copy files and index

cp file_name file_name_copy
cp -r files files_copy
cp -rv files files_copy # you can see the process

move , rename file or index

mv file directory/
mv file directory/renamed file
mv file renamed_file # rename

remove

rm file
rm -r directory 
rm -ri directory #will remind you every time you remove a file
# -f :force to remove without any reminding.

create or remove a index

mkdir directory
rmdir directory # remove but only empty directory

tree structure of linux index

bin

executable binary files , all users have the right to run

boot

the core exists in it

dev

it is short for device.
All the devices are illustrated as a file.

etc

In general, all the relative settings exists in it.

home

Store the user's private stuff.

root

The administrator 's files.

mnt

Mount index

opt

install large software.

proc

intermediate information, virtually. Only exists in the hardware.

sbin

executable files but only can be ran by super user.

sys

low level hardware information.

tmp

temporary files. such as zip, tar and etc...

usr

applications are generally installed in it.

var

information always vary. Such as log,mails.

frequent commend lines

date and time

date
date -u
# format show
date +%Y--%m--%d

hwclock #hardware time

cal

uptime 

output and investigate command

echo # return the information you put in
cat file # investigate the file's information
more file# turn the page only down
less file # turn the page up and down #'q' can quit.
head #show the head, default 10 lines.
head -3 # show the first 3 lines
tail # show the tail,default 10 lines
tail -f # you can see the latest updates.

see the hardware information

lspci # see the PCI device
lsusb # see the USB device 
-v # you can see more details about those devices

lsmod # see all the modules(drivers)

shutdown and restart

shutdown 
-h #shutdown
-r #restart
such as:
shutdown -h now # shutdown right now
poweroff #shutdown right now
shutdown -h +10   #shutdown after 10 minutes
shutdown -h 23:30 #shutdown at 23:30

reboot # restart right now

zip and tar

要弄清两个概念：打包(tar)和压缩(zip)。打包是指将一大堆文件或目录变成一个总的文件；压缩则是将一个大的文件通过一些压缩算法变成一个小文件。

zip file_name_after_zip.zip myfile #compress the file
unzip file.zip #uncompress the file
gzip file_to_compress

tar -cvf tarName.tar file # gui dang
tar -xvf file # release the tar file
tar -cvzf tar&compressName file #plus -z tar and compress at the same time, call the gzip 

find

locate keyword # needs a database, default refresh one time a day
# use updatedb,you can update the db immediately. 

find position parameters

find . -name *keyword*
find / -name *keyword*
find / -name *.conf
find / -perm 777 # the belonging right is 777
find / -type d # d represents all the index
find . -name "a*" -exec ls -l {} \; #find the files and pass them as parameters to run the following command

other find conditions

-name
-perm
-user
-group
-ctime
-type
-size