Input redirection: command <file
Output redirection: command> file
Command >> file additional written
Command> files emptied write
Error information is written to the file command 2> file is written to clear the error message
2 command >> file additional write error message
All correct error message written to the file command &> file retains the original file contents, additional file written on the back
ls> xiaolu the original you want to print the screen contents of the above print to a file
Because it is written emptied only once content.
wc -l <anaconda-ks.cfg file to find the number of rows
Pipe symbol | will command a command to process b
ls -l | wc -l to see how many files
echo linuxprobe | passwd --stdin linuxprobe Linux probe reset a user's password
echo "hahaha" | mail -s "hohoho" linuxprobe send a message
* Wildcard ls / dev / sda * displays the contents of all sd
ls -l ./dev/sda[0-9]
Variables $
PRICE=5
echo $ PRICE print out of 5
echo Price is $PRICE
Escape \ echo Price is \ $$ PRICE
Back quotes `` shell script Chapter IV
echo `uptime` commands to print directly to the screen
alias haha = "systemctl restart network" is equivalent to the systemctl restart network assigned to haha, haha is restarted after the input card.
PATH: BASH assistant
DEATH = "/ usr / local / share / info" $ DEATH went into the info directory
If you want to share this variable, enter the export DEATH so that other users can also use $ DEATH, this is called a global variable
Everything vim linux file, modify the deployment of a service it is in the service profile
Finish.