I think that you should use a text editor. I like vim myself. That will give you LOTS of power when viewing files and then when you want to edit them you will already know the basics.
Here are some of the advantages of using a text editor (specifically vim):
- syntax-highlighting
- powerful movement commands
- find
- jump to specific location in a file (called a mark)
- folding (useful when you just want to see function stubbs)
To open your file in readonly mode use this:
vim -R <file name>
Here is a basic navigation guide:
j - move down one line
k - move up one line
h - left one char
l -right one char
ctrl-f - forward one page
ctrl-b - back one page
/<something> - search for something
n - next of whatever you searched for
N - next (search backwards) of whatever you searched for
:q - quit
:q! - quit without saving
:w - save
Here is a link for more information:
http://www.viemu.com/a_vi_vim_graphical_cheat_sheet_tutorial.html
Just to recap, if you will use unix vim is pretty fundamental. I have heard that learning vim is like learning to type. It is the next most useful tool you can learn for programming.
(Just to avoid editor wars you could also look into emacs or another editor, however I personally prefer vim)