==== sample commands ====
<code>
csvgrep -c col1 -m "val1" file.csv | \
csvgrep -c col2 -r "foo|bar" | \
csvcut -c col1,col2,col3 | \
column -t -s,
</code>

demonstrates | regex a or b

Ref:- https://dl.icewarp.com/online_help/203030104.htm - Simple RegEx Tutorial. It talks about the '|' OR operator in regex. For example "foo|bar" matches a string that has either "foo" or "bar" in it.

==== useful links ====
  * https://csvkit.readthedocs.io/en/1.0.6/scripts/csvgrep.html
  * https://github.com/wireservice/csvkit/releases
  * https://csvkit.readthedocs.io/en/latest/scripts/csvgrep.html
  * https://csvkit.readthedocs.io/en/latest/