Toolshed

Toolshed improves the Elixir shell experience by adding a number of IEx helpers. This helps when a normal Unix shell prompt isn't easily accessible like on Nerves. It doesn't require Nerves, though, and all Nerves-specific commands aren't even compiled if you're not using it.

Here's a sample list of helpers:

• cmd - run a command and print out the output
• ping and tcping - check if a remote host is using ICMP or TCP
• ifconfig - list network interfaces
• weather - get the current weather from wttr.in
• speed_test - run a simple speed test to guage network throughput
• top - get a list of the top processes and their OTP applications based on CPU and memory
• tree - list directory contents as a tree
• lsusb - list USB devices

To get a complete list:

iex> h Toolshed

To try it out, add this project to your deps:

def deps do
  [
    {:toolshed, "~> 0.2"}
  ]
end

Rebuild and run in whatever way you prefer. At the IEx prompt, run:

iex> use Toolshed
Toolshed imported. Run h(Toolshed) for more info.
:ok

iex> cmd("echo hello world")
hello world
0

iex> ping "nerves-project.org"
Press enter to stop
Response from nerves-project.org (185.199.108.153): time=4.155ms
Response from nerves-project.org (185.199.108.153): time=10.385ms
Response from nerves-project.org (185.199.108.153): time=12.458ms

iex> top
OTP Application  Name or PID               Reds/Δ      Mbox/Δ     Total/Δ      Heap/Δ     Stack/Δ
nerves_runtime   Nerves.Runtime.Kernel.UE   72M/10M     157/-32    384K/-4642  192K/73K      86/52
system_registry  SystemRegistry.Global      41M/6134K     0/0      694K/192K   192K/0        35/-11
system_registry  SystemRegistry.Processor   61M/6075K     0/0       73K/-1215   73K/0        10/0
system_registry  SystemRegistry.Registrat 1623K/293K      1/1      211K/109K    73K/0        10/0
system_registry  SystemRegistry.Processor  790K/197K     59/3     1011K/4461   502K/0        38/0
undefined        #PID<0.1793.0>            221K/68K       0/0       21K/0      6772/0       504/0
system_registry  SystemRegistry.Processor  382K/58K       0/0       16K/-1227  4185/-1354    22/0
ssh              #PID<0.1786.0>            133K/52K       0/0      4184/1599   2586/1599     10/0
nerves_init_gadg #PID<0.1432.0>            213K/39K       0/0      192K/101K    73K/0        10/0

When you get tired of typing use Toolshed, add it to your .iex.exs.

FAQ

I have some IEx helpers. Would you consider adding them?

Based on using and maintaining Toolshed the past several years, here's what ends up working best:

1. Wrappers for OTP functions that make them easier to remember or format their output nicer for interactive use
2. Simple implementations of shell commands that have strong muscle memory for Linux users
3. Shortcuts to Linux system features (e.g., things that read /sys or /proc)

This project is not a Busybox replacement project or an effort to replicate all of the functionality in shell commands. Erlang/OTP contains an awful lot of built-in functionality. It's not identical to that provided by shell commands, but if there's an easy way to get at it in an IEx helper, that's what we'd like to do.

A lot of these look like Unix commands? Why not run a proper shell?

Yeah, I miss many Unix commands when I'm at the IEx prompt. Switching to a shell is easy on my laptop, but on Nerves devices, it's a pain. Getting a shell prompt on Nerves is possible, but it's limited due to Nerves not containing a full set of commands and it having to be run through Erlang's job control.

Why is everything compiled to toolshed.beam?

When using Toolshed, the helpers are all imported into the IEx shell context for ease of use. It looks like they're all defined in the Toolshed module. In fact, if you don't import Toolshed (or use Toolshed), you can still access the helpers by calling Toolshed.helper(). The problem defining all of the helpers in one module is that it makes toolshed.ex very hard to maintain.

We've experimented with many ways of maintaining the helpers, like using defdelegate and importing all of the helpers into toolshed.ex. There were several problems with these ways including function docs not being in the expected place, code being duplicated, and manual steps. The most annoying issue was that keeping helpers in lots of .beam files had an impact on load time on Nerves devices. The load-time issue is being addressed in OTP 26 more generally.

The end result is that we finally settled on merging all of the helpers at compile-time. The downside to this is that line numbers are wrong in stack traces. Given the history of this issue, this seemed like a good compromise.

You can do so much more with some of these helpers

Definitely. There's so much that I'd like to explore, but time gets in the way. I'm not sold on many decisions that I made, but something was better than nothing. Please help me improve this or make your own IEx helpers library. I'm quite happy to use it too or pull it in as a dependency.

I want to use one of the functions in my program. Is the API stable?

This isn't a normal hex.pm library. Use it for the helpers. If you want some code, copy and paste it or incorporate it into a library. I'd like the flexibility to change the API to improve interactive use.

It would be better if you changed the colors

This also isn't a question, and you've now made me regret naming the project toolshed. Please file your grievances here.