1, alias alias View alias
Example: . 1, Alias 'RM = rm -rf / *': set the alias, rm command equals rm -rf / *
2, unalias rm: delete the alias rm
2, uname display output information (host details)
uname -a: View all (system)
uname -r: Viewing the kernel information
3, hostname view the host name
hostname + name: Change the host name (currently in effect)
hostnamectl set-hostname + name: change the hostname (permanent)
echo "name"> / etc / hostname: Modify the host name (permanent)
4, history View history commands
history + figures: the command-line history display n
! + Number: n-th line Repeat command
5, which view the directory path
6, wc statistics
wc -l count the number of lines
wc -w count the number of words
wc -c statistical character, alphanumeric
7, who show who is logged on (refer to the current)
whoami: Displays the user currently logged on
w: shows who logged in (as long as the logged on will be recorded)
who -p view the number of users currently logged on
8, ping command to test whether the network connectivity
ping -t + ip or domain name: direct-connect
ping -c + digital + ip or domain name: Connect How many times
ping -w + time + ip or domain name: wait timeout (default unit is: seconds)
ping -i + time + ip or domain: how long even a time interval (default units: seconds)
9, kill command to shut down the process
kill + Process ID: Process
kill -9 + process ID: Forced shutdown process
kill -15 + Process ID: Process (not shut down immediately after the process is complete close)
10, du displays the directory and file size for Statistics Note: ls -lh statistics is the file size du actual statistics are occupied by disk size. A minimum of 4k
du -h displays the file size
du -sh total size of the display
11, df -h to view a computer disk usage
12, free to view memory usage
free -h to view memory usage
free -m display in m
free -s continuous refresh
13, data viewing system date and time
On May% Y% m% d day% h h% M% S minutes seconds
Data "the Y +% /% m /% D " view date
data "+% F" View date
data "+% T" time display
data -s “年月日 时间 ” 修改时间