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strrpos

(PHP 4, PHP 5, PHP 7, PHP 8)

strrpos — Cherche la position de la dernière occurrence d'une sous-chaîne dans une chaîne

Description

strrpos(string $haystack, string $needle, int $offset = 0): int|false

Cherche la position numérique de la dernière occurrence de needle dans la chaîne haystack.

Liste de paramètres

haystack

La chaîne dans laquelle chercher.

needle

La chaîne à rechercher.

Antérieur à PHP 8.0.0, si needle n'est pas une chaîne de caractères, elle est convertie en un entier et appliqué en tant que valeur ordinal d'un caractère. Ce comportement est obsolète à partir de PHP 7.3.0, et se fier à celui-ci est fortement déconseillé. En fonction du comportement attendu, needle doit être transtypé explicitement en une chaîne de caractère, ou un appel explicite à chr() doit être exécuté.

offset

Si zéro ou positif, la recherche est effectuée de gauche à droite omettant les premiers offset octets de haystack.

Si négatif, la recherche commence à offset octets de la droite au lieu de depuis le début de haystack. La recherche s'effectue de droite à gauche, cherchant la première occurrence de needle à partir de l'octet sélectionné.

Note:
Ceci est effectivement équivalent à la recherche de la dernière occurrence de needle à ou avant les derniers offset octets.

Valeurs de retour

Retourne la position de la dernière occurrence de needle relativement au début de la chaîne haystack (indépendamment de la direction de recherche ou de l'offset).

Note: Les positions des chaîne de caractères débutent à 0, et pas à 1.

Retourne false si la needle n'a pas été trouvée.

Avertissement

Cette fonction peut retourner false, mais elle peut aussi retourner une valeur équivalent à false. Veuillez lire la section sur les booléens pour plus d'informations. Utilisez l'opérateur === pour tester la valeur de retour exacte de cette fonction.

Historique

Version	Description
8.0.0	`needle` accepte désormais une chaîne vide.
8.0.0	Passing an entier as `needle` is no longer supported.
7.3.0	Passer un entier comme `before_needle` a été rendu obsolète.

Exemples

Exemple #1 Vérifie si une occurrence est trouvée dans une chaîne

Il est facile de faire une erreur quant à la valeur retournée entre "caractère trouvé à la position 0" et "caractère non trouvé". Voici comme détecter cette différence :

<?php

$pos = strrpos($mystring, "b");
if ($pos === false) { // note : 3 signes "="
    // non trouvé ...
}

?>

Exemple #2 Recherche avec des positions

<?php
$foo = "0123456789a123456789b123456789c";

// Chercher pour '0' depuis l'octet 0 (depuis le début)
var_dump(strrpos($foo, '0', 0));

// Chercher pour '0' depuis le 1er octet (après l'octet "0")
var_dump(strrpos($foo, '0', 1));

// Chercher pour '7' depuis le 21ème octet (après l'octet 20)
var_dump(strrpos($foo, '7', 20));

// Chercher pour '7' depuis le 29ème octet (après l'octet 28)
var_dump(strrpos($foo, '7', 28));

// Chercher pour '7' de droite à gauche depuis le 5ème octet depuis la fin
var_dump(strrpos($foo, '7', -5));

// Chercher pour 'c' de droite à gauche depuis le 2ème octet depuis la fin
var_dump(strrpos($foo, 'c', -2));

// Chercher pour '9c' de droite à gauche depuis le 2ème octet depuis la fin
var_dump(strrpos($foo, '9c', -2));
?>

L'exemple ci-dessus va afficher :

int(0)
bool(false)
int(27)
bool(false)
int(17)
bool(false)
int(29)

Voir aussi

strpos() - Cherche la position de la première occurrence dans une chaîne
stripos() - Recherche la position de la première occurrence dans une chaîne, sans tenir compte de la casse
strripos() - Cherche la position de la dernière occurrence d'une chaîne contenue dans une autre, de façon insensible à la casse
strrchr() - Trouve la dernière occurrence d'un caractère dans une chaîne
substr() - Retourne un segment de chaîne

add a note

User Contributed Notes 35 notes

down

brian at enchanter dot net ¶

17 years ago


The documentation for 'offset' is misleading.

