# whetū — a zero-config status line and history picker in Zig ~/install ## Two ways **Download the binary.** Grab the tarball for your platform, check it against the published `SHA256SUMS`, and put it on your `PATH`. Then add one line to your shell config. `$ sha256sum -c SHA256SUMS --ignore-missing && tar -xzf whetuu-*.tar.gz && mv whetuu ~/.local/bin/` [Tarballs and checksums](https://github.com/yamafaktory/whetuu/releases/latest) are on the releases page, for macOS and Linux on x86-64 and ARM64. **Or run the installer.** It does the same thing, and saves you a `uname`. It detects your platform, verifies the download, puts the binary in `~/.local/bin`, and adds the init line to the config of the shell you actually use. Running it twice changes nothing. `$ curl --proto '=https' --tlsv1.2 -fsSL https://yamafaktory.github.io/whetuu/install.sh | sh` [Read the script](https://yamafaktory.github.io/whetuu/install.sh) first if you would rather not pipe to a shell. It verifies nothing you could not verify yourself. Then open a new shell. That is the whole install. Would rather edit your own dotfiles? Run it with `WHETUU_NO_MODIFY=1` and it prints the lines instead of writing them. `whetuu init ` prints them too, along with the file they belong in. A `PATH` line appears only when `~/.local/bin` is not already on your `PATH`. **Needs a [Nerd Font](https://www.nerdfonts.com/).** whetuu draws the git branch, the language logos and the star with Nerd Font glyphs. Most terminal setups already run one, so try it first. If the star and the branch glyph come out as empty boxes, switch your terminal font. ### Uninstalling One line for the program, one for the data. The history store and the version cache live under the XDG directories rather than next to the binary, so removing whetuu never takes your history with it. Run `whetuu paths` first if you want to see both locations, in case `$XDG_DATA_HOME` or `$XDG_CACHE_HOME` moves them on your machine. `$ rm ~/.local/bin/whetuu && rm -rf ~/.local/share/whetuu ~/.cache/whetuu` Then delete the `# whetuu` block from your shell config. ~/demo ## See it in a real shell The status line tracks the branch, the git status and the toolchain version. Pressing the up arrow opens the history picker, which filters as you type and runs what you pick. demo ![A terminal session. The status line tracks the branch, git status and toolchain version. The history picker then filters and runs a command.](https://yamafaktory.github.io/whetuu/demo.gif) ~/modules ## What it shows Left to right, each segment appears only when it is relevant. user\_host **user@host** in bold green, but only over SSH or when you are root, and then in bold red as a warning. directory The current directory with **$HOME** collapsed to **~**. Keeps the anchor plus as many trailing directories as fit the width. git branch Branch glyph and current branch, or **(detached)**, in magenta. git state Any operation underway, in yellow: **(rebasing 2/7)**, **(merging)**, **(cherry-picking)**. Read straight from **.git**, with no extra subprocess. git status Conflicts, stashes, staged, modified, untracked, ahead and behind, in one bracketed group. language Logo and toolchain version in the brand colour, for **39 languages and tools**. Detected from a project manifest, a source file extension, or an infra marker. cmd\_duration Timer glyph and elapsed time, when the last command ran for two seconds or more. character A star, purple by default or in the language brand colour. Turns red after a failed command. ~/picker ## A history picker on the up arrow Commands are recorded once they finish, and only when they exited cleanly and are text, so neither typos nor an image pasted into the terminal enter the store. Each is stored with the directory it ran in. The picker opens scoped to the current directory and falls back to all history when there is none. The command that just broke is the one exception. It sits at the top in red until you run another command, so you can pick it and fix it. It is never stored. whetuu history 2d git commit -m "Cache toolchain versions" 1d cd ~/cf/platform && git push -u origin HEAD 17h docker exec -i PGPASSWORD=x db psql 14m nvim ~/.config/fish/config.fish 11m npm ci 󰦥 **Rows are syntax highlighted.** The command name, flags, paths, variables, quoted strings and operators each take a colour from your terminal theme, so the picker matches the palette you already run. A command too wide for the window loses its middle to a **…** rather than its end, which keeps a run of commands sharing one long prefix apart. - **type**Filter. Every word must match, ignoring case. - **Backspace / Delete**Drop the last character of the search. The cursor never leaves the end of it, so both keys do the same thing. - **↑ / ↓**Move the selection. Up goes further back in time. - **Home / End**Jump to the newest command, or to the oldest one on the list. - **Ctrl+G**Switch between this directory's history and all of it. - **Tab**Copy the selection into the search field to edit or extend. Enter then runs what you typed. - **Enter**Run the selection, or the text you typed after a Tab. Moving the selection goes back to running it. - **Esc**Cancel, leaving whatever you had typed on the command line. ~/commands ## Nothing to run day to day The shell hook drives everything and the picker is on the up arrow, so two of these are called for you and you never type them. This is the whole command surface. `render` and `history add` take flags that only the init scripts pass, namely exit status, duration and width. That is why they are left out here. **A fresh install has neither file.