Try either 

 - `sudo apt-get install php-zip` or
 - `sudo apt-get install php5.6-zip`

Then, you might have to restart your web server.

- `sudo service apache2 restart` or
- `sudo service nginx restart`

If you are installing on centos or fedora OS then use yum in place of apt-get. example:-

`sudo yum install php-zip` or
`sudo yum install php5.6-zip` and 
`sudo service httpd restart`

I&#39;m learning Swift 3 and I&#39;m trying to using `NSNotificationCenter`. Here is my code: 

    func savePost(){
        let postData = NSKeyedArchiver.archivedData(withRootObject: _loadedpost)
        UserDefaults.standard().object(forKey: KEY_POST)
    }
    func loadPost(){
        if let postData = UserDefaults.standard().object(forKey: KEY_POST) as? NSData{
            if let postArray = NSKeyedUnarchiver.unarchiveObject(with: postData as Data) as? [Post]{
                    _loadedpost = postArray
            }
        }
        //codeerror
        NotificationCenter.default().post(NSNotification(name: &quot;loadedPost&quot; as NSNotification.Name, object: nil) as Notification)
    }

and this is the observer: 

    override func viewDidLoad() {
        super.viewDidLoad()
    //codeerorr
        NotificationCenter.default().addObserver(self, selector: Selector((&quot;onPostLoaded&quot;)), name: &quot;loadedPost&quot;, object: nil)
    }
    
    func numberOfSections(in tableView: UITableView) -&gt; Int {
        return 1
    }

It always gives me the error &quot;signal SIGBRT&quot;. When I try to change the name in the observer, it&#39;s not an error, but obviously it didn&#39;t show anything. How do I fix this?

NotificationCenter issue on Swift 3

I have a simple .NET Core project (console app) that I&#39;m trying to compile and run. `dotnet build` succeeds, but I get the following error when I do `dotnet run`:

```none
dotnet run
Project RazorPrecompiler (.NETCoreApp,Version=v1.0) was previously compiled. Skipping compilation.
A fatal error was encountered. The library &#39;hostpolicy.dll&#39; required to execute the application was not found in [path].
```

My project.json looks like this:

    {
      &quot;buildOptions&quot;: {
        &quot;warningsAsErrors&quot;: true
      },
      &quot;dependencies&quot;: {
        &quot;Microsoft.AspNetCore.Razor&quot;: &quot;1.0.0&quot;,
        &quot;Microsoft.NETCore.App&quot;: {
          &quot;type&quot;: &quot;platform&quot;,
          &quot;version&quot;: &quot;1.0.0&quot;
        }
      },
      &quot;description&quot;: &quot;Precompiles Razor views.&quot;,
      &quot;frameworks&quot;: {
        &quot;netcoreapp1.0&quot;: {
          &quot;imports&quot;: [ ]
        }
      },
      &quot;version&quot;: &quot;1.2.0&quot;
    }

What is `hostpolicy.dll`, and why is it missing?

The library hostpolicy.dll was not found

I can&#39;t install php-zip on my Ubuntu VM with the last php5.6.

Can&#39;t find find anything clear on it.

I still get that Apache error : 

    PHP Fatal error:  Class &#39;ZipArchive&#39; not found in /var/www/uta/system/library/PHPExcel/PHPExcel/Writer/...

Thanks

Install php-zip on php 5.6 on Ubuntu

I can't install php-zip on my Ubuntu VM with the last php5.6.
Can't find find anything clear on it.
I still get that Apache error :
<pre><code class="hljs language-vbnet">PHP Fatal error: Class 'ZipArchive' not found in /var/www/uta/system/library/PHPExcel/PHPExcel/Writer/...
</code></pre>
Thanks

I have been trying to get the extension from an uploaded file, searching on google, I got no results.

The file already exists in a path:

    \Storage::get(&#39;/uploads/categories/featured_image.jpg);
    
Now, How can I get the extension of this file above?