It says, "offset may be specified to begin searching an arbitrary number of characters into the string. Negative values will stop searching at an arbitrary point prior to the end of the string."

This is confusing if you think of strrpos as starting at the end of the string and working backwards.

A better way to think of offset is:

- If offset is positive, then strrpos only operates on the part of the string from offset to the end. This will usually have the same results as not specifying an offset, unless the only occurences of needle are before offset (in which case specifying the offset won't find the needle).

- If offset is negative, then strrpos only operates on that many characters at the end of the string. If the needle is farther away from the end of the string, it won't be found.

If, for example, you want to find the last space in a string before the 50th character, you'll need to do something like this:

strrpos($text, " ", -(strlen($text) - 50));

If instead you used strrpos($text, " ", 50), then you would find the last space between the 50th character and the end of the string, which may not have been what you were intending.

down

david dot mann at djmann dot co dot uk ¶

6 years ago


Ten years on, Brian's note is still a good overview of how offsets work, but a shorter and simpler summary is:

    strrpos($x, $y, 50);  // 1: this tells strrpos() when to STOP, counting from the START of $x
    strrpos($x, $y, -50); // 2: this tells strrpos() when to START, counting from the END of $x

Or to put it another way, a positive number lets you search the rightmost section of the string, while a negative number lets you search the leftmost section of the string.

Both these variations are useful, but picking the wrong one can cause some highly confusing results!

down

dave at pixelmetrics dot com ¶

5 years ago


The description of offset is wrong. Here’s how it works, with supporting examples.

Offset effects both the starting point and stopping point of the search. The direction is always right to left. (The description wrongly says PHP searches left to right when offset is positive.)

Here’s how it works:
When offset is positive, PHP searches right to left from the end of haystack to offset. This ignores the left side of haystack.

When offset is negative, PHP searches right to left, starting offset bytes from the end, to the start of haystack. This ignores the right side of haystack.

Example 1:
$foo = ‘aaaaaaaaaa’;
var_dump(strrpos($foo, 'a', 5));
Result: int(10)

Example 2:
$foo = "aaaaaa67890";
var_dump(strrpos($foo, 'a', 5));
Result: int(5)

Conclusion: When offset is positive, PHP searches right to left from the end of haystack.

Example 3:
$foo = "aaaaa567890";
var_dump(strrpos($foo, 'a', 5));
Result: bool(false)

Conclusion: When offset is positive, PHP stops searching at offset.

Example 4:
$foo = ‘aaaaaaaaaa’;
var_dump(strrpos($foo, 'a', -5));
Result: int(6) 

Conclusion: When offset is negative, PHP searches right to left, starting offset bytes from the end. 

Example 5:
$foo = "a234567890";
var_dump(strrpos($foo, 'a', -5));
Result: int(0)

Conclusion: When offset is negative, PHP searches right to left, all the way to the start of haystack.

down

Daniel Brinca ¶

17 years ago


Here is a simple function to find the position of the next occurrence of needle in haystack, but searching backwards  (lastIndexOf type function):

//search backwards for needle in haystack, and return its position
function rstrpos ($haystack, $needle, $offset){
    $size = strlen ($haystack);
    $pos = strpos (strrev($haystack), $needle, $size - $offset);
    
    if ($pos === false)
        return false;
    
    return $size - $pos;
}

Note: supports full strings as needle

down

islandispeace at hotmail dot com ¶

9 years ago


$offset is very misleading, here is my understanding:

function mystrrpos($haystack, $needle, $offset = 0) {
    if ($offset == 0) {
        return strrpos ($haystack, $needle);
    } else {
        return strrpos (substr($haystack, 0, $offset), $needle);
    }
}

down

dmitry dot polushkin at gmail dot com ¶

18 years ago


Returns the filename's string extension, else if no extension found returns false.
Example: filename_extension('some_file.mp3'); // mp3
Faster than the pathinfo() analogue in two times.
<?php
function filename_extension($filename) {
    $pos = strrpos($filename, '.');
    if($pos===false) {
        return false;
    } else {
        return substr($filename, $pos+1);
    }
}
?>

down

fab ¶

19 years ago


RE: hao2lian

There are a lot of alternative - and unfortunately buggy - implementations of strrpos() (or last_index_of as it was called) on this page. This one is a slight modifiaction of the one below, but it should world like a *real* strrpos(), because it returns false if there is no needle in the haystack.

