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这两天研究了一下Fail2ban，发现自0.11版本开始。Fail2ban加入了阶段封禁功能。

也就是如果第一次封禁了以后，如果第二次还错，就增加封禁时间。具体由bantime.factor这个参数控制。

具体需要在jail.local里面增加如下字段：

[jail]
# initial ban time:
bantime = 1h
# incremental banning:
bantime.increment = true
# default factor (causes increment - 1h -> 1d 2d 4d 8d 16d 32d ...):
bantime.factor = 24
# max banning time = 5 week:
bantime.maxtime = 5w

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发现这个功能非常有用，必须收藏起来。

grep -rnw ‘/path/to/somewhere/’ -e ‘pattern’

  • -r or -R is recursive,
  • -n is line number, and
  • -w stands for match the whole word.
  • -l (lower-case L) can be added to just give the file name of matching files.
  • -e is the pattern used during the search

或者

grep -Ril “text-to-find-here” /

  • i stands for ignore case (optional in your case).
  • R stands for recursive.
  • l stands for “show the file name, not the result itself”.
  • / stands for starting at the root of your machine.

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今天在研究Linux下增量备份的时候，发现了一个非常Genius的命令。

用这个命令即可以做到增量备份，又可以最少量的占用硬盘空间。

 

rm -rf backup.3
mv backup.2 backup.3
mv backup.1 backup.2
cp -al backup.0 backup.1
rsync -a --delete source_directory/ backup.0/

 

多的懒得写了，大家自己体会吧。:D

 

Refer：http://www.admin-magazine.com/Articles/Using-rsync-for-Backups/

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Here are steps to setup a user and allow the user access only via FTP (i.e. no SSH) and also limit access to a specific (user home) directory on proftpd:

1. Add new user: adduser newusername
2. Set password: passwd newusername
3. Modify user home directory from default to a new folder:

usermod -d /target/directory username

4. Edit shells file: vi /etc/shells and add /dev/null at the end
5. Modify newusername entry in the passwd file: vi /etc/passwd to add /./ before the newusername so that the entry looks like this:

newusername:x:502:502::/home/ftp/./newusernamehomedirectory/:/dev/null

6. Edit /etc/proftpd/proftpd.conf file and uncomment the line DefaultRoot ~

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grep -rnw '/path/to/somewhere/' -e 'pattern'
  • -r or -R is recursive,
  • -n is line number, and
  • -w stands for match the whole word.
  • -l (lower-case L) can be added to just give the file name of matching files.

Along with these, --exclude, --include, --exclude-dir flags could be used for efficient searching:

  • This will only search through those files which have .c or .h extensions: 
    grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"
  • This will exclude searching all the files ending with .o extension: 
    grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"
  • For directories, it’s possible to exclude a particular directory(ies) through --exclude-dirparameter. For example, this will exclude the dirs dir1/, dir2/ and all of them matching *.dst/: 
    grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"

This works very well for me, to achieve almost the same purpose like yours.

For more options check man grep

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1、查看系统

[root@localhost ~]# cat /etc/issue
CentOS release 6.6 (Final)
[root@localhost ~]# uname -a
Linux localhost.localdomain 2.6.32-042stab106.6 #1 SMP Mon Apr 20 14:48:47 MSK 2015 x86_64 x86_64 x86_64 GNU/Linux

2、安装ShadowSocks

# yum install python-setuptools && easy_install pip
# pip install shadowsocks

3、创建配置文件/etc/shadowsocks.json

[root@localhost /]# touch /etc/shadowsocks.json
[root@localhost /]# vi /etc/shadowsocks.json
{
"server":"138.128.208.158",
"server_port":443,
"local_address": "127.0.0.1",
"local_port":1080,
"password":"MyPass",
"timeout":300,
"method":"rc4-md5"
}

备注：加密方式官方默认使用aes-256-cfb，推荐使用rc4-md5，因为 RC4比AES速度快好几倍。继续阅读

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LINUX

netstat -lntu

as replied by @askmish will give you list of services running on your system on tcp and udp ports where

  • -l = only services which are listening on some port
  • -n = show port number, don’t try to resolve the service name
  • -t = tcp ports
  • -u = udp ports
  • -p = name of the program

You don’t need the ‘p’ parameter as you’re only interested in getting which ports are free and not which program is running on it.

This only shows which ports on your system are used up, though. This doesn’t tell you the status of your network e.g. if you’re behind NAT and you want some services to be accessible from outside. Or if the firewall is blocking the port for outside visitors. In that case, nmap comes to the rescue. WARNING: Use nmap only on networks which are under your control. Also, there are firewall rules which can block nmap pings, you’ll have to fiddle around with options to get correct results.

2016.09.27 更新
netstat -peanut 用这个参数更可以列出是哪个程序在占用哪个端口

Windows

netstat -ano 可以直接列出PID，然后到任务管理器里面可以根据PID查看是哪个程序。

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如下命令

grep -rnw '/path/to/somewhere/' -e "pattern"

-r 或者 -R 为递归查找, -n 是行号 -w 为要求全匹配. -l (小写L) 参数可以只列出文件名.

除此以外, –exclude 或者 –include 参数可以提供更有效的查找。比如:

grep --include=\*.{c,h} -rnw '/path/to/somewhere/' -e "pattern"

这个可以查找扩展名为.c或者.h的文件. –exclude的用法也类似：

grep --exclude=*.o -rnw '/path/to/somewhere/' -e "pattern"

上面这行命令在搜索中会排除扩展名为.0的文件。和包含/不包含文件一样，目录也可以使用 –exclude-dir 和 –include-dir 参数。 比如下面列出怎么使用 –exclude-dir:

grep --exclude-dir={dir1,dir2,*.dst} -rnw '/path/to/somewhere/' -e "pattern"

如果单是遍历查找文件的话可以用

find . -name '*.xml'

如果想遍历删除某种类型的文件的话，可以用

 find . -name '*.xml' -type f -delete

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在Ubuntu中是没有chkconfig这个命令的，如果想要在Ubuntu里面使用类似Chkconfig的命令怎么办呢？

可以试试sysv-rc-conf命令，如果没有安装的话，可以使用apt-get install来安装这个命令。就可以以模拟图形界面的方式来配置各个service的runlevel了。

另外Ubuntu使用Upstart来替代来了传统的sysvinit，详细的使用方法参加：

https://help.ubuntu.com/community/UpstartHowto

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First verify that Tomcat is running on port 8080. Run the following command

# netstat -ntl

The output will look something like

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address               Foreign Address             State
tcp        0      0 127.0.0.1:25                0.0.0.0:*                   LISTEN
tcp        0      0 0.0.0.0:22                  0.0.0.0:*                   LISTEN
tcp        0      0 ::ffff:127.0.0.1:8005       :::*                        LISTEN
tcp        0      0 :::8009                     :::*                        LISTEN
tcp        0      0 :::8080                     :::*                        LISTEN
tcp        0      0 :::22                       :::*                        LISTEN

Run the following command to redirect port 80 traffic to port 8080

# iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

Run the folloing command to verify that redirect is working fine

# iptables -t nat -L

The output will look something like

Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination
REDIRECT   tcp  --  anywhere             anywhere            tcp dpt:http redir ports 8080

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination

Run the following command to remove the routing

# iptables -t nat -D PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

 

FROM: Glass Onion Blog