Grep still greps! | Linux command "grep"

"Could you grep that for me?". Somehow grep beats any Windows equivalent text search tool I know of. I even use my Linux based machine to "grep" information in log files from Windows based machines.
Perhaps this is the most famous and well known command among IT geeks.

Grep supports searching in multiple files stored in multiple directories on any mount point on your machine. Sometimes you have to find something in a log file. But lets say you don't know in which log file you should start. Then the recursive flag would offer an outcome. I won't go into great detail here but these iterations of the grep command I use the most. Obviously this nifty tool can do a lot more than what I am writing here. Regular expressions for example. The full manual can be found here.

Plain grep

grep "{search string}" /some/file

Case insensitive grep

grep -i "{search string}" /some/file

Recursive grep

grep -r "{search string}" /some/directory

Case insensitive and recursive grep

grep -ir "{search string}" /some/directory

Exclude lines with a specific character

grep -v "#" /some/config/file