sock-emoji

A tiny macOS menu-bar / Windows notification-area app written in Go. Send newline-delimited UTF-8 through a named pipe to update its emoji. No notification popups or application window. Linux is not yet supported.

Windows

Build with Go 1.23 or newer; no C compiler is needed:

go build -ldflags=-H=windowsgui -o sock-emoji.exe .
Start-Process .\sock-emoji.exe -WindowStyle Hidden

The GUI build runs without a console window. For console diagnostics, use go run . instead. Look for the initial sock icon in the notification area beside the clock (Windows may put it in the hidden-icons overflow). Right-click the icon and choose Quit to exit.

Send an update from PowerShell:

echo '🧦' | .\sock-emoji.exe
echo '✅ Build finished' | .\sock-emoji.exe

With piped or file-redirected stdin, the executable runs as a short-lived sender: it connects to the running tray instance, streams the input, and exits. It does not create another icon or start a tray instance automatically. If no instance is running, it exits with an error. Long-running producers can send successive newline-delimited updates without closing their output. Use -pipe on the sender to select a custom endpoint.

PowerShell 7 sends UTF-8 by default. In Windows PowerShell 5.1, set this once per session (or in your profile) before piping emoji to an executable:

$OutputEncoding = [System.Text.UTF8Encoding]::new($false)

Otherwise PowerShell 5.1 replaces emoji with question marks before the app receives them. See PowerShell character encoding.

Normal launches without redirected stdin still start the tray app. If your launcher redirects stdin, force tray mode with -listen:

Start-Process .\sock-emoji.exe -WindowStyle Hidden -ArgumentList '-listen'

The existing helper also works without changing PowerShell's output encoding:

.\scripts\send-emoji.ps1 '🧦'
.\scripts\send-emoji.ps1 '✅ Build finished'

The default endpoint is \\.\pipe\sock-emoji. The helper connects with a two-second timeout and writes UTF-8 without a BOM; it works with Windows PowerShell 5.1 and PowerShell 7. Other programs can connect to the same local named pipe and write UTF-8 lines. Avoid shell redirection: Windows named pipes are not Unix FIFOs, and Windows PowerShell's default file encoding is unsuitable.

Windows shows the first Unicode cluster from each message as a stationary icon; the message also appears in its tooltip, truncated to the Windows limit. DirectWrite/Direct2D render Segoe UI Emoji in full color on a transparent background, including supported skin-tone and joined sequences. No additional font installation is needed. Glyph coverage and composite appearance depend on the installed Windows font version; unsupported symbols may appear as boxes. Ordinary text and symbols without color glyphs use white.

The pipe accepts only your Windows account and rejects remote clients. Multiple scripts can connect independently, including while another writer remains connected. Blank lines are ignored; rapid updates coalesce to the latest pending status. A final line without a newline is accepted when the writer disconnects. Messages must be smaller than 1 MiB; NUL-containing lines are ignored. Starting a second app on the same pipe fails rather than replacing the first.

To choose another pipe:

Start-Process .\sock-emoji.exe -WindowStyle Hidden -ArgumentList '-pipe', '\\.\pipe\my-status'
.\scripts\send-emoji.ps1 '✨' -PipeName my-status
echo '✨' | .\sock-emoji.exe -pipe '\\.\pipe\my-status'

For startup at login, place a shortcut to the built executable in the folder opened by shell:startup in the Windows Run dialog. The app also restores its tray icon when Explorer restarts.

macOS

Build

go build -o sock-emoji

This uses cgo plus a tiny Objective-C bridge for the macOS status bar item, so it needs the Xcode Command Line Tools installed.

Run

./sock-emoji

Then in another terminal:

echo "🧦" > ~/sock
# Or forward stdin through a short-lived sender process:
echo "🧦" | ./sock-emoji

The emoji or text will appear in the status bar icon area and update each time the pipe receives new content.

Text is shown as a ticker. By default only one Unicode cluster is visible at a time, so hello appears as h, e, l, l, o instead of taking over the menu bar.

Multiple newline-delimited values may be sent through one write. Rapid updates coalesce to the latest pending status:

printf "🧦\n✨\nOK\n" > ~/sock

Customize pipe path

./sock-emoji -pipe ~/my-sock

Ticker options

./sock-emoji -width 1 -delay 200ms
./sock-emoji -width 3 -delay 100ms

-width controls how many Unicode clusters are visible at once. -delay controls the pause between ticker frames.

Start on login

The macOS-friendly local install is via a per-user LaunchAgent, not a daemon. A LaunchAgent runs inside your login session, so it can show a menu bar item, all without needing root. The included installer builds the binary, installs it under ~/Library/Application Support/sock-emoji, and registers a launchd plist under ~/Library/LaunchAgents.

chmod +x scripts/install-launch-agent.sh scripts/uninstall-launch-agent.sh
scripts/install-launch-agent.sh

The LaunchAgent uses RunAtLoad and intentionally does not set KeepAlive, so choosing Quit from the menu bar item exits the app and launchd leaves it stopped. It starts again at your next login, or when you manually run:

launchctl kickstart -k "gui/$(id -u)/dev.offpeak.sock-emoji"

To customize the installed LaunchAgent:

SOCK_EMOJI_PIPE="$HOME/my-sock" SOCK_EMOJI_WIDTH=3 SOCK_EMOJI_DELAY=100ms scripts/install-launch-agent.sh

To uninstall:

scripts/uninstall-launch-agent.sh

Homebrew

There is a Homebrew formula template at Formula/sock-emoji.rb. Until there is a tagged release with a real SHA-256, install the current branch with:

brew install --HEAD ./Formula/sock-emoji.rb
brew services start sock-emoji

Before publishing a stable release in a tap, create a release tarball and replace the placeholder SHA-256:

git archive --format=tar.gz --prefix=sock-emoji-0.1.0/ -o sock-emoji-0.1.0.tar.gz v0.1.0
shasum -a 256 sock-emoji-0.1.0.tar.gz

Then update:

url "https://github.com/OffPeakEngineer/sock-emoji/archive/refs/tags/v0.1.0.tar.gz"
sha256 "..."
head "https://github.com/OffPeakEngineer/sock-emoji.git", branch: "main"

Once a tap is published, install and start on login with:

brew tap OffPeakEngineer/tap
brew install OffPeakEngineer/tap/sock-emoji
brew services start sock-emoji

The formula's service uses keep_alive false, so the menu bar Quit item stops the app and Homebrew/launchd will not restart it until you run brew services start sock-emoji again or log in again after starting the service.