Linux View user Login system related commands and scripting (vii)

Linux View user Login system related commands and scripting (vii)

View user log in System

1.W shows who's logged in and what's being done

2.who shows who logged in

-R: Show System RunLevel

3.sleep Sleep Command (sleep 5 sleeps 5 seconds after waking up)

4.whoami display user name or UID

5.last: Display/var/log/wtmp file showing user login history and System restart history

-N 3: Displays information about the last 3 times

6.LASTB: Display/var/log/btmp file, display user error login attempt

-N 3: Displays the last 3 bad logon attempts

7.lastlog: Displays the last successful login information for each user;

-U user name: Displays the most recent login information for the specified user

8.basename Displays the last file name

$: Script path and name when executing script

650) this.width=650; "src=" Http://s4.51cto.com/wyfs02/M00/7F/17/wKioL1cTW8iDfvkBAACcinJ97GE231.jpg "title=" Base.jpg "alt=" Wkiol1ctw8idfvkbaaccinj97ge231.jpg "/>

9.mail send and receive mail commands

10.hostname command: Modify the hostname, this is real-time modification, the next reboot does not take effect

For example: If the host name of the current host is empty, or (none), or localhost, change it to willow.com

[-Z ' hostname '] | | [' hostname ' = = ' (none) '-o ' hostname ' = = ' localhost '] && hostname willow.com

11. Generate Random Numbers

random:0-32768

/dev/random:

/dev/urandom:

12. Generate 100 random numbers using random, and find the maximum and minimum values; The script is as follows:

#!/bin/bash

Max=0

Min=0

For I in ' SEQ 1 100 '; Do

Rdom= $RANDOM

[$I = = 1] && min= $RDOM

If [$I-le 99]; Then

Echo-n "$I: $RDOM," Let the random number display one by one be displayed and separated by a colon

Else

echo "$I: $RDOM" Let the last number of random numbers show up

Fi

[$RDOM-gt $MAX] && max= $RDOM

[$RDOM-lt $MIN] && min= $RDOM

Done

echo "Max is $MAX" Maximum number

echo "min is $MIN" minimum number

This article is from the "Xavier Willow" blog, please be sure to keep this source http://willow.blog.51cto.com/6574604/1764786

Linux View user Login system related commands and scripting (vii)