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linux-facl,whoami,who,w,last,lastlog,basename,mail,hostname,$random,case语句

时间:2017-02-23 14:31:36      阅读:259      评论:0      收藏:0      [点我收藏+]

标签:who   facl   whoami   

文件系统访问列表:

FACL:Filesystem Access Control List
利用文件扩展保存额外的访问控制权限

owner>group>other

Owern>facl,user>group>facl,group>other


setfacl
 -m: 设定
  u:UID:perm
  g:GID:perm
 -x:取消
  u:UID
  g:GID


[root@localhost ~]# getfacl /tmp/
getfacl: Removing leading ‘/‘ from absolute path names
# file: tmp/
# owner: root
# group: root
# flags: --t
user::rwx
group::rwx
other::rwx


[root@localhost backup]# setfacl -m u:hadoop:rw inittab
[root@localhost backup]# getfacl inittab
# file: inittab
# owner: root
# group: root
user::rw-
user:hadoop:rw-
group::r--
mask::rw-
other::r--


[root@localhost backup]# setfacl -m g:hive:rw inittab
[root@localhost backup]# getfacl inittab
# file: inittab
# owner: root
# group: root
user::rw-
user:hadoop:rw-
group::r--
group:hive:rw-
mask::rw-
other::r--


[root@localhost backup]# setfacl -m u:hive:rwx inittab
[root@localhost backup]# getfacl inittab
# file: inittab
# owner: root
# group: root
user::rw-
user:hadoop:rw-
user:hive:rwx
group::r--
group:hive:rw-
mask::rwx
other::r--


[root@localhost backup]# setfacl -x g:hive inittab
[root@localhost backup]# getfacl inittab
# file: inittab
# owner: root
# group: root
user::rw-
user:hadoop:rw-
group::r--
mask::rw-
other::r--


[root@localhost backup]#






whoami:显示当前登录用户

[root@localhost backup]# whoami
root
[root@localhost backup]#



终端(terminal,或者叫物理终端): 
是一种设备,不是一个程序,一般说的就是能提供命令行用户界面的设备,典型的是屏幕和键盘,或其他的一些物理终端。
虚拟终端: 
屏幕和键盘只是一个终端,可能不够用,又不想增加设备投入,就产生了虚拟终端。
gnome-terminal,urxvt,mlterm,xterm等等:
是一个程序,职责是模拟终端设备,和虚拟终端的区别表面上在于它以 GUI 形式的窗口出现,内部则是程序结构和系统控制结构有所不同,但本质上差不多。
控制台(console): 
显示系统消息的终端就叫控制台,Linux 默认所有虚拟终端都是控制台,都能显示系统消息。
但有时专指CLI下的模拟终端设备的一个程序,和gnome-terminal,urxvt,mlterm,xterm等相同,只是CLI和GUI界面的区别。一般console有6个,tty1-6,CTRL+ALT+fn切换。还没听说过怎么换console


who:显示登陆终端

[root@localhost backup]# who -H
NAME     LINE         TIME             COMMENT
rhel     tty1         2017-02-17 17:40 (:0)
rhel     pts/0        2017-02-17 17:40 (192.168.1.18)
rhel     pts/1        2017-02-17 17:42 (192.168.1.18)
[root@localhost backup]#


w:显示用户登录信息,比who更详细

[root@localhost backup]# w
 18:46:50 up  1:07,  3 users,  load average: 0.03, 0.02, 0.00
USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU WHAT
rhel     tty1     :0               17:40    1:07m  1.71s  0.16s pam: gdm-password
rhel     pts/0    192.168.1.18     17:40    0.00s  0.21s  0.17s sshd: rhel [priv]
rhel     pts/1    192.168.1.18     17:42   22.00s  0.02s  0.15s sshd: rhel [priv]





last:显示历史登陆信息

[root@localhost backup]# last
rhel     pts/1        192.168.1.18     Fri Feb 17 17:42   still logged in  
rhel     pts/0        192.168.1.18     Fri Feb 17 17:40   still logged in  
rhel     tty1         :0               Fri Feb 17 17:40   still logged in  
reboot   system boot  2.6.32-504.el6.x Fri Feb 17 17:39 - 18:48  (01:08)   
rhel     pts/2        192.168.1.18     Sat Nov 19 22:13 - crash (89+19:26) 
rhel     pts/1        192.168.1.18     Sat Nov 19 21:31 - 00:13  (02:42)   
rhel     pts/0        192.168.1.18     Sat Nov 19 18:17 - 23:30  (05:12)   
rhel     tty2                          Sat Nov 19 17:54 - crash (89+23:45) 
rhel     tty1         :0               Sat Nov 19 17:54 - crash (89+23:45) 
reboot   system boot  2.6.32-504.el6.x Sat Nov 19 17:54 - 18:48 (90+00:53) 
rhel     tty6                          Thu Jun 25 22:04 - crash (512+20:49)
rhel     pts/1        10.4.10.236      Thu Jun 25 21:21 - 21:21  (00:00)   
rhel     pts/1        10.4.10.236      Thu Jun 25 21:20 - 21:20  (00:00)   


[root@localhost backup]# last -n 3
rhel     pts/1        192.168.1.18     Fri Feb 17 17:42   still logged in  
rhel     pts/0        192.168.1.18     Fri Feb 17 17:40   still logged in  
rhel     tty1         :0               Fri Feb 17 17:40   still logged in  


wtmp begins Sun Jun 21 02:26:29 2015
[root@localhost backup]#


lastlog:显示所有用户最近一次成功登陆的信息

[root@localhost backup]# lastlog -u hadoop
Username         Port     From             Latest
hadoop                                     **Never logged in**
[root@localhost backup]#

