Before you start the next section, you may like to clear the terminal window of the previous commands so the output of the following commands can be clearly understood.
At the prompt, type
clear
This will clear all text and leave you with the % prompt at the top of the window.
The command cat can be used to display the contents of a file on the screen. Type:
cat science.txt
As you can see, the file is longer than than the size of the window, so it scrolls past making it unreadable.
The command less writes the contents of a file onto the screen a page at a time. Type
less science.txt
Press the [space-bar] if you want to see another page, and type [q] if you want to quit reading. As you can see, less is used in preference to cat for long files.
The headcommand writes the first ten lines of a file to the screen.
First clear the screen then type
head science.txt
Then type
head -5 science.txt
What difference did the -5 do to the head command? Only shows the first 5 lines
The tail command writes the last ten lines of a file to the screen.
Clear the screen and type
tail science.txt
Q. How can you view the last 15 lines of the file?
tail -15 science.txt