eg:虚拟账户之间互相收发邮件
[root@mail-westos ~]# systemctl start mariadb
[root@mail-westos ~]# systemctl start httpd
[root@mail-westos ~]# systemctl start dovecot
[root@mail-westos ~]# cd /home/vmail/
您在 /var/spool/mail/root 中有新邮件
[root@mail-westos vmail]# ls
163.com redhat.com
[root@mail-westos vmail]# mail westos@linux.com
Subject: 2333
sdfafqeaw
.
EOT
[root@mail-westos vmail]# mailq
Mail queue is empty
[root@mail-westos vmail]# ls
163.com linux.com redhat.com
[root@mail-westos vmail]# cd linux.com/
[root@mail-westos linux.com]# ls
westos
[root@mail-westos linux.com]# cd /etc/dovecot/conf.d/
[root@mail-westos conf.d]# ls
10-auth.conf 20-imap.conf auth-dict.conf.ext
10-director.conf 20-lmtp.conf auth-ldap.conf.ext
10-logging.conf 20-pop3.conf auth-master.conf.ext
10-mail.conf 90-acl.conf auth-passwdfile.conf.ext
10-master.conf 90-plugin.conf auth-sql.conf.ext
10-ssl.conf 90-quota.conf auth-static.conf.ext
15-lda.conf auth-checkpassword.conf.ext auth-system.conf.ext
15-mailboxes.conf auth-deny.conf.ext auth-vpopmail.conf.ext
[root@mail-westos conf.d]# vim 10-auth.conf
15 # There are a few special variables you can use, eg.:
16 #
17 # %u - username
18 # %n - user part in user@domain, same as %u if there's no domain
19 # %d - domain part in user@domain, empty if there's no domain
20 # %h - home directory
30 mail_location = maildir:/home/vmail/%d/%n ##邮件目录
[root@mail-westos conf.d]# vim auth-sql.conf.ext
passdb {
6 driver = sql
7
8 # Path for SQL configuration file, see example-config/dovecot-sql.conf.ext
9 args = /etc/dovecot/dovecot-sql.conf.ext
10 }
[root@mail-westos conf.d]# cp /usr/share/doc/dovecot-2.2.10/example-config/dovecot-sql.conf.ext /etc/dovecot/dovecot-sql.conf.ext
[root@mail-westos conf.d]# vim /etc/dovecot/dovecot-sql.conf.ext
32 driver = mysql ##使用mysql数据库
71 connect = host=localhost dbname=email user=postfix password=postfix ##连接本地email数据库 用户名密码为postfix
78 default_pass_scheme = PLAIN ##明文认证
107 password_query = ##如果密码正确
108 SELECT username, domain, password
109 FROM emailuser WHERE username = '%u' AND domain = '%d' ##从emailuser表中，指定的用户名和域，选择。。。
125 user_query = SELECT maildir, 666 AS uid, 888 AS gid FROM emailuser WHERE username = '%u' ##进入maildir目录
[root@mail-westos conf.d]# vim 10-mail.conf
[root@mail-westos conf.d]# > /var/log/maillog
[root@mail-westos conf.d]# systemctl restart dovecot.service
[root@mail-westos conf.d]# cat /var/log/maillog
Apr 23 21:51:40 mail-westos dovecot: master: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill)
Apr 23 21:51:40 mail-westos dovecot: anvil: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill)
Apr 23 21:51:40 mail-westos dovecot: log: Warning: Killed with signal 15 (by pid=1 uid=0 code=kill)
Apr 23 21:51:40 mail-westos dovecot: master: Dovecot v2.2.10 starting up for imap, pop3, lmtp (core dumps disabled)
Apr 23 21:52:24 mail-westos dovecot: auth: Fatal: Unknown database driver 'mysql'
