第一步：将所有要播放的多媒体文件放在～/music/目录下；
　　
　　 第二步：进入music目录，执行ls > music.lst，则在music目录下生成一个名为music.lst的列表文件，并把music目录下的文件名写入到music.lst文件中；
　　
　　 第三步：运行mplayer -playlist music.lst即可实现列表播放
　　
　　 值得注意的是第二步中，生成的多媒体列表文件music.lst一定要与要播放的多媒体文件保存在同一个目录中，否则mplayer播放时会有找不到文件的错误提示。
　　
　　 如果要删除一些不想听的多媒体文件，则用编辑器打开music.lst列表文件，删除对应的文件名即可，保存时要注意一行一个文件名，不能有空行。
　　
　　 如果要增加文件，执行命令echo filename >> music.lst即可，即可将新增的文件名追加在music.lst列表文件末。

In one of our previous article we have posted an instructional guide on how to secure your Debian/Ubuntu based VPS using IPTABLES/Netfilter.

In the following article we are adding a blacklist to the firewall script which will allow you to block any abusive IP addresses or ranges of IPs in your Debian or Ubuntu based virtual server.

What is iptables?

It is is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different Netfilter modules) and the chains and rules it stores.

Before proceeding any further, make sure you read the article on how to secure/design the firewall in your linux vps. This includes:

Flushing the old firewall rules
Determining service ports
Setting-up default policies
Setting-up your firewall rules
Saving your firewall rules
BLOCKING IPs USING IPTABLES
To block some abusive IP address or range of IPs, you can use the following iptables rules:
## iptables -I INPUT -s 1.2.3.4 -j DROP
## iptables -I INPUT -s 1.2.0.0/16 -j DROP

CREATING THE BLACKLIST
For better readability and maintenance, it is a good idea to have all abusing IPs in one particular file, for example /etc/blacklist.ips. This way, you can add the IP addresses or subnets in this file (one IP or subnet per line) and use the fwall-rules script below to block anything listed in this file.

So, create or edit /usr/local/bin/fwall-rules and make it as follows:

#!/bin/bash
#
# iptables firewall script
# http://www.rosehosting.com
#

IPTABLES=/sbin/iptables
BLACKLIST=/etc/blacklist.ips

echo ” * flushing old rules”
${IPTABLES} –flush
${IPTABLES} –delete-chain
${IPTABLES} –table nat –flush
${IPTABLES} –table nat –delete-chain

echo ” * setting default policies”
${IPTABLES} -P INPUT DROP
${IPTABLES} -P FORWARD DROP
${IPTABLES} -P OUTPUT ACCEPT

echo ” * allowing loopback devices”
${IPTABLES} -A INPUT -i lo -j ACCEPT
${IPTABLES} -A OUTPUT -o lo -j ACCEPT

${IPTABLES} -A INPUT -p tcp ! –syn -m state –state NEW -j DROP
${IPTABLES} -A INPUT -m state –state ESTABLISHED,RELATED -j ACCEPT

## BLOCK ABUSING IPs HERE ##
#echo ” * BLACKLIST”
#${IPTABLES} -A INPUT -s _ABUSIVE_IP_ -j DROP
#${IPTABLES} -A INPUT -s _ABUSIVE_IP2_ -j DROP

echo ” * allowing ssh on port 5622″
${IPTABLES} -A INPUT -p tcp –dport 5622 -m state –state NEW -j ACCEPT

echo ” * allowing ftp on port 21″
${IPTABLES} -A INPUT -p tcp –dport 21 -m state –state NEW -j ACCEPT

echo ” * allowing dns on port 53 udp”
${IPTABLES} -A INPUT -p udp -m udp –dport 53 -j ACCEPT

echo ” * allowing dns on port 53 tcp”
${IPTABLES} -A INPUT -p tcp -m tcp –dport 53 -j ACCEPT

echo ” * allowing http on port 80″
${IPTABLES} -A INPUT -p tcp –dport 80 -m state –state NEW -j ACCEPT

echo ” * allowing https on port 443″
${IPTABLES} -A INPUT -p tcp –dport 443 -m state –state NEW -j ACCEPT