<?php

function my_strrpos($haystack, $needle) {
   $index = strpos(strrev($haystack), strrev($needle));
   if($index === false) {
        return false;
   }
   $index = strlen($haystack) - strlen($needle) - $index;
   return $index;
}

?>

down

-1

escii at hotmail dot com ( Brendan ) ¶

19 years ago


I was immediatley pissed when i found the behaviour of strrpos ( shouldnt it be called charrpos ?) the way it is, so i made my own implement to search for strings.

<?
function proper_strrpos($haystack,$needle){
        while($ret = strrpos($haystack,$needle))
        {       
                if(strncmp(substr($haystack,$ret,strlen($needle)),
                                $needle,strlen($needle)) == 0 )
                        return $ret;
                $haystack = substr($haystack,0,$ret -1 );
        }
        return $ret;
}
?>

down

-2

arlaud pierre ¶

12 years ago


This seems to behave like the exact equivalent to the PHP 5 offset parameter for a PHP 4 version.

<?php
 function strrpos_handmade($haystack, $needle, $offset = 0){

  if($offset === 0) return strrpos($haystack, $needle);
  
  $length = strlen($haystack);
  $size = strlen($needle);

  if($offset < 0) {
    $virtual_cut = $length+$offset;
    $haystack = substr($haystack, 0, $virtual_cut+$size);
    $ret = strrpos($haystack, $needle);
    return $ret > $virtual_cut ? false : $ret;
  } else {
    $haystack = substr($haystack, $offset);
    $ret = strrpos($haystack, $needle);
    return $ret === false ? $ret : $ret+$offset;
  }

}
?>

down

-1

gordon at kanazawa-gu dot ac dot jp ¶

19 years ago


The "find-last-occurrence-of-a-string" functions suggested here do not allow for a starting offset, so here's one, tried and tested, that does:

function my_strrpos($haystack, $needle, $offset=0) {
    // same as strrpos, except $needle can be a string
    $strrpos = false;
    if (is_string($haystack) && is_string($needle) && is_numeric($offset)) {
        $strlen = strlen($haystack);
        $strpos = strpos(strrev(substr($haystack, $offset)), strrev($needle));
        if (is_numeric($strpos)) {
            $strrpos = $strlen - $strpos - strlen($needle);
        }
    }
    return $strrpos;
}

down

-1

shimon at schoolportal dot co dot il ¶

18 years ago


In strrstr function in php 4 there is also no offset.
<?
// by Shimon Doodkin
function chrrpos($haystack, $needle, $offset=false)
{
 $needle=$needle[0];
 $l=strlen($haystack);
 if($l==0)  return false;
 if($offset===false)  $offset=$l-1;
 else
 {
  if($offset>$l) $offset=$l-1;
  if($offset<0) return false;
 }
 for(;$offset>0;$offset--)
  if($haystack[$offset]==$needle)
   return $offset;
 return false;
}
?>

down

-1

anonymous ¶

4 years ago


There is a lot of confusion around how $offset works and I feel it's really quite simple.

If $offset is positive, the operation ignores the first $offset characters of the haystack.
If $offset is negative, the operation ignores the last $offset-1 characters of the haystack (don't ask why -1...).

