plus

Nu Plugin Plus

There is already an add plugin (so we can't define that) but this simple plugin is instead called "plus" and shows how to use a filter with positional arguments to add two numbers (integers). You can watch an example here:

Or here are simple examples of how it works!

Add a number to what is passed to the filter.

Usage:
  > plus {flags} <number> 

flags:
  --help

Add two integers:

> echo 4 | plus 4
━━━━━━━━━━━
 <unknown> 
───────────
         8 
━━━━━━━━━━━

Another!

> echo 4 | plus 4 | plus 4
12

If you give the wrong type, no go!

> echo boo | plus 8
boo is not a number

Combine with other plugins too. Here is an example of listing files, getting the name, calculating the length, and adding 100 to it.

> ls | get name | len | plus 100
━━━┯━━━━━━━━━━━
 # │ <unknown> 
───┼───────────
 0 │ 114 
 1 │ 108 
 2 │ 109 
 3 │ 109 
 4 │ 110 
 5 │ 121 
━━━┷━━━━━━━━━━━

Run Locally

If you want to run the plugin locally, you will nead nushell installed.

$ pip install nushell

You can then start nushell, and interact with the plugin. Make sure your present working directory with the file is added to the PATH. Here are some examples:

export PATH=$PWD:$PATH
$ nu

And then proceed to interact with the plugin, as shown above.

Logging

Logs are printed to /tmp/nu_plugin_plus.log unless you set logging=False when you initialize the plugin.

Build Python

You can optionally build the container, doing a regular make will build a container with nu and the installed python modules:

make
# docker build -t vanessa/nu-plugin-plus .

$ docker run -it vanessa/nu-plugin-plus
root@c7235d999a44:/code# nu
/code> help plus

You can also make a container with a standalone binary - we use pyinstaller to do this.

make standalone
$ docker run -it vanessa/nu-plugin-plus

And execution proceeds as before. We can prove that we don't need the modules anymore because the Dockerfile.standalone does pip3 uninstall -y nushell and it still works. Why might you want to do this? It will mean that your plugin is a single file (binary) and you don't need to rely on modules elsewhere in the system. I suspect there are other ways to compile python into a single binary (e.g., cython) but this was the first I tried, and fairly straight forward. If you find a different or better way, please contribute to this code base!