I have lines like these, and I want to know how many lines I actually have...
09:16:39 AM all 2.00 0.00 4.00 0.00 0.00 0.00 0.00 0.0
If all you want is the number of lines (and not the number of lines and the stupid file name coming back):
wc -l < /filepath/filename.ext
As previously mentioned these also work (but are inferior for other reasons):
awk 'END{print NR}' file # not on all unixes
sed -n '$=' file # (GNU sed) also not on all unixes
grep -c ".*" file # overkill and probably also slower