difft

Compare two files or directories

$ difft [path/to/file_or_directory1] [path/to/file_or_directory2]

$ difft --check-only [path/to/file1] [path/to/file2]

$ difft --display [side-by-side|side-by-side-show-both|inline|json] [path/to/file1] [path/to/file2]

$ difft --ignore-comments [path/to/file1] [path/to/file2]

$ difft --syntax-highlight [on|off] [path/to/file1] [path/to/file2]

$ difft --skip-unchanged [path/to/file_or_directory1] [path/to/file_or_directory2]

$ difft --list-languages

difft [OPTIONS] <FILE1> <FILE2>
difft [OPTIONS] -- <DIR1> <DIR2>

--color {always,auto,never}
    Control when to use ANSI colors in the output.

--display {inline,side-by-side}
    Choose between inline diff or side-by-side column view.

--syntax-highlight {auto,always,never}
    Enable or disable syntax highlighting for file content.

--lang {language}
    Force a specific language parser for the input files.

--line-numbers {auto,always,never}
    Display line numbers next to diffed content.

--tab-width {width}
    Set the number of spaces for a tab character.

--context {lines}
    Number of unchanged lines to show around changes (default: 3).

--diff-context {lines}
    Similar to --context, but for the diff algorithm itself.

--show-skipped-lines
    Show lines that difftastic skipped due to parsing errors.

--byte-changes
    Fall back to byte-level diff for lines with syntax errors.

-h, --help
    Display help message and exit.

-V, --version
    Display version information and exit.

difft (short for difftastic) is a command-line tool that performs semantic, structural diffs on files, contrasting with traditional line-based diff utilities like diff. Instead of just comparing lines, difft parses files into their underlying syntax tree, identifying changes at the token, statement, or expression level. This approach results in more accurate and readable diffs, especially for code, as it can highlight moving blocks of code, renamed variables, or reordered parameters, rather than just showing entire lines as added or removed. It supports over 50 programming languages and various text formats, providing syntax highlighting and configurable output styles (inline or side-by-side).

difft is a third-party tool and not part of standard Linux distributions by default, requiring separate installation. While highly effective for code, its structural parsing can sometimes be slower than traditional line-based diffs for very large files. Its output, while clearer for semantic changes, may be more verbose than diff for trivial differences or non-code text. It's primarily designed for human readability, making it less suitable for scripting or automated parsing compared to diff's more rigid output format.

As difft is not a standard utility, it must be installed. Common methods include: using Cargo (Rust's package manager) with cargo install difftastic; via Homebrew (macOS/Linux) with brew install difftastic; or from pre-built binaries or package managers specific to your distribution.

difft can be configured as Git's default diff tool for a superior code review experience. This is typically done by configuring Git to use difft by setting core.pager to 'difft --patience --display=inline --syntax-highlight=auto' and diff.external to difft globally.

difftastic was created by Wilfred Hughes, with its first public release appearing around 2021. It emerged as a response to the limitations of traditional line-based diff algorithms, which often produce noisy or misleading output for code changes. Its development focused on leveraging modern parsing techniques (specifically tree-sitter) to understand the structure of code, providing a more intelligent and developer-friendly way to visualize changes. It quickly gained popularity in the developer community for its innovative approach.

diff(1), git-diff(1), meld(1), sdiff(1)