shell脚本下载网页图片

#!/bin/bash
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 $url | egrep -o "https?://[a-z.]+")
echo "$baseurl"
curl -s $url | egrep -o "<img src=[^>]*>" |
sed ‘s/<img src=\"\([^"]*\).*/\1/g‘ > /tmp/$$.list
sed -i "s|^/|$baseurl/|" /tmp/$$.list
cd $directory;
while read filename
do
 curl -s -O "$filename" --silent
done < /tmp/$$.list