Match part of string with part of other string - php

Question

I working on a simple search function where I want to match a part of a string with part of another string.
Example:
The search term is: fruitbag
I want to match the product: fruit applebag
I want to create something so that the system matches:
fruitbag
fruit applebag
Or even "fruit" and "bag".
In summary; parts inside a string need to match with parts inside the search term. Is this possible?
$products = array(
'fruit applebag',
'pinapple',
'carrots',
'bananas',
'coconut oil',
'cabbage',
);
if( ! empty( $_POST['search'] ) ) {
$s = $_POST['search'];
$results = array();
foreach( $products as $index => $product ) {
if( preg_match( '/' . $s . '.*/i', $product, $matched ) ) {
$results[] = $matched[0];
}
}
print_r($results);
// This only returns fruit applebag if the search term is something like "fruit ap"
}

Answer 1

Use something like this (split the searched word into two parts and look for a match thas has characters between those two parts):
$products = array(
'fruit applebag',
'pinapple',
'carrots',
'bananas',
'coconut oil',
'cabbage',
);
$s = 'fruitbag';
$results = array();
foreach( $products as $index => $product ) {
for($i=1;$i<strlen($s);$i++){
if(preg_match( '/' . substr($s,0,$i) . '.*'.substr($s,$i+1).'/i', $product, $matched ) ) {
$results[] = $matched[0];
}
}
}
print_r($results);
Output:
Array ( [0] => fruit applebag [1] => fruit applebag )

Answer 2

It is possible, but could be very costly. As stated, your requirement is that any substring of the search term is potentially relevant. So take fruitbag and generate a list of all substrings:
f,r,u,i,t,b,a,g,fr,ru,ui,it,tb,ba,ag,fru,rui,uit,...,bag,...,fruit,...,fruitbag
But you probably don't want that any word with the letter a be a match. So a first approach could be to specify a minimum number of letters (e.g. 3), which will significantly limit the potential matches. But even then... Does it make sense to match fru, or rui?
A better approach would be to use a dictionary, to extract actual words or syllables from your search string. (In your case, extract fruit and bag from fruitbag).
You can find an English dictionary fairly easily.