Software development is more than programming!
按「Win+R」输入「OptionalFeatures」，勾选「NFS服务」中的「NFS客户端」。
查看 nfs server 共享的目录
showmount -e <nfs_server_ip>
挂载（以匿名模式）
mount \\<nfs_server_ip>\<nfs_dir> <local_nfs_volume>
卸载
umount <local_nfs_volume>
本文参考 Youtube 频道：代码真香
Jekyll 是一个静态站点生成器，它是 GitHub 创始人创造的，被非常多的极客使用，阮一峰的博客也是用它搭建。Jekyll 会根据网页源码生成静态文件，包括 html，css，js等。它提供了模板、变量、插件等功能，所以实际上可以用来编写整个网站。但是和WordPress又有很大的不同，原因是jekyll只是一个生成静态网页的工具，不需要数据库支持。它使用 Ruby 编写，通过 Markdown 和 Liquid 模板生成内容。
其他主流的博客搭建方式：
特点：
规划：
brew install ruby
sudo gem install jekyll
sudo gem install jekyll bundler
Gem 安装不上或很慢怎么办？
更换 gem 的源：
gem sources --add https://gems.ruby-china.org/ --remove https://rubygems.org/
创建博客目录：
jekyll new myblog
cd myblog
安装依赖：
sudo bundle install
bundle exec jekyll serve
运行本地博客服务：
默认从 127.0.0.1:4000 访问。
一些文件和目录的作用：
_config.yml：是最重要的配置文件。_post：展示的博客文章。_drafts：草稿，不会展示。_site：生成的静态网站内容。跟 UDP 相比，TCP 是面向连接的、可靠的协议。
两个进程在使用 TCP 传输数据之前必须先使用「三次握手」来建立连接。完成数据交换后，经过「四次挥手」来关闭这个连接。
本文的目的是分析「TCP连接的建立和终止」，可能我的理解是片面的，后续我会不断更新我的理解。
在下面的分析中，我们假设有两个角色：client 和 server。
为了建立可靠的连接，就不能像 UDP 那样，消息发送后就撒手不管。通信的双方必须要确认自己发送的消息对方接收到了才行。那么如何做到这一点呢？一种可行的方法是：发送方在发送的数据中加上一个「标记」，接收方收到数据后要回送一个「应答」，发送方收到接收方的应答后才会认为数据发送成功。
接下来思考一个更加现实的问题：怎样建立 client 和 server 之间的可靠连接呢？
根据上面的分析，自然而然的就想到一种方法：
假设发送数据的时候会给数据加上一个数字 id 做为标记，收到标记为 id+1 的数据才能确认数据发送成功。所以上面的过程可以这样描述为下图的过程：
在这个过程中，数据「10」和「11」代表的是请求，「11」和「21」代表的是应答。
TCP 建立连接是经过三次握手，而上面是通过四次握手建立连接，能不能少握一次呢？减少一次通信肯定能快一点建立连接。回头再看看，这四次握手有没有多余的呢？
从数据传输方向上来看，第二次和第三次都是 server 向 client 发送数据，而且在这之间 server 没有任何其他的数据向 client 传输，那么我们可以将他们合二为一，这样就只剩三次握手了。从四次到三次，提高了数据传输的效率，缩短了建立连接的时间。
这样的话，当 server 将带有请求 11 和应答 20 的数据发送给 client 的时候，client 如何知道 11 和 20 各自的含义呢？其实很简单，给他们取个名字就行了。如下图，用 SYN 标记发送的数据的序号，ACK 用来标记对收到的 SYN 的确认。
再来一个更加详细的图（注意图中 connect 函数和 accept 函数何时返回）：
TCP 连接终止使用四次挥手，这里假设 client 主动关闭连接。
问题又来了，为什么第二次和第三次不能合二为一呢？
