Having trouble editing config.xml (/tmp/config.cache problem?)

wmsigler

I am using a simple PHP script to try to grab a xml file with captive portal information from a website, but I am having trouble in two senses:

If I try to unlink the /tmp/config.cache file, I get all sorts of unexpected behavior and errors like WARNING: Cannot use scalar value as array, and something about foreach(), and it looks like all my captive portal information is wiped out.
If I don't unlink /tmp/config.cache, it looks like any changes to the config.xml are immediately overwritten, and thus nullified, as if nothing happened.

The script is as follows:

#!/usr/local/bin/php

$file = fopen("/conf/config.xml", "r+") or die ("Unable to open /conf/config.xml\r\n");
$subject = file_get_contents("/conf/config.xml");
$replacement = file_get_contents("http://www.ourwebsite.net/cp/xml/captiveportal-config-file.xml") or die("Unable to update xml file!\r\n");

if (strlen($replacement) < 1)
{
   //xml file corrupt or didnt download properly
   die ("XML file corrupt!");
}

$pattern = '/<captiveportal>/';
preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE);
$offset = $matches[0][1];

if ($offset < 1)
{
   // <captiveportal>tag not found, something's wrong
   die("Invalid file! ( <captiveportal>tag not found)");
}

$before = substr($subject, 0, $offset);

$pattern = '/<\/captiveportal>/';
preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE);
$offset = $matches[0][1];

if ($offset < 1)
{
   // <captiveportal>tag not found, something's wrong
   die("Invalid file! (</captiveportal> tag not found)");
}

$after = substr($subject, $offset + 16);

$subject = $before . "\r\n" . $replacement . "\r\n" . $after . "\r\n";

//update xml file
fwrite($file, $subject);

fclose($file);

//delete cache file
unlink("/tmp/config.cache");
echo "Deleted /tmp/config.cache\r\n";

echo "Successfully updated /conf/config.xml\r\n";

?></captiveportal></captiveportal></captiveportal>

wmsigler

It seems when I delete the config.cache, it replaces it with one containing something like i:-1;
From researching around, it seems that I can build an array with parse_config(true) and then overwrite the config.cache file with a serialize()'d config array, however I'm noticing that pfsense's parse_config() function creates an array which somehow loses some of the passthrumac entries, which is not good. Any suggestions on how to fix this behavior?