What is a programming language?

Swift

Since you want to learn programming，Then we should at least know their own learning is what it okay?

Speaking of programming，In fact, the earliest still have to catch up with our big brother Alan Turing God go。At that time Turing invented Turing machine - this thing is very fast hardware，Finish all had easily shortened to two years of World War II where we do not start speaking up，We say that the main，The Turing Machine，Basically it is the first computer!

of course，Textbooks do not say that von Neumann computer is the father of it? Ok，I will not tell you they stir the base to the course ......，Well that is hooked up[……]

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Swift Common Types of data

Swift

Now most of the high-level programming language，All evolved from the classic C language，You grammar which in these programming languages，More or less can be found in the shadow of a fraction of the C language，This is why a lot of people still recommend，From the C programming language into the language of the door。

but，C language is indeed a sufficient old，Many people are directed to write a program target learning to play the APP，You to learn C language ...... sorry，Probably a whole book finished school，You can not write a beautiful beautiful UI interface。

but，anyway，To learn Swift[……]

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Watercress FM song list access

Swift

Swift recently started learning the，It is like "hello world" as，Each language seems to always have a "write Douban FM" project tutorial😶

In short，I started using this process taught to become familiar with the development process，but，Only yesterday did show playlists and display the song Cover，Today adds playback collapsed flash back!

Ok，Even if the newly added code commented out，Original code can not run correctly。You see，There has been such a universal error：
[crayon-68e67[……]

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How to use the gem in the country

Ruby

If you want to know Ruby，Ruby or want to install several software packages on your computer，You can easily use RubyGems a key to download - just like in the Ubuntu apt-get、Similar redhat in the yum etc.。

so，Want to install Ruby packages，You will need to gem。but，In addition to installing gem (if your computer is Linux or osx，It may have been built，Use the command "gem -v" to verify)

But the version may[……]

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Could not load the image referenced from a nib in the bundle running on device

Swift

In use xcode Make a program when，We generally use some pictures instead of stiff off button text，Make the interface more beautiful。

but，When adding pictures，I met when editing storyboard You can display，But the problem when the program is running, but can not be displayed。

View Record found error：

Nations on swift Development of documentation and Q is too small，Even the tutorial is ambiguous - it[……]

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VM most serious vulnerabilities Venom cloud services is threatened!

Exchange of Experience News

This afternoon，I'm knocking Code，Then on the west coast, a vps sent e-mail，Said server to restart Update，And I happen to have a vps is there in his。In addition to hardware and general maintenance accident，Cloud services basically online - after all，“High availability"It is the main subject of cloud services。

but，This time is different，Just today，The new virtual machine loopholes available，Exploit this vulnerability，You can make every minuteBreakthrough virtual machine restrictionsAnd get to the other servers in the same server access! Then use the information to other servers，And then we can continue in-depth infiltration[……]

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Open nat masquerading and port forwarding on ufw

Linux

Possible until now，You have been very skilled how to open nat and port forwarding on Linux - after all, this operation may also require a server at the time of deployment。But its operation is too cumbersome，Especially when we use edit iptables ufw after that，But you can not directly edit the iptables，This time in the end what to do it?

wantUse ufw to open nat masquerading and port forwarding，You can refer to this articleUnder Ubuntu more simple firewall Uncompli[……]

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Ali cloud Ubuntu update image source

Linux

Update：for some reason，Ali cloud is no longer recommended updates the source，Give youThis page，Click to go can help you generate USTC mirror automatically depending on the version update source。

In order to facilitate their own domestic vps server configuration updates，Usually all you need to change and update the source dns，Do not try to patch ............ otherwise life short，NetEase previously used source but recently always cramp，So nowRecommended Ali cloud。

P.S.，You can enter "in a terminal serverlsb_release -a"Command or see"/etc/issue"file[……]

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Under Ubuntu more simple firewall Uncomplicated Firewall

Linux

we all know，Among Linux system has a very fast hardware firewall is called iptables，It can do far exceeds the scope of the firewall, but ......，usually，We only used it as a firewall to use。

but，If you just want a port policy，That does not seem to need to face iptables That lengthy configuration commands。Now，I'll introduce you to the other, a more simple firewall：

Uncomplicated Firewall

A very clear look at the name "uncomplicated fire[……]

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