To understand this instinctively, just imagine the characters being replaced with invalid symbols. Here's an example:

<?php
$hackstack = '0123456789';

// Search the entire sequence 0123456789
var_dump(strrpos($hackstack, '0')); // int(0)
var_dump(strrpos($hackstack, '9')); // int(9)

// Only search ##23456789
var_dump(strrpos($hackstack, '1', 2)); // bool(false)
var_dump(strrpos($hackstack, '2', 2)); // int(2)

// Only search 0123456###
var_dump(strrpos($hackstack, '6', -4)); // int(6)
var_dump(strrpos($hackstack, '7', -4)); // bool(false)

?>

down

-2

su.noseelg@naes, only backwards ¶

22 years ago


Maybe I'm the only one who's bothered by it, but it really bugs me when the last line in a paragraph is a single word. Here's an example to explain what I don't like:



The quick brown fox jumps over the lazy

dog.



So that's why I wrote this function. In any paragraph that contains more than 1 space (i.e., more than two words), it will replace the last space with '&nbsp;'.



<?php

function no_orphans($TheParagraph) {

    if (substr_count($TheParagraph," ") > 1) {

    $lastspace = strrpos($TheParagraph," ");

    $TheParagraph = substr_replace($TheParagraph,"&nbsp;",$lastspace,1);

    }

return $TheParagraph;

}

?>



So, it would change "The quick brown fox jumps over the lazy dog." to "The quick brown fox jumps over the lazy&nbsp;dog." That way, the last two words will always stay together.

down

-4

maxmike at gmail dot com ¶

15 years ago


I've got a simple method of performing a reverse strpos which may be of use.  This version I have treats the offset very simply:
Positive offsets search backwards from the supplied string index.
Negative offsets search backwards from the position of the character that many characters from the end of the string.

Here is an example of backwards stepping through instances of a string with this function:

<?php
function backwardStrpos($haystack, $needle, $offset = 0){
    $length = strlen($haystack);
    $offset = ($offset > 0)?($length - $offset):abs($offset);
    $pos = strpos(strrev($haystack), strrev($needle), $offset);
    return ($pos === false)?false:( $length - $pos - strlen($needle) );
}

$pos = 0;
$count = 0;
echo "Test1<br/>";
while(($pos = backwardStrpos("012340567890", "0", $pos)) !== false){
     echo $pos."<br/>";
    $pos--;
    if($pos < 0){
        echo "Done<br/>";break;
    }
}
echo "---===---<br/>\nTest2<br/>";
echo backwardStrpos("12341234", "1", 2)."<br/>";
echo backwardStrpos("12341234", "1", -2);
?>

Outputs:
Test1
11
5
0
Done
---===---
Test2
0
4

With Test2 the first line checks from the first 3 in "12341234" and runs backwards until it finds a 1 (at position 0)

The second line checks from the second 2 in "12341234" and seeks towards the beginning for the first 1 it finds (at position 4).

This function is useful for php4 and also useful if the offset parameter in the existing strrpos is equally confusing to you as it is for me.

down

-5

alexandre at NOSPAM dot pixeline dot be ¶

16 years ago


I needed to check if a variable that contains a generated folder name based on user input had a trailing slash.



This did the trick:



<?php

    // Detect and remove a trailing slash

    $root_folder = ((strrpos($root_folder, '/') + 1) == strlen($root_folder)) ? substr($root_folder, 0, - 1) : $root_folder;

?>

down

-4

FIE ¶

21 years ago


refering to the comment and function about lastIndexOf()...

It seemed not to work for me the only reason I could find was the haystack was reversed and the string wasnt therefore it returnt the length of the haystack rather than the position of the last needle... i rewrote it as fallows:



<?php

function strlpos($f_haystack,$f_needle) {

      $rev_str = strrev($f_needle);

      $rev_hay = strrev($f_haystack);

      $hay_len = strlen($f_haystack);

      $ned_pos = strpos($rev_hay,$rev_str);

      $result  = $hay_len - $ned_pos - strlen($rev_str);

      return $result;

}

?>



this one fallows the strpos syntax rather than java's lastIndexOf.

I'm not positive if it takes more resources assigning all of those variables in there but you can put it all in return if you want, i dont care if i crash my server ;).



