Text viewer

To view text in linux, there are several tools that one can use. The purpose of the text viewer is to view the text file and not editing it. Some of it also equipped with search function to ease reading.
If you are using GUI, you can use gedit, which is available if you are using gnome desktop environment. Gedit works as both editor and viewer. If you are using KDE desktop, you can use KEdit.

In the absence of GUI, a few tools can be used, such as less and more. These 2 tools is quite similar with only the difference in name.
To use less:
# less filename

and similarly to use more:
# more filename

Another tool that can be used is cat. Cat's purpose is to concatenate 2 file into one, but if used to a single file, cat will display the file to standard output. To use cat:
# cat filename