DiskPulse

Per-volume disk space monitor in your macOS menu bar. Shows usage percentage, color-coded bars, and free space at a glance.

Why

Disk space disappears silently — node_modules, Docker images, Xcode derived data — and you don't notice until something fails. I wanted my boot volume usage always visible in the menu bar, with all mounted volumes a click away. DiskPulse uses the APFS "important usage" API so the numbers actually reflect what macOS will make available.

Features

• Menu bar shows boot volume usage % with drive icon
• Popup lists all mounted volumes with usage bars
• Color-coded: green (<75%), orange (75-90%), red (90%+)
• Per-volume details: used / free / total
• Volume categories: Boot, Internal, External, Network
• Hover to see mount point path
• Click any volume to open in Finder
• Auto-refresh every 30 seconds + manual refresh button
• Uses APFS "important usage" capacity for accurate free space
• Background-only (no dock icon)

Install

Using the build script (recommended):

cd DiskPulse
chmod +x build.sh
./build.sh
open DiskPulse.app

Or compile manually:

cd DiskPulse
swiftc -parse-as-library -o DiskPulse DiskPulse.swift
./DiskPulse

Or build a .app bundle manually (no dock icon):

cd DiskPulse
swiftc -parse-as-library -o DiskPulse DiskPulse.swift
mkdir -p DiskPulse.app/Contents/MacOS
cp DiskPulse DiskPulse.app/Contents/MacOS/
cp Info.plist DiskPulse.app/Contents/
open DiskPulse.app

Quickstart

1. Build and launch: swiftc -parse-as-library -o DiskPulse DiskPulse.swift && ./DiskPulse
2. Look for the drive icon + percentage in your menu bar
3. Click to see all volumes with usage bars
4. Orange = 75-90% used, Red = 90%+ (time to clean up)
5. Click any volume row to open it in Finder

Examples

Glance at boot volume usage: The menu bar shows a drive icon and percentage like "67%". Green means plenty of space. Orange (75-90%) means it is time to audit. Red (90%+) means clean up now.

Check all volumes at once: Click the menu bar icon to see every mounted volume with a colored usage bar, used/free/total breakdown, and volume category (Boot, Internal, External, Network).

Open a volume in Finder: Click any volume row in the popup to open that volume directly in Finder. Useful for quickly navigating to an external drive or network share.

Spot an external drive filling up: Plug in an external SSD. DiskPulse picks it up on the next 30-second refresh (or click Refresh). The popup shows it under "External" with its own usage bar so you can see at a glance whether there is room for a Time Machine backup or file transfer.

Compare purgeable vs. real free space: DiskPulse uses the APFS "important usage" capacity API, which accounts for purgeable space (caches macOS can reclaim). This is why DiskPulse may report more free space than df -- it reflects what macOS will actually make available.

Testing

DiskPulse has no automated test suite (single-file SwiftUI app). Verify correctness manually:

1. Compile check -- swiftc -parse-as-library -o DiskPulse DiskPulse.swift should complete with zero errors and zero warnings.
2. Launch check -- run ./DiskPulse or open DiskPulse.app. A drive icon with a percentage should appear in the menu bar within a few seconds.
3. Popup check -- click the menu bar icon. All mounted non-hidden volumes should appear with colored usage bars.
4. Color coding -- verify green bars for volumes under 75%, orange for 75-90%, red for 90%+.
5. Click-to-open -- click a volume row. Finder should open to that volume's mount point.
6. Refresh -- click the Refresh button. The scan timestamp at the bottom should update.
7. External volume -- plug in a USB drive or mount a network share, then refresh. The new volume should appear.
8. Background-only -- verify no dock icon appears. On macOS, run: osascript -e 'tell application "System Events" to get name of every process whose background only is true' and confirm DiskPulse is in the list.

Troubleshooting

• No icon in menu bar — macOS may hide it if the bar is full. Try closing other menu bar apps.
• Percentage seems wrong — DiskPulse uses APFS "important usage" capacity which accounts for purgeable space. This is more accurate than df.
• External drives not showing — Only non-hidden volumes are listed. Time Machine and system snapshots are filtered out.

Requirements

• macOS 14.0+ (Sonoma or later)
• Swift 6.0+ compiler

License

MIT