linux常用

1.linux目录（以centos7为例）

linux下，一切皆文件。文件皆存在于目录之中。

/    根目录

/bin    软链接，指向 /usr/bin/目录，存储常用命令
/sbin   /usr/sbin/         
/lib     /usr/lib/
/lib64  /usr/lib64/

 

2.关闭selinux

selinux是linux的一个内核模块

暂时关闭selinux

setenforce 0

永久关闭selinux

vim /etc/sysconfig/selinux

进入vim修改selinux文件

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of three values:
#     targeted - Targeted processes are protected,
#     minimum - Modification of targeted policy. Only selected processes are protected. 
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

原本的 SELINUX=enforcing，修改为上标色代码所示，重启服务器，则永久性关闭selinux。

3. /etc/passwd 文件

name:password:uid:gid:comment:home:shell |-->文件格式