Apr 23 21:52:24 mail-westos dovecot: master: Error: service(auth): command startup failed, throttling for 2 secs ##没有识别mysql
Apr 23 21:52:24 mail-westos dovecot: pop3-login: Disconnected: Auth process broken (disconnected before auth was ready, waited 0 secs): user=<>, rip=172.25.254.41, lip=172.25.254.241, secured, session=<S4DO299N/wCsGf4p>
[root@mail-westos conf.d]# yum search dovecot ##查找和dovecot有关的软件
已加载插件：langpacks
============================= N/S matched: dovecot =============================
dovecot-mysql.x86_64 : MySQL back end for dovecot
dovecot-pgsql.x86_64 : Postgres SQL back end for dovecot
dovecot-pigeonhole.x86_64 : Sieve and managesieve plug-in for dovecot
dovecot.i686 : Secure imap and pop3 server
dovecot.x86_64 : Secure imap and pop3 server
名称和简介匹配 only，使用“search all”试试。
[root@mail-westos conf.d]# yum install dovecot-mysql.x86_64 -y
[root@mail-westos conf.d]# systemctl restart dovecot.service
[root@mail-westos conf.d]# id vmail
uid=666(vmail) gid=888(vmail) 组=888(vmail)
[root@mail-westos conf.d]# vim /etc/dovecot/dovecot-sql.conf.ext
[1]+ 已停止 vim /etc/dovecot/dovecot-sql.conf.ext
[root@mail-westos conf.d]# fg
vim /etc/dovecot/dovecot-sql.conf.ext
[root@mail-westos conf.d]# systemctl restart dovecot.service
[kiosk@foundation41 Desktop]$ telnet 172.25.254.241 110 ##没有识别数据库
Trying 172.25.254.241...
Connected to 172.25.254.241.
Escape character is '^]'.
-ERR Disconnected: Auth process broken
Connection closed by foreign host.
[kiosk@foundation41 Desktop]$ telnet 172.25.254.241 110 ##连接服务器的110端口
Trying 172.25.254.241...
Connected to 172.25.254.241.
Escape character is '^]'.
+OK [XCLIENT] Dovecot ready.
user lee@redhat.com
+OK
pass lee
+OK Logged in.
list
+OK 0 messages:
.
quit
+OK Logging out.
Connection closed by foreign host.
[kiosk@foundation41 Desktop]$ thunderbird
pop3 110 smtp 25
邮件搭建
[root@mail-westos vmail]# postfix+mysql+dovecot
[root@mail-westos vmail]# extmail ##下载
Red Hat System Administration III
###################################单元 十一Bash Scripts
##########################Bash脚本基础
BASH = GNU Bourne-Again Shell,BASH 是 GNU 组织开发和推广的一个项目。
Bash脚本类似批处理,简单来讲就是把许多的指令集合在一起,并提供循环、条件、判断等重要功能,语法简单实用,用以编写程序,大大简化管理员的操作,并可以完成图形工具所无法实现的功能。
如何创建新shell脚本?
1. 创建包含bash命令的文本文件。文件的第一行应为:
#!/bin/bash
2. 使文件可执行(使用chmod +x scripts)
3. 将文件放置在用户的$PATH的目录中
~/bin – 用于用户的私有程序
/usr/local/bin – 本地开发、系统上的其他人使用的脚本
/usr/local/sbin - 本地开发、由root使用的脚本
直接运行脚本和使用source命令运行脚本是不同的!
查看shell
[root@server database]# cat /etc/shells
脚本调试模式:
#!/bin/bash -x
# bash -x scripts
eg:
[root@server mnt]# vim test.sh
#!/bin/bash
echo hello world!
[root@server mnt]# bash -x test.sh
+ echo hello 'world!'
hello world
引用和转义
引用和转义在shell解析字符串时用于去除字符串中特殊字符或保留词语的特殊含义。这会导致按字面处理字符串,而不是展开变量或将其部分内容视作具有特殊含义。
引用有三种类型:
弱引用：
将字符串放置在双引号中,保留字符串中所有字符的文字值,$、` 、和!字符除外。换言之,变量扩展和命令扩展在双引号内仍起作用。
echo “can I have a $FRUIT”
echo “The current time is $(date +%r).”