~SILENT WIND OF DOOM WOOSH!

down

-5

jafet at g dot m dot a dot i dot l dot com ¶

17 years ago


Full strpos() functionality, by yours truly.

<?php
function conforming_strrpos($haystack, $needle, $offset = 0)
{
    # Why does strpos() do this? Anyway...
    if(!is_string($needle)) $needle = ord(intval($needle));
    $haystack = strval($haystack);
    # Parameters
    $hlen = strlen($haystack);
    $nlen = strlen($needle);
    # Come on, this is a feature too
    if($nlen == 0)
    {
        trigger_error(__FUNCTION__.'(): Empty delimiter.', E_USER_WARNING);
        return false;
    }
    $offset = intval($offset);
    $hrev = strrev($haystack);
    $nrev = strrev($needle);
    # Search
    $pos = strpos($hrev, $nrev, $offset);
    if($pos === false) return false;
    else return $hlen - $nlen - $pos;
}
?>

Note that $offset is evaluated from the end of the string.

Also note that conforming_strrpos() performs some five times slower than strpos(). Just a thought.

down

-3

dixonmd at gmail dot com ¶

17 years ago


<?php

        $pos = strlen(string $haystack) - strpos (strrev(string $haystack), strrev(string $needle)) - strlen(string $needle);

?>



         If in the needle there is more than one character then in php 4 we can use the above statement for finding the position of last occurrence of a substring in a string instead of strrpos. Because in php 4 strrpos uses the first character of the substring.



eg : 

<?php

        $haystack = "you you you you you";

        $needle = "you";

        $pos1 = strlen($haystack) - strpos (strrev($haystack), strrev($needle)) - strlen($needle);

        echo $pos1 . "<br>";

        $pos2 strrpos($haystack, $needle);

        echo $pos2 . "<br>";

?>

down

-2

stevewa ¶

8 years ago


i wanted to find a leading space BEFORE a hyphen

Crude Oil (Dec) 51.00-56.00 

so I had to find the position of the hyphen 

then subtract that position from the length of the string (to make it a negative number)
and then walk left toward the beginning of the string, looking for the first space before the hyphen

ex:
$str_position_hyphen  = strpos($line_new,"-",$str_position_spread);

$line_new_length = strlen($line_new);

$str_position_hyphen_from_end = $str_position_hyphen - $line_new_length;

echo "hyphen position from end = " . $str_position_hyphen_from_end . "<br />\n";
            
            
$str_position_space_before_hyphen  = strrpos($line_new, " ", $str_position_hyphen_from_end);

echo "*** previous space= " . $str_position_space_before_hyphen . "<br />\n";
            
$line_new = substr_replace($line_new, ",", $str_position_space_before_hyphen, 1  );    
    
echo $line_new . "<br /><br />\n";

down

-5

lee at 5ss dot net ¶

21 years ago


I should have looked here first, but instead I wrote my own version of strrpos that supports searching for entire strings, rather than individual characters.  This is a recursive function.  I have not tested to see if it is more or less efficient than the others on the page.  I hope this helps someone!



<?php

//Find last occurance of needle in haystack

function str_rpos($haystack, $needle, $start = 0){

    $tempPos = strpos($haystack, $needle, $start);

    if($tempPos === false){

        if($start == 0){

            //Needle not in string at all

            return false;

        }else{

            //No more occurances found

            return $start - strlen($needle);

        }

    }else{

        //Find the next occurance

        return str_rpos($haystack, $needle, $tempPos + strlen($needle));

