item preprocessing allows extracting content, based on regexp. a way to extract the number of matches is desired.
for example, the apache status page has scoreboard like this :
here we would have to count the number of occurrences of each letter to know how many processes are in each state.
a vague idea how this could work - a regexp like this :
would have either some syntax for the output field, or there would be a choice between "output" and "number of matches". the latter would allow to specify which capture group to use. in this example, it would return 7.