[root@localhost backup]# lastlog
Username         Port     From             Latest
root             pts/1    10.4.10.226      Thu Jun 25 14:24:23 -0700 2015
bin                                        **Never logged in**
daemon                                     **Never logged in**
adm                                        **Never logged in**
lp                                         **Never logged in**
sync                                       **Never logged in**
shutdown                                   **Never logged in**
halt                                       **Never logged in**



[root@localhost backup]# basename /etc/abc/me
me
[root@localhost backup]#






[root@localhost backup]# cat /etc/fstab | mail -s "how are you?" root
[root@localhost backup]# mail
Heirloom Mail version 12.4 7/29/08.  Type ? for help.
"/var/spool/mail/root": 1 message 1 new
>N  1 root                  Fri Feb 17 19:04  32/1406  "how are you?"
& 1
Message  1:
From root@localhost.localdomain  Fri Feb 17 19:04:58 2017
Return-Path: <root@localhost.localdomain>
X-Original-To: root
Delivered-To: root@localhost.localdomain
Date: Fri, 17 Feb 2017 19:04:58 -0800
To: root@localhost.localdomain
Subject: how are you?
User-Agent: Heirloom mailx 12.4 7/29/08
Content-Type: text/plain; charset=us-ascii
From: root@localhost.localdomain (root)
Status: R



#
# /etc/fstab
# Created by anaconda on Sun Jun 21 02:15:00 2015
#
# Accessible filesystems, by reference, are maintained under ‘/dev/disk‘
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=57d85756-7680-4c7c-9125-6ad67dae2c45 /                       ext4    defaults        1 1
UUID=2622a4b4-ddc9-47a3-aa2b-f06bc9bec085 /boot                   ext4    defaults        1 2
UUID=33d94759-fa01-4c4f-b4ac-bf3a1fe5e84f swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0


& q
Held 1 message in /var/spool/mail/root
[root@localhost backup]#
[root@localhost backup]#



[root@localhost backup]# mail -s "how are you?" root < /etc/fstab
[root@localhost backup]# mail
Heirloom Mail version 12.4 7/29/08.  Type ? for help.
"/var/spool/mail/root": 4 messages 1 new
    1 root                  Fri Feb 17 19:04  33/1417  "how are you?"
    2 root                  Fri Feb 17 19:06  33/1417  "how are you?"
    3 root                  Fri Feb 17 19:06  33/1417  "how are you?"
>N  4 root                  Fri Feb 17 19:06  32/1406  "how are you?"
& 4
Message  4:
From root@localhost.localdomain  Fri Feb 17 19:06:45 2017
Return-Path: <root@localhost.localdomain>
X-Original-To: root
Delivered-To: root@localhost.localdomain
Date: Fri, 17 Feb 2017 19:06:45 -0800
To: root@localhost.localdomain
Subject: how are you?
User-Agent: Heirloom mailx 12.4 7/29/08
Content-Type: text/plain; charset=us-ascii
From: root@localhost.localdomain (root)
Status: R



#
# /etc/fstab
# Created by anaconda on Sun Jun 21 02:15:00 2015
#
# Accessible filesystems, by reference, are maintained under ‘/dev/disk‘
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=57d85756-7680-4c7c-9125-6ad67dae2c45 /                       ext4    defaults        1 1
UUID=2622a4b4-ddc9-47a3-aa2b-f06bc9bec085 /boot                   ext4    defaults        1 2
UUID=33d94759-fa01-4c4f-b4ac-bf3a1fe5e84f swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0


& q
Held 4 messages in /var/spool/mail/root
[root@localhost backup]#





[root@localhost backup]# hostname cxiong
[root@localhost backup]# hostname
cxiong
[root@localhost backup]# echo $HOSTNAME
localhost
[root@localhost backup]#




生成随机数
RANDOM: 0-32768


随机数生成器:熵池
/dev/random:如果熵池为空,则会阻塞进程

/dev/urandom:如果熵池为空,则不会阻塞进程


[root@localhost ~]# !bash
bash random.sh
1:12418
2:11349
3:26745
4:11226
5:8126
6:5194
7:3741
8:8878
9:13050
10:10280
the max random is:26745
the min random is:3741
[root@localhost ~]# cat random.sh
#!/bin/bash


declare -i max=0
declare -i min=0


for i in {1..10};do
 tmp=`echo "$RANDOM"`
 echo "$i:$tmp"
 if [ $i -eq 1 ];then
  min=$tmp
  max=$tmp
 else
  if [ $tmp -gt $max ];then
   max=$tmp
  elif [ $tmp -lt $min ];then
   min=$tmp
  fi
 fi
done


echo "the max random is:$max"
echo "the min random is:$min"



[root@localhost ~]#




case语句:选择结构


case SWITCH in   (SWITCH为值)
value1)
  statement
  ...
  ;;    (语句以双分号结尾)
value2)
  statement
  ...
  ;;
*)
  statement
  ...
  ;;
esac    (esac结尾)



[root@localhost ~]# cat case.sh
#!/bin/bash


case $1 in
[0-9] )
 echo "digit";;
[a-Z] )
 echo "zimu";;
*)
 echo "else";;
esac
[root@localhost ~]#





linux-facl,whoami,who,w,last,lastlog,basename,mail,hostname,$random,case语句

标签:who   facl   whoami   

原文地址:http://f1yinsky.blog.51cto.com/12568071/1900396

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