echo ” * allowing smtp on port 25″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 25 -j ACCEPT

echo ” * allowing submission on port 587″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 587 -j ACCEPT

echo ” * allowing imaps on port 993″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 993 -j ACCEPT

echo ” * allowing pop3s on port 995″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 995 -j ACCEPT

echo ” * allowing imap on port 143″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 143 -j ACCEPT

echo ” * allowing pop3 on port 110″
${IPTABLES} -A INPUT -p tcp -m state –state NEW -m tcp –dport 110 -j ACCEPT

echo ” * allowing ping responses”
${IPTABLES} -A INPUT -p ICMP –icmp-type 8 -j ACCEPT

# DROP everything else and Log it
${IPTABLES} -A INPUT -j LOG
${IPTABLES} -A INPUT -j DROP

#
# Block abusing IPs
# from ${BLACKLIST}
#
if [[ -f “${BLACKLIST}” ]] && [[ -s “${BLACKLIST}” ]]; then
echo ” * BLOCKING ABUSIVE IPs”
while read IP; do
${IPTABLES} -I INPUT -s “${IP}” -j DROP
done < <(cat “${BLACKLIST}”) fi # # Save settings # echo ” * SAVING RULES” if [[ -d /etc/network/if-pre-up.d ]]; then if [[ ! -f /etc/network/if-pre-up.d/iptables ]]; then echo -e “#!/bin/bash” > /etc/network/if-pre-up.d/iptables
echo -e “test -e /etc/iptables.rules && iptables-restore -c /etc/iptables.rules” >> /etc/network/if-pre-up.d/iptables
chmod +x /etc/network/if-pre-up.d/iptables
fi
fi

iptables-save > /etc/fwall.rules
iptables-restore -c /etc/fwall.rules

make sure the script is executable by adding an ‘x’ bit to it:
chmod +x /usr/local/bin/fwall-rules
APPLYING THE RULES
To apply the firewall rules and block the abusers, you need to just execute the fwall-rules script and that’s it.

## fwall-rules
* flushing old rules
* setting default policies
* allowing loopback devices
* allowing ssh on port 5622
* allowing ftp on port 21
* allowing dns on port 53 udp
* allowing dns on port 53 tcp
* allowing http on port 80
* allowing https on port 443
* allowing smtp on port 25
* allowing submission on port 587
* allowing imaps on port 993
* allowing pop3s on port 995
* allowing imap on port 143
* allowing pop3 on port 110
* allowing ping responses
* BLOCKING ABUSIVE IPs
* SAVING RULES

[download id=”8″]

apt-get install ocaml camlp4-extra
git clone https://github.com/OCamlPro/opam.git
cd opam
./configure
make
sudo make install

apt-get install m4 libcurl4-gnutls-dev libfuse-dev libsqlite3-dev
opam init //**if error( opam init https://opam.ocaml.org/1.1 )
opam update
opam install google-drive-ocamlfuse

安装成功后，进入Google Project建立一个Project
https://console.developers.google.com/project

进入项目的API设置开启Drive API

建立一个OAuth验证ID

建立项目的Client ID

记录下这两个生成的参数做稍后使用

进入/root/.opam/system/bin/目录绑定项目
cd /root/.opam/system/bin/
./google-drive-ocamlfuse -headless -label googledrive -id ##Client ID##.apps.googleusercontent.com -secret ##secret key##
执行完上述指令会返回一个https的网址在浏览器粘贴到浏览器后会进入google页面询问是否允许访问该项目，选accept然后记录下浏览器页面返回的密码，粘贴进去回车即可。
进入~/.gdfuse/googledrive
cd ~/.gdfuse/googledrive
nano config
编辑config修改内容例如
verification_code= [key returned from browser]
client_id= [eg. 123123231.apps.googleusercontent.com]
client_secret= [eg. ASDQWEWGSD!$@#@#ASD]
完成配置加载Google Drive远端存储到本地/googledrive

mkdir /googledrive
cd ~/.opam/system/bin
./google-drive-ocamlfuse -label googledrive /googledrive

if you get swapon failed: Operation not permitted Error even if you run as root it is because in your VPS swap creation is not allowed follow below steps to Create Fake Swap in OpenVZ VPS

