21: Viewing files with less

  Wurm lab

So far we have covered listing the contents of directories and moving/copying/deleting either files and/or directories. Now we will quickly cover how you can look at files. The less command lets you view (but not edit) text files. We will use the echo command to put some text in a file and then view it:

learner@:learning_unix$ echo "Call me Ishmael."
Call me Ishmael.
learner@:learning_unix$ echo "Call me Ishmael." > opening_lines.txt
learner@:learning_unix$ ls
opening_lines.txt
learner@:learning_unix$ less opening_lines.txt

On its own, echo isn’t a very exciting Unix command. It just echoes text back to the screen. But we can redirect that text into an output file by using the > symbol. This allows for something called file redirection.

Careful when using file redirection (>), it will overwrite any existing file of the same name

When you are using less, you can bring up a page of help commands by pressing h, scroll forward a page by pressing space, or go forward or backwards one line at a time by pressing j or k. To exit less, press q (for quit). The less program also does many other useful things (including text searching).