shell下获取指定后缀的文件

#!/usr/bin/bash
Folder_A=`pwd`
cd $Folder_A
for file_a in ${Folder_A}/*
do
filepath=`basename $file_a`
if [[ ${filepath:0-3:3} -eq "txt" ]]   ##以txt文件为例##
then
echo $filepath

else

echo 0
fi
done