stristr
(PHP 4, PHP 5)
stristr — strstr() 函数的忽略大小写版本
说明
string stristr ( string $haystack , mixed $needle [, bool $before_needle = false ] )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。
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 #1 stristr() 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
?>
Example #2 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
?>
Example #3 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
PHP stristr note #1
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'
PHP stristr note #2
Use it to emulate the before_needle php V5.3 :
<?php
if($pos=stripos($h,$n)) $string=substr($h,0,$pos);
?>
PHP stristr note #3
Quick way to use this with an array for a needle:
<?php
$arr = array('search_term1','search_term2','search_term3');
foreach($arr as $key => $search_needle) {
if(stristr($haystack, $search_needle) != FALSE) {
echo 'execute this code if found';
}
}
?>
PHP stristr note #4
if stristr($message,'viagra')
or stristr($message,'cialis')
)
{
die();
}
Works quite well in any Shoutbox, Forum, Guestbook, Mailform, etcetera.
Just enter between the definitions and sending the message to the DB, et voila. ^_^
PHP stristr note #5
Active item item in menu:
<?php
function aim($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 stristr note #6
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() ) ) {
}
?>
PHP stristr note #7
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); $e = explode("-",$i); while (list($index,$value) = each($e)){
$param = rtrim(strrev(stristr(strrev($value),'=')),"=");
$setting = ltrim(stristr($value,'='),"=");
echo "Array index is ".$index." and value is ".$value." ";
echo "Parameter is ".$param." and is set to ".$setting." ";
}
?>
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 ~]#
PHP stristr note #8
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.';
}
?>PHP stristr note #9
<?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');
?>
PHP stristr note #10
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 stristr note #11
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
来自 http://www.php100.com/cover/php/2233.html
