PHP 5.6.14 is available


(PHP 4, PHP 5)

stristrCase-insensitive strstr()


string stristr ( string $haystack , mixed $needle [, bool $before_needle = false ] )

Returns all of haystack starting from and including the first occurrence of needle to the end.



The string to search in


If needle is not a string, it is converted to an integer and applied as the ordinal value of a character.


If TRUE, stristr() returns the part of the haystack before the first occurrence of the needle (excluding needle).

needle and haystack are examined in a case-insensitive manner.

Return Values

Returns the matched substring. If needle is not found, returns FALSE.


Version Description
5.3.0 Added the optional parameter before_needle.
4.3.0 stristr() was made binary safe.


Example #1 stristr() example

stristr($email'e'); // outputs
echo stristr($email'e'true); // As of PHP 5.3.0, outputs US

Example #2 Testing if a string is found or not

'Hello World!';
stristr($string'earth') === FALSE) {
'"earth" not found in string';
// outputs: "earth" not found in string

Example #3 Using a non "string" needle

stristr($string97); // 97 = lowercase a
// outputs: APPLE


Note: This function is binary-safe.

See Also

  • strstr() - Find the first occurrence of a string
  • strrchr() - Find the last occurrence of a character in a string
  • stripos() - Find the position of the first occurrence of a case-insensitive substring in a string
  • strpbrk() - Search a string for any of a set of characters
  • preg_match() - Perform a regular expression match

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User Contributed Notes 8 notes

13 years ago
There was a change in PHP 4.2.3 that can cause a warning message
to be generated when using stristr(), even though no message was
generated in older versions of PHP.

The following will generate a warning message in 4.0.6 and 4.2.3:
  stristr("haystack", "");
  $needle = "";  stristr("haystack", $needle);

This will _not_ generate an "Empty Delimiter" warning message in
4.0.6, but _will_ in 4.2.3:
  unset($needle); stristr("haystack", $needle);

Here's a URL that documents what was changed:
Techdeck at Techdeck dot org
12 years ago
An example for the stristr() function:

= "I like php";
if (
stristr("$a", "LikE PhP")) {
print (
"According to \$a, you like PHP.");

It will look in $a for "like php" (NOT case sensetive. though, strstr() is case-sensetive).

For the ones of you who uses linux.. It is similiar to the "grep" command.
Actually.. "grep -i".
giz at gbdesign dot net
7 years ago
Just been caught out by stristr trying to converting the needle from an Int to an ASCII value.

Got round this by casting the value to a string.

if( !stristr( $file, (string) $myCustomer->getCustomerID()  ) ) {
// Permission denied
art at awilton dot dotcom
9 years ago
handy little bit of code I wrote to take arguments from the command line and parse them for use in my apps.


= implode(" ",$argv); //implode all the settings sent via clie
$e = explode("-",$i); // no lets explode it using our defined seperator '-'

       //now lets parse the array and return the parameter name and its setting
       // since the input is being sent by the user via the command line
       //we will use stristr since we don't care about case sensitivity and
       //will convert them as needed later.

while (list($index,$value) = each($e)){

//lets grap the parameter name first using a double reverse string
       // to get the begining of the string in the array then reverse it again
       // to set it back. we will also "trim" off the "=" sign

$param = rtrim(strrev(stristr(strrev($value),'=')),"=");

//now lets get what the parameter is set to.
       // again "trimming" off the = sign

$setting = ltrim(stristr($value,'='),"=");

// now do something with our results.
       // let's just echo them out so we can see that everything is working

echo "Array index is ".$index." and value is ".$value."\r\n";
"Parameter is ".$param." and is set to ".$setting."\r\n\r\n";



when run from the CLI this script returns the following.

[root@fedora4 ~]# php a.php -val1=one -val2=two -val3=three

Array index is 0 and value is a.php
Parameter is  and is set to

Array index is 1 and value is val1=one
Parameter is val1 and is set to one

Array index is 2 and value is val2=two
Parameter is val2 and is set to two

Array index is 3 and value is val3=three
Parameter is val3 and is set to three

[root@fedora4 ~]#
notepad at codewalkers dot com
10 years ago

function stristr_reverse($haystack, $needle) {
$pos = stripos($haystack, $needle) + strlen($needle);
substr($haystack, 0, $pos);
$email = '';
stristr_reverse($email, 'er');
// outputs USER

greg at no_ggmac_reply dot com
4 years ago
Beware the example given here:

if stristr($message,'viagra')
or stristr($message,'cialis')

stristr does not search for words, it finds matching substrings.  So, for example, the check for 'cialis' will trigger on 'specialist'
1 year ago
I think there is a bug in php 5.3 in stristr with uppercase Ä containing other character

if you search only with täry it works, but as soon as the word is tärylä  it does not. TÄRYL works fine
tomas dot nesrovnal at yourspirit dot cz
6 years ago
Active item item in menu:

function aim($page) {
stristr($_SERVER['REQUEST_URI'], $page)) {
' class="active"';


<style type="text/css">
.active {color: red;}

print '<a href=""'. aim('hello-world') .'>HW</a>';
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