solution which I will discuss in the next post.