强引用：
将字符串放置在单引号中,保留字符串中所有字符的文字值,同时禁用所有扩展:
echo “Make $$$ Fast”
rm 'untitled folder'
转义：
非引用的是转义字符。它保留了下一个字符的文字值。(例如,$PATH是确切的字符串$PATH,而不是PATH变量的内容。)
echo Make $$$ Fast!
ls untitled folder
[root@server0 ~]# echo # not a comment #
[root@server0 ~]# echo # not a comment #
# not a comment
[root@server0 ~]# echo # not a comment #
# not a comment #
[root@server0 ~]# echo '# not a comment #'
# not a comment #
[root@server0 ~]# echo '$HOME'
$HOME
[root@server0 ~]# echo '`pwd`'
`pwd`
[root@server0 ~]# echo '"Hello,world"'
"Hello,world"
[root@server0 ~]# echo "$HOME"
/root
[root@server0 ~]# echo "`pwd`"
/root
[root@server0 ~]# echo ""Hello, world""
Hello, world
[root@server0 ~]# echo "$HOME"
$HOME
[root@server0 ~]# echo "\`pwd\`"
`pwd`
[root@server0 ~]# echo ""Hello, world""
"Hello, world"
Shell变量
shell变量用于为稍后在脚本中使用的名称指定值,并且仅限于shell命令行或从中声明变量的脚本。
若要定义或指定值:
FRUIT=apple
若要参考或使用变量:
$FRUIT
${FRUIT}
[root@server0 ~]# FIRST=John
[root@server0 ~]# LAST=Doe
[root@server0 ~]# echo $FIRST $LAST
John Doe
[root@server0 ~]# echo $FIRST_$LAST
Doe
[root@server0 ~]# echo ${FIRST}_$LAST
John_Doe
命令替换
命令替换在子shell中执行指定命令并用命令输出替换脚本中的命令替换。
语法:
$(shell command)
示例:
touch datafile.$(id -un)
TODAY=$(date +%Y-%m-%d)
[root@server0 ~]# TAROUTPUT=$(tar cvf /tmp/backup.tar $(find /etc -type f -mtime 1))
tar: Removing leading `/' from member names
[root@server0 ~]# echo $TAROUTPUT
/etc/hosts.allow /etc/hosts.deny /etc/sysconfig/iptables /etc/xinetd.d/tftp /etc/rht
/etc/firewalld/zones/public.xml.old /etc/firewalld/firewalld.conf.old /etc/xinetd.conf
算术运算符
算术运算符指的是可以在程序中实现加、减、乘、除等数学运算的运算符。
operator meaning
<VARIABLE>++ 增量后
<VARIABLE>-- 减量后
- 减法
+ 加法
** 幂运算
* 乘法
/ 除法
% 余数
+= 加等
-= 减等
Shell计算命令:
用$[]表示数学运算。
# echo $[1+2]
# a=1; echo $[$[$a+1]*2]
[root@server mnt]# [ "1" -lt "2" ] && echo yes|| echo no
yes
[root@server mnt]# [ "1" -gt "2" ] && echo yes|| echo no
no
[root@server mnt]# [ "1" -le "2" ] && echo yes|| echo no
yes
[root@server mnt]# [ "1" -ge "2" ] && echo yes|| echo no
no
[root@server mnt]# [ "1" -ne "2" ] && echo yes|| echo no
yes
[root@server mnt]# [ "1" -eq "2" ] && echo yes|| echo no
no
[root@server mnt]# a=5
[root@server mnt]# [ "$a" -gt "0" -a "$a" -lt "10" ] && echo yes|| echo no
yes
用expr表示数学运算。
# echo `expr 1 + 2`
用let指示数学运算。
# let A=1+2
# echo $A
用(())表示数学运算。bash内建功能,效率高。
#!/bin/bash
for ((i=1;i<10;i++))
do
((j+=i))
done
echo $j
