根据已有目录结构从目标目录中提取

echo $#
if [ $# -lt 2 ]; then
    echo "input basis folder base:"
    read src
    echo "input target folder base:"
    read target
    echo "input output folder base:"
    read output
else
    src=$1
    target=$2
    output=$3
fi
echo "input param: "$src" "$target" "$output
if [ ! -d "$src" ]; then
    echo "invalid src folder"
    exit 1
fi
if [ ! -d "$target" ]; then
    echo "invalid target folder"
    exit 2
fi
if [ ! -d "$output" ]; then
    mkdir -p "$output"
fi

function extract(){
    targetFile=${1#*/}
    targetFile=${targetFile#*/}
#    echo "coping "$targetFile"  to "$output"/"$targetFile
    if [ -f $target"/"$targetFile ]; then    
#    echo "coping "$target"/"$targetFile"  to "$output"/"$targetFile
    cp --preserve $target"/"$targetFile $output"/"$targetFile
    fi    
}
function extractFolder(){
    targetFile=${1#*/}
    targetFile=${targetFile#*/}
#    echo "coping "$targetFile"  to "$output"/"$targetFile
    if [ -d $target"/"$targetFile ]; then    
    echo "creating folder "$target"/"$targetFile"  to "$output"/"$targetFile
    mkdir -p $output"/"$targetFile
    fi    
}

function read_dir(){
for file in `ls $1` 
do
 if [ -d $1"/"$file ] 
 then
 extractFolder $1"/"$file
 read_dir $1"/"$file
 else
 #echo "dealing file  "$1"/"$file 
 extract $1"/"$file 
 fi
done
} 
read_dir $src

./extract.sh ./BuildRoot ./b7r6 ./output