虽然第二次和第三次都是 server 向 client 传输数据，但是 TCP 是全双工的，一方关闭不影响另一方的数据传输，在这两次传输之间 server 可能需要继续等待 client 发出的尚未收到的数据或处理之前收到的数据，如果硬要合到一起，对 client 而言，这个过程可能要阻塞一段时间，性能就会下降。
之前一直使用 MacBook Pro 办公，而且读研的时候折腾过一阵 Emacs。出于按键习惯的原因，我把 Caps 按键和 Ctrl 按键交换了，感觉效率确实高了一些。久而久之就习惯了这种按键方式。
在 MacBook Pro 上更换的方法是：
后来我入手了梦寐以求的 FILCO 出品的 Majestouch MINILA，不仅手感好，还支持 DIP 开关，掰一下开关就实现 Caps 键和 Ctrl 键的交换了！
老板人好，上个月给配了一台 Surface Laptop，16 GB 内存加 512 GB SSD。笔记本的配置还是比较爽的，但是按键不知道咋改……像我这种有强迫症、爱折腾的程序猿怎么能忍，于是我习惯性的去找 Google 大哥帮忙。找到一个感觉很原始但是确实有效的方法（on Windows 10）：
按键：「Win + R」;
输入：「regedit」，打开注册表；
依次进入：HKEY_LOCAL_MACHINE ==> System ==> CurrentControlSet ==> Control ==> KeyBoard Layout；
右击「KeyBoard Layout」，依次选择「新建」=> 「二进制值」；
将「新值 #1」重命名为 Scancode Map；
右击 「Scancode Map」，选择「修改」；
输入如下值并保存：
重启生效。
通俗讲 HTTP 协议就是在网络上传输（发布和接受）HTML 的协议，用于浏览器和服务器的通信。
下面进行一个小测试：
客户端：MacBook Pro（192.168.0.103）的 Chrome 浏览器。
服务端：Windows（192.168.0.105）上的 TCP 调试工具。
服务器要先开启，工作模式为：「TCP 服务器」，端口设置为：「8888」。
浏览器地址栏输入：「192.168.0.105:8888」。
服务端接收到请求：
GET / HTTP/1.1
Host: 192.168.0.105:8888
Connection: keep-alive
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.102 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
在服务端的发送信息窗口输入：
HTTP/1.1 200 ok
<h1>Hello World</h1>
客户端显示如下页面：
You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run jekyll serve, which launches a web server and auto-regenerates your site when a file is updated.
To add new posts, simply add a file in the _posts directory that follows the convention YYYY-MM-DD-name-of-post.ext and includes the necessary front matter. Take a look at the source for this post to get an idea about how it works.
Jekyll also offers powerful support for code snippets:
def print_hi(name)
puts "Hi, #{name}"
end
print_hi('Tom')
#=> prints 'Hi, Tom' to STDOUT.Check out the Jekyll docs for more info on how to get the most out of Jekyll. File all bugs/feature requests at Jekyll’s GitHub repo. If you have questions, you can ask them on Jekyll Talk.
