common /pat/ slen, slimit, srchst, shftab
 
integer slen			# length of search string; init: 0
integer slimit			# when equal to slen, limits string
				# searching to beginning of input buffer
byte srchst(MAXLINE)		# holds current search string
byte shftab(-128:127)		# holds amount to shift search string
				# along input when mismatch occurs.