diff and patch
Published on 2006-05-22.
A mini tutorial in the usage of diff and patch.
Create the patch file:
$ diff -u old-file.txt new-file.txt > changes.diff
Use the patch in order to change old-file.txt to new-file.txt:
$ patch old-file.txt changes.diff
$ patch < changes.diff
patch will rename old-file.txt to old-file.txt.orig and save the new file with the changes as old-file.txt. old-file.txt is now identical to new-file.txt
If you want to reverse the process you can do it with:
$ patch -R old-file.txt changes.diff
$ patch -R < changes.diff
diff can also be used to display the difference between content in directories.
$ diff /home/user/foo /home/user/bar