Unified diff

File Format
Name	Unified diff
Ontology	Electronic File Formats Archiving Unified diff
Extension(s)	.patch, .diff
Released	1991

Unified diff (or diff unified format, unified context diff, unidiff) is a diff format commonly used for patch files.

Identification

Unlike other diff formats, Unified diff has lines that begin with "@@".

Specifications

• Unified Diff Format - Ad-hoc specification by Guido van Rossum
• GNU Diffutilis manual: Detailed Description of Unified Format

Software

• GNU Diffutils: diff (with -u option), patch

Sample files

• Example from the GNU Diffutils manual
• http://www.apache.org/dist/httpd/patches/ ...

Links

• Wikipedia: Diff has a section on Unified diff