For getting a substring of UTF-8 characters, I highly recommend mb_substr
<?php
$utf8string = "cakeæøå";
echo substr($utf8string,0,5);
// output cake#
echo mb_substr($utf8string,0,5,'UTF-8');
//output cakeæ
?>
(PHP 4, PHP 5, PHP 7)
substr — Return part of a string
$string
, int $start
[, int $length
] )
Returns the portion of string specified by the
start and length parameters.
stringThe input string. Must be one character or longer.
start
If start is non-negative, the returned string
will start at the start'th position in
string, counting from zero. For instance,
in the string 'abcdef', the character at
position 0 is 'a', the
character at position 2 is
'c', and so forth.
If start is negative, the returned string
will start at the start'th character
from the end of string.
If string is less than
start characters long, FALSE will be returned.
Example #1 Using a negative start
<?php
$rest = substr("abcdef", -1); // returns "f"
$rest = substr("abcdef", -2); // returns "ef"
$rest = substr("abcdef", -3, 1); // returns "d"
?>
length
If length is given and is positive, the string
returned will contain at most length characters
beginning from start (depending on the length of
string).
If length is given and is negative, then that many
characters will be omitted from the end of string
(after the start position has been calculated when a
start is negative). If
start denotes the position of this truncation or
beyond, FALSE will be returned.
If length is given and is 0,
FALSE or NULL, an empty string will be returned.
If length is omitted, the substring starting from
start until the end of the string will be
returned.
Example #2 Using a negative length
<?php
$rest = substr("abcdef", 0, -1); // returns "abcde"
$rest = substr("abcdef", 2, -1); // returns "cde"
$rest = substr("abcdef", 4, -4); // returns false
$rest = substr("abcdef", -3, -1); // returns "de"
?>
Returns the extracted part of string; or FALSE on failure, or
an empty string.
| Version | Description |
|---|---|
| 7.0.0 |
If string is equal to
start characters long, an empty string will be
returned. Prior to this version, FALSE was returned in this case.
|
| 5.2.2 - 5.2.6 |
If the start parameter indicates the position of
a negative truncation or beyond, false is returned. Other versions get
the string from start.
|
Example #3 Basic substr() usage
<?php
echo substr('abcdef', 1); // bcdef
echo substr('abcdef', 1, 3); // bcd
echo substr('abcdef', 0, 4); // abcd
echo substr('abcdef', 0, 8); // abcdef
echo substr('abcdef', -1, 1); // f
// Accessing single characters in a string
// can also be achieved using "square brackets"
$string = 'abcdef';
echo $string[0]; // a
echo $string[3]; // d
echo $string[strlen($string)-1]; // f
?>
Example #4 substr() casting behaviour
<?php
class apple {
public function __toString() {
return "green";
}
}
echo "1) ".var_export(substr("pear", 0, 2), true).PHP_EOL;
echo "2) ".var_export(substr(54321, 0, 2), true).PHP_EOL;
echo "3) ".var_export(substr(new apple(), 0, 2), true).PHP_EOL;
echo "4) ".var_export(substr(true, 0, 1), true).PHP_EOL;
echo "5) ".var_export(substr(false, 0, 1), true).PHP_EOL;
echo "6) ".var_export(substr("", 0, 1), true).PHP_EOL;
echo "7) ".var_export(substr(1.2e3, 0, 4), true).PHP_EOL;
?>
Output of the above example in PHP 7:
1) 'pe' 2) '54' 3) 'gr' 4) '1' 5) '' 6) '' 7) '1200'
Output of the above example in PHP 5:
1) 'pe' 2) '54' 3) 'gr' 4) '1' 5) false 6) false 7) '1200'
Returns FALSE on error.