    }

}

?>

down

-4

Christ Off ¶

17 years ago


Function to truncate a string
Removing dot and comma
Adding ... only if a is character found

function TruncateString($phrase, $longueurMax = 150) {
    $phrase = substr(trim($phrase), 0, $longueurMax);
    $pos = strrpos($phrase, " ");
    $phrase = substr($phrase, 0, $pos);
    if ((substr($phrase,-1,1) == ",") or (substr($phrase,-1,1) == ".")) {
        $phrase = substr($phrase,0,-1);
    }
    if ($pos === false) {
        $phrase = $phrase;
    }
    else {
        $phrase = $phrase . "...";
    }
return $phrase;
}

down

-4

kavih7 at yahoo dot com ¶

18 years ago


<?php

###################################################

#

# DESCRIPTION:

# This function returns the last occurance of a string,

# rather than the last occurance of a single character like

# strrpos does. It also supports an offset from where to

# start the searching in the haystack string.

#

# ARGS:

# $haystack (required) -- the string to search upon

# $needle (required) -- the string you are looking for

# $offset (optional) -- the offset to start from

#

# RETURN VALS:

# returns integer on success

# returns false on failure to find the string at all

#

###################################################



function strrpos_string($haystack, $needle, $offset = 0)

{

    if(trim($haystack) != "" && trim($needle) != "" && $offset <= strlen($haystack))

    {

        $last_pos = $offset;

        $found = false;

        while(($curr_pos = strpos($haystack, $needle, $last_pos)) !== false)

        {

            $found = true;

            $last_pos = $curr_pos + 1;

        }

        if($found)

        {

            return $last_pos - 1;

        }

        else

        {

            return false;

        }

    }

    else 

    {

        return false;

    }

}

?>

down

-4

jonas at jonasbjork dot net ¶

19 years ago


I needed to remove last directory from an path, and came up with this solution:

<?php

  $path_dir = "/my/sweet/home/";
  $path_up = substr( $path_dir, 0, strrpos( $path_dir, '/', -2 ) )."/";
  echo $path_up;

?>

Might be helpful for someone..

down

-5

nexman at playoutloud dot net ¶

20 years ago


Function like the 5.0 version of strrpos for 4.x.
This will return the *last* occurence of a string within a string.

    function strepos($haystack, $needle, $offset=0) {        
        $pos_rule = ($offset<0)?strlen($haystack)+($offset-1):$offset;
        $last_pos = false; $first_run = true;
        do {
            $pos=strpos($haystack, $needle, (intval($last_pos)+(($first_run)?0:strlen($needle))));
            if ($pos!==false && (($offset<0 && $pos <= $pos_rule)||$offset >= 0)) {
                $last_pos = $pos;
            } else { break; }
            $first_run = false;
        } while ($pos !== false);
        if ($offset>0 && $last_pos<$pos_rule) { $last_pos = false; }
        return $last_pos;
    }

If my math is off, please feel free to correct.
  - A positive offset will be the minimum character index position of the first character allowed.
  - A negative offset will be subtracted from the total length and the position directly before will be the maximum index of the first character being searched.

returns the character index ( 0+ ) of the last occurence of the needle. 

* boolean FALSE will return no matches within the haystack, or outside boundries specified by the offset.

down

-5

php dot net at insite-out dot com ¶

22 years ago


I was looking for the equivalent of Java's lastIndexOf(). I couldn't find it so I wrote this:



<?php

/*

Method to return the last occurrence of a substring within a 

string

*/

function last_index_of($sub_str,$instr) {

    if(strstr($instr,$sub_str)!="") {

        return(strlen($instr)-strpos(strrev($instr),$sub_str));

    }

    return(-1);

}

?>



It returns the numerical index of the substring you're searching for, or -1 if the substring doesn't exist within the string.

down

-3

php NO at SPAMMERS willfris SREMMAPS dot ON nl ¶

18 years ago


<?php
/*******
 ** Maybe the shortest code to find the last occurence of a string, even in php4
 *******/
function stringrpos($haystack,$needle,$offset=NULL)
{
    return strlen($haystack)
           - strpos( strrev($haystack) , strrev($needle) , $offset)
           - strlen($needle);
}
// @return   ->   chopped up for readability.
?>

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-3

ZaraWebFX ¶

21 years ago


this could be, what derek mentioned:

<?
function cut_last_occurence($string,$cut_off) {
    return strrev(substr(strstr(strrev($string), strrev($cut_off)),strlen($cut_off)));
}    

