各位兄弟姐妹，关于扩展名的问题，说了半天也没个结果啊。

寂寞烈火

linux里的文件的扩展名只是给人看的,对文件类型的判断,linux是看头不看尾!
例如:
/home/lee#touch a.gz
/home/lee#ls a.gz
a.gz
/home/lee#file a.gz
a.gz: empty
/home/lee#echo abc>;>;a.gz
/home/lee#file a.gz
a.gz: ASCII text
/home/lee#gzip url
/home/lee#file url.gz
url.gz: gzip compressed data, was "url", from Unix
/home/lee#mv url.gz url.txt
/home/lee#file url.txt
url.txt: gzip compressed data, was "url", from Unix
看明白了吗?