这是一款很好用的工具包

				#!/usr/local/bin/gawk -f				#				# make-sub-lm --				#	extract a lower-order backoff LM from a higher order one.				#				# usage: make-sub-lm maxorder= lm-file > sub-lm-file				#				# $Header: /home/srilm/devel/utils/src/RCS/make-sub-lm,v 1.2 1998/11/09 05:54:12 stolcke Exp $				#								BEGIN {					maxorder=2;				}				NF==0 {					print; next;				}				/^ngram *[0-9][0-9]*=/ {					order = substr($2,1,index($2,"=")-1);					if (order 					next;				}				/^\\[0-9]-grams:/ {					currorder=substr($0,2,1);					if (currorder 						print;					} else {						print "\n\\end\\";						exit;					}					next;				}				/^\\/ {					print; next;				}				currorder {					if (currorder < maxorder) {						print;					} else if (currorder == maxorder) {						#						# delete backoff weight for maximal ngram						#						if (NF == currorder + 2) {							$NF = "";						}						print;					}					next;				}				{ print }