| TCP | UDP | |
|---|---|---|
| connection | connection-oriented | connectionless |
| reliability | yes | no |
| speed | slower | faster |
| header size | 20 bytes | 8 bytes |
| ordering | rearrange packets in the order specified | no order |
| streaming of data | byte stream, buffered | entire message, sent once |
| used by other protocols | HTTP, HTTPS, FTP, SMTP, Telnet | DNS, DHCP, TFTP, SNMP, RIP |
| occasion | require high reliability, large amount of data | need fast, efficient transmission, small amount of data |
代表请求已被接受，需要继续处理。
服务器已经接收到请求头，并且客户端应继续发送请求主体，或者如果请求已经完成，忽略这个响应。
服务器已经理解了客户端的请求，并将通过Upgrade消息头通知客户端采用不同的协议来完成这个请求。
请求已成功，请求所希望的响应头或数据体将随此响应返回。
请求已经被实现，而且有一个新的资源已经依据请求的需要而创建，且其URI已经随Location头信息返回。
服务器已接受请求，但尚未处理。
服务器成功处理了请求，没有返回任何内容。
服务器成功处理了请求，但没有返回任何内容。与204响应不同，此响应要求请求者重置文档视图。
服务器已经成功处理了部分GET请求。
被请求的资源有一系列可供选择的回馈信息，每个都有自己特定的地址和浏览器驱动的商议信息。用户或浏览器能够自行选择一个首选的地址进行重定向。
被请求的资源已永久移动到新位置，并且将来任何对此资源的引用都应该使用本响应返回的若干个URI之一。
要求客户端执行临时重定向。
对应当前请求的响应可以在另一个URI上被找到。
表示资源未被修改，因为请求头指定的版本If-Modified-Since或If-None-Match。在这种情况下，由于客户端仍然具有以前下载的副本，因此不需要重新传输资源。
被请求的资源必须通过指定的代理才能被访问。
在这种情况下，请求应该与另一个URI重复，但后续的请求应仍使用原始的URI。
请求和所有将来的请求应该使用另一个URI重复。307和308重复302和301的行为，但不允许HTTP方法更改。
由于明显的客户端错误（例如，格式错误的请求语法，太大的大小，无效的请求消息或欺骗性路由请求），服务器不能或不会处理该请求。
用户没有必要的凭据。
服务器已经理解请求，但是拒绝执行它。
请求失败，请求所希望得到的资源未被在服务器上发现，但允许用户的后续请求。
请求行中指定的请求方法不能被用于请求相应的资源。
请求的资源的内容特性无法满足请求头中的条件，因而无法生成响应实体，该请求不可接受。
客户端必须在代理服务器上进行身份验证。
请求超时。
表示因为请求存在冲突无法处理该请求，例如多个同步更新之间的编辑冲突。
表示所请求的资源不再可用，将不再可用。
服务器拒绝在没有定义Content-Length头的情况下接受请求。
服务器在验证在请求的头字段中给出先决条件时，没能满足其中的一个或多个。
服务器拒绝处理当前请求，因为该请求提交的实体数据大小超过了服务器愿意或者能够处理的范围。
请求的URI长度超过了服务器能够解释的长度，因此服务器拒绝对该请求提供服务。
对于当前请求的方法和所请求的资源，请求中提交的互联网媒体类型并不是服务器中所支持的格式，因此请求被拒绝。
客户端已经要求文件的一部分（Byte serving），但服务器不能提供该部分。
在请求头Expect中指定的预期内容无法被服务器满足，或者这个服务器是一个代理服显的证据证明在当前路由的下一个节点上，Expect的内容无法被满足。
服务器遇到了一个未曾预料的状况，导致了它无法完成对请求的处理。
服务器不支持当前请求所需要的某个功能。
作为网关或者代理工作的服务器尝试执行请求时，从上游服务器接收到无效的响应。
由于临时的服务器维护或者过载，服务器当前无法处理请求。这个状况是暂时的，并且将在一段时间以后恢复。
作为网关或者代理工作的服务器尝试执行请求时，未能及时从上游服务器（URI标识出的服务器，例如HTTP、FTP、LDAP）或者辅助服务器（例如DNS）收到响应。
服务器不支持，或者拒绝支持在请求中使用的HTTP版本。
[TOC]
sed is a stream editor. A stream editor is used to perform basic text transformations on an input stream (a file or input from a pipeline).
sed OPTIONS... [SCRIPT] [INPUTFILE...]
