Explode string and preserve delimiter/seperator in php

Question

I need to split multiple data packets to single chunk

$packets="
*TS01,868323025167807,205004181116,GPS:3;S33.792541;E151.066264;58;347;1.46,STT:202;0,MGR:1555391,ADC:0;13.84;1;38.89;2;4.14,EVT:1#*TS01,868323025167807,205104181116,GPS:3;S33.786623;E151.060349;66;309;1.10,STT:202;0,MGR:1556426,ADC:0;13.78;1;38.70;2;4.14,EVT:1#*TS01,868323025167807,205204181116,GPS:3;S33.779947;E151.052654;47;313;1.10,STT:202;0,MGR:1557577,ADC:0;13.65;1;38.70;2;4.14,EVT:1#*TS01,868323025167807,205304181116,GPS:3;S33.776746;E151.051546;52;346;1.09,STT:202;0,MGR:1557980,ADC:0;13.85;1;38.14;2;4.14,EVT:1#*TS01,868323025167807,205404181116,GPS:3;S33.768219;E151.048295;63;338;1.08,STT:202;0,MGR:1559134,ADC:0;13.62;1;37.95;2;4.14,EVT:1#*TS01,868323025167807,205504181116,GPS:3;S33.763735;E151.047204;0;0;1.08,STT:202;0,MGR:1559699,ADC:0;12.84;1;37.95;2;4.14,EVT:1#*TS01,868323025167807,205518181116,GPS:3;S33.763707;E151.047218;0;0;1.07,STT:2;0,MGR:1559699,ADC:0;12.84;1;37.95;2;4.14,EVT:F0;200#";

One valid packet looks like below

*TS01,868323025167807,205004181116,GPS:3;S33.792541;E151.066264;58;347;1.46,STT:202;0,MGR:1555391,ADC:0;13.84;1;38.89;2;4.14,EVT:1#

Means every packet start with * and end with #

I did the following

$no_of_packets=substr_count($packets, '*');
        if($no_of_packets>1){
//explode with #
    $packets=explode("#",$msg)
}

I got array like below

[0] => *TS01,868323025167807,205004181116,GPS:3;S33.792541;E151.066264;58;347;1.46,STT:202;0,MGR:1555391,ADC:0;13.84;1;38.89;2;4.14,EVT:1
    [1] => *TS01,868323025167807,205104181116,GPS:3;S33.786623;E151.060349;66;309;1.10,STT:202;0,MGR:1556426,ADC:0;13.78;1;38.70;2;4.14,EVT:1
    [2] => *TS01,868323025167807,205204181116,GPS:3;S33.779947;E151.052654;47;313;1.10,STT:202;0,MGR:1557577,ADC:0;13.65;1;38.70;2;4.14,EVT:1
    [3] => *TS01,868323025167807,205304181116,GPS:3;S33.776746;E151.051546;52;346;1.09,STT:202;0,MGR:1557980,ADC:0;13.85;1;38.14;2;4.14,EVT:1
    [4] => *TS01,868323025167807,205404181116,GPS:3;S33.768219;E151.048295;63;338;1.08,STT:202;0,MGR:1559134,ADC:0;13.62;1;37.95;2;4.14,EVT:1
    [5] => *TS01,868323025167807,205504181116,GPS:3;S33.763735;E151.047204;0;0;1.08,STT:202;0,MGR:1559699,ADC:0;12.84;1;37.95;2;4.14,EVT:1
    [6] => *TS01,868323025167807,205518181116,GPS:3;S33.763707;E151.047218;0;0;1.07,STT:2;0,MGR:1559699,ADC:0;12.84;1;37.95;2;4.14,EVT:F0;200

The '#' is missing . If i go thru the loop and append '#' to each packets it will be too slow as I have 1000+ packets sometime

I need to preserve '#' and split by '#'

I tried the solution from Is there way to keep delimiter while using php explode or other similar functions? but it gave last empty array too

Possible duplicate of [Is there way to keep delimiter while using php explode or other similar functions?](http://stackoverflow.com/questions/2938137/is-there-way-to-keep-delimiter-while-using-php-explode-or-other-similar-function) — anon, Dec 07 '16 at 04:54
`It will be slow as I have 1000+ packages` and this is concluded, how? I've done [a little bench on the two answers](http://pastebin.com/0fxAByJN) and concluded that looping though is around `62.68%` faster than regex. — Xorifelse, Dec 07 '16 at 05:45

Zbynek Vyskovsky - kvr000 · Accepted Answer · 2016-12-07T06:21:03.303

2

The best is to set empty separator and use positive look behind / look ahead for # character and any character respectively:

$list = preg_split('/(?<=#)(?=.)/', $msg);

(?<=#) is positive look behind for # character, (?=.) is positive look ahead for any character (this avoids generating empty string at the end).

Actually, if * is part of separator, the following regexp would work even better (more reliably):

$list = preg_split('/(?<=#)(?=\*)/', $msg);

edited Dec 07 '16 at 06:21

answered Dec 07 '16 at 04:55

Zbynek Vyskovsky - kvr000

18,186
3
35
43

(?=.) is awesome – sumit Dec 07 '16 at 05:01

score 0 · Answer 2 · answered Dec 07 '16 at 05:09

0

This code will help you for getting you your desired output -

$arr = explode("*", $packets);
array_shift($arr);
$result = array();
for($i = 0; $i<count($arr); $i++){
array_push($result, "*".$arr[$i]);
}
print_r($result);

answered Dec 07 '16 at 05:09

Rahul Khandelwal Systematix

141
10

I am not sure why this has been down-voted, it works and it should be faster in execution than the excepted answer. – Xorifelse Dec 07 '16 at 05:14

Explode string and preserve delimiter/seperator in php

2 Answers2