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diff

Introduction​

This cheat sheet provides a quick reference for some common diff (file comparison) commands and concepts. diff is a command-line utility used to compare files and highlight the differences between them, typically line by line.

diff Concepts​

Comparison Modes​

diff can be used in various modes, including unified and context modes.

  • Unified format (default):

    diff file1 file2

  • Context format:

    diff -c file1 file2

Output Format​

diff can generate output in various formats, including side-by-side and unified formats.

  • Side-by-side format:

    diff -y file1 file2

  • Unified format:

    diff -u file1 file2

Ignore Whitespace​

You can instruct diff to ignore whitespace differences.

  • Ignore all whitespace changes:
    diff -w file1 file2

Recursive Comparison​

diff can be used to compare directories recursively.

  • Compare two directories:
    diff -r directory1 directory2

Patching​

diff can generate patch files that represent the differences between two files.

  • Create a patch file from differences:

    diff -u original_file modified_file > patch_file.patch

  • Apply a patch file to a file:

    patch -p1 < patch_file.patch

Ignore Case​

You can make diff ignore case when comparing files.

  • Ignore case when comparing:
    diff -i file1 file2

diff Command-Line​

  • Compare two files and display the differences:

    diff file1 file2

  • Compare two directories and display the differences:

    diff -r directory1 directory2

  • Generate a patch file from differences:

    diff -u original_file modified_file > patch_file.patch

  • Apply a patch file to a file:

    patch -p1 < patch_file.patch

  • Compare files while ignoring whitespace differences:

    diff -w file1 file2

  • Compare files while ignoring case differences:

    diff -i file1 file2

Conclusion​

This cheat sheet covers some common diff (File Comparison) commands and concepts. diff is a versatile command-line utility for comparing and highlighting differences between files and directories; refer to the official diff documentation for more in-depth information and advanced usage.