[root@server] free -m total used free Mem: 4096 104 3991 -/+ buffers/cache: 104 3991
Swap: 0 0 0

create shell script file add lines like below
[root@server] vi fakeswap.sh

#!/bin/bash
SWAP=”${1:-512}”
NEW=”$[SWAP*1024]”; TEMP=”${NEW//?/ }”; OLD=”${TEMP:1}0″
umount /proc/meminfo 2> /dev/null
sed “/^Swap\(Total\|Free\):/s,$OLD,$NEW,” /proc/meminfo > /etc/fake_meminfo
mount –bind /etc/fake_meminfo /proc/meminfo
free -m

[root@server] chmod +x fakeswap.sh
[root@server] sh fakeswap.sh [root@server] free -m total used free Mem: 4096 104 3991 -/+ buffers/cache: 104 3991 Swap: 512 0 512 to create 1024MB Swap run like below [root@server] sh fakeswap.sh 1024 [root@server] free -m total used free Mem: 4096 104 3991 -/+ buffers/cache: 104 3991 Swap: 1024 0 1024 – See more at: http://linux-problem-solver.blogspot.sg/2013/08/create-fake-swap-in-openvz-vps-if-you-get-swapon-failed-operation-not-permitted-error.html#sthash.Eeknzpcf.dpuf

apt-get install shorewall
cp /usr/share/doc/shorewall/examples/one-interface/interfaces /etc/shorewall/interfaces
cp /usr/share/doc/shorewall/examples/one-interface/policy /etc/shorewall/policy
cp /usr/share/doc/shorewall/examples/one-interface/rules /etc/shorewall/rules
cp /usr/share/doc/shorewall/examples/one-interface/zones /etc/shorewall/zones

Now open /etc/shorewall/policy file and change the line:
net all DROP info
removing info directive given it fills the system logs:
net all DROP
Now open /etc/shorewall/rules and add the following rules at the bottom of the file:
HTTP/ACCEPT net $FW
SSH/ACCEPT net $FW
FTP/ACCEPT net $FW
# real apache since varnish listens on port 80
#ACCEPT net $FW tcp 8080
ACCEPT net:192.168.1.10 $FW TCP 22

vi /etc/shorewall/shorewall.conf STARTUP_ENABLED=No —— STARTUP_ENABLED=Yes
vi /etc/default/shorewall startup=0 —— startup=1

/etc/init.d/shorewall start

apt-get –purge remove exim4
apt-get –purge remove exim4-base
dpkg -l | grep exim
dpkg -P exim_name

经过多方查阅资料，终于将exim4的配置搞定了，结果才发现，原来是这么简单。下面我就把我配置的过程写出来，与大家分享。
1）在命令行输入dpkg-reconfigure exim4-config来进行配置。
2）将配置文档分拆成小文件吗？（否）
3）邮件系统配置的常见模式：（互联网站；直接通过 SMTP 发送或接收信件）
4）系统邮件名称：（我的机器名默认的）
5）要监听的入站 SMTP 连接的 IP 地址：（空白，就是什么都不写）
6）其它可接受的邮件目的地址：（ localhost.localdomain:debian:localhost）
注：我的主机名是debian
7）中转(relay)邮件的域名： （空白）
8）为这些主机进行邮件转发：（空白）
9）保持最小 DNS 查询量吗(按需拔号 Dial-on-Demand)？ （否）

测试发邮件
echo “text” | mail -s “title” xxxxxxx@qq.com

Setup bash and update the system

cp /etc/skel/.bashrc /root/.bashrc
apt-get update
apt-get dist-upgrade

Configure hostname correctly

Make sure to have the following two lines (with the same format) at the top of your /etc/hosts file

