Linux Basics

 

查看当前用户

whoami

远程访问

1.SSH

ssh [email protected]

获得帮助

以ls 命令为例 

1. man ls

2. ls --help

3. man -K ls

查看主机上所有与 ls 有关的 man 信息。

4.whatis ls

5.apropos ls

进程

ps -A

查看所有

 

进程监控命令 top

 

 

目录结构

/bin/ User commands and binaries.  
/boot/ Files used by the boot loader. 
/dev/ Device files.  
/etc/ System configuration files.  
/home/ User’s home directories.  
/lib/ Shared libraries and kernel modules.  
/media/ Removable media is usually mounted here .  
/mnt/ Temporary mounted file systems are usually mounted here.  
/opt/ Add-on application software packages.  
/proc/ Kernel and process status data is stored in here in text-file  format.  
/root/ The root user’s home directory.  
/sbin/ System binaries.  
/srv/ Data for services provided by this host.  
/tmp/ Directory for temporary files.  
/usr/ User utilities, libraries, and applications.  
/var/ Variable or transient files and data, for example logs, mail queues, and print jobs. 

 

 

文件类型

- File  
d Directory  
l Link  
c Character devices  
b Block devices  
s Socket  
p Named pipe

 

 

授权

# chmod u+x myfile 

# chmod u-x,og+w myfile  
# chmod 654 myfile

# chmod u=g myfile

# chmod -R u+x /usr/local/bin/*

-R 递归授权

 

0 --- None  
1 --x Execute  
2 -w- Write  
3 -wx Write and execute  
4 r-- Read  
5 r-x Read and execute  
6 rw- Read and write  
7 rwx Read, write, and execute

 

umask 命令

很重要哦，如果没有设置，默认创建文件后权限是666，创建目录后权限是777，很危险的哦。

要通过 umask 命令来修改

umask 0022

 

 

属主关系

改变属主关系：chown

# chown robinmyfile  
# chown robin:admin myfile  
# chown -R robin:admin /home/jsmith/*

 

 

空间和大小

查看文件大小信息

du -sh 

查看磁盘使用信息

df -h

 

 

查看文档

cat 

more

less 

grep localhost /etc/hosts

-r 递归查找

grep -r localhost /etc

支持正则表达式哦

grep 'host$' *

 

 

查找文件

find /opt -type f -iname oracle*

以root用户运行，查找没有有效归属用户和组的文件

find / -nouser -o -nogroup