<?php
$str = '1,"4052","B00K6ED81S",,"Bottle, white - 6,5 l, WENKO","Good design!","Bottle, white 6,5 l, WENKO",,,"item","23",23,"23",23,31.22,31.22,,1,,,,0,8,"4",,0,,0,0,,0,,0,0,0,,';
$pos=1; // set $pos to make sure while loop does not end directly.
$newstr = "";
$prevPos = 0;
$skip = false; // flag to know if replace should be done or not
while($pos != false){
$pos = strpos($str, '"', $prevPos); // find " in string after prevPos
$part = substr($str, $prevPos, $pos+1-$prevPos); // substring the part (first time it runs it will be '1,"' then '4052"')
if($skip){ // if it's between two " (a string) skip the replace
//echo "skip " . $part . "\n";
$skip =!$skip; // change the flag
$newstr .= $part;
}else{ // if it's not in a string do the replace on the $part
//echo "!skip " . $part . "\n";
$newstr .= str_replace(",", ";", $part);
$skip =!$skip; // change the flag.
}
$prevPos = $pos+1; // set new $prevPos
}
// if the loop ends and there is no more " in the string we need to replace , to ; on the rest of the string.
// we know the loop ended at strlen($newstr), so that is the $part.
if($pos<strlen($str)) $newstr .= str_replace(",", ";", substr($str, strlen($newstr)));
echo $str . "\n";
echo $newstr;