To expand on the previous answers:
From
man(1)
Code:
-P pager
Use specified pager. Defaults to “less -sR” if color support is
enabled, or “more -s”. Overrides the MANPAGER environment vari‐
able, which in turn overrides the PAGER environment variable.
Using
% man cat | less
is exactly the same as just using
% man cat
.
As for searching, you can either use the
/ key in less, or use
% man ls | egrep pattern
Both methods support regular expressions are are basically the same, the (e)grep method is more suited for commandline/scripted use, while the interactive search in less is for interactive use.