<?php
var_dump(substr('a', 2)); // bool(false)
?>
For getting a substring of UTF-8 characters, I highly recommend mb_substr
<?php
$utf8string = "cakeæøå";
echo substr($utf8string,0,5);
// output cake#
echo mb_substr($utf8string,0,5,'UTF-8');
//output cakeæ
?>
may be by following functions will be easier to extract the needed sub parts from a string:
<?php
after ('@', 'biohazard@online.ge');
//returns 'online.ge'
//from the first occurrence of '@'
before ('@', 'biohazard@online.ge');
//returns 'biohazard'
//from the first occurrence of '@'
between ('@', '.', 'biohazard@online.ge');
//returns 'online'
//from the first occurrence of '@'
after_last ('[', 'sin[90]*cos[180]');
//returns '180]'
//from the last occurrence of '['
before_last ('[', 'sin[90]*cos[180]');
//returns 'sin[90]*cos['
//from the last occurrence of '['
between_last ('[', ']', 'sin[90]*cos[180]');
//returns '180'
//from the last occurrence of '['
?>
here comes the source:
<?php
function after ($this, $inthat)
{
if (!is_bool(strpos($inthat, $this)))
return substr($inthat, strpos($inthat,$this)+strlen($this));
};
function after_last ($this, $inthat)
{
if (!is_bool(strrevpos($inthat, $this)))
return substr($inthat, strrevpos($inthat, $this)+strlen($this));
};
function before ($this, $inthat)
{
return substr($inthat, 0, strpos($inthat, $this));
};
function before_last ($this, $inthat)
{
return substr($inthat, 0, strrevpos($inthat, $this));
};
function between ($this, $that, $inthat)
{
return before ($that, after($this, $inthat));
};
function between_last ($this, $that, $inthat)
{
return after_last($this, before_last($that, $inthat));
};
// use strrevpos function in case your php version does not include it
function strrevpos($instr, $needle)
{
$rev_pos = strpos (strrev($instr), strrev($needle));
if ($rev_pos===false) return false;
else return strlen($instr) - $rev_pos - strlen($needle);
};
?>
Anyone coming from the Python world will be accustomed to making substrings by using a "slice index" on a string. The following function emulates basic Python string slice behavior. (A more elaborate version could be made to support array input as well as string, and the optional third "step" argument.)
<?php
function py_slice($input, $slice) {
$arg = explode(':', $slice);
$start = intval($arg[0]);
if ($start < 0) {
$start += strlen($input);
}
if (count($arg) === 1) {
return substr($input, $start, 1);
}
if (trim($arg[1]) === '') {
return substr($input, $start);
}
$end = intval($arg[1]);
if ($end < 0) {
$end += strlen($input);
}
return substr($input, $start, $end - $start);
}
print py_slice('abcdefg', '2') . "\n";
print py_slice('abcdefg', '2:4') . "\n";
print py_slice('abcdefg', '2:') . "\n";
print py_slice('abcdefg', ':4') . "\n";
print py_slice('abcdefg', ':-3') . "\n";
print py_slice('abcdefg', '-3:') . "\n";
?>
The $slice parameter can be a single character index, or a range separated by a colon. The start of the range is inclusive and the end is exclusive, which may be counterintuitive. (Eg, py_slice('abcdefg', '2:4') yields 'cd' not 'cde'). A negative range value means to count from the end of the string instead of the beginning. Both the start and end of the range may be omitted; the start defaults to 0 and the end defaults to the total length of the input.
The output from the examples:
c
cd
cdefg
abcd
abcd
efg
Hmm ... this is a script I wrote, whitch is very similar to substr, but it isn't takes html and bbcode for counting and it takes portion of string and show avoided (html & bbcode) tags too ;]
Specially usefull for show part of serach result included html and bbcode tags
<?php
/**
* string csubstr ( string string, int start [, int length] )
*
* @author FanFataL
* @param string string
* @param int start
* @param [int length]
* @return string
*/
function csubstr($string, $start, $length=false) {
$pattern = '/(\[\w+[^\]]*?\]|\[\/\w+\]|<\w+[^>]*?>|<\/\w+>)/i';
$clean = preg_replace($pattern, chr(1), $string);
if(!$length)
$str = substr($clean, $start);
else {
$str = substr($clean, $start, $length);
$str = substr($clean, $start, $length + substr_count($str, chr(1)));
}
$pattern = str_replace(chr(1),'(.*?)',preg_quote($str));
if(preg_match('/'.$pattern.'/is', $string, $matched))
return $matched[0];
return $string;
}
?>
Using this is similar to simple substr.
Greatings ;]
...
[English]
I created python similar accesing list or string with php substr & strrev functions.
