ncdu-zig
Description
Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don't have an entire graphical setup available, but it is a useful tool even on regular desktop systems. Ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed.
This Zig implementation
This branch represents an experimental rewrite of ncdu using the Zig programming language. It is supposed to be fully compatible (in terms of behavior, UI and CLI flags) with the C version, so it can eventually be used as a drop-in replacement.
Since Zig itself is still very much unstable and things tend to break with each release, I can't in good conscience publish this rewrite as a proper release of ncdu (...yet). I intent to maintain the C version as long as necessary while Zig matures and gets more widely supported among Linux/BSD systems.
This rewrite is a test-bed for various improvements to the design of ncdu that would impact large parts of its codebase. The improvements may also be backported to the C version, depending on how viable a proper Zig release is.
Implementation status
Missing features:
- Lots of informational UI windows
- Directory refresh
- File deletion
- Opening a shell
Improvements compared to the C version
Already implemented:
- Significantly reduced memory usage, achieved by:
- Removing pointers between nodes that are not strictly necessary for basic tree traversal (this impacts all code in the C version of ncdu).
- Using separate structs for directory, file and hard link nodes, each storing only the information necessary for that particular type of node.
- Using an arena allocator and getting rid of data alignment.
- Improved performance of hard link counting (fixing #121).
- Add support for separate counting hard links that are shared with other directories or unique within the directory (issue #36).
- Faster --exclude-kernfs thanks to
statfs()caching. - Improved handling of Unicode and special characters.
- Remembers item position when switching directories.
Potentially to be implemented:
- Faster --exclude-pattern matching
- Multithreaded scanning
- Exporting a JSON dump after scanning into RAM
- Transparent dump (de)compression by piping through gzip/bzip2/etc
Regressions compared to the C version
Aside from this implementation being unfinished:
- Assumes a UTF-8 locale and terminal.
- No doubt somewhat less portable.
- Listing all paths for a particular hard link requires a full search through the in-memory directory tree.
- Not nearly as well tested.
- Directories that could not be opened are displayed as files.
Requirements
- Latest Zig compiler
- Some sort of POSIX-like OS
- ncurses libraries and header files
Install
todo