Using PHP, how can I read a server's error page? - php

I want to read a server's reply for a certain request, modify it to my needs, and send it to the site visitor. get_headers() works perfectly for the headers, but if the requested file is missing (404), and that's exactly what I want to use, get_file_contents(), readfile() and other functions I've tried all break with the warning/error that the file is missing instead of reading the replied stream into a variable.
So what I want is a function similar to get_headers() only for the rest of the data, like a get_data() that doesn't cancel. Is there such a thing?
Thanks for reading.

Use curl_exec. It will always return the body unless the CURLOPT_FAILONERROR option is set to TRUE.
Here's an example:
$url = 'http://www.example.com/thisrequestwillerror';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_HEADER, false);
// This is the default, but just making sure...
curl_setopt($curl, CURLOPT_FAILONERROR, false);
// Execute and return as a string
$str = curl_exec($curl);
curl_close($curl);
// Dump the response body
var_dump($str);
Wrap this in a function and use it wherever you need to get an HTTP response body in your application.

Related

cURL retrieve only header without doing HEAD

So I am trying to retrieve only headers using cURL with the following:
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_HEADER, true); // we want headers
curl_setopt ($ch, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_TIMEOUT,10);
$output = curl_exec($ch);
The problem is that while trying to get headers of large file the script uses all the memory. I would like to avoid getting also the body and I have tried to use:
curl_setopt($ch, CURLOPT_NOBODY, true);
The problem is that this issues a HEAD request instead of GET. And some website retrun an error when you request with HEAD.
Is there any way with curl to retrieve only header without doing HEAD request?
First, don't use CURLOPT_RETURNTRANSFER as that's the option that makes it keep the entire response in memory.
Then, two options:
A) use a write callback and make that abort the transfer as soon as the first byte of the body is returned. There's a write callback example in the PHP.net docs.
B) use CURLOPT_RANGE and ask for only the first byte to be retrieved, 0-0. This avoids the write callback but has the downside that not all HTTP servers and URLs will acknowledge it.
If you dont have to use cURL, you could use get_headers(). By default get_headers uses a GET request to fetch the headers. And you could also modify that request by using stream_context_set_default()
$headers = get_headers('http://example.com');
More Info: PHP: get_headers

What am I doing wrong here (CURL), no matter what I try it returns empty/null

$url = "http://www.reddit.com/r/{mysubreddit}/new.json";
$fields = "sort=new";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $fields);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$data = curl_exec($ch);
curl_close($ch);
var_dump($data);
{mysubreddit} is whatever subreddit I wanna check. It works fine to just grab that url via postman, or even in the browser. But when I use PHP/CURL, it returns empty. I've tried replacing the URL, with another URL to another site, and it works fine, so the curl part is working fine.
Is there something with reddit that I have to set? headers? or explicitly tell it for JSON? Or what?
I thought it might have to do with POST, but I tried GET to, still empty/null.
$url = "http://www.reddit.com/r/{mysubreddit}/new.json?sort=new";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$data = curl_exec($ch);
curl_close($ch);
That doesnt work either
You just need to add:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
As others have mentioned, reddit is sending you a 302 redirect to https. You would be able to see that by examining the headers returned by curl_getinfo().
Enabling redirect following, as sorak describes, will work. However, it's not a good solution - you will make two HTTP requests on every single API call. This is a completely unnecessary waste of network and increases the execution time of your script. Instead, just change the url that you're requesting to be from https://www.reddit.com/ in the first place.