| 选项 | 解释 |
|---|---|
| -f script-file | 添加script-file到命令 |
| -i [suffix] | 就地编辑。suffix指定备份文件后缀名 |
| -n/–quiet/ – slient | slient |
| -e script | 添加script到命令 |
命令结构：
[address[, address]] instruction [argument-list]
类似于awk的范围模式。$表示最后一行。
| 指令 | 解释 |
|---|---|
| a (append) | append text after a line |
| c (change) | change lines with text |
| d (delete) | stop processing the current line, immediately start next cycle |
| i (insert) | insert text before a line |
| N (next without write) | add a newline to the pattern space, then append the next line of input to the pattern space |
| n (next) | print the pattern space, then replace the pattern space with the next line of input |
| p (print) | print the pattern space |
| q (quit) | exit |
| r filename (read) | read text of a file |
| s (substitute) | format: s/regexp/replacement/[flags] |
| w filename (write) | write the pattern space to filename |
### 控制结构
| 符号 | 解释 |
|---|---|
| ! (NOT) | not |
| {} | 将一组指令括起来，用$;$将多条指令隔开 |
| :label | 标记一个位置，作为跳转目标 |
| b [label] | 无条件转移 |
| t [label] | 匹配成功则转移 |
### 暂存空间
| 符号 | 解释 |
|---|---|
| g | 将暂存空间的内容复制到模式空间中，模式空间中原来的内容丢失 |
| G | 将一个换行符和暂存空间中的内容append到模式空间中 |
| h | 将模式空间中的内容复制到暂存空间中，暂存空间中原来的内容丢失 |
| H | 将一个换行符和模式空间中的内容append到暂存空间中 |
| x | 交换模式空间和暂存空间中的内容 |
### regular expression extensions
| symbol | explanation |
|---|---|
| \w | any “word” character (字母、数组、下划线) |
| \W | any “non-word” character |
| \b | a word boundary |
| \B | every but on a word boundary |
| \s | whitespace characters (空格、tab、暂存空间和模式空间中的回车) |
| \S | non-whitespace characters |
| \< | beginning of a word |
| \> | end of a word |
| \` | start of pattern space, different from ^ |
| \’ | end of pattern space, different from $ |
An awk program is a sequence of patterns and actions that tell what to look for in the input data and what to do when it’s found.
注意：for (expression in array) statements 中的expression是array的index而不是array的element
function name(parameter-list) {
statements
return result
}
注：getline < file和getline var < file可以用在BEGIN中进行“预处理”（不会设置NR变量）。
| hostname | ip address | status |
|---|---|---|
| mnode01 | 10.2.152.21 | slave |
| mnode02 | 10.2.152.22 | slave |
| mnode04 | 10.2.152.24 | master & slave |
systemctl stop firewalld && systemctl disable firewalld
mnode01
ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode02
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode04
mnode02
ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode01
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode04
mnode04
ssh-keygen -t rsa
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode01
ssh-copy-id -i ~/.ssh/id_rsa.pub mnode02
/var/lib/mesos/
/var/lib/zookeeper/
/etc/mesos*/
/etc/zookeeper/
/etc/marathon/
rpm -Uvh http://repos.mesosphere.io/el/7/noarch/RPMS/mesosphere-el-repo-7-3.noarch.rpm
yum -y install mesos marathon mesosphere-zookeeper
echo 4 > /var/lib/zookeeper/myid
vim /etc/zookeeper/conf/zoo.cfg
# 在最后添加
# server.4 = 10.2.152.24:2888:3888
# 2888端口用于集群成员的信息交换
# 3888端口是在leader挂掉时用来选举新的leader用
vim /etc/mesos/zk
# 内容为：
# zk://10.2.152.24:2181/mesos
# 设置quorum的值（master节点数目除以2向上取整）
echo 1 > /etc/mesos-master/quorum
mkdir -p /etc/marathon/conf
echo 10.2.152.24 > /etc/mesos-master/hostname
echo 10.2.152.24 > /etc/marathon/conf/hostname
cp /etc/mesos/zk /etc/marathon/conf/master
cp /etc/mesos/zk /etc/marathon/conf/zk
sed -i 's|mesos|marathon|g' /etc/marathon/conf/zk
systemctl start zookeeper && systemctl start mesos-master && systemctl start marathon
主要配置内容:
/var/lib/zookeeper/myid
/etc/zookeeper/conf/zoo.cfg
/etc/mesos/zk
/etc/mesos-master/quorum
/etc/mesos-master/hostname
/etc/marathon/conf/hostname
/etc/marathon/conf/master
/etc/marathon/conf/zk
rpm -Uvh http://repos.mesosphere.io/el/7/noarch/RPMS/mesosphere-el-repo-7-3.noarch.rpm
yum -y install mesos
mnode01
echo 10.2.152.21 > /etc/mesos-slave/hostname
vim /etc/mesos/zk
# 内容编辑为:
# zk://10.2.152.24:2181/mesos
mnode02
echo 10.2.152.22 > /etc/mesos-slave/hostname
vim /etc/mesos/zk
# 内容编辑为:
# zk://10.2.152.24:2181/mesos
mnode04
echo 10.2.152.24 > /etc/mesos-slave/hostname
mnode01, mnode02 and mnode04
systemctl start mesos-slave
on mnode04
mesos-execute --master="10.2.152.24:5050" --name="cluster-test" --command="sleep 40"
mesos的管理页面中会显示
using the following command:
curl -u '${user_name}' https://api.github.com/user/repos -d "{\"name\":\"${repo_name}\"}"
execute the following commands:
touch README.md
echo "# ${repo_name}" >> README.md
git init
git add .