** `whetuu paths` marks the missing one rather than hiding it, until the first command is recorded and the first toolchain version is cached. With neither **$HOME** nor the matching XDG variable set it says so, because then whetuu has nowhere to write. ~/performance ## Renders in about 2 ms A status line runs before every command, which makes it the one thing in your shell that has to be quick. The slowest module runs as a task via `std.Io` while the rest run alongside it, so a render takes about as long as its slowest probe rather than the sum of them all. Measured with `hyperfine --warmup 40 --runs 400` on a 13th gen i9-13900H, ReleaseFast, pinned to the performance cores on an otherwise idle machine. In the monorepo the whole status line takes about as long as `git status` on its own. **Outside a repository neither subprocess runs.** whetuu walks up from the current directory looking for the repository, which is a handful of `stat` calls, and only starts git once it has found one. That is what makes a directory with no repository and no project cost a millisecond. **A slow repository cannot hang your shell.** Both subprocesses are bounded. Git gets 250 ms and the toolchain probe gets 200 ms, and they run at the same time, so the worst case is the larger of the two. Given a git that hangs for 30 seconds, the status line still returns in 257 ms. It simply drops the git segment. **And a status line stays out of git's way.** The call passes `--no-optional-locks`, so git reads the index without refreshing it. It never takes `index.lock`, which a `git commit` in another terminal would then fail to take. **A big history does not slow the picker.** The up arrow reads the most recent few megabytes rather than the whole store, so it opens in about 20 ms on a store of 70 MB just as it does on one of 400 KB. Nothing is deleted to keep it that way. Years of history stay on disk. ~/security ## Nothing leaves your machine A status line sees every command you run, and the picker keeps them. That is a lot to hand a small tool, so here is exactly what whetuu does and does not do. No network There is no socket, no HTTP client and no sync anywhere in the binary. No telemetry and no update check. There is no account and no server to opt out of. Two files Running, whetuu writes exactly two. The history store, created with mode **600** and reset to it on every write, so one left readable by an older version corrects itself. And a cache of toolchain version strings at **~/.cache/whetuu/versions**, which holds nothing else and can be deleted whenever you like. Spec paths only The binary goes in **~/.local/bin**, the history store under **$XDG\_DATA\_HOME** and the version cache under **$XDG\_CACHE\_HOME**. No directory of our own in your **$HOME**. **whetuu paths** prints both data locations. One install edit The installer appends the init line to the config of the shell in **$SHELL**, and nothing else. Not the config of a shell you do not use, and never twice. A **PATH** line joins it only when **~/.local/bin** is not already on your **PATH**. **WHETUU\_NO\_MODIFY=1** makes it print them instead. Skip a command Start a command with a space and it is never recorded. Use it for the ones carrying a token. Only successful commands are stored at all. No shell, ever whetuu runs two subprocesses: **git** and the toolchain version probe, and neither outside a repository or a project. Both get a fixed list of arguments rather than a command line, so nothing you type is ever interpreted as a command. State like a rebase in progress is read straight out of **.git** with no subprocess at all. Escapes defanged Every control byte in a command, a branch name or a directory becomes a **?** before it reaches your terminal. A repository you just cloned cannot repaint your screen or move your cursor through whetuu. Nothing to configure No config file means no config parser, no theme format and nothing of yours being executed at startup. The attack surface is the binary and the two commands above. One caveat The language module picks which toolchain to probe from the files in the current directory, so entering an untrusted repository can make whetuu run something like **node --version**. It runs whatever your **PATH** resolves, never a binary from the repository. Checkable downloads The Linux builds are static musl with no runtime dependencies, and every release ships a **SHA256SUMS** file. The source is [on GitHub](https://github.com/yamafaktory/whetuu) and builds from it with one command.