Comparing and Merging Files

diff, diff3, sdiff, cmp, and patch

Edition 1.3, for diff 2.5 and patch 2.1

September 1993

• Overview
• What Comparison Means
  • Hunks
  • Suppressing Differences in Blank and Tab Spacing
  • Suppressing Differences in Blank Lines
  • Suppressing Case Differences
  • Suppressing Lines Matching a Regular Expression
  • Summarizing Which Files Differ
  • Binary Files and Forcing Text Comparisons
• diff Output Formats
  • Two Sample Input Files
  • Showing Differences Without Context
    • Detailed Description of Normal Format
    • An Example of Normal Format
  • Showing Differences in Their Context
    • Context Format
      • Detailed Description of Context Format
      • An Example of Context Format
      • An Example of Context Format with Less Context
    • Unified Format
      • Detailed Description of Unified Format
      • An Example of Unified Format
    • Showing Which Sections Differences Are in
      • Showing Lines That Match Regular Expressions
      • Showing C Function Headings
    • Showing Alternate File Names
  • Showing Differences Side by Side
  • Controlling Side by Side Format
    • An Example of Side by Side Format
  • Making Edit Scripts
    • ed Scripts
      • Detailed Description of ed Format
      • Example ed Script
    • Forward ed Scripts
    • RCS Scripts
  • Merging Files with If-then-else
    • Line Group Formats
    • Line Formats
    • Detailed Description of If-then-else Format
    • An Example of If-then-else Format
• Comparing Directories
• Making diff Output Prettier
  • Preserving Tabstop Alignment
  • Paginating diff Output
• diff Performance Tradeoffs
• Comparing Three Files
  • A Third Sample Input File
  • Detailed Description of diff3 Normal Format
  • diff3 Hunks
  • An Example of diff3 Normal Format
• Merging From a Common Ancestor
  • Selecting Which Changes to Incorporate
  • Marking Conflicts
  • Generating the Merged Output Directly
  • How diff3 Merges Incomplete Lines
  • Saving the Changed File
• Interactive Merging with sdiff
  • Specifying diff Options to sdiff
  • Merge Commands
• Merging with patch
  • Selecting the patch Input Format
  • Applying Imperfect Patches
    • Applying Patches with Changed White Space
    • Applying Reversed Patches
    • Helping patch Find Inexact Matches
  • Removing Empty Files
  • Multiple Patches in a File
  • Messages and Questions from patch
• Tips for Making Patch Distributions
• Invoking cmp
  • Options to cmp
• Invoking diff
  • Options to diff
• Invoking diff3
  • Options to diff3
• Invoking patch
  • Applying Patches in Other Directories
  • Backup File Names
  • Reject File Names
  • Options to patch
• Invoking sdiff
  • Options to sdiff
• Incomplete Lines
• Future Projects
  • Suggested Projects for Improving GNU diff and patch
    • Handling Changes to the Directory Structure
    • Files that are Neither Directories Nor Regular Files
    • File Names that Contain Unusual Characters
    • Arbitrary Limits
    • Handling Files that Do Not Fit in Memory
    • Ignoring Certain Changes
  • Reporting Bugs
• Concept Index