Merge pull request #746 from kelvins/master

Fixed some duplicate words in the English version.

en/02.1.md

@@ -17,7 +17,7 @@ While this might seem to be a shallow problem at the top, but when the codebase
 
 For other languages there are many variables when it comes to writing code, every language is good for its use case, but Go is a little special in that turf because it was designed at a company which is the very synonym of the Internet (and distributed computing), typically the flow of writing code goes from Python to Java to C++ for optimization purposes, but the problem is that almost all languages which are widely in use right now were written decades ago when 1GB storage came at a much higher price compared to now, where storage and computing has gotten cheap. Computers are getting multiples cores these days and the "old languages" don't harness concurrency in a way that go does, not because those languages are  bad, but simply because that usecase wasn't relevant when the languages evolved.
 
-So to mitigate all the problems that Google faced with the current tools, they wrote a systems language called Go, which you are about to learn! There are many many advantages to using golang, and there might be disadvantages too for every coin has both sides. But significant improvements in places like code formatting, since they designed the language in such a way that there won't be wars on how to format code, the gocode written by anyone in the world (assuming they know and use `gofmt`) will look exactly the same, this won't seem to matter until you work in a team! also when the company uses automated code review or some other fancy technique then in other languages which don't have strict and standard formatting rules then the code might get screwed up, but not in go!
+So to mitigate all the problems that Google faced with the current tools, they wrote a systems language called Go, which you are about to learn! There are many advantages to using golang, and there might be disadvantages too for every coin has both sides. But significant improvements in places like code formatting, since they designed the language in such a way that there won't be wars on how to format code, the gocode written by anyone in the world (assuming they know and use `gofmt`) will look exactly the same, this won't seem to matter until you work in a team! also when the company uses automated code review or some other fancy technique then in other languages which don't have strict and standard formatting rules then the code might get screwed up, but not in go!
 
 Go was designed with concurrency in mind, please note that parallelism != concurrency, there is an amazing post by Rob Pike on the golang blog, blog.golang.org, you will find it there, it is worth a read.
 

en/06.4.md

@@ -49,7 +49,7 @@ Refresh the page and you'll see the following:
 
 Figure 6.7 hijacking the session has succeeded.
 
-Here we see that we can hijack sessions between different browsers, and actions performed in one one browser can affect the state of a page in another browser. Because HTTP is stateless, there is no way of knowing that the session id from firefox is simulated, and chrome is also not able to know that it's session id has been hijacked.
+Here we see that we can hijack sessions between different browsers, and actions performed in one browser can affect the state of a page in another browser. Because HTTP is stateless, there is no way of knowing that the session id from firefox is simulated, and chrome is also not able to know that it's session id has been hijacked.
 
 ## prevent session hijacking
 

en/09.1.md

@@ -21,7 +21,7 @@ As can be seen from the figure, to complete a CSRF attack, the victim must compl
 -1. Log into trusted site A, and store a local Cookie.
 -2. Without going through existing site A, access the dangerous link to site B.
 
-As a reader you may be asking: "If I do not meet the above two conditions, I will will not be subjected to CSRF attacks." Yes this is true, however you cannot guarantee that the following does not occur:
+As a reader you may be asking: "If I do not meet the above two conditions, I will not be subjected to CSRF attacks." Yes this is true, however you cannot guarantee that the following does not occur:
 
 - You cannot guarantee that when you are logged into a site, the site didn't launch any hidden tabs.
 - You cannot guarantee that when you close your browser, your cookies will immediately expire and your last session will have ended.
@@ -37,7 +37,7 @@ You might be a little scared after reading the section above. But fear is a good
 
 Preventative measures against CSRF attacks can be taken on both the server and client sides of a web application. However, CSRF attacks are most effectively thwarted on the server side.
 
-There are many ways of preventing CSRF attacks on the server side. Most approaches stem from from the following two aspects:
+There are many ways of preventing CSRF attacks on the server side. Most approaches stem from the following two aspects:
 
 1. Maintaining proper use of GET, POST and cookies.
 2. Including a pseudo-random number with non-GET requests.

en/09.4.md

@@ -60,7 +60,7 @@ SQL injection attacks can be devastating -how can do we even begin to defend aga
 1. Strictly limit permissions for database operations so that users only have the minimum set of permissions required to accomplish their work, thus minimizing the risk of database injection attacks.
 2. Check that input data has the expected data format, and strictly limit the types of variables that can be submitted. This can involve regexp matching, or using the strconv package to convert strings into other basic types for sanitization and evaluation.
 3. Transcode or escape from pairs of special characters ( '"\&*; etc. ) before persisting them into the database. Go's `text/template` package has a `HTMLEscapeString` function that can be used to return escaped HTML.
-4. Use your database's parameterized query interface. Parameterized statements use parameters instead of concatenating user input variables in embedded SQL statements; in other words, they do not directly splice ​​SQL statements. For example, using the the `Prepare` function in Go's `database/sql` package, we can create prepared statements for later execution with `Query` or `Exec(query string, args... interface {})`.
+4. Use your database's parameterized query interface. Parameterized statements use parameters instead of concatenating user input variables in embedded SQL statements; in other words, they do not directly splice ​​SQL statements. For example, using the `Prepare` function in Go's `database/sql` package, we can create prepared statements for later execution with `Query` or `Exec(query string, args... interface {})`.
 5. Before releasing your application, thoroughly test it using professional tools for detecting SQL injection vulnerabilities and to repair them, if they exist. There are many online open source tools that do just this, such as sqlmap, SQLninja, to name a few.
 6. Avoid printing out SQL error information on public webpages. Attackers can use these error messages to carry out SQL injection attacks. Examples of such errors are type errors, fields not matching errors, or any errors containing SQL statements.
 

