I believe it is customary to use an environment
variable PAGER to allow overriding of less (or
more, or whatever the system default is). In ksh-speak:
case $pagefile in
*.bz2)
bzcat $pagefile | ${PAGER:-less} ;;
*.gz)
zcat $pagefile | ${PAGER:-less} ;;
*)
${PAGER:-less} $pagefile ;;
esac
-- Jim