Is that possible to use grep on a continuous stream? What I mean is sort of a tail -f <file> command, but with grep on the output in order to keep only the lines that interest me. I've tried tail -f <file> | grep pattern but it seems that grep can only be executed once tail finishes, that is to say never.
![How to 'grep' a continuous stream?](https://cdn-ak-scissors.b.st-hatena.com/image/square/98d6f053a97a87156775f60757c60865d0f2c47d/height=288;version=1;width=512/https%3A%2F%2Fcdn.sstatic.net%2FSites%2Fstackoverflow%2FImg%2Fapple-touch-icon%402.png%3Fv%3D73d79a89bded)