PHP Get string between bracket tags

Question

Why doesn't this work?

<?php

function GetBetween($var1="",$var2="",$pool) {

    $temp1 = strpos($pool,$var1)+strlen($var1);
    $result = substr($pool,$temp1,strlen($pool));
    $dd=strpos($result,$var2);

    if($dd == 0) {
         $dd = strlen($result);
    }

    return substr($result,0,$dd);
}

$str = "[id]159828[/id][name][/name]";

$str =  GetBetween("[name]","[/name]",$str);

echo $str;
?>

Returns:

[/name]

Works fine if there is something in there. I need it to return NOTHING if its not found.

Thanks!

If nothing is between those fields $dd is first equal to 0 and then changed to be the length of the result. This makes your final call substr($result,0,7). If you have a value between the name brackets $dd is never set to 0 and the secondary assignment does not happen. Get rid of the if($dd == 0)... block. — Mike
– Mike, Commented Aug 3, 2013 at 1:32
No use setting default values for $var1 and $var2 if $pool is a required parameter of GetBetween(). Put $pool as the first parameter if you want to make the others optional. — ironcito
– ironcito, Commented Aug 3, 2013 at 1:50

theftprevention · Accepted Answer · 2013-08-03 01:35:43Z

Everything works fine up until $result. You have:

$result = substr($pool,$temp1,strlen($pool));

We have $temp1 = 15, and strlen($pool) = 22, so this is equivalent to:

$result = substr("[id]159828[/id][name][/name]", 15, 22)

You may want to omit the $length argument here, so that substr just returns the remainder of the string after position 15. Either way, $result is equal to "[/name]".

This means that $dd is going to equal 0, since the strpos of "[/name]" in $result is at the very beginning. The if() statement then changes $dd to strlen($result), which is 7. Then, the return value is substr($result,0,$dd), or $substr("[/name]",0,7), which evaluates to "[/name]".

To fix this, you need to remove the if() statement entirely.

That way, $dd is left at zero, so the return value is a substring of zero length, which is what you wanted: an empty string.

user1646111 · Accepted Answer · 2013-08-03 01:43:06Z

1

just add this check:

if(substr($pool, strpos($pool, $var1), strlen("$var1$var2")) == "$var1$var2")
return false;

Then:

function GetBetween($var1="",$var2="",$pool) {
    if(substr($pool, strpos($pool, $var1), strlen("$var1$var2")) === "$var1$var2"){
      return false;
    }
    $temp1 = strpos($pool,$var1)+strlen($var1);
    $result = substr($pool,$temp1,strlen($pool));
    $dd=strpos($result,$var2);

    if($dd == 0) {
         $dd = strlen($result);
    }

    return substr($result,0,$dd);
}

answered Aug 3, 2013 at 1:43

user1646111

Comments

pajaja · Accepted Answer · 2013-08-03 01:43:24Z

1

You can use regular expressions to match the stuff between two values. For example

function between($v1, $v2, $str){
    $v1 = preg_quote($v1, '~');
    $v2 = preg_quote($v2, '~');
    if(preg_match("~$v1(.*)$v2~", $str, $tmp)){
       return $tmp[1];
    }else{
       return "";
    }
}

Or even without empty return since $tmp[1] will be null if there is no match.

answered Aug 3, 2013 at 1:43

pajaja

2,2124 gold badges27 silver badges34 bronze badges

Comments

calcinai · Accepted Answer · 2013-08-03 01:46:20Z

0

If you're always parsing the same format, you can try a sscanf()

It's quite nice for defining a format then reading variables out without using regular expression matching.

eg.

$str = "[id]159828[/id][name][/name]";
sscanf($str, "[id]%d[/id][name]%[^[/name]]", $id, $name);

$id and $name will be populated with the (even empty) values.

answered Aug 3, 2013 at 1:46

calcinai

2,62716 silver badges25 bronze badges

Collectives™ on Stack Overflow

PHP Get string between bracket tags

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related