git commit -m "first commit"
git remote add origin https://github.com/${user_name}/${repo_name}.git
git push -u origin master
this is my shell script git-create, I made it executable and added it’s path to my PATH environment variable for convenience:
user_name='lightjameslyy'
repo_name=$1
test -z $repo_name && echo "Repo name required." 1>&2 && exit 1
curl -u ${user_name} https://api.github.com/user/repos -d "{\"name\":\"${repo_name}\"}"
touch README.md
echo "# ${repo_name}" >> README.md
git init
git add .
git commit -m "first commit"
git remote add origin https://github.com/${user_name}/${repo_name}.git
git push -u origin master
Typically, gzip files are sotred with a .gz extension.
gzip :gzip sourcefile
This wil compress the file and change the name to sourcefile.gz.
gzip -r directory1
gzip -l test.gz
From -1(–fast) to -9(–best):
gzip -9 sourcefile
.gz filegzip -d test.gz
or
gunzip test.gz
Files compressed with bzip2 are generally given a .bz2 file extension.
bz2bzip2 testfile
This will compress the file and give it the name testfile.bz2.
gzip) The number represents the block size that utility manages to implement its compression.
bzip2 -9 testfile
The default behavior is the -9 flag.
.bz2 filebzip2 -d testfile.bz2
xzxz testfile
This will process the file and produce a file called file.xz.
xz -l testfile.xz
.xz filexz -d testfile.xz
tar czvf test.tar.gz directory1
tar tzvf test.tar.gz
tar xzvf test.tar.gz
To use archiving with bzip2, you can replace the -z flag, which is gzip-specific, with the -j flag.
tar cjvf test.tar.bz2 directory1
tar tjvf test.tar.bz2
tar xjvf teat.tar.bz2
Any remotely recent versions of tar have added similar functionality for xz compression. These follow the exact same format using the -J flag.
tar cJvf test.tar.xz directory1
tar tJvf test.tar.xz
tar xJvf test.tar.xz
open terminal and type in the following commands:
> defaults write com.apple.finder AppleShowAllFiles YES
> killall Finder
then relaunch Finder, the hidden files should be visible.
open terminal and type in the following commands:
> defaults write com.apple.finder AppleShowAllFiles NO
> killall Finder
then relaunch Finder, the hidden files should be invisible.
