how to set user agent for get_headers PHP function - php

I know It's easy to set user agent for curl but my code is based on get_headers, by default get_headers user agent is empty.
thanks for any help.

Maybe this?
ini_set('user_agent', 'Mozilla/5.0');

For anyone else coming here, the best option (instead of a server-wide change, which who knows what might break), is to use stream context options (the user agent option, in particular).
The PHP documentation already shows an example for change the HTTP method (sadly, also using a global setting 🤦).
In any case, the code would be something like:
$context = stream_context_create([
'http' => [
'user_agent' => 'Mozilla/5.0'
]
]);
$headers = get_headers('http://example.com', true, $context);

get_headers only specifies the data sent by the server to the client (in this case, PHP), it doesn't specify request headers.
If you're trying to find the user agent the get_headers request was made with, you'll have to use:
ini_get('user_agent');
For more documentation see the links below:
http://us3.php.net/get_headers
http://us3.php.net/manual/en/filesystem.configuration.php#ini.user-agent

Related

Calling an external API using a server [duplicate]

I have to send an SMS by making an HTTP request via GET method. The link contains information in the form of GET variables, e.g.
http://www.somelink.com/file.php?from=12345&to=67890&message=hello%20there
After I run the script it has to be as if someone clicked the link and activated the SMS sending process.
I have found some links about get request and curl and what not, it’s all so confusing!
I think the easiest way to make an HTTP request via GET method from PHP is using file_get_contents().
<?php
$response = file_get_contents('http://example.com/send-sms?from=12345&to=67890&message=hello%20there');
echo $response;
Don’t forget to see the notes section for info on PHP configuration required for this to work. You need to set allow_url_fopen to true in your php.ini.
Note that this works for GET requests only and that you will have no access to the headers (request, nor response). Also, enabling allow_url_fopen might not be a good choice for security reasons.
The easiest way is probably to use cURL. See https://web.archive.org/web/20180819060003/http://codular.com/curl-with-php for some examples.
Lets assume that we want to retrive http://www.google.com
$cURL = curl_init();
$setopt_array = array(CURLOPT_URL => "http://www.google.com", CURLOPT_RETURNTRANSFER => true, CURLOPT_HTTPHEADER => array());
curl_setopt_array($cURL, $setopt_array);
$json_response_data = curl_exec($cURL);
print_r($json_response_data);
curl_close($cURL);
/*
cURL is preinstalled by goDaddy.com and many other php hosting providers
it is also preinstalled in wamp and xampp
good luck.
*/

Why does ini_get('user_agent') doesn't work with file_get_contents() in php?

I have a situation like this.
A crawler script fetches the content of the URL using
file_get_contents().
It sets the user agent as "CrawlerBot" just
above the line where file_get_contents() is called using
ini_set('user_agent').
My concern is when I write ini_get('user_agent') in the code of URL, it gets a blank value. However when I use $_SERVER['HTTP_USER_AGENT'] it detects the correct user agent. Both the files are hosted on same server.
Anybody aware why does it happen?
That's not what ini_get() does. It's for retrieving server configuration values (the configuration of your server), not request-specific values like the user agent sent by a requesting browser/script/whatever.
So, you can use ini_get() to find out what user agent value, if any, is set for requests made by your server, like the one you are actually making. You cannot use it to find out the user agent of a request made to your server.
Here is an example of code to set user agent and retrive a ressource with file_get_contents.
//Set uri
$uri = 'http://example.com';
//Init context
$ctx = stream_context_create(
array(
'http' => array(
'user_agent' => 'MySuperAgent/3.0'
)
)
);
//Try to retrieve content
if (($data = file_get_contents($uri, false, $ctx)) === false) {
die('file_get_contents error');
}
ps : Note that the context array should be under http key even for https ressources.
ps2 : I strongly suggests that you set the timeout and maximum acceptable redirections on the context to avoid slowdown in your application.

How to send information to a REST server via url PHP

I have been given a URL that I need PHP to post data to, anonymously, without the end user knowing about it.
The exact structure is:
https://example.com/api/rest/example/createSubscription?email=1#1.com&subscriberNumber=12345JD&subscriberGroup=shop&firstName=Joe&lastName=Bloggs&offerCode=ex1&licenseParameters="STARTDATE%3D2014-08-11%26ENDDATE%3D2014-09-11"
Obviously this is a dynamic URL and I have set it up to be. I am not sure about the best way to approach this issue. Would it be a PUT http_request? I have tried that using the following but it returns a 400 error.
$url = 'https://example.com/api/rest/example/createSubscription?email=1#1.com&subscriberNumber=12345JD&subscriberGroup=shop&firstName=Joe&lastName=Bloggs&offerCode=ex1&licenseParameters="STARTDATE%3D2014-08-11%26ENDDATE%3D2014-09-11"';
$options = array(
'method' => 'PUT',
'timeout' => 15,
'header' => "Content-type: html/txt",
);
$response = http_request($url, $options);
As for your last comment, if the subscription is created simply opening the url in the browser then it is a GET request.
You can perform a GET request using file_get_contents
It's really strange you use PUT method with GET paramater.
After checking php manual here you don't use correctly this methode. that's why the server can't understand your request.
you can look after this function to do a PUT request

How to add a parameter to the request header sent by a PHP script?