Use: str($string,$pattern)
About the python pattern,
http://docs.python.org/release/1.5.1p1/tut/strings.html
http://effbot.org/zone/python-list.htm
About of pattern structures
[start:stop:step]
Example,
<?php
$s = "fatihmertdogancan";
echo str($s,"1:9:-2");
echo "<br/>";
echo str($s,"1:-3:-2");
echo "<br/>";
echo str($s,"1:-11:-5");
echo "<br/>";
echo str($s,"1:9:4");
?>
Output,
thetoacn
eht
aom
htan
This is function phpfiddle link: http://phpfiddle.org/main/code/e82-y5d
or source;
<?php
function str($str,$pattern){
//[start:stop:step]
//pattern -> ([-]?[0-9]*|\s):([-]?[0-9]*|\s):([-]?[0-9]*|\s)
preg_match("/([-]?[0-9]*|\s?):([-]?[0-9]*|\s?):?([-]?[0-9]*|\s?)/", $pattern, $yakala);
$start = $yakala[1];
$stop = $yakala[2];
$step = $yakala[3];
if(empty($start) && empty($stop) && $step == "-1"){//istisna durum
return strrev($str);
}else if(empty($start) && empty($stop) && isset($step)){//istisna durum
$rev = "";
$yeni = "";
if($step[0] == "-" && $stop != "-1"){$rev = "VAR";}
$atla = abs($step);
for($i = 0; $i <= strlen($str); $i++){
$offset = $i*$atla;
if(isset($str[$offset])){
$yeni = $yeni.$str[$offset];
}
}
if($rev != "VAR"){
return substr($yeni,0,strlen($str)-1);
//"hepsi boş, step dolu o da +";
}else{
return strrev(substr($yeni,0,strlen($str)-1));
//"hepsi boş, step dolu o da -";
}
}
if(empty($start) && empty($stop) && empty($step)){
return $str;
//"hepsi boş";
}else if(empty($start)){
if(isset($stop) && empty($step)){
$rev = "";
if($stop[0] == "-"){$rev = "VAR";}
if($rev != "VAR"){
return substr($str,0,$stop);
//"start ve step boş, stop dolu"
}else{
return strrev(substr($str,0,$stop));
//"start ve step boş, stop -1";
}
}else if(isset($stop) && isset($step)){
$rev = "";
if($stop[0] == "-"){$rev = "VAR";}
$yeni = "";
if($step == 1){
if($rev != "VAR"){
return $str;
//"start boş, stop ve step dolu, step 1";
}else{
return strrev(substr($str,0,abs($stop))); //abs -> mutlak değer (-5 = 5)
//"start boş, stop -, step dolu, step 1";
}
}else{
$atla = abs($step);
for($i = 0; $i <= strlen($str); $i++){
$offset = $i*$atla;
if(isset($str[$offset])){
$yeni = $yeni.$str[$offset];
}
}
if($rev != "VAR"){
return substr($yeni,0,$stop);
//"start boş, step ve stop dolu";
}else{
return strrev(substr($yeni,0,abs($stop)));
//"start boş, step ve stop -";
}
}
}
//start boş değilse
}else if(!empty($start)){
if(isset($stop) && empty($step)){
$rev = "";
if($stop[0] == "-"){$rev = "VAR";}
if($rev != "VAR"){
return substr($str,$start,$stop);
//return "step boş, start ve stop dolu";
}else{
return strrev(substr($str,0,abs($stop)));
//"step boş, start ve stop dolu, stop -";
}
}else if(isset($stop) && isset($step)){
//hepsi dolu
$rev = "";
if($stop[0] == "-"){$rev = "VAR";}
$yeni = "";
if($step == 1){
if($rev != "VAR"){
return substr($str,$start,$stop);
//"hepsi dolu, step 1";
}else{
return substr($str,$start,abs($stop));
//"hepsi dolu, step 1, stop -";
}
}else{
if($stop[0] == "-"){$rev = "VAR";}
$atla = abs($step);
for($i = 0; $i <= strlen($str); $i++){
$offset = $i*$atla;
if(isset($str[$offset])){
$yeni = $yeni.$str[$offset];
}
}
if($rev != "VAR"){
return substr($yeni,$start,$stop);
//"hepsi dolu";
}else{
return strrev(substr($yeni,$start,abs($stop)));
//"hepsi dolu, stop -";
}
}
}
}
}
?>
Good works..
