Pager example

pager.sh

#!/bin/bash

# Function that picks the best available pager
pager() {
  # if stdout is not to a TTY, copy directly w/o paging
  [ -t 1 ] || { cat; return; }

  if [ -n "$PAGER" ]; then  ## honor the user's choice, if they have a pager configured
    "$PAGER"
  elif command -v less >/dev/null 2>&1; then
    less
  elif command -v more >/dev/null 2>&1; then
    more
  else
    echo "WARNING: No pager found; falling back to cat" >&2
    cat
  fi
}

# Alternative function
# pager() {
# [ -t 1 ] || { cat; return; }
# less
# }

usage () {
  echo 'USAGE: '
  echo '  pager.sh -l '
}

while getopts "lh" option; do
    case $option in
        l)
          list='true'
          ;;
        h)
          usage
          exit 0
          ;;
        *)
          usage
          exit 0
          ;;
    esac
done
shift $(($OPTIND - 1))

if [ "$list" = 'true' ]; then
pager <<'EOF'
here is our documentation
several pages of content here
etc, etc, etc
EOF
fi