PHP cURL: Basics: Difference between revisions

{{Nav PHP cURL}}

'''''cURL basics'''''

|Step 2)||'''curl_setopt()''' ||- Set Curl options you wish to run

|-

|-

|Step 3)||'''curl_exec()''' ||- With the options set execute Curl

== Preparation ==

Create a new text file in folder C:\curl_2\UniServer\'''www''' named '''remote_page.php''' with the following  content:

   //Gets the IP address

This page and server (curl_2) simulates a page on a remote server.

'''''Test'':'''

* Run server curl_2: Double click on C:\curl_2\UniServer\'''Start.exe''' Click tray icon 3 and Click Start UniServer

* Result: '''Your IP is 127.0.0.1''' - displayed

== Example 1 - Download and display a page ==

Create a new text file in folder C:\curl_1\UniServer\'''www''' and name it '''test1.php''' add the following content:

|-

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  $curl_handle=curl_init('http://localhost:82/remote_page.php');

  curl_exec($curl_handle);

  curl_close($curl_handle);

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* Initialize Curl and optionally set URL (required in this example)

{|

|'''curl_init()'''

|Creates a memory area where all our Curl options are stored. We have passed it a URL which is duly stored in this memory area.

|'''$curl_handle'''

|This variable contains the location of the memory area created by curl_init(). It is used to inform other functions where to find the memory area.

| '''curl_exec()'''

|Think of the memory area as a list of pending tasks to be performed. These are run using curl_exec(), it takes a single parameter $curl_handle. Since we have not told Curl what to do with the output it defaults to the standard stream, in other words serves the downloaded page to the user requesting '''test1.php'''.

|'''curl_close()'''

|This closes Curl and frees memory, it takes a single parameter $curl_handle.     

'''''Test'':'''

* Run server curl_1: Double click on C:\curl_1\UniServer\'''Start.exe''' Click tray icon 1 and Click Start UniServer

* Result: '''Your IP is 127.0.0.1''' - displayed.

OK! The above was not an impressive demonstration, hence change '''test1.php''' to this:

  $curl_handle=curl_init('http://www.php.net/');

  curl_exec($curl_handle);

  curl_close($curl_handle);

* Result: PHP home page is displayed in the browser.

Your server has downloaded the page and served it to a user (you in this example)

   

== Example 2 - Download and display a page ==

I mentioned when you initialize Curl the URL is optional. If not specified you need to add an additional line.

curl_setopt($curl_handle,CURLOPT_URL,'value');   

The function set Curl option '''curl_setopt()''' takes three parameters:

* '''$curl_handle''' Location of memory block

Create a new text file in folder C:\curl_1\UniServer\'''www''' and name it '''test2.php''' add the following content

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  $curl_handle=curl_init();

  curl_setopt($curl_handle,CURLOPT_URL,'http://localhost:82/remote_page.php');

  curl_exec($curl_handle);

  curl_close($curl_handle);

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* Initialize Curl and save memory location in variable $curl_handle

'''''Test'':'''

* Run both servers

* Result: '''Your IP is 127.0.0.1''' - displayed.

One refinement is to rename variable  $curl_handle to '''$ch''' this just saves a bit of typing.  

  $ch=curl_init();

  curl_setopt($ch,CURLOPT_URL,'http://localhost:82/remote_page.php');

  curl_exec($ch);

  curl_close($ch);

'''''[[#top | Top]]'''''

Create a new text file in folder C:\curl_1\UniServer\'''www''' and name it '''test3.php''' add the following content

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$ch=curl_init();

curl_setopt($ch,CURLOPT_URL,'http://localhost:82/remote_page.php');

curl_close($ch);

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* Initialize Curl and save memory location in variable $ch

'''''Test'':'''

* Run servers

* Result: '''TEST 3 Your IP is 127.0.0.1''' - displayed.

Create a new text file in folder C:\curl_1\UniServer\'''www''' and name it '''test4.php''' add the following content

|-

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$ch=curl_init();

curl_setopt($ch,CURLOPT_URL,'http://localhost:82/remote_page.php');

if (empty($buffer)){

}

else{

   // Extract IP address  

     $ip = $ipmatch[0]; // Save IP to variable

     print $ip;                                 

  }

}

|

* Check buffer empty will need to do something in the final script if empty

'''''Test'':'''

* Run servers

* Result:

There was data returned using curl.

Buffer content = Your IP is 127.0.0.1

127.0.0.1

'''''[[#top | Top]]'''''

Replace the following URL in test4.php  

with one of the following and run the script.

'''''[[#top | Top]]'''''