Image crawlers are very useful when we need to download all the images that appear in a web page. Instead of going through the HTML sources and picking all the images, we can use a script to parse the image files and download them automatically. Let's see how to do it.
Let's write a Bash script to crawl and download the images from a web page, as follows:
#!/bin/bash
#Desc: Images downloader
#Filename: img_downloader.sh
if [ $# -ne 3 ];
then
echo "Usage: $0 URL -d DIRECTORY"
exit -1
fi
for i in {1..4}
do
case $1 in
-d) shift; directory=$1; shift ;;
*) url=${url:-$1}; shift;;
esac
done
mkdir -p $directory;
baseurl=$(echo $url | egrep -o "https?://[a-z.]+")
echo Downloading $url
curl -s $url | egrep -o "<img src=[^>]*>" | sed 's/<img src=\"\([^"]*\).*/\1/g' > /tmp/$$.list
sed -i "s|^/|$baseurl/|" /tmp/$$.list
cd $directory;
while read filename;
do
echo Downloading $filename
curl -s -O "$filename" --silent
done...