进行Qt开发时，程序写好后在本机能运行，但是打包的.exe文件在没有安装Qt的机器上不能运行。原因：因为采用了动态编译，一起打包的dll文件都是动态库。解决方法是采用静态编译。
言归正传，下面就是我静态编译Qt的过程（我使用的版本是Qt5.5.1）。
1) 确保已经安装了Qt 5.5.1。
2) 下载Qt 5.5.1的源码：http://download.qt.io/archive/qt/5.5/5.5.1/single/ 。
3) 安装python。
4) 把源码解压到C盘（我的路径是C:\qt-everywhere-opensource-src-5.5.1）。编辑C:\qt-everywhere-opensource-src-5.5.1\qtbase\mkspecs\win32-g++\qmake.conf，找到QMAKE_LFLAGS和QMAKE_LFLAGS_DLL，后面赋值为 –static：
QMAKE_LFLAGS = -static
QMAKE_LFLAGS_DLL = -static
保存，退出。
5) 打开终端：windows键==>all apps==>Qt 5.5.1==>Qt 5.5.1 for Desktop (MinGW 4.9.2 32 bit)，切换路径到C:\qt-everywhere-opensource-src-5.5.1。
6) configure：
configure -confirm-license -opensource -platform win32-g++ -release -static -ltcg -prefix "C:\Qtstatic" -qt-sql-sqlite -qt-sql-odbc -plugin-sql-sqlite -plugin-sql-odbc -qt-zlib -qt-libpng -qt-libjpeg -opengl desktop -no-qml-debug -nomake tests -nomake examples -skip qtwebkit -qt-pcre -no-compile-examples
（C:\Qtstatic为安装路径，可自定义）
7) mingw32-make
8) mingw32-make install
注：make和make install 需要的时间较多，可能要3到4个小时
9) 添加编译选项
打开QtCreator==>Tools==>options==>build&run==>QtVersions==>add==>选择C:\Qtstatic\bin\qmake.exe==>apply
10）done^_^
change to an appropriate directory (mine is /usr/local) and unzip the 4 packages:
tar -jxvf gmp-6.1.0.tar.bz2
tar -zxvf mpfr-3.1.3.tar.gz
tar -zxvf mpc-1.0.3.tar.gz
tar -zxvf gcc-5.3.0.tar.gz
> cd /usr/local/gmp-6.1.0
> ./configure
> make -j2
> make install -j2
NOTICE:
(1) If there are errors such as “Permission denied…“, you need to switch to super user and repeat the process.
(2) The header and library genetated by gmp should already be located under /usr/local/include and /usr/local/lib.
> cd /usr/local/mpfr-3.1.3
> ./configure --with-gmp-include=/usr/local/include --with-gmp-lib=/usr/local/lib
> make -j2
> make install -j2
> cd /usr/local/mpc-1.0.3
> ./configure
> make -j2
> make install -j2
> export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib
NOTICE:
Don’t forget to change the environment variable $LD_LIBRARY_PATH which is necessary for compiling gcc later.
> cd /usr/local/gcc-5.3.0
> mkdir build
> cd build
> ../configure --prefix=/usr/local/gcc --enable-threads=posix --disable-checking --enable-languages=c,c++ --disable-multilib --with-gmp=/usr/local/lib --with-mpfr=/usr/local/lib --with-mpc=/usr/local/lib
> make -j2
> make install -j2
NOTICE:
while make, I have the following errors:
...[s-attrtab]...
...[all-stage1-gcc]...
...[stage1-bubble]...
this means you need to add swap partition, I made it by editing /etc/sysctl.conf
changing
vm.swappiness = 0
to
vm.swappiness = 60
then restart the operating system, continue from make -j2.
> yum remove gcc
> yum remove gcc-c++
> updatedb
> cd /usr/bin
> ln -s /usr/local/gcc/bin/gcc gcc
> ln -s /usr/local/gcc/bin/g++ g++
> vim /etc/man_db.conf add entry: ``` MANDATORY_MANPATH /usr/local/gcc/share/man ``` save and exit.
> gcc -v
see whether the version is 5.3.0.
I started my hexo blog last year, and recently I get down to adding content frequently. So, I begin with learning besic markdown. The following tips are from http://www.markdowntutorial.com/.
To make a phrase italic in Markdown, you can surround words with an underscore ( _ ).Similarly, to make phrases bold in Markdown, you can surround words with two asterisks ( ** ).
for example:
italic:
_this_ ==> this
bold:
**this** ==> this
italic and bold:
**_this_** ==> this
You can’t really make a header bold, but you can italicize certain words.for example:
##Header _two_
To create an inline link, you wrap the link text in brackets ( [ ] ), and then you wrap the link in parenthesis ( ( ) ).