<?Php
### SUB STRING BY WORD USING substr() and strpos() #####
### THIS SCRIPT WILL RETURN PART OF STRING WITHOUT WORD BREAK ###
$description = ‘your description here your description here your description here your description here your description here your description here your description hereyour description here your description here’ // your description here .
$no_letter = 30 ;
if(strlen($desctiption) > 30 )
{
echo substr($description,0,strpos($description,’ ‘,30)); //strpos to find ‘ ‘ after 30 characters.
}
else {
echo $description;
}
?>
<?php
/**
* string substrpos(string $str, mixed $start [[, mixed $end], boolean $ignore_case])
*
* If $start is a string, substrpos will return the string from the position of the first occuring $start to $end
*
* If $end is a string, substrpos will return the string from $start to the position of the first occuring $end
*
* If the first character in (string) $start or (string) $end is '-', the last occuring string will be used.
*
* If $ignore_case is true, substrpos will not care about the case.
* If $ignore_case is false (or anything that is not (boolean) true, the function will be case sensitive.
* Both of the above: only applies if either $start or $end are strings.
*
* echo substrpos('This is a string with 0123456789 numbers in it.', 5, '5');
* // Prints 'is a string with 01234';
*
* echo substrpos('This is a string with 0123456789 numbers in it.', '5', 5);
* // Prints '56789'
*
* echo substrpos('This is a string with 0123456789 numbers in it and two strings.', -60, '-string')
* // Prints 's is a string with 0123456789 numbers in it and two '
*
* echo substrpos('This is a string with 0123456789 numbers in it and two strings.', -60, '-STRING', true)
* // Prints 's is a string with 0123456789 numbers in it and two '
*
* echo substrpos('This is a string with 0123456789 numbers in it and two strings.', -60, '-STRING', false)
* // Prints 's is a string with 0123456789 numbers in it and two strings.'
*
* Warnings:
* Since $start and $end both take either a string or an integer:
* If the character or string you are searching $str for is a number, pass it as a quoted string.
* If $end is (integer) 0, an empty string will be returned.
* Since this function takes negative strings ('-search_string'):
* If the string your using in $start or $end is a '-' or begins with a '-' escape it with a '\'.
* This only applies to the *first* character of $start or $end.
*/
// Define stripos() if not defined (PHP < 5).
if (!is_callable("stripos")) {
function stripos($str, $needle, $offset = 0) {
return strpos(strtolower($str), strtolower($needle), $offset);
}
}
function substrpos($str, $start, $end = false, $ignore_case = false) {
// Use variable functions
if ($ignore_case === true) {
$strpos = 'stripos'; // stripos() is included above in case it's not defined (PHP < 5).
} else {
$strpos = 'strpos';
}
// If end is false, set it to the length of $str
if ($end === false) {
$end = strlen($str);
}
// If $start is a string do what's needed to make it an integer position for substr().
if (is_string($start)) {
// If $start begins with '-' start processing until there's no more matches and use the last one found.
if ($start{0} == '-') {
// Strip off the '-'
$start = substr($start, 1);
$found = false;
$pos = 0;
while(($curr_pos = $strpos($str, $start, $pos)) !== false) {
$found = true;
$pos = $curr_pos + 1;
}
if ($found === false) {
$pos = false;
} else {
$pos -= 1;
}
} else {
// If $start begins with '\-', strip off the '\'.
if ($start{0} . $start{1} == '\-') {
$start = substr($start, 1);
}
$pos = $strpos($str, $start);
}
$start = $pos !== false ? $pos : 0;
}
// Chop the string from $start to strlen($str).
