依据几列的值删除重复行
输入
1.txt
a 1 1
a 1 2
a b 3
a c 4
a c 5
a c 6
a d 7
a d 8
a e 9
a f 10
a f 11
输出
2.txt
a b 3
a e 9
先把1.txt按照指定的几列（第1,2列）排序
sort -k1,1 -k2,2 1.txt > 3.txt
awk
'{last=$0; chr=$1;start=$2; getline; if( chr == $1 && start ==
$2 ) {print last" 1";print $0" 1";} else {print last" 0";print
$0" 0";}}' 3.txt
> 4.txt
awk 'BEGIN{getline;print
$0" "0;}{last=$0; chr=$1;start=$2; getline; if( chr == $1 &&
start == $2 ) {print last" 1";print $0" 1";} else {print
last" 0";print $0" 0";}}' 4.txt
> 5.txt
awk '$4 == 0 && $5 == 0' 5.txt | awk '{print $1" "$2" "$3;}' > 2.txt