Patch
The patch command is a powerful tool used to apply patches to files. A patch is essentially a set of instructions that modifies one or more files, often to fix bugs or add new features. Patches are usually created by comparing the original file with its modified version and then expressing the differences between them.
Usage
The most common use case for patch is to apply patches created by developers to test software versions before they’re released. For example, a developer might create a patch to fix a bug in a piece of open-source software. They would save this patch as a file (e.g., fix_bug.patch) and then distribute it to users who want to try out the updated version.
To apply a patch using patch, you simply run the command followed by the path to the original file (-p option is used to specify how much of the directory structure to remove):
bash
patch -p1 < fix_bug.patch
If everything goes smoothly, the modified files will be updated.
Special Hacks
One interesting aspect of patch is its ability to revert changes made by a previous patch. You can do this using the -R option (for „reverse“) followed by the same options used when applying the original patch:
bash
patch -p1 -R < fix_bug.patch
Experience Level
This command would be useful for intermediate Linux users who are comfortable working with terminal commands and have a basic understanding of how patches work. It’s not something that beginners should worry about, but it can be very useful when dealing with software development and testing.
However, if you’re interested in becoming proficient in using patch, I’d recommend learning more about the diff command (which is what patch is based on) and understanding how to create and apply patches manually.