Linux--facl and Users and Linux terminals

File system access list

Facl:filesystem Access Control List

Save additional access control permissions with file extensions

Setfacl

-M: Set

U:uid:perm

G:gid:perm

-X Cancel

Setfacl-x u:hive five.sh

Getfacl

Several commands:

W:show who was logged on and what they was doing

Who:show who's logged on

Every 5 seconds, check to see if Hadoop is logged in, such as logging in, showing that it is logged in, and exiting

Sleep

Whoami:print effective UserID

Last: Displays the/var/log/wtmp file, showing the user login history and System restart history

-N #: Displays information about recent # times

LASTB:/var/log/btmp file, displaying user error login attempts

-N #:

Lastlog: Displays the last successful login information for each user;

-U USERNAME: Displays recent login information for a specific user

BaseName:

$: Script path and name when executing script

Mail:

Hostname: Display host name

If the host name of the current host is empty, or (none), or ckh.com, change it to Localhost.localdomain

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

Generate random numbers

random:0-32768

Random number generator: Entropy pool

/dev/random:

/dev/urandom:

Terminal type:

Console: Consoles

pty#: Physical Terminal (VGA)

tty#: Virtual Terminal (VGA)

ttys#: Serial Terminal

pts/#: Pseudo Terminal

Write a script that generates 10 random numbers using random, and finds the maximum and minimum values;

#!/bin/Bash#declare-I. max=0Declare-I. min=0 forIinch{1..Ten}; DoMyrand=$RANDOM [$I-eq1] && min=$MYRANDif[$I-le9]; Then        Echo-N"$MYRAND,"    Else        Echo "$MYRAND"    fi[$MYRAND-GT $MAX] && max=$MYRAND [$MYRAND-lt $MIN] && min=$MYRAND Done

Linux--facl and Users and Linux terminals