(Perl) HTTP GET -- Read Response from Stream

Demonstrates how to send an HTTP GET for a web page, and then read the response from a Stream. The purpose is to fulfill a situation such as the following: "I have a URL and just want the <head> </head> portion of the HTML. This would avoid having to download a potentially enormous web page just to get at header information, such as the <styles>."

Chilkat Perl Downloads

Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

$rest = chilkat::CkRest->new();

# In this example, we'll get the web page at http://www.nytimes.com/pages/business/index.html
# The domain is "www.nytimes.com", and the path is "/pages/business/index.html"

# If we have only the full URL to begin with, it can be loaded into the Chilkat URL object to
# access the parts:
$url = chilkat::CkUrl->new();
$url->ParseUrl("http://www.nytimes.com/pages/business/index.html");

$bAutoReconnect = 1;
$success = $rest->Connect($url->host(),$url->get_Port(),$url->get_Ssl(),$bAutoReconnect);

# Send the GET request (This sends the GET request, but does not read the response.)
$success = $rest->SendReqNoBody("GET",$url->path());
if ($success != 1) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

# Read the response header.
$responseStatusCode = $rest->ReadResponseHeader();
if ($responseStatusCode < 0) {
    print $rest->lastErrorText() . "\r\n";
    exit;
}

print "Response status code = " . $responseStatusCode . "\r\n";

# We expect a 200 response status.
if ($responseStatusCode != 200) {

    # If the response status code is not 200, we could check for a redirect status code and 
    # then follow it, read the entire response (as shown here), or just call rest.Disconnect
    $errResponse = $rest->readRespBodyString();
    if ($rest->get_LastMethodSuccess() != 1) {
        print $rest->lastErrorText() . "\r\n";
    }
    else {
        print $errResponse . "\r\n";
    }

    exit;
}

$bodyStream = chilkat::CkStream->new();
# Set a 10 second read timeout for the stream. 
# (Give up if no data arrives within 10 seconds after calling a read method.)
$bodyStream->put_ReadTimeoutMs(10000);

# Create a background thread task to read the response body (which feeds
# it to the bodyStream object.)
# readResponseBodyTask is a Task
$readResponseBodyTask = $rest->ReadRespBodyStreamAsync($bodyStream,1);

# Start the task. 
$success = $readResponseBodyTask->Run();

# Read the HTTP response body until the "</head>" is seen, or until
# the end-of-stream is reached.

$sbBody = chilkat::CkStringBuilder->new();
$exitLoop = 0;
while (!$exitLoop and ($bodyStream->get_EndOfStream() != 1)) {

    $bodyText = $bodyStream->readString();
    if ($bodyStream->get_LastMethodSuccess() == 1) {
        $sbBody->Append($bodyText);
        if ($sbBody->Contains("</head>",0)) {
            $exitLoop = 1;
        }

    }
    else {
        $exitLoop = 1;
    }

}

# Cancel the remainder of the task...
$readResponseBodyTask->Cancel();

# Ensure we're disconnected from the server.
$maxWaitMs = 50;
$rest->Disconnect($maxWaitMs);

print "----" . "\r\n";
print $sbBody->getAsString() . "\r\n";
print "----" . "\r\n";
print "Successfully received the body up to the desired point." . "\r\n";