Using input fields I can get the extension like this:

    Input::file(&#39;thumb&#39;)-&gt;getClientOriginalExtension();

Thanks.

Get an image extension from an uploaded file in Laravel

I&#39;ve been reviewing the documentation and API for Laravel Collections, but don&#39;t seem to find what I am looking for:

I would like to retrieve an array with model data from a collection, but only get specified attributes.

I.e. something like `Users::toArray(&#39;id&#39;,&#39;name&#39;,&#39;email&#39;)`, where the collection in fact holds all attributes for the users, because they are used elsewhere, but in this specific place I need an array with userdata, and only the specified attributes.

There does not seem to be a helper for this in Laravel? - How can I do this the easiest way?

Get only specific attributes with from Laravel Collection

Does PHP 7 support strict typing for resources? If so, how?

For example:


    	declare (strict_types=1);
    
    	$ch = curl_init ();
    	test ($ch);
    
    	function test (resource $ch)
    	{

    	}

The above will give the error: 

&gt; Fatal error: Uncaught TypeError: Argument 1 passed to test() must be an instance of resource, resource given

A var_dump on `$ch` reveals it to be **resource(4, curl)**, and the manual says `curl_init ()` returns a resource.

Is it at all possible to strictly type the `test()` function to support the `$ch variable`?

PHP 7 and strict &quot;resource&quot; types

How to redirect to previous page in laravel5.2 like URI Referrer in php.

I&#39;ve tried $request-&gt;url(); 
but it gets the current url. 

I&#39;ve a form and list pages.There are many lists that redirects to form.but I want to go to that specific page after submit.

For Ex:There are a Project and Client list. If I go to form from project then it should go to project and if I go to form from client list It should go to client list page after submitting a form.

 

Redirect url to previous page in laravel

I don&#39;t know if this going to happen, but I will try it.

For past hour I did research on image upload safety. I learned that there a lot of functions to test the upload.

In my project, I need to be safe with images uploaded. There also may be a really big amount of it and it may require a lot of bandwidth, so buying an API is not an option.

So I decided to get a full PHP script for REALLY secure image upload. I also think it will help for many of people out there, because it&#39;s impossible to find really secure one. But I am not expert in php, so it&#39;s really headache for me to add some functions, so I will ask for this community help to create one full script of REALLY secure image upload.

Really great topics about that are here (however, they are just telling what is needed to do the trick, but not how to do this, and as I said I am not a master on PHP, so I am not able to do this all by myself):
https://stackoverflow.com/questions/4166762/php-image-upload-security-check-list
https://security.stackexchange.com/questions/32852/risks-of-a-php-image-upload-form

In summary, they are telling that this is what is needed for security image upload (I will quote from the above pages):

&gt;  - Disable PHP from running inside the upload folder using .httaccess.
&gt;  - Do not allow upload if the file name contains string &quot;php&quot;.
&gt;  - Allow only extensions: jpg,jpeg,gif and png.
&gt;  - Allow only image file type.
&gt;  - Disallow image with two file type.
&gt;  - Change the image name. Upload to a sub-directory not root directory.

&gt; Also:
&gt; 
&gt;  - Re-process the image using GD (or Imagick) and save the processed    image. All others are just fun boring for hackers&quot;
&gt;  - As rr pointed out, use move_uploaded_file() for any upload&quot;
&gt;  - By the way, you&#39;d want to be very restrictive about your upload       folder. Those places are one of the dark corners where many exploits  
&gt; happen. This is valid for any type of upload and any programming      
&gt; language/server. Check      
&gt; https://www.owasp.org/index.php/Unrestricted_File_Upload
&gt;  - Level 1: Check the extension (extension file ends with)
&gt;  - Level 2: Check the MIME type ($file_info =    getimagesize($_FILES[&#39;image_file&#39;]; $file_mime = $file_info[&#39;mime&#39;];)
&gt;  - Level 3: Read first 100 bytes and check if they have any bytes in the    following range: ASCII 0-8, 12-31 (decimal).
&gt;  - Level 4: Check for magic numbers in the header (first 10-20 bytes of    the file). You can find some of the files header bytes from
&gt; here:   
&gt; http://en.wikipedia.org/wiki/Magic_number_%28programming%29#Examples
&gt;  - You might want to run &quot;is_uploaded_file&quot; on the    $_FILES[&#39;my_files&#39;][&#39;tmp_name&#39;] as well. See   
&gt; http://php.net/manual/en/function.is-uploaded-file.php

