# bottom

[![Build Status](https://travis-ci.com/ClementTsang/rustop.svg?token=1wvzVgp94E1TZyPNs8JF&branch=master)](https://travis-ci.com/ClementTsang/rustop)

A top clone, written in Rust.  Inspired by both [gtop](https://github.com/aksakalli/gtop) and [gotop](https://github.com/cjbassi/gotop)

![Quick demo recording](assets/recording_1.gif)
*Note that the background you see is not part of the app, that's just because I use a slightly transparent background*

## Installation

### Linux

You can install by cloning and using ``cargo build --release``, or download the pre-compiled binary in Releases.  Note this needs the nightly toolchain if you are building.

### Windows

This is still in development.

### MacOS

Currently, I'm unable to test on MacOS, so I'm not sure how well this will work, if at all.  I'll try to source MacOS hardware to test this application.

## Usage

### Command line options

* ``-h``, ``--help`` to show the help screen and exit (basically has all of the below CLI option info).

* ``-a``, ``--avgcpu`` enables showing the average CPU usage on rustop

* ``-c``, ``--celsius`` displays the temperature type in Celsius.  This is the default.

* ``-f``, ``--fahrenheit`` displays the temperature type in Fahrenheit.  This is the default.

* ``-k``, ``--kelvin`` displays the temperature type in Kelvin.  This is the default.

* ``-v``, ``--version`` displays the version number and exits.

* ``-r <RATE>``, ``--rate <RATE>`` will set the refresh rate in *milliseconds*.  Pick a range from 250ms to ``UINT_MAX``.  Defaults to 1000ms, and higher values may take more resources due to more frequent polling of data, and may be less accurate in some circumstances.

### Keybinds (some may not be available on certain operating systems)

#### General

* ``q``, ``Esc``, or ``Ctrl-C`` to quit.

* ``Up/k``, ``Down/j``, ``Left/h``, ``Right/l`` to navigate between panels.  This currently doesn't have much functionality but will change in the future.

#### Processes Panel

* ``dd`` to kill the selected process (currently only on Linux) - **I would highly recommend you to be careful using this, lest you accidentally kill the wrong process**.

* ``c`` to sort by CPU usage.  Sorts in descending order by default.  Press again to reverse sorting order.

* ``m`` to sort by memory usage.  Sorts in descending order by default.  Press again to reverse sorting order.

* ``p`` to sort by PID.  Sorts in ascending order by default.  Press again to reverse sorting order.

* ``n`` to sort by process name.  Sorts in ascending order by default.  Press again to reverse sorting order.

### Mouse Actions

[* Scrolling either scrolls through the list if the panel is a table (Temperature, Disks, Processes), or zooms in and out if it is a chart.]: <>

* Scrolling currently only scrolls through the list if you are on the Processes panel.  This will change in the future.

## Regarding Process Use Percentage (on Linux)

I cannot guarantee whether they are 100% accurate.  I'm using a technique I found online which seems to be a better indicator of process use percentage at the current time, rather than pulling from, say, ``ps`` (which is average CPU usage over the *entire lifespan* of the process).  I found the options from the library I used to get other data (heim) to be a bit too inaccurate in my testing.

For reference, the formula I am using to calculate CPU process usage is along the lines of:

```rust
let idle = idle + iowait;
let non_idle = user + nice + system + irq + softirq + steal + guest;

let total = idle + non_idle;
let prev_total = prev_idle + prev_non_idle; // Both of these values are calculated using the same formula from the previous polling

let total_delta : f64 = total - prev_total;
let idle_delta : f64 = idle - prev_idle;

let final_delta : f64 = total_delta - idle_delta;

//...

// Get utime and stime from reading /proc/<PID>/stat
let after_proc_val = utime + stime;
(after_proc_val - before_proc_val) / cpu_usage * 100_f64; //This gives your use percentage.  before_proc_val comes from the previous polling
```

Any suggestions on more accurate data is welcome!  Note all other fields should be accurate.

## Thanks

* As mentioned, this project is very much inspired by both [gotop](https://github.com/cjbassi/gotop) and [gtop](https://github.com/aksakalli/gtop) .

* This application was written with the following libraries:
  * [chrono](https://github.com/chronotope/chrono)
  * [clap](https://github.com/clap-rs/clap)
  * [crossterm](https://github.com/TimonPost/crossterm)
  * [failure](https://github.com/rust-lang-nursery/failure)
  * [fern](https://github.com/daboross/fern)
  * [futures-rs](https://github.com/rust-lang-nursery/futures-rs)
  * [futures-timer](https://github.com/rustasync/futures-timer)
  * [heim](https://github.com/heim-rs/heim)
  * [log](https://github.com/rust-lang-nursery/log)
  * [sysinfo](https://github.com/GuillaumeGomez/sysinfo)
  * [tokio](https://github.com/tokio-rs/tokio)
  * [tui-rs](https://github.com/fdehau/tui-rs) (note I used a fork due to some issues I faced, you can find that [here](https://github.com/ClementTsang/tui-rs))

## Why

I was looking to try writing more things in Rust, and I love the gotop tool.  And thus, this project was born.