en/12.4.md

@@ -1,6 +1,6 @@
 # 12.4 Backup and recovery
 
-In this section, we'll discuss another aspect of application management: data backup and recovery on production servers. We often encounter situations where production servers don't behave as as we expect them to. Server network outages, hard drive malfunctions, operating system crashes and other similar events can cause databases to become unavailable. The need to recover from these types of events has led to the emergence of many cold standby/hot standby  tools that can help to facilitate disaster recovery remotely. In this section, we'll explain how to backup deployed applications in addition to backing up and restoring any MySQL and Redis databases you might be using.      
+In this section, we'll discuss another aspect of application management: data backup and recovery on production servers. We often encounter situations where production servers don't behave as we expect them to. Server network outages, hard drive malfunctions, operating system crashes and other similar events can cause databases to become unavailable. The need to recover from these types of events has led to the emergence of many cold standby/hot standby  tools that can help to facilitate disaster recovery remotely. In this section, we'll explain how to backup deployed applications in addition to backing up and restoring any MySQL and Redis databases you might be using.      
 
 ## Application Backup
 
@@ -174,7 +174,7 @@ As you can see, importing and exporting database is a fairly simple matter. If y
 
 ## Redis backup
 
-Redis is one of the most popular NoSQL databases, and both hot and cold backup techniques can also be used in systems which use it. Like MySQL, Redis also supports master/slave mode, which is ideal for implementing hot backups (refer to Redis' official documentation to learn learn how to configure this; the process is very straightforward). As for cold backups, Redis routinely saves cached data in memory to the database file on-disk. We can simply use the rsync backup method described above to synchronize it with a non-local machine. 
+Redis is one of the most popular NoSQL databases, and both hot and cold backup techniques can also be used in systems which use it. Like MySQL, Redis also supports master/slave mode, which is ideal for implementing hot backups (refer to Redis' official documentation to learn how to configure this; the process is very straightforward). As for cold backups, Redis routinely saves cached data in memory to the database file on-disk. We can simply use the rsync backup method described above to synchronize it with a non-local machine. 
 
 ## Redis recovery
 

en/13.1.md

@@ -4,7 +4,7 @@ Anything you intend to do well must first be planned well. In our case, our inte
 
 ## GOPATH and project settings
 
-Let's proceed by assuming that our GOPATH points to a folder with with an ordinary directory name (if not, we can easily set up a suitable directory and set its path as the GOPATH). As we've describe earlier, a GOPATH can contain more than one directory: in Windows, we can set this as an environment variable; in linux/OSX systems, GOPATH can be set using `export`, i.e: `export gopath=/path/to/your/directory`, as long as the directory which GOPATH points to contains the three sub-directories: `pkg`, `bin` and `src`. Below, we've placed the source code of our new project in the `src` directory with the tentative name `beelog`. Here are some screenshots of the Windows environment variables as well as of the directory structure.   
+Let's proceed by assuming that our GOPATH points to a folder with an ordinary directory name (if not, we can easily set up a suitable directory and set its path as the GOPATH). As we've describe earlier, a GOPATH can contain more than one directory: in Windows, we can set this as an environment variable; in linux/OSX systems, GOPATH can be set using `export`, i.e: `export gopath=/path/to/your/directory`, as long as the directory which GOPATH points to contains the three sub-directories: `pkg`, `bin` and `src`. Below, we've placed the source code of our new project in the `src` directory with the tentative name `beelog`. Here are some screenshots of the Windows environment variables as well as of the directory structure.   
 
 ![](images/13.1.gopath.png?raw=true)
 

en/14.6.md

@@ -10,7 +10,7 @@ In fact, `net/http/pprof` simply exposes runtime profiling data from the `runtim
 
 ## pprof support in Beego 
 
-The Beego framework currently supports pprof, however it is not not turned on by default. If you need to test the performance of your application, (for instance by viewing the execution goroutine) such information from Go's default package "net/http/pprof" already has this feature. Because beego has repackaged the ServHTTP function, you can not open the default feature included in pprof. This resulted in beego supporting pprof internally.
+The Beego framework currently supports pprof, however it is not turned on by default. If you need to test the performance of your application, (for instance by viewing the execution goroutine) such information from Go's default package "net/http/pprof" already has this feature. Because beego has repackaged the ServHTTP function, you can not open the default feature included in pprof. This resulted in beego supporting pprof internally.
 
 - First in our `beego.Run` function, we choose whether or not to automatically load the performance pack according to our configuration variable (in this case, PprofOn):