stristr()

(PHP 4, PHP 5, PHP 7)

strstr()函数的忽略大小写版本

说明

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

返回$haystack字符串从$needle第一次出现的位置开始到结尾的字符串。

参数

$haystack

在该字符串中查找。

$needle

如果$needle不是一个字符串，那么它将被转换为整型并被视为字符顺序值。

$before_needle

若为TRUE，strstr()将返回$needle在$haystack中的位置之前的部分(不包括 needle)。

参数$needle和$haystack将以不区分大小写的方式对待。

返回值

返回匹配的子字符串。如果$needle未找到，返回FALSE。

更新日志

范例

Example #1stristr()范例

<?php
  $email = 'USER@EXAMPLE.com';
  echo stristr($email, 'e'); // 输出 ER@EXAMPLE.com
  echo stristr($email, 'e', true); // 自 PHP 5.3.0 起，输出 US
?>

测试字符串的存在与否

<?php
  $string = 'Hello World!';
  if(stristr($string, 'earth') === FALSE) {
    echo '"earth" not found in string';
  }
// 输出: "earth" not found in string
?>

使用非字符串 needle

<?php
  $string = 'APPLE';
  echo stristr($string, 97); // 97 = 小写字母 a
// 输出: APPLE
?>

注释

Note:此函数可安全用于二进制对象。

参见

• strstr()查找字符串的首次出现
• strrchr()查找指定字符在字符串中的最后一次出现
• stripos()查找字符串首次出现的位置（不区分大小写）
• strpbrk()在字符串中查找一组字符的任何一个字符
• preg_match()执行匹配正则表达式

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

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".

<?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
?>

I think there is a bug in php 5.3 in stristr with uppercase Ä containing other character
http://pastebin.com/5bP6uztY
if you search only with täry it works, but as soon as the word is tärylä it does not. TÄRYL works fine

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>'; 
?>

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'

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 ~]#