####The Latest News from [the BBC](www.bbc.com/news) is shown as below:
The other link type is called a reference link. As the name implies, the link is actually a reference to another place in the document.
Do you want to [see something fun][a fun place]?
Well, do I have [the website for you][another fun place]!
[a fun place]: www.zombo.com
[another fun place]: www.stumbleupon.com
is shown as below:
Do you want to see something fun?
Well, do I have the website for you!
Images also have two styles, just like links. To create an inline image, you’ll use the same syntax as an inline link.
 is shown as below:
For a reference image, you’ll follow the same pattern as a reference link. You’ll precede the Markdown with an exclamation point, then provide two brackets for the alt text, and then two more for the image tag. At the bottom of your Markdown page, you’ll define an image for the tag.
![The first father][First Father]
![The second first father][Second Father]
[First Father]: http://octodex.github.com/images/founding-father.jpg
[Second Father]: http://octodex.github.com/images/foundingfather_v2.png
is shown as below:
A blockquote is a sentence or paragraph that’s been specially formatted to draw attention to the reader. To create a block quote, all you have to do is preface a line with the “greater than” caret (>). For example:
> "Her eyes had called him and his soul had leaped at the call. To live, to err, to fall, to triumph, to recreate life out of life!"
“Her eyes had called him and his soul had leaped at the call. To live, to err, to fall, to triumph, to recreate life out of life!”
You can also place a caret character on each line of the quote. This is particularly useful if your quote spans multiple paragraphs. For example:
> —Of whom are you speaking? Stephen asked at length.
>
> Cranly did not answer.
—Of whom are you speaking? Stephen asked at length.
Cranly did not answer.
To create an unordered list, you’ll want to preface each item in the list with an asterisk ( * ). Each list item also gets its own line. For example, a grocery list in Markdown might look like this:
* Milk
* Eggs
* Salmon
* Butter
An ordered list is prefaced with numbers, instead of asterisks. Take a look at this recipe:
1. Crack three eggs over a bowl
2. Pour a gallon of milk into the bowl
3. Rub the salmon vigorously with butter
4. Drop the salmon into the egg-milk bowl
To make a list with more depth, or, to nest one list within another, all you have to do is to remember to indent each asterisk one space more than the preceding item. For example:
* Tintin
* A reporter
* Has poofy orange hair
* Friends with the world's most awesome dog
* Haddock
* A sea captain
* Has a fantastic beard
* Loves whiskey
* Possibly also scotch?
1. Crack three eggs over a bowl.
Now, you're going to want to crack the eggs in such a way that you don't make a mess.
If you _do_ make a mess, use a towel to clean it up!
2. Pour a gallon of milk into the bowl.
Basically, take the same guidance as above: don't be messy, but if you are, clean it up!
3. Rub the salmon vigorously with butter.
By "vigorous," we mean a strictly vertical motion. Julia Child once quipped:
> Up and down and all around, that's how butter on salmon goes.
4. Drop the salmon into the egg-milk bowl.
Here are some techniques on salmon-dropping:
* Make sure no trout or children are present
* Use both hands
* Always have a towel nearby in case of messes
Now, you’re going to want to crack the eggs in such a way that you don’t make a mess.
If you do make a mess, use a towel to clean it up!
Basically, take the same guidance as above: don’t be messy, but if you are, clean it up!
Rub the salmon vigorously with butter.
By “vigorous,” we mean a strictly vertical motion. Julia Child once quipped:
Up and down and all around, that’s how butter on salmon goes.
Drop the salmon into the egg-milk bowl.
Here are some techniques on salmon-dropping:
Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)
is shown as below:
Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)
Do I contradict myself?··
Very well then I contradict myself,··
(I am large, I contain multitudes.)
is shown as below(a dot represents a space):
Do I contradict myself?
Very well then I contradict myself,
(I am large, I contain multitudes.)
Next you can update your site name, avatar and other options using the _config.yml file in the root of your repository (shown below).