This is a command to search the internet in one of search engines: Google, Yandex and Duckduckgo and open the results in Links2. The usage is as follows:
s <g,y,d> <search arguments>
Here is an example google search for '10 most useful bash commands':
s g 10 most useful bash commands
Here is the same search in Duckduckgo:
s d 10 most useful bash commands
Here is a yandex search for 'what is the best search engine':
s y what is the best search engine
I think this is a great time saver, allowing you to quickly look things up when you are working from within the command line