Retry if failed to open stream: HTTP request failed! 1 PHP - php

Question

Im trying to open an api and extract some data and about 1/5 times the script runs it errors with a
PHP Warning: file_get_contents(http://192.168.1.52/home.cgi): failed to open stream: HTTP request failed! 1
I would like to retry opening the api on error and then follow through with the rest of the code
This is running on a Pi using PHP5
$inverterDataURL = "http://".$dataManagerIP."/home.cgi";
$context = stream_context_create(array('http'=>array('protocol_version'=>'1.1')));
$result = file_get_contents('http://192.168.1.11/home.cgi', false, $context);
20% of the time when running the script it errors trying to open the api and without the api being open i can't grab any data out of it.
the rest of the script runs through fine when it opens correctly

Answer 1

You should use a loop for the retry logic that breaks when the result succeeds. A do ... while loop is used here because it guarantees that it'll be run at least once (therefore guaranteeing that $result will be set to something). When the file_get_contents fails, $result will be false:
<?php
$context = stream_context_create(array('http'=>array('protocol_version'=>'1.1')));
do {
$result = file_get_contents('http://127.0.0.1/home.cgi', false, $context);
if (!$result) {
echo "Waiting 3 seconds.\n";
sleep(3);
}
} while( !$result);
If the server goes down, you'll probably want something to break the loop after a few tries. This bit will stop trying after 5 failures.
<?php
$context = stream_context_create(array('http'=>array('protocol_version'=>'1.1')));
$attempts = 0;
do {
$attempts++;
echo "Attempt $attempts\n";
$result = file_get_contents('http://127.0.0.1/home.cgi', false, $context);
if (!$result) {
echo "Attempt $attempts has failed. Waiting 3 seconds.\n";
sleep(3);
}
} while( !$result && $attempts < 5);