This is a gem:

If you want your bash scripts to use a default value for your variable $ABC but still want to override that variable on the prompt, do

```bash
: ${ABC:="DefaultContent"}
```

in your script. And

```bash
ABC="SpecialContent" ./yourscript.sh
```

#BashIsBeautiful (okay, not really, the code is ugly af) #FOSS #Linux #Tips

https://stackoverflow.com/questions/4609668/override-a-variable-in-a-bash-script-from-the-command-line