装完maven后查看maven版本
mvn -v
提示
-bash: /opt/apache-maven-3.2.2/bin/mvn: Permission denied
权限不够，chmod a+x /opt/apache-maven-3.2.2/bin/mvn(a:所有用户 +:增加权限 x:执行权限)
Mac下mvn -v提示Permission denied
原文：https://www.cnblogs.com/bichen-01/p/11973557.html
