[Resolved] Parse a long string

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I have a Variable with a string (from a TCP/IP port) roughly 600 characters long. The string is actually a data transmission packet which is seperated into SEGMENTS and FIELDS

Each SEGMENT is preceeded by a (Hex 1E). Within the Segment there are FIELD Identifiers preceeded by (Hex 1C), then the Field ID, then Data.

For Example:

$MyCapturedString="(Hex 1E)AM01(Hex 1C)A1123456(Hex 1C)C420050101";

Where AM, A1, and C4 are Field Identifiers, and 01, 123456, and 20050101 is data for those fields.

The problem is that there are many possible fields (400+) and most times only Some of those fields are transmitted to the string. (It's a variable format).

Any ideas on the best method to parse the string into:
$AM=01, $a!=123456, $C4=20050101

[MikeSnead]

If you know all the field and segment prefixes (the hex 1C and 1E pieces) and all the identifiers are two characters long, then you can cut up the string based on the prefixes. Then it would be a task of taking all those string chunks and pulling off the first two characters and using them as keys in an associative array with the rest of the chunk as the data to hold.

All this can be done with the built in string functions.

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For example?

Sounds like this is exactly what I am looking for, a quick browse through php.net I didn't see any function which would break a string into multiple arrays based upon multiple identifiers.

[MikeSnead]

Here's a hacked together example... it works for the example string, but I haven't tested it otherwise. It assumes you'll never see the '1E' or '1C' in the data parts of the string.

<?php

$MyCapturedString="1EAM011CA11234561CC420050101";

$capture = preg_split('/1E|1C/', $MyCapturedString, -1, PREG_SPLIT_NO_EMPTY);

$count = count($capture);

for ( $i = 0 ; $i < $count ; $i++ )
{
	$name = substr($capture[$i], 0, 2);
	$data = substr($capture[$i], 2);

$field["$name"] = $data;
}

print_r($field);

?>

That code gave me this output:

Array ( [AM] => 01 [A1] => 123456 [C4] => 20050101 )

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Thanks for your help... But 1E and 1C are actual escape sequences as defined below:

$segment="\x1E"; //SEGMENTS (Hex 1E)
$group="\x1D"; //GROUPS (Hex 1D)
$field="\x1C"; //FILEDS (Hex 1C)

So I actually need to break base dupon Escape sequences, then the field identifiers

[MikeSnead]

Just gotta change the pattern then 🙂

$capture = preg_split('/(\\x1E)|(\\x1C)/', $MyCapturedString, -1, PREG_SPLIT_NO_EMPTY);

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Wow... Thanx.. Worked great.... You may be my new hero.. I hat regEx

[MikeSnead]

Hehe... I guess you just found the problem with using $field again... I was just about to post back 🙂

Glad to help... this was actually my first time using a regular expression, lol.