In case, you are looking for a quick string search within files on a Windows machine, you can use the “findstr” tool:
findstr /i /s "my_string_abc" <folder path>
In the abve example, we use the following modifiers:
/i indicates do a case insensitive search
/s search in sub directories
using * instead of <folder path> would search for all files from the current folder and below.
You can also find additional information about findstr at http://ss64.com/nt/findstr.html