Count the number of output lines in Linux 2016-06-15 23:27
If the output or a text file is not too long we can know how many lines. But sometimes the output is to long to show them in one screen. At this point you need wc command to count the numbers of output lines. For example there are many log files like following.
[root@localhost log]# ll
total 234328
-rw-r--r-- 1 root root 0 May 23 13:56 access.log
-rw-r--r-- 1 root root 0 May 23 13:56 error.log
-rw-r--r-- 1 root root 0 May 23 13:56 external.log
-rw-r--r-- 1 root root 50582 Jun 16 11:02 info.log
-rw-r--r-- 1 root root 14579 May 23 14:11 info.log.2016-05-23
-rw-r--r-- 1 root root 8699 May 24 10:24 info.log.2016-05-24
-rw-r--r-- 1 root root 204397 May 25 19:32 info.log.2016-05-25
-rw-r--r-- 1 root root 1672696 May 26 20:07 info.log.2016-05-26
-rw-r--r-- 1 root root 9147 May 27 15:55 info.log.2016-05-27
-rw-r--r-- 1 root root 2696198 May 28 21:29 info.log.2016-05-28
-rw-r--r-- 1 root root 6937430 May 30 23:46 info.log.2016-05-30
-rw-r--r-- 1 root root 5117172 May 31 21:10 info.log.2016-05-31
-rw-r--r-- 1 root root 5066278 Jun 1 22:42 info.log.2016-06-01
-rw-r--r-- 1 root root 15548054 Jun 2 23:57 info.log.2016-06-02
-rw-r--r-- 1 root root 5348536 Jun 3 22:04 info.log.2016-06-03
-rw-r--r-- 1 root root 22020182 Jun 4 22:14 info.log.2016-06-04
-rw-r--r-- 1 root root 35066747 Jun 6 22:43 info.log.2016-06-06
-rw-r--r-- 1 root root 71681271 Jun 7 23:42 info.log.2016-06-07
-rw-r--r-- 1 root root 30729998 Jun 8 23:59 info.log.2016-06-08
-rw-r--r-- 1 root root 48426 Jun 9 00:57 info.log.2016-06-09
-rw-r--r-- 1 root root 45870 Jun 11 11:11 info.log.2016-06-11
-rw-r--r-- 1 root root 6397876 Jun 12 20:43 info.log.2016-06-12
-rw-r--r-- 1 root root 14144587 Jun 13 23:57 info.log.2016-06-13
-rw-r--r-- 1 root root 12854805 Jun 14 20:31 info.log.2016-06-14
-rw-r--r-- 1 root root 4182759 Jun 15 16:07 info.log.2016-06-15
-rw-r--r-- 1 root root 0 May 23 13:56 MonthTaskService.log
-rw-r--r-- 1 root root 0 May 23 13:56 performance.log
Let's count the number of log files.
[root@localhost mallUserGoodsService]# ll | wc -l
28
detail of wc command
wc means word count. You can use it to count the number of words or the line number.
- -c count the byte
- -m count the character
- -l count the line
- -w count the words
examples are here
[root@localhost log]# cat wc_test.txt
This is a test file
test the wc command
wc can count the words, number of lines
[root@localhost log]# wc wc_test.txt
3 17 80 wc_test.txt
[root@localhost log]# wc wc_test.txt -l
3 wc_test.txt
[root@localhost log]# wc wc_test.txt -w
17 wc_test.txt
[root@localhost log]# wc wc_test.txt -c
80 wc_test.txt