...,$0)}' passwd#awk 'NF{print $0 "\n"}' passwd#awk 'NF;NF{print ""}' passwd4.数字每3位以逗号为分隔符(eg:12,345,678)#sed ':a;s/\B[0-9]\{3\}\>/,&/;ta'#sed -r -e :a -e 's/(.*[0-9])([0-9]{3})/\1,\2/;ta'#awk '{while(match($0,/[0-9][0-9][0-9][0-9]+/)){$0=sprintf("%s,%s",substr($0...