Preg_match

dcjones

Hi all,

With the past help of NogDog who kindly gave me a solution to a preg_match issue, and resolved my POST, I now have an additional problem.

I have a $_GET variable which contains dynamic data.

Example:
$GET['msg'] = "bus1,d,34"
$GET['msg'] = "EZY123"
$_GET['msg'] = "1347987"

I need to be able to redirect the script depending on the content of the $_GET statement.

This is what I am working with:

$pattern = '/[a-z_]+?/i'; 

if($_GET['msg'] == "bus"){

$inboundmsg = $_GET['msg'];
$inboundmobile= $_GET['source'];
header ("location: script1");

}elseif (preg_match ($pattern, $_GET['msg'])) {

$inboundmsg = $_GET['msg'];
$inboundmobile= $_GET['source'];
header ("location: script2 ");

} else {
$inboundmsg = $_GET['msg'];
	$inboundmobile= $_GET['source'];
	header ("location: script3 ");
}

So if $_GET['msg'] = "bus1,d,34" redirect to script1, and so no.

Can anyone please help.

NogDog

Depending on exactly what the criteria are, you may not need (or want) to use preg_match. For instance, the first condition might be:

if(substr($_GET['msg'], 0, 3) == 'bus') {

The same code/logic could be applied to the next one if "EZY" is the controlling factor.

dcjones

Hi Charles,

Many thanks for your reply.

The issue I have is the $_GET['msg'] could contain any combination, like:

$GET['msg'] = "BA1234"; Will always start with some alpha characters, could be 2 or three, followed by a numbers, again could be 3 or 4 in length.
$GET['msg'] = "EZY1344";
$GET['msg'] = "AA1444";
$GET['msg'] = "BM1234";
$_GET['msg'] = "TCX321";

$GET['msg'] = "Bus1,D,34"; // Will always be a combination, will always start with "bus" and followed by a number, and alpha then a number.
$GET['msg'] = "Bus18,F,16";
$_GET['msg'] = "Bus11,A,7";

$_GET['msg'] = "1337987"; // this one will always be numeric.

Do you have any suggestions.

dcjones

Hi Charles,

I think this works, but is there a better way.

$BusInfoSplit1 = substr($_GET['busstop'],0,3);
$BusInfoSplit2 = substr($_GET['busstop'],3);
$BusChunks = explode(",", $BusInfoSplit2);
$BusStopNo = $BusChunks[0];
$Zone = $BusChunks[1];
$Row = $BusChunks[2];


if($BusInfoSplit1 == "bus"){
header ("location: scrip1.php");
}

$pattern = '/[a-z_]+?/i'; 

if (preg_match ($pattern, $_GET['msg'])) {

$inboundmsg = $_GET['msg'];
$inboundmobile= $_GET['source'];
header ("location: script2.php");

} else {

header ("location: script23.php");
}

NogDog

My thought would actually be to look at how this data is being generated and see if there is a different way to supply it to your PHP script. Whenever you start doing this sort of parsing, it tends to get a bit inefficient; but more importantly, it can become a maintenance nightmare as the front end evolves and the patterns change or new ones are added.

For instance, if this is coming from some JavaScript, I might create a JSON object with the data in that JS, then send that object to PHP and let it parse it into an array via the [man]json_decode/man function. Or maybe just have the front-end page send the data as separate get elements (maybe including one that tells you which option is being used).

johanafm

But if you stick with the setup you have currently, I'd at least use if statements to create three top branches for the code for each of the input types. It becomes somewhat easier to read when you don't start running code that is only applicable in one of the cases before you check if that is necessary, and actually running code which shouldn't be run for 2 out of 3 cases is inefficient.

iif(substr($_GET['msg'], 0, 3) == 'bus') { 

}
else if (is_numeric($_GET['msg'])) {

}
else {

}