====== Shell scripting ======
Here will be some useful examples and snippet

===== Links =====
  * Bash single quotes and double quotes: https://askubuntu.com/a/605440
  * lockrun: http://www.unixwiz.net/tools/lockrun.html
  * solo: https://www.timkay.com/solo/
  * Prevent CRON from overlapping: https://ma.ttias.be/prevent-cronjobs-from-overlapping-in-linux/
  * bash colors: https://stackoverflow.com/a/28938235/4485894

===== Debug scripts =====

<code bash>
# sh -x some-script-name.sh
</code>

===== Differences between single and double quotes =====

Single quotes won't interpolate anything, but double quotes will. For example: variables, backticks, certain \ escapes, etc.

<code bash>
$ echo "$(echo "upg")"
upg

$ echo '$(echo "upg")'
$(echo "upg")
</code>