terminal command to open new chromium tab
Solution 1:
A couple of options to consider...
1) Find an existing instance of Chromium, activate the window, and send Ctrl+t to open a new tab:
xdotool search --onlyvisible --name 'Chromium' windowactivate --sync key --clearmodifiers --window 0 ctrl+t
2) Open the about:blank page in a new tab:
chromium-browser 'about:blank'
#1 does exactly what you want.
#2 is cheesy.
Solution 2:
Open a New Tab and look at the Developer Tools - Sources tab. URL for New Tab is:
chrome-search://local-ntp/local-ntp.html
This will open a new tab in existing Chromium instance:
chromium chrome-search://local-ntp/local-ntp.html