Header() substitute

Hi I am new to php and want to know some alternate function for the header('location:mysit.php');
I am in a scenario that I am sending the request like this:
header('Location: http://localhost/(some external site).php'&?var='test')
something like this but what I wanna do is that I want to send values of variables to the external site but I actually dont want that page to pop out.
I mean variables should be sent to some external site/page but on screen I want to be redirected to my login page. But seemingly I dont know any alternative please guide me. Thx.
You are searching for PHP cUrl:
$ch = curl_init();
// set URL and other appropriate options
curl_setopt($ch, CURLOPT_URL, "http://www.example.com/");
curl_setopt($ch, CURLOPT_HEADER, 0);
// grab URL and pass it to the browser
curl_exec($ch);
// close cURL resource, and free up system resources
curl_close($ch);
Set the location header to the place you actually want to redirect the browser to and use something like cURL to make an HTTP request to the remote site.
The way you usually would do that is by sending those parameters by cURL, parse the return values and use them however you need.
By using cURL you can pass POST and GET variables to any URL.
Like so:
$ch = curl_init('http://example.org/?aVariable=theValue');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$result = curl_exec($ch);
curl_close($ch);
Now, in $result you have the response from the URL passed to curl_init().
If you need to post data, the code needs a little more:
$ch = curl_init('http://example.org/page_to_post_to.php');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, 'variable1=value1&variable2=value2');
$result = curl_exec($ch);
curl_close($ch);
Again, the result from your POST reqeust is saved to $result.
You could connect to another URL in the background in numerous ways. There's cURL ( http://php.net/curl - already mentioned here in previous comments ), there's fopen ( http://php.net/manual/en/function.fopen.php ), there's fsockopen ( http://php.net/manual/en/function.fsockopen.php - little more advanced )

Simple Curl request not working

I have a function make_curl_request to make curl request.
/**
* General Function to make curl request */
function make_curl_request($url, $data)
{
ob_start();
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
curl_exec($ch);
curl_close($ch);
$strCurlResponse = ob_get_contents();
ob_end_clean();
return $strCurlResponse;
}
I am calling it like:
$strGatewayResponse = make_curl_request( REQUEST_URL, compact('strMobileNo', 'strKeywords', 'strApiKey') );
I tried the things but can't get my code working fine. Currently its just return string("") as the output. Where am i going wrong?
My target is to simple post few data to next page located on other domain and get its xml response and parse it and display it. Is there any other simple and good solution?
The problem is that you've got RETURNTRANSFER set to TRUE, which means curl returns its output instead of directly outputting it. However, you're not capturing that output in a variable, so it's dropping on the floor.
You've got two options
a) remove the ob_*() functions to remove the PHP buffering and then do
$data = curl_exec($ch)
if ($data === FALSE) {
die("Curl failed: " . curL_error($ch));
}
after which $data contains the contents of the URL you've fetched.
b) remove the RETURNTRANSFER option, and let curl do its normal "output to client directly" thing, which then gets captured by the PHP output buffering.
Try by adding a row:
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
FALSE to stop cURL from verifying the peer's certificate. Alternate certificates to verify against can be specified with the CURLOPT_CAINFO option or a certificate directory can be specified with the CURLOPT_CAPATH option.
it's not ok to send a curl POST without a header.
please find the following link. it may help
OAuth, PHP, Rest API and curl gives 400 Bad Request

curl CLI to curl PHP

I use the following command in some old scripts:
curl -Lk "https:www.example.com/stuff/api.php?"
I then record the header into a variable and make comparisons and so forth. What I would really like to do is convert the process to PHP. I have enabled curl, openssl, and believe I have everything ready.
What I cannot seem to find is a handy translation to convert that command line syntax to the equivalent commands in PHP.
I suspect something in the order of :
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
// What goes here so that I just get the Location and nothing else?
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
// Get the response and close the channel.
$response = curl_exec($ch);
curl_close($ch);
The goal being $response = the data from the api “OK=1&ect”
Thank you
I'm a little confused by your comment:
// What goes here so that I just get the Location and nothing else?
Anyway, if you want to obtain the response body from the remote server, use:
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($ch);
If you want to get the headers in the response (i.e.: what your comment might be referring to):
curl_setopt($ch, CURLOPT_HEADER, 1);
If your problem is that there is a redirection between the initial call and the response, use:
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);

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