$str = substr($str, $start);
// If $end is a string, do exactly what was done to $start, above.
if (is_string($end)) {
if ($end{0} == '-') {
$end = substr($end, 1);
$found = false;
$pos = 0;
while(($curr_pos = strpos($str, $end, $pos)) !== false) {
$found = true;
$pos = $curr_pos + 1;
}
if ($found === false) {
$pos = false;
} else {
$pos -= 1;
}
} else {
if ($end{0} . $end{1} == '\-') {
$end = substr($end, 1);
}
$pos = $strpos($str, $end);
}
$end = $pos !== false ? $pos : strlen($str);
}
// Since $str has already been chopped at $start, we can pass 0 as the new $start for substr()
return substr($str, 0, $end);
}
?>
I needed a function like lpad from oracle, or right from SQL
then I use this code :
<?php
function right($string,$chars)
{
$vright = substr($string, strlen($string)-$chars,$chars);
return $vright;
}
echo right('0r0j4152',4);
?>
Result:
4152
------------------------------------------------
This function is really simple, I just wanted to share, maybe helps someone out there.
regards,
Regarding the utf8_substr function from lmak: The pattern '/./u' doesn't match newline characters. This means that the substring from 0 to the total length of the string will miss the number of characters in the end matching the number of newlines in the string. To fix this one can add the s modifier (PCRE_DOTALL) in the pattern:
<?php
function utf8_substr($str,$start)
{
preg_match_all("/./su", $str, $ar);
if(func_num_args() >= 3) {
$end = func_get_arg(2);
return join("",array_slice($ar[0],$start,$end));
} else {
return join("",array_slice($ar[0],$start));
}
}
?>
Here we have gr8 function which simply convert ip address to a number using substr with negative offset.
You can need it if you want to compare some IP addresses converted to a numbers.
For example when using ip2country, or eliminating same range of ip addresses from your website :D
<?php
function ip2no($val)
{
list($A,$B,$C,$D) = explode(".",$val);
return
substr("000".$A,-3).
substr("000".$B,-3).
substr("000".$C,-3).
substr("000".$D,-3);
}
$min = ip2no("10.11.1.0");
$max = ip2no("111.11.1.0");
$visitor = ip2no("105.1.20.200");
if($min<$visitor && $visitor<$max)
{ echo 'Welcome !'; }
else
{ echo 'Get out of here !'; }
?>
To quickly trim an optional trailing slash off the end of a path name:
if (substr( $path, -1 ) == '/') $path = substr( $path, 0, -1 );
Truncate a float number. Similar to the Excel trunc function.
<?php
function truncate_number($val,$decimals=2){
$number=array();
$number=explode(".",$val);
$result=0;
if (count($number)>1){
$result = $number[0] . "." . substr($number[1],0,$decimals);
} else {
$result = $val;
}
unset($number);
return $result;
}
echo truncate_number(99.123456,2); //result = 99.12
echo truncate_number(99.123456,5); //result = 99.12345
echo truncate_number(99.123456,1); //result = 99.1
?>
Adding the $limit parameter introduced a bug that was not present in the original. If $limit is small or negative, a string with a length exceeding the limit can be returned. The $limit parameter should be checked. It takes slightly more processing, but it is dwarfed in comparison to the use of strlen().
<?php
function short_name($str, $limit)
{
// Make sure a small or negative limit doesn't cause a negative length for substr().
if ($limit < 3)
{
$limit = 3;
}
// Now truncate the string if it is over the limit.
if (strlen($str) > $limit)
{
return substr($str, 0, $limit - 3) . '...';
}
else
{
return $str;
}
}
?>
I have developed a function with a similar outcome to jay's
Checks if the last character is or isnt a space. (does it the normal way if it is)
It explodes the string into an array of seperate works, the effect is... it chops off anything after and including the last space.
<?php
function limit_string($string, $charlimit)
{
if(substr($string,$charlimit-1,1) != ' ')
{
$string = substr($string,'0',$charlimit);
$array = explode(' ',$string);
array_pop($array);
$new_string = implode(' ',$array);
return $new_string.'...';
}
else
{
return substr($string,'0',$charlimit-1).'...';
}
}
?>
<?php
//removes string from the end of other
function removeFromEnd($string, $stringToRemove) {
$stringToRemoveLen = strlen($stringToRemove);
$stringLen = strlen($string);
$pos = $stringLen - $stringToRemoveLen;
$out = substr($string, 0, $pos);
return $out;
}
$string = 'picture.jpg.jpg';
$string = removeFromEnd($string, '.jpg');
?>
Well this is a script I wrote, what it does is chop up long words with malicious meaning into several parts. This way, a chat in a table will not get stretched anymore.
