Compare differences between 2 text files

Use cmp for binary files.

Initital situation: You have the source tree of the original project and your improved version of the project:

.
|-- project.org/
`-- project.new/

Create the patch file with:

diff -Naur project.org project.new > improvement.patch

If your editor is set to change the amount of whitespace (which may be useful, eg. when it automatically deletes trailing spaces) in project.new/ than you shold ignore this in the diff command in order not to confuse the receiver of the patch:

diff -Naurw project.org project.new > improvement.patch

Initital situation: You have the source tree of the project to be patched and the patch file:

.
|-- project.toBePatched/
`-- improvement.patch

Patch the project with:

  cd project.toBePatched
  patch -p1 < ../improvement.patch

You can test also try out first what the patch actually would do withou changing anything:

patch -p1 --dry-run < ../improvement.patch

More info at http://www.kegel.com/academy/opensource.html#patches