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(PHP 4, PHP 5)
strrchr — Sucht das letzte Vorkommen eines Zeichens in einem String
Diese Funktion gibt den letzten Teil von haystack beginnend mit dem letzten Vorkommen von needle bis zum Ende von haystack zurück.
Die Zeichenkette, in der gesucht werden soll.
Enthält needle mehr als ein Zeichen, wird nur das erste Zeichen verwendet. Damit unterscheidet sich das Verhalten der Funktion gegenüber strstr().
Ist needle kein String, wird der Parameter in einen Integerwert konvertiert, der dem Ordinalwert des Zeichens entspricht.
Die Funktion gibt den einen Teil der Zeichenkette zurück, wird needle nicht gefunden, ist der Rückgabewert FALSE.
| Version | Beschreibung |
|---|---|
| 4.3.0 | Die Funktion ist jetzt Binary safe. |
Beispiel #1 strrchr()-Beispiel
<?php
// hole das letzte Verzeichnis aus $PATH
$dir = substr (strrchr ($PATH, ":"), 1);
// hole alles nach dem letzten "Neue-Zeile"
$text = "Zeile 1\nZeile 2\nZeile 3";
$last = substr (strrchr ($text, 10), 1 );
?>
Hinweis: Diese Funktion ist binary safe.
Easiest way to get the domain off of an email:
<?php
$domain = strrchr($email, '@');
// gets @gmail.com, with the preceding @.
?>
It's not perfect (see above in the manual), but it's pretty damn good.
this functions returns the full path of the current directory.
<?php
function CurrentFullPath()
{
$root = $_SERVER['DOCUMENT_ROOT'] ;
$self = $_SERVER['PHP_SELF'] ;
return $root.mb_substr($self,0,-mb_strlen(strrchr($self,"/"))) ;
}
echo CurrentFullPath() ;
/*
If path is $path = "/home/me/www/pictures/control.php" ;
It will return :
/home/me/www/pictures
*/
?>
Here is my function that returns the type of a file. I fint it easier to add other types of files, and simplier than the rest i have seen around.
<?php
function findExt($filename){
$exts = array(
'.jpg' => 'image',
'.png' => 'image',
'.php' => 'php',
'.html' => 'html',
'.swf' => 'flash',
'.gz' => 'compressed',
'.tar' => 'compressed',
);
$ext = strrchr($filename,'.');
if ($exts[$ext]) { return $exts[$ext]; }
else { return "unknown"; }
}
?>
a KiSS variant of a previous note
<?php
function fcheck($f = "test.doc")
{
$fd = array(".xls" => "Microsoft Excel Worksheet",".doc" => "Microsoft Word Document",".pdf" => "Adobe Reader PDF File");
$s = $fd[strrchr($f,'.')];
if (!empty($s))
{
return $s;
}
else
{
return "Unknown file type";
}
}
?>
strrchr is useful also in determining file extensions.
Here is a sample code that determines the file type based on its file extension. This is useful in displaying the files in your page, without using the database for the file description list.
<?php
/* File Extension Display using arrays
by: Emmanuel Quiban (Philippines)
BSCS 2002, AdU
21-May-2008
*/
// Sample file
$filesample = "Mydocu.doc";
//Array for file description. You can expand the array list further with other file types you want
$filedes = array(
"Microsoft Excel Worksheet",
"Microsoft Word Document",
"Adobe Reader PDF File");
//Array for file extensions. Please take note that positions between the two arrays should be in sync with each other for correct file description.
$fileext = array(".xls", ".doc", ".pdf");
//This gets the file extension
$ext = strrchr($filesample,'.');
//This conditional statement checks if the file extension given is in the array and matches it with the file description
if (in_array($ext,$fileext)) {
//Search the array
$ext2 = array_search($ext, $fileext);
//Since the result of the array_search is in integer, you can now assign it as an array value
$filetype = $filedes[$ext2];
//Show the result
echo $filetype;
} else {
$filetype = "Unknown file type";
}
?>
-----
The output of the script above is:
Microsoft Word Document
Let's say even if the filename looks like "My.Docu.doc", strrchr still gets the value ".doc" because it gets the last occurance of the dot.
