Is there a way to display/list statements and symbols of a certain type in Metamath?

[Humanities Clinic]

Is there a way to display/list/show *only* statements and symbols of a certain type in Metamath? eg.

only all constant symbols

only all $a

Also: only all variables (and their typecodes)

Lastly, 

(A) Can the format of the output be changed?

(B) How does one pipe the output to a file?

[Humanities Clinic]

Hi, does anybody have an answer for this? By the way, what I meant is using the Metamath executable..

[Humanities Clinic]

Oh after very close reading of Dr Wheeler's / Megil's book, I found that `show statement /full` does it..