Going back to good old fashioned MUMPs this works for INTs:

CALLS(rtn) ;
n NSP,EXT,VER,ROU,LAST,LINE
  ; NSP = namespace
  ; EXT = extension/type of routine e.g. INT
  ; VER = version, default is zero
  ; ROU = routine name
; LAST = last line or routine i.e. number of lines
s ROU=$g(rtn)
i ROU="" u 0 w !,"No routine reference supplied" q
s NSP="%SYS",EXT="INT",VER=0,LINE=""
  s ROU=$g(rtn)_"."_EXT_"."_VER
  ; get last line
  s LAST=$$LENGTH^%R(ROU,NSP)
  i LAST>0 d
  . f i=1:1:LAST d
  . . s LINE=$$LINE^%R(ROU,i,NSP)
  . . ; check first character of line against ASCII value
  . . ; ignore anything below 48 which is zero
  . . i $a($e(LINE,1))>47 u 0 w !,i,?10,LINE
  q