127.0.0.1 localhost.localdomain localhost
xxx.xxx.xxx.xxx web1.myserver.com web1

Note: xxx.xxx.xxx.xxx is the public IP address assigned to your server.
Install all needed packages

apt-get install php5 mysql-server mysql-client apache2 iptables phpmyadmin varnish shorewall vsftpd php5-cli php5-curl php5-dev php5-gd php5-idn php5-imagick php5-imap php5-memcache php5-ming php5-pspell php5-recode php5-snmp php5-sqlite php5-tidy php5-xcache php5-xmlrpc php-apc php-pear php-xml-rpc postfix apg ca-certificates heirloom-mailx

MySQL/PhpMyAdmin:

mysql root password: xxx
repeat mysql root password: xxx
web server to reconfigure automatically: apache2
configure database for phpmyadmin with dbconfig-common? Yes
Password of the database’s administrative user: xxx
Password for phpmyadmin: xxx
Password confirmation: xxx

Postfix:

Select Internet Site
System mail name: (insert here the FQDN, for example web1.myserver.com)

Setup FTP

Stop VSFTP server:

/etc/init.d/vsftpd stop

Create backup configuration:

mv /etc/vsftpd.conf /etc/vsftpd.conf.backup

Add new configuration:

listen=YES
listen_port=21
anonymous_enable=NO
local_enable=YES
guest_enable=YES
guest_username=nobody
user_sub_token=$USER
local_root=/var/www/vhosts/$USER
virtual_use_local_privs=YES
user_config_dir=/etc/vsftpd/users
pam_service_name=vsftpd_local_and_virtual
chroot_local_user=YES
chroot_list_enable=YES
chroot_list_file=/etc/vsftpd/chroot_list
ftpd_banner=Welcome to my ftp server
write_enable=YES
download_enable=YES
dirlist_enable=YES
local_umask=022
dirmessage_enable=YES
xferlog_enable=YES
xferlog_file=/var/log/xferlog
connect_from_port_20=YES
connect_timeout=60
data_connection_timeout=300
idle_session_timeout=300
local_max_rate=0
max_clients=0
max_per_ip=3

Create an empty chroot_list file:

touch /etc/vsftpd/chroot_list

Start VSFTP server:

/etc/init.d/vsftpd start

Setup Apache

Stop Apache web server:

/etc/init.d/apache2 stop

Backup Apache configuration:

cp /etc/apache2/apache2.conf /etc/apache2/apache2.conf.backup

Edit the following lines in /etc/apache2/apache2.conf

From Timeout 300 to Timeout 45
From KeepAliveTimeout 5 to KeepAliveTimeout 15
Change the mpm_prefork_module section like the following:

StartServers 5
MinSpareServers 5
MaxSpareServers 10
ServerLimit 400
MaxClients 400
MaxRequestsPerChild 10000

Edit /etc/apache2/ports.conf and change the port 80 with 8080 since we are going to use Varnish:

NameVirtualHost *:8080
Listen 8080

Change the port (from 80 to 8080) also in the default virtual host /etc/apache2/sites-enabled/000-default Now restart Apache:

/etc/init.d/apache2 restart

Setup Varnish

Stop Varnish daemon:

/etc/init.d/varnish stop

Open /etc/varnish/default.vcl and make sure the backend section is like this:

backend default {
.host = “127.0.0.1”;
.port = “8080”;
.connect_timeout = 600s;
.first_byte_timeout = 600s;
.between_bytes_timeout = 600s;
}

Now edit /etc/default/varnish and set the DAEMON_OPTS variable like this:

DAEMON_OPTS=”-a :80 \
-T localhost:6082 \
-f /etc/varnish/default.vcl \
-p thread_pools=4 \
-p thread_pool_max=1500 \
-p listen_depth=2048 \
-p lru_interval=1800 \
-h classic,169313 \
-p max_restarts=6 \
-p connect_timeout=600 \
-p send_timeout=2000 \
-s malloc,2G”

Restart Varnish:

