cless

A less-like terminal pager with tree-sitter syntax highlighting.

Features

• less-compatible keybindings: number-prefix counts (5j, 100G, 50%), line / page / half-page motion, top / bottom / percent jumps, horizontal scroll
• Search: /pattern and ?pattern, repeat with n / N, smart-case (all-lowercase pattern is case-insensitive), matches shown in reverse video
• Line filter: &pattern shows only matching lines, &!pattern excludes, empty & clears; multiple & combine (AND), smart-case like search
• Marks, multi-file, and tail-follow: m/' marks, :n/:p to switch files, F to follow a growing file (tail -f)
• Line wrapping on by default (-S chops), optional line numbers (-N), startup positioning (+N / +G / +/pat, -p pat)
• stdin / pipes: cat file | cless (keys still read from the terminal)
• Tree-sitter highlighting for 15 languages: Rust, Python, JavaScript, TypeScript (incl. TSX), JSON, Go, Bash, TOML, YAML, HTML, CSS, C, Markdown
• citruszest palette (from zootedb0t/citruszest.nvim) emitted as truecolor ANSI
• Language detection: file extension → special filenames (.bashrc etc.) → shebang

Installation

Recommended: cargo binstall (downloads a prebuilt binary, no C toolchain needed)

cargo binstall cless

This pulls a prebuilt binary from GitHub Releases. Supported targets: x86_64-unknown-linux-gnu / aarch64-unknown-linux-gnu / x86_64-apple-darwin / aarch64-apple-darwin / x86_64-pc-windows-msvc.

If you don't have cargo-binstall yet: cargo install cargo-binstall.

Building from source

cargo install --path .
# or
cargo build --release   # target/release/cless

Building from source requires a C compiler because each tree-sitter parser is written in C (macOS: xcode-select --install, Ubuntu: apt install build-essential). The release binary is ~10 MB.

Usage

cless <file>...                 # one or more files (:n / :p to switch)
cless -N -S <file>              # line numbers; chop long lines instead of wrapping
cless +/TODO <file>             # open positioned at the first match of TODO
cless +G <file>                 # open at the end (like tail)
cat file | cless                # read from stdin

Flags: -S chop long lines (wrap is the default), -N line numbers, -p pattern start at the first match (alias of +/pattern), +N / +G / +/pattern startup positioning.

Keybindings

 Movement
   j, ↓, ENTER, ^E, ^N       one line down
   k, ↑, ^Y, ^P               one line up
   SPACE, f, ^F, ^V, PgDn    one window down
   b, ^B, PgUp                one window up
   d, ^D                      half-window down
   u, ^U                      half-window up
   g, <, HOME                 first line   ([N]g jumps to line N)
   G, >, END                  last line    ([N]G jumps to line N)
   p, %                       [N] percent into the file
   ←, →                       horizontal half-screen scroll

 Searching
   /pattern                   search forward
   ?pattern                   search backward
   n                          repeat last search
   N                          repeat in the reverse direction
   &pattern                   show only matching lines (&!pat excludes,
                              & alone clears; multiple & combine)

 Marks & files
   m<letter>                  set a mark at the current position
   '<letter>                  jump to a mark   ('' jumps to the previous position)
   :n, :p                     next / previous file
   F                          follow the file (tail -f); any key stops

 Other
   -S                         toggle line wrapping / chopping
   -N                         toggle line numbers
   =, ^G, :f                  show current file position (and filter state)
   r, R, ^L                   repaint the screen
   h, H                       help screen
   q, Q, ZZ, ^C               quit

Number prefix: most movement keys accept a repeat count or line number (e.g. 5j, 100G, 30%).

Customising the palette

Colors are defined as FG_* constants at the top of src/highlight.rs, and color_for(name) maps tree-sitter capture names (keyword, function, string, ...) to those colors. Edit and rebuild to change the theme.

The 26 supported capture names live in HIGHLIGHT_NAMES and follow the standard tree-sitter / Neovim naming conventions.

Architecture

Limitations

• Cannot open binary or non-UTF-8 files
• stdin cannot be combined with file arguments (it can't be re-read for :n/:p)
• No theme-switch flag (color changes require a rebuild)
• No config file; & filters reset on file switch (:n/:p) and when following (F)

License

Dual-licensed under MIT or Apache-2.0; users may choose either (Rust ecosystem standard).

• LICENSE-MIT
• LICENSE-APACHE

SPDX identifier: MIT OR Apache-2.0

Contributions

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this repository shall be dual-licensed as above, without any additional terms or conditions.