循环
for循环用于值列表中的相同命令的重复。
[root@server0 ~]# for HOST in host{1..3};do echo $HOST;done
host1
host2
host3
[root@server0 ~]# for NUM in $(seq 2 2 8);do echo $NUM;done
2
4
6
8
循环与计算结合:
#!/bin/bash
for ((i=1;i<=100;i++))
do
((j+=i))
#j=`expr $j + $i`
#let j+=i
#j=$[j+=i]
done
echo $j
也可以写成一行:
# for((i=0; i<=100; i++));do j=`expr $j + $i` ;done;echo $j
数据库备份示例:
#!/bin/bash
for DB in $(mysql -e "show databases;" -E -N | grep -v '^*' | grep -v 'schema$')
do
echo "Backing up $DB"
mysqldump $DB > /dbbackup/$DB.dump
done
echo ""
for DBDUMP in /dbbackup/*
do
SIZE=$(stat --printf "%s " $DBDUMP)
echo "$DBDUMP
$SIZE"
done
eg:输出ip脚本
[root@mail-westos mnt]# vim show_ip.sh
1 #!/bin/bash
2 ip=$(ifconfig eth0 |grep inet |grep inet6 -v |awk -F " " '{print $2}')
3 hostname=`hostname`
4 echo "${hostname}'s ipaddress is : $ip"
[root@mail-westos mnt]# sh show_ip.sh ##执行脚本方式2
eg:
[root@mail-qq mnt]# vim host_check.sh
1 #!/bin/bash
2 for NA in {1..40}
3 do
4 ping -c1 -w1 172.25.254.$NA &> /dev/null && echo 172.25.254.$NA is up ||echo 172.25.254.$NA is down
[root@mail-qq mnt]# chmod +x host_check.sh ##执行脚本方式1
[root@mail-qq mnt]# ./host_check.sh
eg:自动创建用户
[root@mail-qq mnt]# vim userfile
1 user1
2 user2
3 user3
[root@mail-qq mnt]# vim passfile
1 123
2 234
3 345123
[root@mail-qq mnt]# vim create_user.sh
1 #!/bin/bash
2 MAX=`wc -l $1|cut -d " " -f 1`
3 for NUM in $(seq 1 $MAX)
4 do
5 NAME=`sed -n ${NUM}p $1`
6 PASSWORD=`sed -n ${NUM}p $2`
7 useradd $NAME
8 echo $PASSWORD |passwd --stdin $NAME
9 done
[root@mail-qq mnt]# sh create_user.sh userfile passfile
eg:输出10以内偶数
[root@server mnt]# vim test.sh
#!/bin/bash
for NUM in `seq 2 2 10`
do
echo $NUM
done
[root@server mnt]# sh test.sh
2
4
6
8
10
eg:10s倒计时 ，每次不换行刷新 carriage return ##man echo
#!/bin/bash
for ((i=10;i>0;i--))
do
echo -n "After ${i}s is end "
echo -ne " "
sleep 1
done
eg:1分10秒倒计时 #######################
#!/bin/bash
MIN=1
for ((i=3;i>0;i--))
do
while
[ "$i" -eq "0" -a "$MIN" -gt "0" ]
do
echo -n "After ${MIN}:${i} is end"
echo -ne " "
i=59
((MIN--))
done
echo -n "After ${MIN}:${i} is end"
echo -ne " "
sleep 1
done
eg:
[root@server mnt]# vim test.sh
#!/bin/bash
for NAME in /etc/hello /etc/passwd /etc/group
do
ls -l $NAME &> /dev/null && echo $NAME is exist || echo $NAME is not exist
done
[root@server mnt]# sh test.sh
/etc/hello is not exist
/etc/passwd is exist
/etc/group is exist