#!/bin/sh

ncpu=$(sysctl -n hw.ncpuonline)
temp=$(mktemp -d)

find ${@:-.} -maxdepth 1 -type f \( -iname "*.jpg" \
                                 -o -iname "*.jpeg" \
                                 -o -iname "*.png" \
                                 -o -iname "*.gif" \
                                 -o -iname "*.heic" \
                                 -o -iname "*.tif" \
                                 \) | sort -R > $temp/filelist.txt

count=$(( $(wc -l < $temp/filelist.txt) / ncpu ))

( cd $temp && split -l $count $temp/filelist.txt )

for f in $temp/x*
do
    nsxiv -ati < $f &
done