patch

Additional Notes

patch is a text-processing command used to apply changes from a diff file. It applies diff output to source files, making it essential for distributing and applying code changes.

Always run patch with --dry-run first to verify the patch applies cleanly. The -pN option strips leading path components from diff filenames.

Syntax

patch [options] [file...]

Parameters

• options: Flags that change how patch behaves.
• file: Text file to read or process.

Common Options

• -pN: Strip N leading path components.
• -R: Reverse a patch.
• --dry-run: Preview whether the patch applies.

Examples

patch < fix.diff
patch -p1 < changes.patch
patch --dry-run -p1 < changes.patch

Practical Notes

Use --dry-run first when applying patches from another system or project.