Well, this is a strange thing to do, but say you want to know how fast an application is processing data. how to tell? Enter strace, and… a bit of wc -l with the assistance of tee and 2>&1 proper redirection.

strace -p 9653 2>&1 | tee >(wc -l)

where 9653 is the process id (pid) and wc -l is the command you want to pipe to!

read(4, "2.74.2.34 - - [26/05/2015:15:15"..., 8192) = 8192
read(4, "o) Version/7.1.6 Safari/537.85.1"..., 8192) = 8192
read(4, "ident/6.0)\"\n91.233.154.8 - - [26"..., 8192) = 8192
^C1290

1290 lines in the output.. perfect, thats what I wanted to know, roughly how quickly this log parser is going thru my logs 😀