linux awk命令中如何提取任意列

1、测试数据

root@PC1:/home/test2# cat test.txt
01 02 03 04 05 06 07 08 09 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40

2、

root@PC1:/home/test2# for i in 1 3 5; do awk -v a=$i '{printf("%s ", $a)} END {printf("\n")}' test.txt >> temp; done  ## 提取1,3,5列
root@PC1:/home/test2# ls
temp  test.txt
root@PC1:/home/test2# cat temp  ## 生成转置文件
01 11 21 31
03 13 23 33
05 15 25 35

3、

root@PC1:/home/test2# ls
temp  test.txt
root@PC1:/home/test2# for i in `seq $(head -n 1 temp | awk '{print NF}')`; do cut -d " " -f $i temp | awk '{printf("%s ", $0)}END{printf("\n")}' >> result.txt; done
root@PC1:/home/test2# ls
result.txt  temp  test.txt
root@PC1:/home/test2# cat result.txt   ## 提取结果
01 03 05
11 13 15
21 23 25
31 33 35