001、
(base) [email protected]:/home/test4# ls a.txt (base) [email protected]:/home/test4# cat a.txt ## 测试数据 This is 1 This is 2 This is 3 This is 4 This is 5 (base) [email protected]:/home/test4# sed = a.txt ## 在每一行之前插入编号 1 This is 1 2 This is 2 3 This is 3 4 This is 4 5 This is 5