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", "");
OR
$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:
http://groups.google.ca/groups?selm=cvshholzgra1031224321%40cvsserver
Descrição
Retorna tudo de haystack apartir da
primeira ocorrência de needle até o final.
Parâmetros
-
haystack -
A string onde será feita a busca.
-
needle -
Se
needlenão é uma string, ela é convertida para inteiro e é usado como valor ordinal do caractere. -
before_needle -
Se
TRUE(o padrão éFALSE), stristr() retorna a parte dehaystackantes da primeira ocorrência deneedle.
needle e haystack
são examinadas de uma maneira que não diferencia maiúsculas e minúsculas.
Valor Retornado
Retorna a substring encontrada. Se needle não
for encontrada, retorna FALSE.
Changelog
| Versão | Descrição |
|---|---|
| 5.3.0 |
Adicionado o parâmetro opcional before_needle.
|
| 4.3.0 | stristr() tornou-se binary safe. |
Exemplos
Exemplo #1 Exemplo da stristr()
<?php
$email = 'USER@EXAMPLE.com';
echo stristr($email, 'e'); // outputs ER@EXAMPLE.com
echo stristr($email, 'e', true); // A partir do PHP 5.3.0, mostra US
?>
Exemplo #2 Testing if a string is found or not
<?php
$string = 'Hello World!';
if(stristr($string, 'earth') === FALSE) {
echo '"earth" not found in string';
}
// outputs: "earth" not found in string
?>
Exemplo #3 Using a non "string" needle
<?php
$string = 'APPLE';
echo stristr($string, 97); // 97 = lowercase a
// outputs: APPLE
?>
Notas
Nota: Esta função é binary-safe.
Veja Também
- strstr() - Encontra a primeira ocorrencia de uma string
- strrchr() - Encontra a ultima ocorrência de um caractere em uma string
- substr() - Retorna uma parte de uma string
- preg_match() - Perform a regular expression match
Active item item in menu:
<?php
function aim($page) {
if(stristr($_SERVER['REQUEST_URI'], $page)) {
return ' class="active"';
}
}
?>
usage:
<style type="text/css">
.active {color: red;}
</style>
<?php
print '<a href="http://example.com/page/hello-world/"'. aim('hello-world') .'>HW</a>';
?>
<?php
function stristr_reverse($haystack, $needle) {
$pos = stripos($haystack, $needle) + strlen($needle);
return substr($haystack, 0, $pos);
}
$email = 'USER@EXAMPLE.com';
echo stristr_reverse($email, 'er');
// outputs USER
?>
Beware the example given here:
if stristr($message,'viagra')
or stristr($message,'cialis')
)
{
die();
}
stristr does not search for words, it finds matching substrings. So, for example, the check for 'cialis' will trigger on 'specialist'
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.
<?php
if( !stristr( $file, (string) $myCustomer->getCustomerID() ) ) {
// Permission denied
}
?>
An example for the stristr() function:
<?php
$a = "I like php";
if (stristr("$a", "LikE PhP")) {
print ("According to \$a, you like PHP.");
}
?>
It will look in $a for "like php" (NOT case sensetive. though, strstr() is case-sensetive).
For the ones of you who uses linux.. It is similiar to the "grep" command.
Actually.. "grep -i".
You can use strstr() or stristr() to validate data!
Check this out:
<?php
function validate_email($input) {
if (!stristr($input, '@')) {
return false;
}
return true;
}
function validate_url($input) {
if (!stristr($input, 'http://')) {
return false;
}
return true;
}
?>
Simple example:
<?php
if (!validate_email($_POST['email'])) {
print 'You did not enter a valid email adress';
}
if (!validate_url($_POST['url'])) {
print 'You did not enter a valid url.';
}
?>
handy little bit of code I wrote to take arguments from the command line and parse them for use in my apps.
<?php
$i = implode(" ",$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";
echo "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 ~]#
Use it to emulate the before_needle php V5.3 :
<?php
//$h = haystack, $n = needle
if($pos=stripos($h,$n)) $string=substr($h,0,$pos);
?>
if stristr($message,'viagra')
or stristr($message,'cialis')
)
{
die();
}
Works quite well in any Shoutbox, Forum, Guestbook, Mailform, etcetera.
Just enter between the definitions and sending the message to the DB, et voila. ^_^
