ll -a | grep a |awk '{print $1,$3}' >> awk.txt

1, list all files info in current dir, match a in every column content.

2,format output column1 and column 3 to file awk.txt.

Hopely help u easily to learn shell comand! more Info about awk to office website or refer https://www.cnblogs.com/xudong-bupt/p/3721210.html.