Get and Set Environment Variables

Jul 10, 2017 · 103 words · 1 minute read

#env #environment #get #os #set #var #variable #variables

Environment variables are a useful way to work with sensitive information (think passwords) which your code needs to work with, but don’t need to be checked into your code base. With Go, you can both get and set these details using the os library.

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package main

import (
    "fmt"
    "os"
)

func main() {
    // Outputs your 'visual' env var (in my case 'vim' (set in ~/.bashrc))
    fmt.Println(os.Getenv("VISUAL"))

    // Create your own environment variable
    os.Setenv("Site", "GoLangCode")
    fmt.Println(os.Getenv("Site"))

    // Equals empty string if doesn't exist
    fmt.Println(os.Getenv("missing"))
}

Exit an Application, With or Without an Error Code – Apr 17, 2020
Exiting an application in Go happens anyway when the main() function is complete, but the purpose of this post is to show you how to force that to happen. Perhaps at an earlier stage than the end of your code, perhaps with an error code too. This is a well established method in POSIX systems, whereby a program can return a 0-255 integer to indicate if the program ran successfully, and if not, why not.
Build a Basic Web Scraper in Go – Oct 26, 2019
This is a single page web scraper, it uses the goquery library to parse the html and allow it to be queried easily (like jQuery). There is a Find method we can use to query for classes and ids in same way as a css selector. In our example we use this to get the latest blog titles from golangcode. If you needed to search an entire site, you could implement a query to follow and recall a link urls.
Creating & Writing to Temp Files – Jul 6, 2018
We programmers often use temporary files and this example shows how we can create and write to one. We used the ioutil package which has functions for just this. The TempFile() accepts a folder and a prefix. As the folder we get the os’ temp directory (which would be /tmp on unix systems) and for the prefix we use a string, but if we don’t want one, we just pass an empty string.

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Author: Edd Turtle

Edd is the Lead Developer at Hoowla, a prop-tech startup, where he spends much of his time working on production-ready Go and PHP code. He loves coding, but also enjoys cycling and camping in his spare time.

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