Comparing and Merging Files

This file documents the GNU diff, diff3, sdiff, and cmp commands for showing the differences between files and the GNU patch command for using their output to update files.

This is Edition 2.8, dated 23 March 2002, for diffutils 2.8 and patch 2.5.4.

Overview		Preliminary information.
1. What Comparison Means		What file comparison means.

2. diff Output Formats		Formats for two-way difference reports.
3. Incomplete Lines		Lines that lack trailing newlines.
4. Comparing Directories		Comparing files and directories.
5. Making diff Output Prettier		Making diff output prettier.
6. diff Performance Tradeoffs		Making diff smarter or faster.

7. Comparing Three Files		Formats for three-way difference reports.
8. Merging From a Common Ancestor		Merging from a common ancestor.

9. Interactive Merging with sdiff

Interactive merging with sdiff.

10. Merging with patch		Using patch to change old files into new ones.
11. Tips for Making and Using Patches		Tips for making and using patch distributions.

12. Invoking cmp		Compare two files byte by byte.
13. Invoking diff		Compare two files line by line.
14. Invoking diff3		Compare three files line by line.
15. Invoking patch		Apply a diff file to an original.
16. Invoking sdiff		Side-by-side merge of file differences.

17. Standards conformance		Conformance to the POSIX standard.
18. Future Projects		If you think you've found a bug or other shortcoming.

A. Copying This Manual		How to make copies of this manual.
B. Concept Index		Index of concepts.