basename example.tar.gz .tar.gz
# => example
FILE="example.tar.gz"
echo "${FILE%%.*}"
# => example
echo "${FILE%.*}"
# => example.tar
echo "${FILE#*.}"
# => tar.gz
echo "${FILE##*.}"
# => gz
# 在bash中可以这么写
filename=$(basename "$fullfile")
extension="${filename##*.}"
filename="${filename%.*}"
原文：http://www.jb51.net/article/51592.htm