-----
You can also make it as a function, like this:
<?php
/* File Extension Display using arrays
by: Emmanuel Quiban (Philippines)
BSCS 2002, AdU
21-May-2008
*/
function getFileType($yourfile){
$filedes = array(
"CompuServe GIF Image",
"JPEG Image",
"Portable Network Graphics (PNG) Image"
);
$fileext = array(".gif",".jpg",".png");
$ext = strrchr($yourfile,'.');
if (in_array($ext,$fileext)) {
$ext2 = array_search($ext, $fileext);
$filetype = $filedes[$ext2];
} else {
$filetype = "Unknown file type";
}
return $filetype;
}
?>
i just recently did a function, that uses strrchr to format - let's say a currency - with 2 decimals. can also be done using number_format but you may NOT always want an automatic rounding of your decimals. thats there this function comes in handy:
<?php
function formatTwoDecimals($value, $trim)
{
$after_comma = substr(strrchr($value, $trim), 0, 3);
$in_front_of_comma = (int) $value;
$final = $in_front_of_comma . $after_comma;
return $final;
}
echo formatTwoDecimals("365.6078985", ".");
?>
this will produce
365.60
instead of
365.61
which will show up then you use number_format.
Final get file name and extension into an array with or without dot, using strrchr and strrchr_reverse.
Note our use of !==. Now work if the position of $needle in $haystack was the 0th (first) character like ".htaccess"
<?
//strxchr(string haystack, string needle [, bool int leftinclusive [, bool int rightinclusive ]])
function strxchr($haystack, $needle, $l_inclusive = 0, $r_inclusive = 0){
//Note our use of !==. Now work if the position of $needle in $haystack was the 0th (first) character.
if(strrpos($haystack, $needle) !== false){
//Everything before last $needle in $haystack.
$left = substr($haystack, 0, strrpos($haystack, $needle) + $l_inclusive);
//Switch value of $r_inclusive from 0 to 1 and viceversa.
$r_inclusive = ($r_inclusive == 0) ? 1 : 0;
//Everything after last $needle in $haystack.
$right = substr(strrchr($haystack, $needle), $r_inclusive);
//Return $left and $right into an array.
$a = array($left, $right);
return $a;
}else{
return false;
}
}
?>
Repley
to: repley at freemail dot it
the code works very well, but as i was trying to cut script names (e.g.: $_SERVER["SCRIPT_NAME"] => /index.php, cut the string at "/" and return "index.php") it returned nothing (false). i've modified your code and now it works also if the needle is the first char.
- regards from germany
<?php
//strxchr(string haystack, string needle [, bool int leftinclusive [, bool int rightinclusive ]])
function strxchr($haystack, $needle, $l_inclusive = 0, $r_inclusive = 0){
if(strrpos($haystack, $needle)){
//Everything before last $needle in $haystack.
$left = substr($haystack, 0, strrpos($haystack, $needle) + $l_inclusive);
//Switch value of $r_inclusive from 0 to 1 and viceversa.
$r_inclusive = ($r_inclusive == 0) ? 1 : 0;
//Everything after last $needle in $haystack.
$right = substr(strrchr($haystack, $needle), $r_inclusive);
//Return $left and $right into an array.
return array($left, $right);
} else {
if(strrchr($haystack, $needle)) return array('', substr(strrchr($haystack, $needle), $r_inclusive));
else return false;
}
}
?>
Get file name and extension into an array with or without dot, using strrchr and strrchr_reverse.
<?
//strxchr(string haystack, string needle [, bool int leftinclusive [, bool int rightinclusive ]])
function strxchr($haystack, $needle, $l_inclusive = 0, $r_inclusive = 0){
if(strrpos($haystack, $needle)){
//Everything before last $needle in $haystack.
$left = substr($haystack, 0, strrpos($haystack, $needle) + $l_inclusive);
//Switch value of $r_inclusive from 0 to 1 and viceversa.
$r_inclusive = ($r_inclusive == 0) ? 1 : 0;
//Everything after last $needle in $haystack.
$right = substr(strrchr($haystack, $needle), $r_inclusive);
//Return $left and $right into an array.
