shell to insert the value of the PAGER variable before invoking the
command. echo echoes back its argument: in this case, it echoes the
current PAGER value, less.

man more
Displays the more manual. This time, man should have invoked the less
pager.

less has lots of features that more lacks. For example, you can scroll
backward with the b key. You can also move up and down (even sideways)
with the arrow keys. less won't exit when it reaches the end of the man
page; it will wait for you to press q.

You can try out some less-specific commands, like b, to verify that they
don't work with more and that you are indeed using more.

unset PAGER
If you don't want to specify a pager anymore, you can unset the variable.
man will then use more by default, just as it did before you set the
variable.

echo $PAGER
Because PAGER has been unset, echo won't print anything.

PS1=hello:

Figure 6.2: Changing the prompt
\begin{figure}\par\par\begin{list}{}{ \setlength{\rightmargin}{\leftmargin}
\ra... ...o~My~prompt~is~\$PS1} \par My~prompt~is~hello: \par
hello:\end{list}\end{figure}