Brad Lucas

Programming, Clojure and other interests

Loading File Into Node Repl

July 25, 2017

So the day after writing a post about working in multiple languages I find myself in front of Node writing in JavaScript. Nothing big to start.

I was writing things in a file and then executing them with node file.js when I decided it was time to work inside the Node repl.

For this the question became how do you load your file and have access to the functions and variables.

The answer:


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Programming Languages ADD

July 24, 2017

It is common to assume in the programming world that any competent programmer should be able to learn a new programming language in a few days and be productive within a week or so. Many will brag about their knowledge of multiple languages and how they did this in that and that in this.

The whole concept of a full-stack developer speaks to this same idea. These roles require people to know everything from the front-end (JavaScript, CSS, a framework, etc) to the middle-ware (Python, JavaScript, a framework, etc) to the database (SQL).

I've found this myself. In fact, my last project required me to move between Bash, Java, Python and Clojure daily and sometimes throughout the day.

I wonder though if some sort of specialization might be better. In my last project I wished to focus exclusively on Clojure but that didn't work out.


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Csv Headers

July 23, 2017

To show the headers for each csv file in a directory.

#!/bin/bash

# Echo the header lines for all the cvs files in the current directory

for filename in *.csv;
do
  # echo $filename;
  line=$(head -n 1 $filename);
  echo $line;
done

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Bash With An Empty Environment

July 22, 2017

When writing bash scripts that look for environment variables it is a good idea to check that these environment variables exist at the top of the script. For this you do things like the following.

if [[ -z $LOG ]]; then
  echo "Missing LOG environment variable"
fi

Now once you've created your environment variable how can you test your script for the case where the environment variable doesn't exist? For this you can open another bash shell with no environment variables. An empty environment if you will. To do this try the following.

$ env -i bash --norc --noprofile

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Mac Cleaner

July 21, 2017

Ran out of space on the MacBook and found this free Mac cleaner application that worked well.

AppCleaner from FreeMacSoft

Works well.


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