Here&#39;s a big part of it, but still that&#39;s not all. (If you know something more which could help to make the upload even safier, please share.)

**THIS IS WHAT WE GOT NOW**

 - Main PHP:

        function uploadFile ($file_field = null, $check_image = false, $random_name = false) {
           
        //Config Section    
        //Set file upload path
        $path = &#39;uploads/&#39;; //with trailing slash
        //Set max file size in bytes
        $max_size = 1000000;
        //Set default file extension whitelist
        $whitelist_ext = array(&#39;jpeg&#39;,&#39;jpg&#39;,&#39;png&#39;,&#39;gif&#39;);
        //Set default file type whitelist
        $whitelist_type = array(&#39;image/jpeg&#39;, &#39;image/jpg&#39;, &#39;image/png&#39;,&#39;image/gif&#39;);
     
        //The Validation
        // Create an array to hold any output
        $out = array(&#39;error&#39;=&gt;null);
                    
        if (!$file_field) {
          $out[&#39;error&#39;][] = &quot;Please specify a valid form field name&quot;;           
        }
     
        if (!$path) {
          $out[&#39;error&#39;][] = &quot;Please specify a valid upload path&quot;;               
        }
            
        if (count($out[&#39;error&#39;])&gt;0) {
          return $out;
        }
     
        //Make sure that there is a file
        if((!empty($_FILES[$file_field])) &amp;&amp; ($_FILES[$file_field][&#39;error&#39;] == 0)) {
             
        // Get filename
        $file_info = pathinfo($_FILES[$file_field][&#39;name&#39;]);
        $name = $file_info[&#39;filename&#39;];
        $ext = $file_info[&#39;extension&#39;];
                   
        //Check file has the right extension           
        if (!in_array($ext, $whitelist_ext)) {
          $out[&#39;error&#39;][] = &quot;Invalid file Extension&quot;;
        }
                   
        //Check that the file is of the right type
        if (!in_array($_FILES[$file_field][&quot;type&quot;], $whitelist_type)) {
          $out[&#39;error&#39;][] = &quot;Invalid file Type&quot;;
        }
                   
        //Check that the file is not too big
        if ($_FILES[$file_field][&quot;size&quot;] &gt; $max_size) {
          $out[&#39;error&#39;][] = &quot;File is too big&quot;;
        }
                   
        //If $check image is set as true
        if ($check_image) {
          if (!getimagesize($_FILES[$file_field][&#39;tmp_name&#39;])) {
            $out[&#39;error&#39;][] = &quot;Uploaded file is not a valid image&quot;;
          }
        }
    
        //Create full filename including path
        if ($random_name) {
          // Generate random filename
          $tmp = str_replace(array(&#39;.&#39;,&#39; &#39;), array(&#39;&#39;,&#39;&#39;), microtime());
                           
          if (!$tmp || $tmp == &#39;&#39;) {
            $out[&#39;error&#39;][] = &quot;File must have a name&quot;;
          }     
          $newname = $tmp.&#39;.&#39;.$ext;                                
        } else {
            $newname = $name.&#39;.&#39;.$ext;
        }
                   
