niji to the bug

find 
     base command, doesn't change
. 
     the top directory you're seeking in.  Could put a relative or absolute path here.
-type f 
     Narrowing down the kind of files you're seeking, in this case to regular files. 
     You could narrow it down in other ways, e.g. -name "*.c"
-exec egrep -H "string I'm seeking" {} \;
     the grep command in question. 
     The only thing I have a very here is the egrep switch (and the string).
     -H lists filename and the match
     -l just lists the filename; less informative but cleaner.
     {} \; is necessary syntax for the exec argument to find.