<?php
function text($string,$limit=20,$chop=10){
$text = explode(" ",$string);
while(list($key, $value) = each($text)){
$length = strlen($value);
if($length >=20){
for($i=0;$i<=$length;$i+=10){
$new .= substr($value, $i, 10);
$new .= " ";
}
$post .= $new;
}
elseif($length <=15){
$post .= $value;
}
$post .= " ";
}
return($post);
}
// for example, this would return:
$output = text("Well this text doesn't get cut up, yet thisssssssssssssssssssssssss one does.", 10, 5);
echo($output); // "Well this text doesn't get cup up, yet thiss sssss sssss sssss sssss sss one does."
?>
I hope it was useful.. :)
Just a little function to cut a string by the wanted amount. Works in both directions.
<?php
function cutString($str, $amount = 1, $dir = "right")
{
if(($n = strlen($str)) > 0)
{
if($dir == "right")
{
$start = 0;
$end = $n-$amount;
} elseif( $dir == "left") {
$start = $amount;
$end = $n;
}
return substr($str, $start, $end);
} else return false;
}
?>
Enjoy ;)
Split a string to an array of strings specified by an array of lengths:
<?php
function split_by_lengths($inString, $arrayLengths)
{
$output = array();
foreach ($arrayLengths as $oneLength)
{
$output[] = substr($inString, 0, $oneLength);
$inString = substr($inString, $oneLength);
}
return ($output);
}
?>
split_by_lengths('teststringtestteststring', array(4,6,4,4,6)) returns:
array('test','string','test','test','string')
Don't use it on user input without some error handling!
I wanted to work out the fastest way to get the first few characters from a string, so I ran the following experiment to compare substr, direct string access and strstr:
<?php
/* substr access */
beginTimer();
for ($i = 0; $i < 1500000; $i++){
$opening = substr($string,0,11);
if ($opening == 'Lorem ipsum'){
true;
}else{
false;
}
}
$endtime1 = endTimer();
/* direct access */
beginTimer();
for ($i = 0; $i < 1500000; $i++){
if ($string[0] == 'L' && $string[1] == 'o' && $string[2] == 'r' && $string[3] == 'e' && $string[4] == 'm' && $string[5] == ' ' && $string[6] == 'i' && $string[7] == 'p' && $string[8] == 's' && $string[9] == 'u' && $string[10] == 'm'){
true;
}else{
false;
}
}
$endtime2 = endTimer();
/* strstr access */
beginTimer();
for ($i = 0; $i < 1500000; $i++){
$opening = strstr($string,'Lorem ipsum');
if ($opening == true){
true;
}else{
false;
}
}
$endtime3 = endTimer();
echo $endtime1."\r\n".$endtime2."\r\n".$endtime3;
?>
The string was 6 paragraphs of Lorem Ipsum, and I was trying match the first two words. The experiment was run 3 times and averaged. The results were:
(substr) 3.24
(direct access) 11.49
(strstr) 4.96
(With standard deviations 0.01, 0.02 and 0.04)
THEREFORE substr is the fastest of the three methods for getting the first few letters of a string.
If you need just a single character from the string you don't need to use substr(), just use curly braces notation:
<?php
// both lines will output the 3rd character
echo substr($my_string, 2, 1);
echo $my_string{2};
?>
curly braces syntax is faster and more readable IMHO..
Add on to (a function originally written by) "Matias from Argentina": str_format_number function.
Just added handling of $String shorter then $Format by adding a side to start the fill and a string length to the while loop.
<?php
function str_format_number($String, $Format, $Start = 'left'){
//If we want to fill from right to left incase string is shorter then format
if ($Start == 'right') {
$String = strrev($String);
$Format = strrev($Format);
}
if($Format == '') return $String;
if($String == '') return $String;
$Result = '';
$FormatPos = 0;
$StringPos = 0;
while ((strlen($Format) - 1) >= $FormatPos && strlen($String) > $StringPos) {
//If its a number => stores it
if (is_numeric(substr($Format, $FormatPos, 1))) {
$Result .= substr($String, $StringPos, 1);
$StringPos++;
//If it is not a number => stores the caracter
} else {
$Result .= substr($Format, $FormatPos, 1);
}
//Next caracter at the mask.
