Linux添加环境变量的几种方法

最近在安装ansible，安装后命令找不到

[root@center ansible-2.7.5]# python setup.py install

安装后 查看相关版本

[root@center ansible-2.7.5]# ansible --version
-bash: ansible: command not found

查看可执行文件目录为

[root@center ansible-2.7.5]# /usr/local/bin/ansible --version
ansible 2.7.5
config file = None
configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
ansible python module location = /usr/local/lib/python2.7/site-packages/ansible-2.7.5-py2.7.egg/ansible
executable location = /usr/local/bin/ansible
python version = 2.7.8 (default, Jan 9 2019, 14:25:24) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]

[root@center ansible-2.7.5]# echo $PATH
/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

当前PATH 并没有/usr/local/bin，因此需要将/usr/local/bin添加到环境变量中
下面列出三种添加方法

1、直接用export命令：

export PATH=/usr/local/bin:$PATH
[root@center ansible-2.7.5]# echo $PATH
/usr/local/bin:/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

但是这种方法只会对当前用户及当前命令行窗口生效，退出后就会丢失

2、编辑修改.bashrc文件:

vim /root/.bashrc 
#在最后一行添上：
export PATH=/usr/local/bin:$PATH

这种方法只会对当前用户生效，需重启系统

3、编辑修改profile文件:

vim /etc/profile
export PATH=/usr/local/bin:$PATH

这种方法对所有用户生效，需重启系统

所以我们配置时需要结合1-2或者1-3
配置完之后再次执行ansible
[root@center ansible-2.7.5]# ansible --version
ansible 2.7.5
config file = None
configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
ansible python module location = /usr/local/lib/python2.7/site-packages/ansible-2.7.5-py2.7.egg/ansible
executable location = /usr/local/bin/ansible
python version = 2.7.8 (default, Jan 9 2019, 14:25:24) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]