//    example: cut off the last occurence of "limit"
    $str = "select delta_limit1, delta_limit2, delta_limit3 from table limit 1,7";
    $search = " limit";
    echo $str."\n";
    echo cut_last_occurence($str,"limit");
?>

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griffioen at justdesign dot nl ¶

20 years ago


If you wish to look for the last occurrence of a STRING in a string (instead of a single character) and don't have mb_strrpos working, try this:

    function lastIndexOf($haystack, $needle) {
        $index        = strpos(strrev($haystack), strrev($needle));
        $index        = strlen($haystack) - strlen(index) - $index;
        return $index;
    }

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-4

mijsoot_at_gmail_dot_com ¶

17 years ago


To begin, i'm sorry for my English.
So, I needed of one function which gives me the front last position of a character. 
Then I said myself that it should be better to make one which gives the "N" last position.

$return_context = "1173120681_0__0_0_Mijsoot_Thierry";

// Here i need to find = "Mijsoot_Thierry"

//echo $return_context."<br />";// -- DEBUG

function findPos($haystack,$needle,$position){
    $pos = strrpos($haystack, $needle);
    if($position>1){
        $position --;
        $haystack = substr($haystack, 0, $pos);
        $pos = findPos($haystack,$needle,$position);
    }else{
        // echo $haystack."<br />"; // -- DEBUG
        return $pos;
    }
    return $pos;
}

var_dump(findPos($return_context,"_",2)); // -- TEST

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genetically altered mastermind at gmail ¶

19 years ago


Very handy to get a file extension:
$this->data['extension'] = substr($this->data['name'],strrpos($this->data['name'],'.')+1);

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-4

tsa at medicine dot wisc dot edu ¶

20 years ago


What the heck, I thought I'd throw another function in the mix.  It's not pretty but the following function counts backwards from your starting point and tells you the last occurrance of a mixed char string:



<?php

function strrposmixed ($haystack, $needle, $start=0) {

   // init start as the end of the str if not set

   if($start == 0) {

       $start = strlen($haystack);

   }

   

   // searches backward from $start

   $currentStrPos=$start;

   $lastFoundPos=false;

   

   while($currentStrPos != 0) {

       if(!(strpos($haystack,$needle,$currentStrPos) === false)) {

           $lastFoundPos=strpos($haystack,$needle,$currentStrPos);

           break;

       }

       $currentStrPos--;

   }

   

   if($lastFoundPos === false) {

       return false;

   } else {

       return $lastFoundPos;

   }

}

?>

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purpleidea ¶

18 years ago


I was having some issues when I moved my code to run it on a different server.
The earlier php version didn't support more than one character needles, so tada, bugs. It's in the docs, i'm just pointing it out in case you're scratching your head for a while.

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info at qrworld dot net ¶

10 years ago


I made a function using strrpos to get the extension of a file.

function getExtension($file) {
  $pos = strrpos($file, '.');
  if($pos===false){
    return false;
  } else {  
    return substr($file, $pos+1);
  }
}

The link of the post where I took the code is:

http://softontherocks.blogspot.com/2013/07/obtener-la-extension-de-un-fichero-con.html

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pb at tdcspace dot dk ¶

17 years ago


what the hell are you all doing. Wanna find the *next* last from a specific position because strrpos is useless with the "offset" option, then....

ex: find 'Z' in $str from position $p,  backward...

while($p > -1 and $str{$p} <> 'Z') $p--;

Anyone will notice $p = -1 means: *not found* and that you must ensure a valid start offset in $p, that is >=0 and < string length. Doh

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-6

tremblay dot jf at gmail dot com ¶

10 years ago


I created an easy function that search a substring inside a string.
It reverse the string and the substring inside an strpos and substract the result to the length of the string.

if (!function_exists("real_strrpos")) {
   function real_strrpos($haystack,$needle) {
      $pos  = strlen($haystack);
      $pos -= strpos(strrev($haystack), strrev($needle) );
      $pos -= strlen($needle);
      return $pos;
   }
}

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