$FormatPos++;
}
if ($Start == 'right') $Result = strrev($Result);
return $Result;
}
?>
Using a 0 as the last parameter for substr().
As per examples
<?php $var = substr($var, 4); ?>
works no problem. However
<?php $var = substr($var, 4, 0); ?>
will get you nothing. Just a quick heads up
You might expect substr('123456', 6) to return an empty string. Instead it returns boolean FALSE.
This behavior should be mentioned in the Return Values section of the manual. Instead it is only mentioned in the Parameters section.
If you need an empty string instead of a boolean FALSE you should typecast the result to a string.
<?php
$a = substr('123456', 6); // equivalent to $a = FALSE
$a = (string) substr('123456', 6); // equivalent to $a = '';
?>
Substring utf-8 strings!
very simple!
<?php
function substru($str,$from,$len){
return preg_replace('#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'. $from .'}'.'((?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){0,'. $len .'}).*#s','$1', $str);
}
?>
I created some functions for entity-safe splitting+lengthcounting:
<?php
function strlen_entities($text)
{
preg_match_all(
'/((?:&(?:#[0-9]{2,}|[a-z]{2,});)|(?:[^&])|'.
'(?:&(?!\w;)))s',$text,$textarray);
return count($textarray[0]);
}
function substr_entities($text,$start,$limit=0)
{
$return = '';
preg_match_all(
'/((?:&(?:#[0-9]{2,}|[a-z]{2,});)|(?:[^&])|'.
'(?:&(?!\w;)))s',$text,$textarray);
$textarray = $textarray[0];
$numchars = count($textarray)-1;
if ($start>=$numchars)
return false;
if ($start<0)
{
$start = ($numchars)+$start+1;
}
if ($start>=0)
{
if ($limit==0)
{
$end=$numchars;
}
elseif ($limit>0)
{
$end = $start+($limit-1);
}
else
{
$end = ($numchars)+$limit;
}
for ($i=$start;$i<=$end;$i++)
{
$return .= $textarray[$i];
}
return $return;
}
}
?>
/** what:IF A SUBSTR FROM THE GIVEN ARRAY VALUES IS IN FULL STR
* This Function makes it possible to ask php like the way if
* there is this or that word/letter and/or signs within any
* full Context such as HTML a Text or something for example
* @:return true if one of the arr value(s) found in $string
* note: altenatively $array can also be a textstring if you
* just look out for one occurance of a word in a full text
*/ function substrisInString($string,$array)
{ $count=0;
if(is_array($array))
{ foreach($array as $val)
{ if(substr_count($string,$val)>0)
{$count++;}
}
}
else //str instead of arrayvals sent
{ if(substr_count($string,$array)>0)
{$count++;}
}
return($count>0)?true:false;
}
II use my random password generator class
<?php
/*
* Ali GOREN
*
*
*/
class SifreOlusturucu {
//var $boyut; test
function __construct($boyut = 8) { // 8 default, 14 or more good and recommended length
$this->boyut = $boyut;
}
function sifreOlustur() {
//$this->boyut;
$karakterler = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()_-=+;:,.?';
$sifre = substr( str_shuffle( $karakterler ), 0, $this->boyut);
print_r($sifre);
}
}
$olustur = new SifreOlusturucu(16);
$olustur->sifreOlustur(); // output: wIsLiXzH1uP@hqSm
substr() exhibits rather unexpected behavior with respect to when it returns "" and when it returns FALSE. Specifically, the following appears to hold (tested on PHP 5.4.19):
* if $string is "", it always returns FALSE
* if ($start >= 0) and ($start >= strlen($string)) it returns FALSE
* if ($start >= 0) and ($length<($start - strlen($string))) it returns FALSE
* if ($start < 0) then it returns FALSE if *and only if* $length<-strlen($string).
No other cases return FALSE.
Note that in the last case, the position indicated by $start doesn't actually matter!
Also worth noting is that if you supply a $start that is < -strlen($string), it will be treated exactly as if you had set $start = strlen($string).
