baijian

tail -f => tail --follow=descriptor
tail -F => tail --follow=name --retry

example1:
-----start----
first:
tail -f testfile
tail -F testfile
then:
rm -f testfile

baijian

~/.m2/settings.xml
<proxies>
  <proxy>
    <active>true</active>
    <protocol>http</protocol>
    <host>proxy.somewhere.com</host>
    <port>8080</port>
    <username>proxyuser</username>
    <password>somepassword</password>
    <nonProxyHosts>www.google.com|*.somewhere.com</nonProxyHosts>

baijian

Maven have three lifecycles:clean default and site.
====
**clean lifecycle**
it has three phases
pre-clean
clean:delete the project's build directory(default target directory)
post-clean

**site lifecycle**
it is concerned with generating documentation for a project.

baijian

before we start to create a project using maven, 
maybe we should set a proxy.....
we can use maven archetype plugin to help us to 
create a maven project , you can see archtype 
as a existing template.

>>mvn archetype:generate
then terminal will prompt you to choose a number(choose a template), 
because there are a lot of choices, so you can use filter to 
filter some like input "quick", then you can see 

baijian

===
pom.xml file is essentially the project's metadata file 
that describes the various aspects of the project.
It describes the project's name, group, version, 
dependecies, and many other things.
===
Ok, as we have create a project with maven and 
import it into eclipse, when we develop the project 
we want to use a jar file in our local repository(for example jzmq.jar), 
so we add the jar file into our local repository first, 

baijian

>> crontab -e 
* * * * * env > ~/env.tmp

bash shell
>>env > ~/env.tmp2

compare two file: evn.tmp and env.tmp2, you will know why your job can run through shell but can't run through cron.

baijian

```
sudo apt-get install build-essential autoconf automake \
                     libtool libfcgi-dev spawn-fcgi \
                     libssl-dev nginx git-core
```
###fcgiwrap
```
git clone https://github.com/gnosek/fcgiwrap.git
cd fcgiwrap/
autoreconf -i

baijian

### Install virtualbo
https://www.virtualbox.org/wiki/Downloads

### Install vagrant
http://downloads.vagrantup.com/

### 
```
> vagrant init
this command just generate a Vagrantfile, this file describe the kind of machine and 

baijian

>client

ssh-keygen,一直Enter,得到一对rsa的公钥私钥对.

scp id_rsa.pub user@server.com:~/

>server

确保/root权限为750

baijian

命令导出数据库表or数据:

>mysqldump -u用戶名 -p密码 -d 數據库名 表名 脚本名;

导出数据库所有表结构
>mysqldump -uroot -password -d dbname > db.sql

导出数据库table表接口
>mysqldump -uroot -ppassword -d dbname table > table.sql