I'm trying to use a web service REST API for which I need to add a parameter for authorization (with the appropriate key, of course) to get a XML result. I'm developing in PHP. How can I add a parameter to the request header in such a situation?
Edit: The way I'm doing the request right now is $xml = simplexml_load_file($query_string);
Are you using curl? (recommended)
I assume that you are using curl to do these requests towards the REST API, if you aren't; use it.
When using curl you can add a custom header by calling curl_setopt with the appropriate parameters, such as in below.
curl_setopt (
$curl_handle, CURLOPT_HTTPHEADER,
array ('Authentication-Key: foobar')
); // make curl send a HTTP header named 'Authentication-key'
// with the value 'foobar'
Documentation:
PHP: cURL - Manual
PHP: curl_setopt - Manual
Are you using file_get_contents or similar?
This method is not recommended, though it is functional.
Note: allow_url_fopen needs to be enabled for file_get_contents to be able to access resources over HTTP.
If you'd like to add a custom header to such request you'll need to create yourself a valid stream context, as in the below snippet:
$context_options = array(
'http' =>array (
'method' => 'GET',
'header' => 'Authentication-Key'
)
);
$context = stream_context_create ($context_options);
$response = file_get_contents (
'http://www.stackoverflow.com', false, $context_options
);
Documentation:
PHP: file_get_contents - Manual
PHP: stream_context_create - Manual
PHP: Runtime Configuration, allow_url_fopen
I'm using neither of the above solutions, what should I do?
[Post OP EDIT]
My recommendation is to fetch the data using curl and then pass it off to the parser in question when all the data is received. Separate data fetching from the processing of the returned data.
[/Post OP EDIT]
When you use $xml = simplexml_load_file($query_string);, the PHP interpreter invokes it's wrapper over fopen to open the contents of a file located at $query_string. If $query_string is a remote file, the PHP interpreter opens a stream to that remote URL and retrieves the contents of the file there (if the HTTP response code 200 OK). It uses the default stream context to do that.
There is a way to alter the headers sent by altering that stream context, however, in most cases, this is a bad idea. You're relying on PHP to always open all files, local or remote, using a function that was meant to take a local file name only. Not only is it a security problem but it also could be the source of a bug that is very hard to track down.
Instead, consider splitting the loading of the remote content using cURL (checking the returned HTTP status code and other sanity checks) and then parsing that content into a SimpleXMLElement object to use. When you use cURL, you can set any headers you want to send with the request by invoking something similar to curl_setopt($ch, CURLOPT_HTTPHEADER, array('HeaderName' => 'value');
Hope this helps.

How to load a URL and only get back the last 20k of it

I have been made aware of the Accept-Range header.
I have a URL that I am calling that always returns a 2mb file. I don't need this much and only need the last section 20-50k.
I am not sure how to go about using it? Would I need to use cURL? I am currently using file_get_contents().
Would someone be able to provide me with an example / tutorial?
Thanks.
EDIT: If this isn't possible then what is post on about? Here ...
EDIT: Ulrika! I'm not insane.
This is possible using the Range header, provided the server supports it. See the HTTP 1.1 spec. You would want to send a header in the following format in your request:
Range: bytes=-50000
This would give you the last 50,000 bytes. Adjust to whatever you need.
You can specify this header in file_get_contents using a context. For example:
// Create a stream
$opts = array(
'http'=>array(
'method' => "GET",
'header' => "Range: bytes=-50000\r\n"
)
);
$context = stream_context_create($opts);
// Open the file using the HTTP headers set above
$file = file_get_contents('http://www.example.com/', false, $context);
If you were to file_get_contents() and dump that to a passthrough 'cache' file on disk, then you could use the unix/linux tail -c to only grab back the last 20kb or so. This doesn't mitigate the actual transfer, but gets that 20kb into the application.
This is indeed possible - see this question for an example of the HTTP headers sent and received
you can't do that. You're going to have to load the entire file (which is sent in its entirety, sequentially, by the source server), and just discard most of it.
What you're asking is like "I'm tuning to this radio station on my car stereo and I only want to hear the last 5 minutes of the show, without having to wait for the rest to complete or change channels".

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