Table of Contents

Overview
1. What Comparison Means

1.1 Hunks
1.2 Suppressing Differences in Blank and Tab Spacing
1.3 Suppressing Differences in Blank Lines
1.4 Suppressing Case Differences
1.5 Suppressing Lines Matching a Regular Expression
1.6 Summarizing Which Files Differ
1.7 Binary Files and Forcing Text Comparisons

2. diff Output Formats

2.1 Two Sample Input Files
2.2 Showing Differences Without Context

2.2.1 Detailed Description of Normal Format
2.2.2 An Example of Normal Format

2.3 Showing Differences in Their Context

2.3.1 Context Format

2.3.1.1 Detailed Description of Context Format
2.3.1.2 An Example of Context Format
2.3.1.3 An Example of Context Format with Less Context

2.3.2 Unified Format

2.3.2.1 Detailed Description of Unified Format
2.3.2.2 An Example of Unified Format

2.3.3 Showing Which Sections Differences Are in

2.3.3.1 Showing Lines That Match Regular Expressions
2.3.3.2 Showing C Function Headings

2.3.4 Showing Alternate File Names

2.4 Showing Differences Side by Side

2.4.1 Controlling Side by Side Format
2.4.2 An Example of Side by Side Format

2.5 Making Edit Scripts

2.5.1 ed Scripts

2.5.1.1 Detailed Description of ed Format
2.5.1.2 Example ed Script

2.5.2 Forward ed Scripts
2.5.3 RCS Scripts

2.6 Merging Files with If-then-else

2.6.1 Line Group Formats
2.6.2 Line Formats
2.6.3 Detailed Description of If-then-else Format
2.6.4 An Example of If-then-else Format

3. Incomplete Lines
4. Comparing Directories
5. Making diff Output Prettier

5.1 Preserving Tab Stop Alignment
5.2 Paginating diff Output

6. diff Performance Tradeoffs
7. Comparing Three Files

7.1 A Third Sample Input File
7.2 Detailed Description of diff3 Normal Format
7.3 diff3 Hunks
7.4 An Example of diff3 Normal Format

8. Merging From a Common Ancestor

8.1 Selecting Which Changes to Incorporate
8.2 Marking Conflicts
8.3 Generating the Merged Output Directly
8.4 How diff3 Merges Incomplete Lines
8.5 Saving the Changed File

9. Interactive Merging with sdiff

9.1 Specifying diff Options to sdiff
9.2 Merge Commands

10. Merging with patch

10.1 Selecting the patch Input Format
10.2 Revision Control
10.3 Applying Imperfect Patches

10.3.1 Applying Patches with Changed White Space
10.3.2 Applying Reversed Patches
10.3.3 Helping patch Find Inexact Matches
10.3.4 Predicting what patch will do

10.4 Creating and Removing Files
10.5 Updating Time Stamps on Patched Files
10.6 Multiple Patches in a File
10.7 Applying Patches in Other Directories
10.8 Backup Files
10.9 Backup File Names
10.10 Reject File Names
10.11 Messages and Questions from patch

10.11.1 Controlling the Verbosity of patch
10.11.2 Inhibiting Keyboard Input
10.11.3 patch Quoting Style

10.12 patch and the POSIX Standard
10.13 GNU patch and Traditional patch

11. Tips for Making and Using Patches

11.1 Tips for Patch Producers
11.2 Tips for Patch Consumers
11.3 Avoiding Common Mistakes
11.4 Generating Smaller Patches

12. Invoking cmp

12.1 Options to cmp

13. Invoking diff

13.1 Options to diff

14. Invoking diff3

14.1 Options to diff3

15. Invoking patch

15.1 Options to patch

16. Invoking sdiff

16.1 Options to sdiff

17. Standards conformance
18. Future Projects

18.1 Suggested Projects for Improving GNU diff and patch

18.1.1 Handling Multibyte and Varying-Width Characters
18.1.2 Handling Changes to the Directory Structure
18.1.3 Files that are Neither Directories Nor Regular Files
18.1.4 File Names that Contain Unusual Characters
18.1.5 Outputting Diffs in Time Stamp Order
18.1.6 Ignoring Certain Changes

18.2 Reporting Bugs

A. Copying This Manual

A.1 GNU Free Documentation License

A.1.1 ADDENDUM: How to use this License for your documents

B. Concept Index