cat

cat(选项)(参数) 显示文件的内容，tac为cat的反向输出

-b：为非空行编号

?

1 2 3 4 5 6 7

[root@bogon admin]# cat -b a      1  hive:x:5000:5000:hive:/home/hive:/bin/bash        2  u2:x:5003:5004::/home/u2:/bin/bash      3  u3:x:5004:5005::/home/u3:/bin/bash      4        user1:x:5005:5007::/home/user1:/bin/bash      5  user2:x:5006:5008::/home/user2:/bin/bash

 -e或-E：为每行行尾添加个$

?

1 2 3 4 5 6 7

[root@bogon admin]# cat -e a hive:x:5000:5000:hive:/home/hive:/bin/bash$ $ u2:x:5003:5004::/home/u2:/bin/bash$ u3:x:5004:5005::/home/u3:/bin/bash$       user1:x:5005:5007::/home/user1:/bin/bash$ user2:x:5006:5008::/home/user2:/bin/bash$

 -n：为每一行编号，包括空行

?

1 2 3 4 5 6 7

[root@bogon admin]# cat -n a      1  hive:x:5000:5000:hive:/home/hive:/bin/bash      2       3  u2:x:5003:5004::/home/u2:/bin/bash      4  u3:x:5004:5005::/home/u3:/bin/bash      5        user1:x:5005:5007::/home/user1:/bin/bash      6  user2:x:5006:5008::/home/user2:/bin/bash

 -s：将所有连续的空白行都转换为一行

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

[root@bogon admin]# cat -n b      1  q      2  w      3       4       5  e      6  r      7       8       9  t [root@bogon admin]# cat -ns b      1  q      2  w      3       4  e      5  r      6       7  t

 -t或-T：将制表符tab键转换为^I

?

1 2	[root@bogon admin]# cat -t c ^Ithis is a table^I^I

 

 

 

扩展：

1.将b文件和c文件合并到c，并显示

?

1 2 3 4 5 6 7 8 9 10 11 12

[root@bogon admin]# cat b c > d [root@bogon admin]# cat d q w     e r     t     this is a table