/etc/init.d/varnish restart

Setup MySQL

MySQL is already configured. You only need to log slow queries (that is often usefult during slow load page investigation). Todo it, open /etc/mysql/my.cnf and decomment the following two lines:

log_slow_queries = /var/log/mysql/mysql-slow.log
long_query_time = 2

Configure Shorewall firewall rules

Copy the default configuration for one interface:

cp /usr/share/doc/shorewall/examples/one-interface/interfaces /etc/shorewall/interfaces
cp /usr/share/doc/shorewall/examples/one-interface/policy /etc/shorewall/policy
cp /usr/share/doc/shorewall/examples/one-interface/rules /etc/shorewall/rules
cp /usr/share/doc/shorewall/examples/one-interface/zones /etc/shorewall/zones

Now open /etc/shorewall/policy file and change the line:

net all DROP info

removing info directive given it fills the system logs:

net all DROP

Now open /etc/shorewall/rules and add the following rules at the bottom of the file:

HTTP/ACCEPT net $FW
SSH/ACCEPT net $FW
FTP/ACCEPT net $FW

# real apache since varnish listens on port 80
#ACCEPT net $FW tcp 8080

NOTE: in case you want to allow ICMP (Ping) traffic from a specific remote hosts you need to add a rule similar to the following where xxx.xxx.xxx.xxx is the remote IP address, before the Ping(DROP) rule:

Ping(ACCEPT) net:xxx.xxx.xxx.xxx $FW

Now edit /etc/default/shorewall and change startup=0 to startup=1 You are now ready to start the firewall:

/etc/init.d/shorewall start

Setup Postfix

Stop postfix server:

/etc/init.d/postfix stop

Edit /etc/mailname and set your server domain name, for example:

server1.mycompany.com

Then, in order to monitor mail traffic coming from PHP you need to edit /etc/php5/apache2/php.ini. Go to [mail function] section and set the following two options:

sendmail_path = /usr/local/bin/sendmail-wrapper
auto_prepend_file = /usr/local/bin/env.php

Now create the two files above:

sendmail-wrapper:

#!/bin/sh
logger -p mail.info sendmail-wrapper.sh: site=${HTTP_HOST}, client=${REMOTE_ADDR}, script=${SCRIPT_NAME}, pwd=${PWD}, uid=${UID}, user=$(whoami)
/usr/sbin/sendmail -t -i $*

env.php:

Now make they both have executable flag:

chmod +x /usr/local/bin/sendmail-wrapper
chmod +x /usr/local/bin/env.php

Add also /usr/local/bin/ to the open_basedir php list in /etc/apache2/conf.d/phpmyadmin.conf

php_admin_value open_basedir /usr/share/phpmyadmin/:/etc/phpmyadmin/:/var/lib/phpmyadmin/:/usr/local/bin/

Restart Postfix:

/etc/init.d/postfix start

Prepare environment

Create all needed directories and files

mkdir /root/cron_scripts
mkdir -p /var/www/vhosts
mkdir -p /etc/vsftpd/users
touch /etc/vsftpd/passwd

Now download all tools to manage the server locally:

wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/ADD_ALIAS.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/ADD_DOMAIN.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/ADD_ALIAS.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/ADD_FTP_VIRTUAL_USER.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/ALIAS_LIST.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/DEL_ALIAS.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/DEL_DOMAIN.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/DEL_FTP_VIRTUAL_USER.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/DOMAIN_LIST.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/MYSQL_CREATE.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/UPDATE_ALL_FTP_PASSWORD.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/UPDATE_FTP_PASSWORD.sh
chmod 770 *.sh

Download also the tools that will be used with cron:

cd /root/cron_scripts
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/cron_scripts/backup_mysql.sh
wget https://raw.githubusercontent.com/matteomattei/servermaintenance/master/LAMP/cron_scripts/mysql_optimize.sh
chmod 770 *.sh

Edit /root/ADD_DOMAIN.sh and change ADMIN_EMAIL variable with your email address.
Edit /root/MYSQL_CREATE.sh and change the variable MYSQL_ROOT_PASSWORD with your MySQL root password.
Edit /root/cron_scripts/backup_mysql.sh and change the variable DB_PASSWORD with your MySQL root password and MAIL_NOTIFICATION with your email address.
Edit /root/cron_scripts/mysql_optimize.sh and change the variable MYSQL_ROOT_PASSWORD with your MySQL root password.

