工作中遇到一个小需求，需要对一系列的文件进行重命名。
原始格式是string_1.obj,现在想把文件名中的数字变成定长的，不足位数往前补零，即变成string_001.obj这种形式。
自己学着写了个脚本，很菜的，贴上来请大家指点一下。
#! /bin/bash
# this script is used to rename files
# the orignal filename is as XXXX_1.obj
# and the final filename is as XXX_0001.obj the width of the num is given as a parameter
rm result.txt
export suffix=".obj"
find . -name "*$suffix" > result.txt
cat result.txt | while read oneline
do
export orifilename=${oneline##*/} #cut off the path of filename
export prefilename=${orifilename%_*} #without "_"
export numfilename=${oneline##*_}
export numfilename=${numfilename%.*} #get the num in filename
((i=$1-${#numfilename})) #get the num of zero which is needed
export zeros=`echo $numfilename | awk '{printf "%0'"$i"'d",0}{print}'`
export finalfilename=$prefilename"_"$zeros$suffix
#echo "$orifilename, $finalfilename"
# rename "s/$orifilename/$finalfilename/" ./$finalfilename
mv $orifilename $finalfilename
done
echo "Done"
