Day 1:

ls: lists directories cd : switch directories pwd: displays the current directory mkdir: creates a new directory rmdir: remove an empty directory cp: copy files or directories rm: remove file or directory mv: move files and directories, or change the names of files and directories

ls: lists directories:

-a: all the files, together with hidden files (files beginning with.). -d: list only the directory itself, not the file data in the directory (usually) -l: long data string listing, including file attributes, permissions and other data; (common)

ls -l ls -ld ls -a

###############

cd : switch directories

examples: Use the mkdir command to create the runoob directory mkdir runoob # create dir named runoob

Use the absolute path to switch to the runoob directory cd /root/runoob # change to dir /root/runoob

Use the relative path to switch to the runoob directory cd - # change to the dir to last dir you have changed

cd ~ # change to home dir for current user

cd .. # change to upper dir

##########

pwd: displays the current directory mkdir: creates a new directory

-m: permissions for configuration files! Direct configuration, do not need to see the default permissions (umask) face ~ -p: to help you directly create the required directory (including the directory above) recursively! mkdir -p /test/hhh # create two dirs and one belones to another

rmdir: remove an empty directory rmdir dirname # remove a dir named dirname

##################

cp: copy files or directories

cp file1 file2 # copy the content of file1 to file2 cp file1 /mnt/files # copy file named file1 to /mnt/file

rm: remove file or directory

rm file #just remove a file

rm -fr dirname # force remove a dir named dirname rm -fr file # force remove a file named file

mv: move files and directories, or change the names of files and directories

mv file1 /mnt # move file named file1 to /mnt dir mv file1 file2 #rename file1 to file2 ,and it can be rename dir

more less vi vim cd pwd ls su passwd chgrp chown mv cp touch mkdir rm ssh [email protected] -p port ifconfig -a ip addr show eth0

#####################################

Day 2:

init # system run level Commands: 0 Power-off the machine. init 0 6 Reboot the machine init 6 2, 3, 4, 5 Start runlevelX.target unit init 2/3/4/5 1, s, S Enter rescue mode init 1 init 0/3/5/6 basiclly you should know

date # show date date "+%Y~%m~%d %H-%M-%S" # show date or time in custom format wget http://url ##download something from the url curl -o/O http://url ##download something from the url

ps: to see process on the system To see every process on the system using standard syntax: ps -e ps -ef ps -eF ps -ely

To see every process on the system using BSD syntax: ps ax ps axu

netstat -altnp |grep 22 ss -anlpe kill -9 pid
uname -n/r/o

uname --help # when you meet a command you don't know how to use it you should to know use '--help' or 'man uname ' to help you

Day 3:

lscpu /cat /proc/cpuinfo

top

df -hm df -hT

free -hm

killall -9 [process name]
killall5 -9 [process name]

eg : killall -9 httpd # kill all process by force related to httpd kill -9 httpd # kill main process by force named httpd

uname -a # print all info uanme -n # print node name uname -o # print operating-system type uanme -r # print kernel version

#The uptime command prints how long the system has been running and the average load on the system. The uptime command displays the following information: the current time, how long the system has been running, how many users are currently logged in, and the average load of the system over the past 1 minute, 5 minutes, and 15 minutes.

uptime

who # which user and which session using by user

last #last time who logged into the system successfully lastb #last time who logged into the system falied

wc -l # to count lines from input wc -w # to count how many words from input