$a = array($left, $right);
return $a;
}else{
return false;
}
}
//start test
$haystack = "unknown.txt.log.......gif.....jpeg";
$needle = ".";
$l_inclusive = 1; //1 for inclusive mode, 0 for NOT inclusive mode
$r_inclusive = 1; //1 for inclusive mode, 0 for NOT inclusive mode
$a = strxchr($haystack, $needle, $l_inclusive, $r_inclusive);
if($a){echo "Left: <strong>" . $a[0] . "</strong><br /> Right: <strong>" . $a[1] . "</strong>";}else{echo "Failed!";}
//end test
?>
Thanks to all.
Repley
just a small addition to carlos dot lage at gmail dot com note which makes it a bit more useful and flexible:
<?php
// return everything up to last instance of needle
// use $trail to include needle chars including and past last needle
function reverse_strrchr($haystack, $needle, $trail) {
return strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) + $trail) : false;
}
// usage:
$ns = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 0));
$ns2 = (reverse_strrchr($_SERVER["SCRIPT_URI"], "/", 1));
echo($ns . "<br>" . $ns2);
?>
to marcokonopacki at hotmail dot com.
I had to make a slight change in your function for it to return the complete needle inclusive.
// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{
// Returns everything before $needle (inclusive).
//return substr($haystack,0,strpos($haystack,$needle)+1);
// becomes
return substr($haystack,0,strpos($haystack,$needle)+strlen($needle));
}
Note: the +1 becomes +strlen($needle)
Otherwise it only returns the first character in needle backwards.
A quick way to get file's extension (if it has one, otherwise you get an empty string), which can be used when you want to rename the file but keep the old extension. Or for similar purposes. Temporary variable is used just because it's slightly faster to store the value than to run the strrchr() function again.
<?php
$ext = substr(($t=strrchr("file.ext",'.'))!==false?$t:'',1);
?>
$filename = 'strrchr_test.php';
print strrchr( $filename, '.' );
Result:
.php
$other_filename = 'strrchr_test.asp.php';
print strrchr( $other_filename, '.' );
Result:
.php
I used dchris1 at bigpond dot net dot au 's reverse strrchr and reduced it to one line of code and fixed it's functionality - the real strrchr() returns FALSE if the needle is not found, not the haystack :)
<?php
// reverse strrchr()
function reverse_strrchr($haystack, $needle)
{
return strrpos($haystack, $needle) ? substr($haystack, 0, strrpos($haystack, $needle) +1 ) : false;
}
?>
The function provided by marcokonopacki at hotmail dot com isn't really a reverse-version of strrchr(), rather a reverse version of strchr(). It returns everything from the start of $haystack up to the FIRST instance of the $needle. This is basically a reverse of the behavior which you expect from strchr(). A reverse version of strrchr() would return everything in $haystack up to the LAST instance of $needle, eg:
<?php
// reverse strrchr() - PHP v4.0b3 and above
function reverse_strrchr($haystack, $needle)
{
$pos = strrpos($haystack, $needle);
if($pos === false) {
return $haystack;
}
return substr($haystack, 0, $pos + 1);
}
?>
Note that this function will need to be modified slightly to work with pre 4.0b3 versions of PHP due to the return type of strrpos() ('0' is not necessarily 'false'). Check the documentation on strrpos() for more info.
A function like this can be useful for extracting the path to a script, for example:
<?
$string = "/path/to/the/file/filename.php";
echo reverse_strrchr($string, '/'); // will echo "/path/to/the/file/"
?>
strrchr is also very useful for finding the extension of a file. For example:
$ext = strrchr($filename, ".");
and $ext will contain the extension of the file, including a ".", if the file has an extension, and FALSE if the file has no extension. If the file has multiple extensions, such as "evilfile.jpg.vbs", then this construction will just return the last extension.
<?
// Reverse search of strrchr.
function strrrchr($haystack,$needle)
{
// Returns everything before $needle (inclusive).
return substr($haystack,0,strpos($haystack,$needle)+1);
}
$string = "FIELD NUMBER(9) NOT NULL";
echo strrrchr($string,")"); // Will print FIELD (9)
?>
this functions returns the name of the current directory.
<?php
function currentd() {
return substr(strrchr(`pwd`, '/'), 1);
}
?>
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