#!bin/bash
#program:
# this program shows "hello world" in your screen.
#history:
#2015/01/01 Richard first release
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
echo -e "hello world! \a \n"
exit 0
~/.bashrc 里修改alias
source ~/.bashrc 然后生效
原文：http://my.oschina.net/u/1423127/blog/399222