difv

Review and tweak your Git changes side by side, in the terminal.

Like the VS Code diff editor, cut down to the part you actually use before a commit: see what changed, jump between files, fix the small things, move on.

┌ Changes (4) ────────┬ HEAD / Before ──────────┬ Working Tree / Current ─────┐
│ M src/auth.ts       │ 1 const timeout = 3000  │ 1 const timeout = 5000      │
│ D src/old.ts        │ 2 oldCall()             │ 2 newCall()                 │
│ M src/user.ts       │                         │ 3 anotherLine()             │
│ A src/utils.ts      │ 3 return user           │ 4 return user               │
└─────────────────────┴─────────────────────────┴─────────────────────────────┘
 [settings ,] [help ?]                                             1-4/4

Install

brew install noih/tap/difv

Homebrew installs a prebuilt binary and needs no toolchain. With a Rust toolchain you can build from the repository or a clone instead:

cargo install --git https://github.com/noih/difv
cargo install --path .

cargo install puts difv in ~/.cargo/bin and wants Rust 1.88 or newer (edition 2024 and let chains). Either way git has to be on your PATH: difv shells out to it rather than linking a git library.

Platforms: Apple Silicon macOS, and Linux on x86_64 and arm64. Homebrew refuses on an Intel Mac rather than serving a binary nobody asked for, and cargo install still builds there. Windows is not supported: difv ignores SIGTSTP so Ctrl+Z can be undo, and it looks for its config under $XDG_CONFIG_HOME or $HOME, neither of which Windows has. Nothing else stands in the way, so a port is mostly those two spots.

Usage

difv

Run it inside a Git repository. It takes no arguments — HEAD on the left, the working tree on the right, untracked files included — beyond --version and --help.

The Current pane is editable: focus it and type. There is no mode to enter and no mode to leave, which does mean q and r type a letter while you are in it. Esc first.

The footer carries [settings ,] and [help ?] — click either, or press its key. The right of the footer shows which rows are on screen. Either panel takes the keyboard and the mouse while it is open, so nothing you do to it reaches the diff underneath.

Mouse works too: click a file, click to place the cursor, drag to select. The wheel scrolls whichever pane the pointer is over and focuses it, so you rarely need Shift+Tab at all. A sideways two-finger swipe scrolls horizontally, in terminals that report it (WezTerm, kitty, and Ghostty do; iTerm2 and macOS Terminal.app do not). Shift or Option + wheel scrolls sideways too, and ← → always work. Drag the border between two panes to resize them; the proportion survives a terminal resize.

Because difv captures the mouse, your terminal's own selection is off while it runs — hold Shift (or Option in iTerm2) while dragging to get it back. Ctrl+C copies through pbcopy, wl-copy, xclip or xsel, whichever is installed, and also emits OSC 52, so the copy reaches your local clipboard even over SSH or inside tmux.

difv expects the files to be moving under it — a formatter, a build, a rebase, another editor. If one changes on disk, difv picks it up; if you have unsaved edits in it, difv flags it instead and refuses to save over the other write. * marks a file with unsaved edits, ! one that was rewritten under them; the Current pane's title carries the * too, for when the file list is hidden.

CJK and other wide characters count as the two columns they are drawn in, so the cursor, the selection and the scroll bound all land where the text is.

Configuration

Optional, at $XDG_CONFIG_HOME/difv/config.toml (or ~/.config/difv/config.toml). XDG_CONFIG_HOME belongs to the freedesktop base directory spec rather than to difv — it moves every tool's config at once. Set DIFV_HOME to move difv's alone; both config.toml and layout.toml follow it.

Indentation and line endings are detected from each file; those settings are the fallback for files that give nothing to detect from.

detect_indent = true
indent_width = 2          # 1-16
use_tabs = false
detect_line_ending = true
line_ending = "lf"        # "lf" or "crlf"
scroll_lines = 3          # diff rows per wheel notch, 1-16
remember_layout = true
momentum_delay_ms = 300   # ignore scrolling for this long after a keystroke, 0-1000

Set either detect_* to false to force the fixed value everywhere.

A trackpad keeps sending scroll events after your fingers leave it, and those arriving just after a keystroke drag the view off the line you are editing. momentum_delay_ms ignores scrolling for that long after each keystroke. Set it to 0 if you have turned inertia off in System Settings → Accessibility → Pointer Control → Trackpad Options, or if you prefer the wheel to always answer.

, opens the same settings inside difv: ↑ ↓ to pick one, ← → to change it, Esc to close. A change applies at once and is written to config.toml straight away — there is no save step. That rewrite replaces the whole file, so comments you added by hand do not survive a change made from the panel; edit the file directly if you want to keep them.

With remember_layout on, pane widths you drag are written to layout.toml beside the config when difv exits, and restored on the next run. Delete that file to go back to the default split.

Status

The viewer and the editor are in. Soft wrap, syntax highlighting, word-level diff, and search come after.

Cutting a release

brew install works off the binaries a tag builds, and the tap is a second, tiny repository that points at them:

1. git tag v1.0.0 && git push origin v1.0.0. The release workflow builds Apple Silicon macOS and Linux on both architectures, attaches the tarballs and their checksums, and generates difv.rb with those checksums filled in.
2. Copy that difv.rb from the release into noih/homebrew-tap as Formula/difv.rb. The homebrew- prefix is what makes brew install noih/tap/difv find it, and one tap holds any later tools too.

Step 2 is one file per release; a token in this repository could push it, at the cost of a secret that can write to another repository.