linux中批量修改文件名

一、批量修改文件名
问题：某个目录下面有很多文件，现在将含有“bak”的文件中的bak改为_BAK_
1、shell版 ${var/pattern/replacement}
for file in `find /path -name "*bak*" -type f`
do
mv $file ${file/bak/_BAK_}
done

2、sed版
find /path -name "*bak*" | sed -r -n 's/(.*)bak(.*)/mv & \1_BAK_\2/e'
find /path -name "*bak*" | sed -r -n 's/(.*)bak(.*)/mv & \1_BAK_\2/'|sh
但是效率低，

3、awk版
for file in `find /path -name "*bak*" -type f`
do
echo "$file"|awk 'BEGIN{FS="bak";OFS="_BAK_"}{printf "mv "$0" ";$1=$1;print $0}'
done

4、rename版
find /path -name "*bak*" | xargs -i rename "bak" "_BAK_" {}