# monitor

A terminal system monitor written in **Gleam** — sits between **htop** and **btop**.

| From htop | From btop |
|-----------|-----------|
| Dense process table (PID, USER, PRI, NI, VIRT, RES, S, CPU%, MEM%, TIME+, Command) | Color meters & sparklines for CPU / memory / swap |
| Sort by column, filter (`/`), kill (`k`) | Per-core CPU bars |
| Keyboard + mouse navigation | Clean alternate-screen TUI |

## Requirements

- Linux (`/proc`)
- [Gleam](https://gleam.run) + Erlang/OTP
- A modern terminal (truecolor optional, 256-color fine)

## Run

```sh
# if Erlang isn't on PATH (NixOS):
nix develop   # or: nix-shell -p gleam beamPackages.erlang
gleam run
```

## Keys

| Key | Action |
|-----|--------|
| `↑` / `u` · `↓` / `j` | Move selection (htop-style: `k` is kill, not up) |
| `PgUp` / `PgDn` | Page |
| `g` / `G` | Top / bottom |
| `c` `m` `p` `t` `n` | Sort by CPU / MEM / PID / TIME / name (press again to reverse) |
| `T` | Toggle tree: sort by value, then group each hot PID with its PPID family |
| `r` | Reverse sort (highest-first by default for CPU/MEM/TIME) |
| `/` | Filter (substring on command, user, pid, ppid) |
| `k` / `K` | Kill selected process (SIGTERM, confirms) |
| `Space` | Force refresh |
| `h` / `?` | Help |
| `q` / `Esc` | Quit |

## Mouse

| Action | Effect |
|--------|--------|
| Click process row | Select that process |
| Click table header (PID / CPU% / MEM% / TIME+ / Command) | Sort by that column (again to reverse) |
| Scroll wheel | Move selection |
| Right-click process | Select and confirm kill (SIGTERM) |
| Click (help / kill dialog) | Close help · cancel kill confirm |

## Architecture

```
src/
  monitor.gleam   entrypoint
  app.gleam       event loop, keys, refresh
  ui.gleam        layout & rendering (etch)
  sys.gleam       /proc collectors
  format.gleam    bars, sizes, sparklines
```

Built with [etch](https://hex.pm/packages/etch) for the TUI backend.