Reading and editing text

To see a whole file, there is cat:

$ cat /etc/hostname

For a large file cat is awkward: it dumps everything at once and the start scrolls away. Then you use less:

$ less /var/log/syslog

Inside less, the arrows and PageUp/PageDown scroll, /word searches forward, n repeats the search, q quits. Often you only need the edges of a file:

$ head notes.txt          # first 10 lines
$ head -n 3 notes.txt     # first 3 lines instead of 10
$ tail notes.txt          # last 10 lines
$ tail -f /var/log/syslog # follow new lines as they are written

For editing, nano is enough in Part I. I