Ignoring Things

Objectives

• Configure Git to ignore specific files.
• Understand why ignoring files can be useful.

Questions

• How can I tell Git to ignore files I don’t want to track?

Ignoring files

What if we have files that we do not want Git to track for us, like backup files created by our editor or intermediate files created during data analysis? Let’s create a few dummy files:

$ mkdir receipts
$ touch a.png b.png c.png receipts/a.jpg receipts/b.jpg

and see what Git says:

$ git status

Putting these files under version control would be a waste of disk space. What’s worse, having them all listed could distract us from changes that actually matter, so let’s tell Git to ignore them.

We do this by creating a file in the root directory of our project called .gitignore:

$ nano .gitignore

Type the text below into the .gitignore file:

*.png
receipts/

Save the file and exit your editor.

Verify that the file contains the files to ignore.

$ cat .gitignore

Can (usually must) track .gitignore. Helps others

$ git add .gitignore
$ git commit -m "Ignore png files and the receipts folder."
$ git status

If we want to override our ignore settings, we can use git add -f to force Git to add something. For example, git add -f a.csv.

We can also always see the status of ignored files if we want:

$ git status --ignored

Nested ignoring also works.

Also possible to ignore all extensions for example, except a given file by using ! in your .gitignore

*.png           # ignore all png files
!final.png      # except final.png

Note also that, if you’ve previously committed .png files in this lesson, they will not be ignored with this new rule. Only future additions of .png files to the root directory will be ignored.

Exercise 1

Given a directory structure that looks like:

receipts/data
receipts/images
receipts/plots
receipts/analysis

How would you ignore all of the contents in the receipts folder, but not receipts/data?

Hint: think a bit about how you created an exception with the ! operator before.

Exercise 2

Assuming you have an empty .gitignore file, and given a directory structure that looks like:

receipts/data/market_position/gps/a.dat
receipts/data/market_position/gps/b.dat
receipts/data/market_position/gps/c.dat
receipts/data/market_position/gps/info.txt
receipts/plots

What’s the shortest .gitignore rule you could write to ignore all .dat files in receipts/data/market_position/gps? Do not ignore the info.txt.

Exercise 3

You wrote a script that creates many intermediate log-files of the form log_01, log_02, log_03, etc. You want to keep them but you do not want to track them through git.

1. Write one .gitignore entry that excludes files of the form log_01, log_02, etc.

2. Test your “ignore pattern” by creating some dummy files of the form log_01, etc.

3. You find that the file log_01 is very important after all, add it to the tracked files without changing the .gitignore again.

Continue with

07. Remotes in GitHub