spacedisplay-zig

Fast and lightweight terminal app to scan and analyze used disk space written in Zig.

Previous implementation in Rust can be found here.

Zig app is WIP so it lacks some features of Rust app.

Features

• Fast scanning and low memory footprint (~6MiB per 100k directories, number of files doesn't matter)
• Terminal UI that allows to use it through SSH
• Full mouse support (if terminal supports it)
• Small (~0.5MB on Linux with debug-info stripped), static binary without extra dependencies

Installation

From source

To build spacedisplay from source you'll need zig 0.15.2 installed.

zig build -Doptimize=ReleaseSafe

Built binary will be in zig-out/bin/spacedisplay. Copy it somewhere in your PATH.

If you need smaller binary you can strip debug info, but then you'll not get any stacktraces if you encounter any bugs.

Basic usage

Run the binary in your terminal and give it a path to scan. For example:

spacedisplay ~

Keyboard controls:

Key	Action
Ctrl+C	Quit
Home/End	Jump to first/last file/dir
Up/Down	Move up and down inside files list
Enter, Right	Open selected directory
Esc, Backspace, Left	Go to the parent directory

If your terminal supports it, you can also move around with your mouse.

Performance

spacedisplay is efficient in both speed and memory footprint. So scan speed is mainly limited by disk access to gather metadata. Here are some test results with time in seconds that takes to fully scan root partition.

Platform	Files+Dirs	spacedisplay	File Manager
Ubuntu 24.04	850K	1.3s	9.3s

In test above default file manager is Files in Ubuntu.

spacedisplay is also lightweight in terms of memory usage. Most memory is used only to store scanned directory tree (without files) and directory names. To scan ~100k dirs it takes ~6MiB of RAM (measured in Ubuntu 24.04). Exact amount of memory depends on how long directory names are but given such low consumption it shouldn't be a problem ever.

Performance tests

Performance of spacedisplay can be measured (relatively to other tools) via performance.sh. For performance measurement hyperfine is used. It will also measure performance of spacedisplay-rs if it is found in zig-out dir under name spacedisplay-rs.

This script doesn't measure actual hard drive speed since warmup is used and filesystem information is cached at OS level. On first run scan time will be much higher due to slow calls to hard drive.

Results on some platforms:

Ubuntu 24.04 (750k files)

Command	Mean [s]	Min [s]	Max [s]	Relative
spacedisplay-zig	1.331 ± 0.021	1.312	1.381	1.00
spacedisplay-rs	2.129 ± 0.024	2.096	2.168	1.60 ± 0.03
du -sh	1.356 ± 0.016	1.326	1.379	1.02 ± 0.02