Configure CRON

Edit /etc/crontab and add the following lines at the bottom:

# mysql optimize tables
3 4 * * 7 root /root/mysql_optimize.sh

# mysql backup
32 4 * * * root /root/backup_mysql.sh

Git是目前最流行的版本管理系统，学会Git几乎成了开发者的必备技能。

Git有很多优势，其中之一就是远程操作非常简便。本文详细介绍5个Git命令，它们的概念和用法，理解了这些内容，你就会完全掌握Git远程操作。

git clone
git remote
git fetch
git pull
git push
本文针对初级用户，从最简单的讲起，但是需要读者对Git的基本用法有所了解。同时，本文覆盖了上面5个命令的几乎所有的常用用法，所以对于熟练用户也有参考价值。

一、git clone

远程操作的第一步，通常是从远程主机克隆一个版本库，这时就要用到git clone命令。

git clone <版本库的网址>
比如，克隆jQuery的版本库。
git clone https://github.com/jquery/jquery.git
该命令会在本地主机生成一个目录，与远程主机的版本库同名。如果要指定不同的目录名，可以将目录名作为git clone命令的第二个参数。
git clone <版本库的网址> <本地目录名>
git clone支持多种协议，除了HTTP(s)以外，还支持SSH、Git、本地文件协议等，下面是一些例子。

git clone http[s]://example.com/path/to/repo.git/
git clone ssh://example.com/path/to/repo.git/
git clone git://example.com/path/to/repo.git/
git clone /opt/git/project.git
git clone file:///opt/git/project.git
git clone ftp[s]://example.com/path/to/repo.git/
git clone rsync://example.com/path/to/repo.git/
SSH协议还有另一种写法。

git clone [user@]example.com:path/to/repo.git/
通常来说，Git协议下载速度最快，SSH协议用于需要用户认证的场合。各种协议优劣的详细讨论请参考官方文档。

二、git remote

为了便于管理，Git要求每个远程主机都必须指定一个主机名。git remote命令就用于管理主机名。

不带选项的时候，git remote命令列出所有远程主机。

git remote
origin
使用-v选项，可以参看远程主机的网址。

git remote -v
origin git@github.com:jquery/jquery.git (fetch)
origin git@github.com:jquery/jquery.git (push)
上面命令表示，当前只有一台远程主机，叫做origin，以及它的网址。

克隆版本库的时候，所使用的远程主机自动被Git命名为origin。如果想用其他的主机名，需要用git clone命令的-o选项指定。

git clone -o jQuery https://github.com/jquery/jquery.git
git remote
jQuery
上面命令表示，克隆的时候，指定远程主机叫做jQuery。

git remote show命令加上主机名，可以查看该主机的详细信息。

git remote show <主机名>
git remote add命令用于添加远程主机。

git remote add <主机名> <网址>
git remote rm命令用于删除远程主机。

git remote rm <主机名>
git remote rename命令用于远程主机的改名。

git remote rename <原主机名> <新主机名>
三、git fetch

一旦远程主机的版本库有了更新（Git术语叫做commit），需要将这些更新取回本地，这时就要用到git fetch命令。

git fetch <远程主机名>
上面命令将某个远程主机的更新，全部取回本地。

默认情况下，git fetch取回所有分支（branch）的更新。如果只想取回特定分支的更新，可以指定分支名。

git fetch <远程主机名> <分支名>
比如，取回origin主机的master分支。

git fetch origin master
所取回的更新，在本地主机上要用”远程主机名/分支名”的形式读取。比如origin主机的master，就要用origin/master读取。

git branch命令的-r选项，可以用来查看远程分支，-a选项查看所有分支。

git branch -r
origin/master

git branch -a
* master
remotes/origin/master
上面命令表示，本地主机的当前分支是master，远程分支是origin/master。

取回远程主机的更新以后，可以在它的基础上，使用git checkout命令创建一个新的分支。

git checkout -b newBrach origin/master
上面命令表示，在origin/master的基础上，创建一个新分支。

此外，也可以使用git merge命令或者git rebase命令，在本地分支上合并远程分支。

git merge origin/master
# 或者
git rebase origin/master
上面命令表示在当前分支上，合并origin/master。

