join指令

檔案1.txt

root:x:0:0:root:/root:/bin/bash

檔案2.txt

root:x:0:root

join -t ‘ ‘ -1 4 檔案1.txt -2 3 檔案2.txt

 root:x:0:0:root:/root:/bin/bash root:x:0:root

join -t ‘:’ -1 4 檔案1.txt -2 3 檔案2.txt

0:root:x:0:root:/root:/bin/bash:root:x:root