Ignoring Things
Overview
Teaching: 5 min
Exercises: 0 minQuestions
How can I tell Git to ignore files I don’t want to track?
Objectives
Configure Git to ignore specific files.
Explain why ignoring files can be useful.
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
On branch main
Untracked files:
(use "git add <file>..." to include in what will be committed)
a.png
b.png
c.png
receipts/
nothing added to commit but untracked files present (use "git add" to track)
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
$ cat .gitignore
*.png
receipts/
These patterns tell Git to ignore any file whose name ends in .png
and everything in the receipts
directory.
(If any of these files were already being tracked,
Git would continue to track them.)
Once we have created this file,
the output of git status
is much cleaner:
$ git status
On branch main
Untracked files:
(use "git add <file>..." to include in what will be committed)
.gitignore
nothing added to commit but untracked files present (use "git add" to track)
The only thing Git notices now is the newly-created .gitignore
file.
You might think we wouldn’t want to track it,
but everyone we’re sharing our repository with will probably want to ignore
the same things that we’re ignoring.
Let’s add and commit .gitignore
:
$ git add .gitignore
$ git commit -m "Ignore png files and the receipts folder."
$ git status
On branch main
nothing to commit, working directory clean
As a bonus, using .gitignore
helps us avoid accidentally adding to the repository files that we don’t want to track:
$ git add a.png
The following paths are ignored by one of your .gitignore files:
a.png
Use -f if you really want to add them.
If we really want to override our ignore settings,
we can use git add -f
to force Git to add something. For example,
git add -f a.dat
.
We can also always see the status of ignored files if we want:
$ git status --ignored
On branch main
Ignored files:
(use "git add -f <file>..." to include in what will be committed)
a.png
b.png
c.png
receipts/
nothing to commit, working directory clean
Ignoring Nested Files
Given a directory structure that looks like:
receipts/data receipts/plots
How would you ignore only
receipts/plots
and notreceipts/data
?Solution
If you only want to ignore the contents of
receipts/plots
, you can change your.gitignore
to ignore only the/plots/
subfolder by adding the following line to your .gitignore:receipts/plots/
This line will ensure only the contents of
receipts/plots
is ignored, and not the contents ofreceipts/data
.As with most programming issues, there are a few alternative ways that one may ensure this ignore rule is followed. The “Ignoring Nested Files: Variation” exercise has a slightly different directory structure that presents an alternative solution. Further, the discussion page has more detail on ignore rules.
Including Specific Files
How would you ignore all
.png
files in your root directory except forfinal.png
? Hint: Find out what!
(the exclamation point operator) doesSolution
You would add the following two lines to your .gitignore:
*.png # ignore all png files !final.png # except final.png
The exclamation point operator will include a previously excluded entry.
Note also that because you’ve previously committed
.png
files in this lesson they will not be ignored with this new rule. Only future additions of.png
files added to the root directory will be ignored.
Ignoring Nested Files: Variation
Given a directory structure that looks similar to the earlier Nested Files exercise, but with a slightly different directory structure:
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.Solution
If you want to ignore the contents of
receipts/
but not those ofreceipts/data/
, you can change your.gitignore
to ignore the contents of receipts folder, but create an exception for the contents of thereceipts/data
subfolder. Your .gitignore would look like this:receipts/* # ignore everything in receipts folder !receipts/data/ # do not ignore receipts/data/ contents
Ignoring all data Files in a Directory
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 inresult/data/market_position/gps
? Do not ignore theinfo.txt
.Solution
Appending
receipts/data/market_position/gps/*.dat
will match every file inreceipts/data/market_position/gps
that ends with.dat
. The filereceipts/data/market_position/gps/info.txt
will not be ignored.
Ignoring all data Files in the repository
Let us assume you have many
.dat
files in different subdirectories of your repository. For example, you might have:results/a.dat data/experiment_1/b.dat data/experiment_2/c.dat data/experiment_2/variation_1/d.dat
How do you ignore all the
.dat
files, without explicitly listing the names of the corresponding folders?Solution
In the
.gitignore
file, write:**/*.dat
This will ignore all the
.dat
files, regardless of their position in the directory tree. You can still include some specific exception with the exclamation point operator.
The Order of Rules
Given a
.gitignore
file with the following contents:*.dat !*.dat
What will be the result?
Solution
The
!
modifier will negate an entry from a previously defined ignore pattern. Because the!*.dat
entry negates all of the previous.dat
files in the.gitignore
, none of them will be ignored, and all.dat
files will be tracked.
Log Files
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 throughgit
.
Write one
.gitignore
entry that excludes files of the formlog_01
,log_02
, etc.Test your “ignore pattern” by creating some dummy files of the form
log_01
, etc.You find that the file
log_01
is very important after all, add it to the tracked files without changing the.gitignore
again.Discuss with your neighbor what other types of files could reside in your directory that you do not want to track and thus would exclude via
.gitignore
.Solution
- append either
log_*
orlog*
as a new entry in your .gitignore- track
log_01
usinggit add -f log_01
Key Points
The
.gitignore
file tells Git what files to ignore.