Table Of Contents
I am using DWM since a couple of years, even wrote a patch to allow the user color its status bar. Since then, I never check out the new code in DWM that was being released because I did not think I would be able to merge the new code with my personalized DWM. That was until I discovered DWM-Patches and learned to use quilt.
What is Quilt?
Well, here is its man description:
Quilt is a tool to manage large sets of patches by keeping track of the changes each patch makes. Patches can be applied, un-applied, refreshed, etc. The key philosophical concept is that your primary output is patches.
Basic usage
Lets see an easy example, suppose the file below:
# fichero.txt
line 1
line 2
line 3
fichero.txt would be our base file.
Creating a patch
To create a new patch, we need to execute quilt new patch1.diff:
$ quilt new patch1.diff
Patch patches/patch1.diff is now on top
Making changes
Now, tell quilt what file we want to edit:
$ quilt edit fichero.txt
File fichero.txt added to patch patches/patch1.diff
Now, we are all set to edit the file, lets write one sentence:
linea 1
edit 1 (by patch1.diff)
linea 2
linea 3
See the changes
Once we have finish editing the file, we can see its diff:
$ quilt diff
Index: _drafts/fichero.txt
===================================================================
--- _drafts.orig/fichero.txt
+++ _drafts/fichero.txt
@@ -1,3 +1,4 @@
linea 1
+edit 1 (by patch1.diff)
linea 2
linea 3
Creating the patch
The patch it is not created yet, for that we need to execute:
$ quilt refresh
Refreshed patch patches/patch1.diff
Manage Patches
All right, now in patches/ there is a patch called patch1.diff, it store our changes to fichero.txt. Right now we only have one patch, in order to undo all the changes and restore fichero.txt to its original state we must execute:
$ quilt pop
Removing patch patches/patch1.diff
Restoring fichero.txt
No patches applied
Now fichero.txt do not have our modification:
$ cat fichero.txt
linea 1
linea 2
linea 3
If we have more than one patch, quilt pop accepts as input the patch name, or -a option to remove all applied patches. Lets create one second patch:
Second patch
Before creating a new patch, it is necessary to apply the first, or if we had many, all of them:
$ quilt push -a
Applying patch patches/patch1.diff
patching file fichero.txt
Now at patch patches/patch1.diff
Now we can create a second patch:
$ quilt new patch2.diff
Patch patches/patch2.diff is now on top
List the patch stack
In order to see how many patchs we have, execute quilt series:
$ quilt series
patches/patch1.diff
patches/patch2.diff
The bottom patch is patch2, right now it is empty, because at the moment we have not edit anything. For this patch we are goint to modify fichero1.txt and create a second one, fichero2.txt
$ quilt add fichero2.txt
File fichero2.txt added to patch patches/patch2.diff
$ quilt add fichero.txt
File fichero.txt added to patch patches/patch2.diff
$ echo "Line created by patch2.diff" >> fichero.txt
$ echo "New file created by patch2.diff" > fichero2.txt
$ quilt diff
Index: _drafts/fichero.txt
===================================================================
--- _drafts.orig/fichero.txt
+++ _drafts/fichero.txt
@@ -2,3 +2,4 @@ linea 1
edit 1 (by patch1.diff)
linea 2
linea 3
+Line created by patch2.diff
Index: _drafts/fichero2.txt
===================================================================
--- /dev/null
+++ _drafts/fichero2.txt
@@ -0,0 +1 @@
+New file created by patch2.diff
Finally, all that is left is apply the changes with quilt refresh:
$ quilt refresh
Refreshed patch patches/patch2.diff
When finished editing, it is recommended to restore the initial state, undoing all the patchs:
$ quilt pop -a
Removing patch patches/patch2.diff
Restoring fichero.txt
Removing fichero2.txt
Removing patch patches/patch1.diff
Restoring fichero.txt
No patches applied
$ ll
-rw-r--r-- 1 hkr hkr 24 Jan 30 18:31 fichero.txt
drwxr-xr-x 2 hkr hkr 4.0K Jan 30 18:29 patches/
drwxr-xr-x 2 hkr hkr 4.0K Jan 30 18:31 .pc/
To apply them again:
$ quilt push -a
Applying patch patches/patch1.diff
patching file fichero.txt
Applying patch patches/patch2.diff
patching file fichero.txt
patching file fichero2.txt
Now at patch patches/patch2.diff
$ ll
-rw-r--r-- 1 hkr hkr 38 Jan 30 18:32 fichero2.txt
-rw-r--r-- 1 hkr hkr 89 Jan 30 18:32 fichero.txt
drwxr-xr-x 2 hkr hkr 4.0K Jan 30 18:29 patches/
drwxr-xr-x 4 hkr hkr 4.0K Jan 30 18:32 .pc/
In order to see a real, more complicated example, visit my DWM repo.
Bibliography
- UsingQuilt | wiki.debian.org
- How To Survive With Many Patches | stuff.mit.edu
Spot a typo?: Help me fix it by contacting me or commenting below!