EHCO command: Display a line of text
"Feature" will print out the content by default, which is most commonly used in the shell.
Syntax
echo option argument
"Common options"-E activates escape characters
\b: Delete the previous character \c: End with a newline symbol \ n: newline and the cursor moves only the beginning of the line \ r: The cursor moves to the beginning of the line, but does not wrap \ t: Insert tab\\: Insert "\" character
Instance
Print the given string directly [[email protected] tmp]# echo "Hello word" hello word//add-e option to activate escape character "\ N "[[email protected] tmp]# echo -e " Hello\nword " helloword//Delete the previous character to add the" \b "escape character [[ email protected] tmp]# echo -e "Hel\blo\nword" heloword//add newline "\ n" and tab means "\ t" [email protected] tmp]# echo -e "A\TB\TC\T\ND\TE\TF" a b cd e f//Displays the shell environment where the current user is logged on [[Email protected] ~]# echo $0-bash View the previous command execution result status [[email protected] ~]# echo $?0//View the current user's home directory path [[email protected] ~ ]# echo $HOME/root//Displays the SHELL environment and path [[email protected] ~]# echo the current user is logged on $SHELL/bin/ bash//But the usual is echo a string to the file,[[email protected] ~]# echo "www.baidu.com" > /tmp/ B.txt | cat&nBsp;/tmp/b.txt
Wall command: Send a message to everybody ' s terminal
"Feature" sends information to each end user
Syntax
Wall ' message '
"Instance" sends content "message" content to all user terminals, including itself, but requires online users
[Email protected] ~]# wall ' message ' [[email protected] ~]# broadcast message from [email protected] (PTS/2) (Fri Apr 22 0 5:44:54): Message
Write command: Send a message to another user
"Feature" sends information to other users,
Syntax
write [users] [TTY]
When you enter the Write users tty# enter the input mode, enter the content you need to enter, and then return to send information to each other, the other party can receive information.
Clear Command: Clear the terminal screen
"Function" clear terminal screen information, referred to as clear screen, shortcut key ctrl+l can be used to indicate the command line input.
Syntax
Clear or Ctrl+l
This command is available when there is too much content on the screen and needs to be re-cleaned, but it is not really clear, it is just the equivalent of a non-informational screen.
Sync Command: Flush file system buffers
"Feature" refreshes the file system's buffers, that is, writes the buffer's files to the hard disk
Syntax
Sync
Uptime Command: Tell how long the system has been running
"Features" show how long the system has been running so far, can see the information is: the current time, the system has been running for a long time, the user is currently logged into the system, the system in the past 1 minutes, 5 minutes, 15 minutes of the average load balance.
Syntax
Uptime
Instance
Add-V option displays version information [[email protected] ~]# UPTIME-VPROCPS version 3.2.8//default command using [[email protected] ~]# uptime 06:10:47 up 5:43 , 3 users, load average:0.01, 0.01, 0.00
This article is from the "Perthon" blog, make sure to keep this source http://perthon.blog.51cto.com/10484057/1766431
Linux Commands---echo, wall, write, clear, sync, uptime commands