        //Check if file already exists on server
        if (file_exists($path.$newname)) {
          $out[&#39;error&#39;][] = &quot;A file with this name already exists&quot;;
        }
    
        if (count($out[&#39;error&#39;])&gt;0) {
          //The file has not correctly validated
          return $out;
        } 
    
        if (move_uploaded_file($_FILES[$file_field][&#39;tmp_name&#39;], $path.$newname)) {
          //Success
          $out[&#39;filepath&#39;] = $path;
          $out[&#39;filename&#39;] = $newname;
          return $out;
        } else {
          $out[&#39;error&#39;][] = &quot;Server Error!&quot;;
        }
             
         } else {
          $out[&#39;error&#39;][] = &quot;No file uploaded&quot;;
          return $out;
         }      
        }
    
    
        if (isset($_POST[&#39;submit&#39;])) {
         $file = uploadFile(&#39;file&#39;, true, true);
         if (is_array($file[&#39;error&#39;])) {
          $message = &#39;&#39;;
          foreach ($file[&#39;error&#39;] as $msg) {
          $message .= &#39;&lt;p&gt;&#39;.$msg.&#39;&lt;/p&gt;&#39;;    
         }
        } else {
         $message = &quot;File uploaded successfully&quot;.$newname;
        }
         echo $message;
        }

 - And the form:

        &lt;form action=&quot;&lt;?php echo $_SERVER[&#39;PHP_SELF&#39;]; ?&gt;&quot; method=&quot;post&quot; enctype=&quot;multipart/form-data&quot; name=&quot;form1&quot; id=&quot;form1&quot;&gt;
        &lt;input name=&quot;file&quot; type=&quot;file&quot; id=&quot;imagee&quot; /&gt;
        &lt;input name=&quot;submit&quot; type=&quot;submit&quot; value=&quot;Upload&quot; /&gt;
        &lt;/form&gt;


So, what I am asking is to help by posting snippets of codes which will help me (and everyone else) to make this Image Upload Script to make super secure.
Or by sharing/creating a full script with all the snippets added.

Full Secure Image Upload Script

I was recently asked to export as a `.zip` file one of my projects on my Git repository.

I have actually never had to do this in the 4 years I have been using Git.

I would prefer an answer that is all done inside command line terminal.



How do I export my project as a .zip of git repository?

I want to parse 2 generators of (potentially) different length with `zip`:

```python
for el1, el2 in zip(gen1, gen2):
    print(el1, el2)
```

However, if `gen2` has less elements, one extra element of `gen1` is &quot;consumed&quot;.

For example,
```python
def my_gen(n:int):
    for i in range(n):
        yield i

gen1 = my_gen(10)
gen2 = my_gen(8)

list(zip(gen1, gen2))  # Last tuple is (7, 7)
print(next(gen1))  # printed value is &quot;9&quot; =&gt; 8 is missing

gen1 = my_gen(8)
gen2 = my_gen(10)

list(zip(gen1, gen2))  # Last tuple is (7, 7)
print(next(gen2))  # printed value is &quot;8&quot; =&gt; OK
```

Apparently, a value is missing (`8` in my previous example) because `gen1` is read (thus generating the value `8`) before it realizes `gen2` has no more elements. But this value disappears in the universe. When `gen2` is &quot;longer&quot;, there is no such &quot;problem&quot;.

**QUESTION**: Is there a way to retrieve this missing value (i.e. `8` in my previous example)? ... ideally with a variable number of arguments (like `zip` does).


***NOTE***: *I have currently implemented in another way by using `itertools.zip_longest` but I really wonder how to get this missing value using `zip` or equivalent.*

***NOTE 2***: *I have created some tests of the different implementations in this REPL in case you want to submit and try a new implementation :) https://repl.it/@jfthuong/MadPhysicistChester*

Content Type	Original Author	Original Content on Stackoverflow
Question	SoCkEt7	View Question on Stackoverflow
Solution 1 - Php	Gareth Parker	View Answer on Stackoverflow

Install php-zip on php 5.6 on Ubuntu

Php Problem Overview

Php Solutions

Solution 1 - Php

The library hostpolicy.dll was not found

NotificationCenter issue on Swift 3

Attributions