The tail command for Linux learning

The Tail command writes the file to standard output starting at the specified point. Using the-f option of the tail command makes it easy to see the log files that are being changed, TAIL-F filename will display the most trailer in filename on the screen, and not only refresh, Enables you to see the latest file content.

1. command format;

tail[necessary parameters [selection parameters] [file]

2. Command function:

Used to display the content at the end of the specified file, and is processed as input when the file is not specified. Common view log files.

3. Command parameters:

-F Loop Read

-Q does not display processing information

-V displays detailed processing information

Number of-c< > bytes displayed

-n< lines > Display rows

--pid=pid is shared with-F, which means that the process ends after the id,pid dies.

-Q,--quiet,--silent never output the header of the file name

-S,--sleep-interval=s is combined with-F, which means sleep s seconds at each repetition interval

4. Usage examples:

Example 1: Displaying the end of a file

Command:

5 Log2014.log

Output:

  1  [[email protected] test]# tail-n 5< /span> Log2014.log   2   3  2014 -09   4   5  2014 -10   6   7  2014 -11    9  2014 -12  10  11  ==============================[[email protected] test]# 

Description

Displays the last 5 lines of the file

Example 2: Looping through the contents of a file

Command:

Tail-f Test.log

Output:

1[[email protected] ~]# Ping192.168.120.204> Test.log &2[1]11891[Email protected] ~]# tail-F Test.log3Ping192.168.120.204(192.168.120.204) About( -) bytes of data.4  -bytes from 192.168.120.204: icmp_seq=1Ttl= -Time=0.038Ms5  -bytes from 192.168.120.204: icmp_seq=2Ttl= -Time=0.036Ms6  -bytes from 192.168.120.204: icmp_seq=3Ttl= -Time=0.033Ms7  -bytes from 192.168.120.204: icmp_seq=4Ttl= -Time=0.027Ms8  -bytes from 192.168.120.204: icmp_seq=5Ttl= -Time=0.032Ms9  -bytes from 192.168.120.204: icmp_seq=6Ttl= -Time=0.026MsTen  -bytes from 192.168.120.204: icmp_seq=7Ttl= -Time=0.030Ms One  -bytes from 192.168.120.204: icmp_seq=8Ttl= -Time=0.029Ms A  -bytes from 192.168.120.204: icmp_seq=9Ttl= -Time=0.044Ms -  -bytes from 192.168.120.204: icmp_seq=TenTtl= -Time=0.033Ms -  -bytes from 192.168.120.204: icmp_seq= OneTtl= -Time=0.027Ms the[Email protected] ~]#

Description

Ping 192.168.120.204 > Test.log &//Ping remote host in background. and output files to Test.log; This practice also allows for more than one file to monitor. Use CTRL + C to terminate.

Example 3: Displaying a file starting from line 5th

Command:

Tail-n +5 Log2014.log

Output:

1 [email protected] test]# cat Log2014.log2  the- on3  the- Geneva4  the-Geneva5  the-Geneva6  the- to7  the- .8  the- -9  the- ,Ten  the- the One  the-Ten A  the- One -  the- A -============================== the[Email protected] test]# Tail-n +5Log2014.log -  the- to -  the- . -  the- - +  the- , -  the- the +  the-Ten A  the- One at  the- A -==============================

The tail command for Linux learning