No need le explication.

4chan.run

#!/bin/bash
if which puf >/dev/null; then
    echo "- system looks fine, let's start -"
else
    echo "*******************************************"
	echo "HOLY DOGSHIT YOU DON'T HAVE PUF, DO YOU ?!"
	echo '"sudo apt-get install puf", slimy bastard !'
    echo "   --- script ending in 10 seconds ---"
    echo "*******************************************"
	sleep 10
	exit
fi
echo ""
read -p "Which 4chan board ? Type the letter ! " boardletter
board="http://boards.4chan.org/$boardletter"
echo ""
echo "# ok, let me retrieve the board pages. Need a few seconds."
wget --quiet "$board/" -O - | grep -o 'thread/[^"]*#' | sed 's/thread\///' | sed 's/#//' >> threads
	i=1
   while [ $i -lt 17 ]; do wget --quiet "$board/$i" -O - | grep -o 'thread/[^"]*#' | sed 's/thread\///' | sed 's/#//' >> threads; let i=1+$i; done
echo ""
echo "# Done ! Now I gonna extract the thread links. Won't be long."
mkdir -p "out"
while read line; do echo "" > "out/$line"; done<threads
cd out
for file in *; do echo "$board/thread/$file" >> ../threadlist; done
cd ..
rm -rf "out"
rm threads
echo ""
echo "# That was quick. Now, let me download every thread and extract its image links. May take a minute or two."
while read line; do wget --quiet "$line" -O - | grep -o '<a href="//i.4cdn.org[^"]*' | sed 's/<a href="\/\//http:\/\//' >> imagelist; done<threadlist
rm threadlist
echo ""
echo "# Allright boy, let's download the images ! This will take long, even longer with slow connection. Go take a dump, or walk the dinosaur. Meanwhile, I let you see how's puf going."
echo ""
mkdir -p "img_$boardletter"
puf -P "img_$boardletter" -i imagelist
rm imagelist
echo ""
echo "---------------------------------------"
echo "Done. You'll find your stuff in the folder img_$boardletter :)"
echo "5 seconds before exit. Have a nice day !"
sleep 5
exit