Use `mdls` on macOS to get the number of pages in PDF files

mdpdfpagecount.sh

#!/usr/bin/env zsh -f
# Purpose: count PDF pages with a variety of tools
#
# From:	Timothy J. Luoma
# Mail:	luomat at gmail dot com
# Date:	2019-12-23

NAME="$0:t:r"

if [[ -e "$HOME/.path" ]]
then
	source "$HOME/.path"
else
	PATH="$HOME/scripts:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin"
fi

for i in "$@"
do

	EXT="$i:e:l"

		# if this file does not end in '.pdf' then skip it
	[[ "$EXT" != "pdf" ]] && continue

		# we try to get the page count with `mdls`
	PAGE_COUNT=$(mdls -raw -name kMDItemNumberOfPages "$i")

		# if mdls cannot get the page count it will return '(null)'
	if [[ "$PAGE_COUNT" == "(null)" ]]
	then
				# we were given more than one arg, so we do need to output the filename
		echo "$i: Unable to determine page count." >>/dev/stderr

	else

		if [[ "$PAGE_COUNT" == "1" ]]
		then
			echo "$i (1 page)"
		else
			echo "$i (${PAGE_COUNT} pages)"
		fi
	fi

done

exit 0

#EOF