四、git pull

git pull命令的作用是，取回远程主机某个分支的更新，再与本地的指定分支合并。它的完整格式稍稍有点复杂。

git pull <远程主机名> <远程分支名>:<本地分支名>
比如，取回origin主机的next分支，与本地的master分支合并，需要写成下面这样。

1
$ git pull origin next:master
如果远程分支是与当前分支合并，则冒号后面的部分可以省略。

git pull origin next
上面命令表示，取回origin/next分支，再与当前分支合并。实质上，这等同于先做git fetch，再做git merge。

git fetch origin
git merge origin/next
在某些场合，Git会自动在本地分支与远程分支之间，建立一种追踪关系（tracking）。比如，在git clone的时候，所有本地分支默认与远程主机的同名分支，建立追踪关系，也就是说，本地的master分支自动”追踪”origin/master分支。

Git也允许手动建立追踪关系。

git branch –set-upstream master origin/next
上面命令指定master分支追踪origin/next分支。

如果当前分支与远程分支存在追踪关系，git pull就可以省略远程分支名。
git pull origin
上面命令表示，本地的当前分支自动与对应的origin主机”追踪分支”（remote-tracking branch）进行合并。

如果当前分支只有一个追踪分支，连远程主机名都可以省略。
git pull
上面命令表示，当前分支自动与唯一一个追踪分支进行合并。

如果合并需要采用rebase模式，可以使用–rebase选项。
git pull –rebase <远程主机名> <远程分支名>:<本地分支名>
五、git push

git push命令用于将本地分支的更新，推送到远程主机。它的格式与git pull命令相仿。
git push <远程主机名> <本地分支名>:<远程分支名>
注意，分支推送顺序的写法是<来源地>:<目的地>，所以git pull是<远程分支>:<本地分支>，而git push是<本地分支>:<远程分支>。

如果省略远程分支名，则表示将本地分支推送与之存在”追踪关系”的远程分支（通常两者同名），如果该远程分支不存在，则会被新建。
git push origin master
上面命令表示，将本地的master分支推送到origin主机的master分支。如果后者不存在，则会被新建。

如果省略本地分支名，则表示删除指定的远程分支，因为这等同于推送一个空的本地分支到远程分支。
git push origin :master
# 等同于
git push origin –delete master
上面命令表示删除origin主机的master分支。

如果当前分支与远程分支之间存在追踪关系，则本地分支和远程分支都可以省略。
git push origin
上面命令表示，将当前分支推送到origin主机的对应分支。

如果当前分支只有一个追踪分支，那么主机名都可以省略。
git push
如果当前分支与多个主机存在追踪关系，则可以使用-u选项指定一个默认主机，这样后面就可以不加任何参数使用git push。
git push -u origin master
上面命令将本地的master分支推送到origin主机，同时指定origin为默认主机，后面就可以不加任何参数使用git push了。

不带任何参数的git push，默认只推送当前分支，这叫做simple方式。此外，还有一种matching方式，会推送所有有对应的远程分支的本地分支。Git 2.0版本之前，默认采用matching方法，现在改为默认采用simple方式。如果要修改这个设置，可以采用git config命令。
git config –global push.default matching
# 或者
git config –global push.default simple
还有一种情况，就是不管是否存在对应的远程分支，将本地的所有分支都推送到远程主机，这时需要使用–all选项。

git push –all origin
上面命令表示，将所有本地分支都推送到origin主机。

如果远程主机的版本比本地版本更新，推送时Git会报错，要求先在本地做git pull合并差异，然后再推送到远程主机。这时，如果你一定要推送，可以使用–force选项。

git push –force origin
上面命令使用–force选项，结果导致在远程主机产生一个”非直进式”的合并（non-fast-forward merge）。除非你很确定要这样做，否则应该尽量避免使用–force选项。

最后，git push不会推送标签（tag），除非使用–tags选项。

git push origin –tags

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sudo apt-get install build-essential