If you are used to working with Linux, you will find a lot of file text in Linux world. Configuration files and log files are usually kept in text format. But those files usually has long content.
You can not view them all in one page. So we need pagination to those files. And to do that, we can use Linux more command.
More command is a command for displaying a long text file per page at a time. More command is a built-in command in Linux.
How to use linux more command
To use more command, we just need to type :
$ more file_name
For example, we want to see the content of syslog file located in /var/log directory. We can type :
$ more /var/log/syslog
We see that an indicator on the bottom left. It shows us number 0%. It means that the file is long enough, so the first page is 0% of the total page. To scroll down, use space button. Then we see that the indicator number is increased.
1) Limit lines per page
When you run more command, it will fill your screen with the content of the file you are seeing using more. You can limit it into some lines for each page. To do this you can use -num option.
For example, you want to limit the lines only 12 lines for each page. Then you can type :
$ more -12 /var/log/syslog
Now it will limit 12 lines per page. When you press spacebar to scroll down, it will show you more 12 lines.
2) Display user message
As we knew, more will display an indicator at the bottom left to show our position in percentage. For those who run more at the first time, he/she may guess how to scroll the page down. To avoid this, we can use -d option that will make more command display a user message like this “[Press space to continue, ‘q’ to quit.]” .
If user press a button other than button ‘space’ and ‘q’ , then more will display a warning message “[Press ‘h’ for instructions.]” .
If you press h button, it will display a help message :
One of the interesting command is the b button. b button allow you to go back to previous page. In other word, b button allow you to scroll up.
You can know that you are in the previous page from the line ...backup 1 page at the top left area.
3) Suppress scroll
With -c option, more will not scroll the page. It will clear the previous page and put the next page or lines there.
$ more -10 -c lynis.log
If you press space button, the next page or lines is still at the same size.
4) Squeeze multiple blank lines
To squeeze it, we can use -s option. Here’s a sample :
When we add -s option :
$ more -s doc_30.txt
5) Search string
If your log file is long enough, it’s not easy to find a string that you want. The search string can help you. Using +/string can search a string for you and put the keyword on the beginning of the line. Let say we want to search “dhclient” in /var/logs/syslog file. Then the syntax is :
$ more +/dhclient /var/log/syslog
Then to continue the search on the next line, you can press / button following by dhclient word.
6) Display content start with specific line
You can also display a content of file start with specific line using +num option. For example, we have a file with 15 lines inside it.
Then we want to display a file named doc_30.txt starting from the line number 5. The command will be like this :
$ more +5 doc_30.txt
Can we use it to display binary file?
The answer is No. More will give you a message about this. Here’s a sample.
More is one of the basic tool to display a content of text file. More cannot be used to display binary file. As usual, we can always type man more or more --help to explore more detail about the usage of more command.