Here are some test cases to illustrate this behavior:
substr("",0,0) === FALSE
substr("",0,4) === FALSE
substr("",-2,4) === FALSE
substr("abc",3,0) === FALSE
substr("abc",3,10) === FALSE
substr("abc",3,-1) === FALSE
substr("abc",0,-4) === FALSE
substr("abc",2,-2) === FALSE
substr("abc",-1,-4) === FALSE
substr("abc",-4,-4) === FALSE
substr("abc",-5,-4) === FALSE
substr("abc",-10,-5) === FALSE
substr("abc",-10,-2) === "a"
substr("abc",-1,-3) === ""
substr("abc",-1,-2) === ""
substr("abc",-2,-3) === ""
substr("abc",0,0) === ""
substr("abc",-3,0) === ""
substr("abc",-10,0) === ""
substr("abc",-3,4) === "abc"
substr("abc",-10,20) === "abc"
substr("abc",-2,-2) === ""
substr("abc",-2,1) === "b"
substr("abc",0,-3) === ""
substr("abc",2,-1) === ""
Frequently we want to check whether one string ends with (or starts with) another. These may be useful:
function str_ends($string,$end){
return (substr($string,-strlen($end),strlen($end)) === $end);
}
function str_begins($string,$start){
return (substr($string,0,strlen($start)) === $start);
}
Example:
if (str_ends ($filename, ".jpg")){
echo "The extension is .jpg";
}
For those who cannot use mb_substr for any reasons, here is a solution for Unicode strings:
function substr_unicode($str, $s, $l = null)
{
$r = '/^.{'.(int)$s.'}(.';
$r .= ($l === null) ? '*)$' : '{'.(int)$l.'})';
$r .= '/su';
preg_match($r, $str, $o); return $o[1];
}
It is EXTREMELY fast compared to the array_slice + join method suggested before, and moderately slower than mb_substr.
Note: you cannot use negative values.
Note 2: use mb_substr whenever you can. Only use this workaround if you can not use the library.
Coming to PHP from classic ASP I am used to the Left() and Right() functions built into ASP so I did a quick PHPversion. hope these help someone else making the switch
function left($str, $length) {
return substr($str, 0, $length);
}
function right($str, $length) {
return substr($str, -$length);
}
When using a value of a wrong type as second parameter , substr() does not return FALSE but NULL although the docs say, it should return FALSE on error.
Prior to PHP 5.3, substr() tries to cast the second parameter to int and doesn't throw any errors. Since PHP 5.3 a warning is thrown.
If you want to have a string BETWEEN two strings, just use this function:
<?php
function get_between($input, $start, $end)
{
$substr = substr($input, strlen($start)+strpos($input, $start), (strlen($input) - strpos($input, $end))*(-1));
return $substr;
}
//Example:
$string = "123456789";
$a = "12";
$b = "9";
echo get_between($string, $a, $b);
//Output:
//345678
?>
Simple UTF-8 Multibyte solution (without mb_substr)
<?php
$string="texto en español";
echo substr($string,0,14); //Outputs: texto en espa�
?>
<?php
$string="texto en español";
echo utf8_encode(substr(utf8_decode($string),0,14)); //Outputs: texto en españ
?>
Using substr() to examine characters of a string without altering the string.
<?php
$string = 'This is my string';
$length = strlen($string);
$myChar = 'm';
for($i = 0; $i < $length; $i++) {
$showString_i = substr($string, $i, 1);
if($myChar == $showString_i) return $i;
}
?>
can also examine subs.
interesting and maybe not so obvious behavior:
print substr('\\test', 2); // est
print substr('\\test',1); // test
if you take a closer look you will realize that the backslash was escaped, still i think it's interesting to mention :)
<?php
//substring without words breaking
$str = "aa bb ccc ddd ee fff gg hhh iii";
echo substr(($str=wordwrap($str,$,'$$')),0,strpos($str,'$$'));
?>
One thing to keep in mind when using string indexes and UTF-8 is that string indexes are NOT multi-byte safe.
<?php
$string = 'äää1';
echo $string[3];
?>
Outputs:
¤
When it logically should output "1". This is not a bug, as PHP 'normal' string functions are not intended to be multi-byte safe. This can be solved by using this function
<?php
/**
*
* @param string $string String to "search" from
* @param int $index Index of the letter we want.
* @return string The letter found on $index.
*/
function charAt($string, $index){
if($index < mb_strlen($string)){
return mb_substr($string, $index, 1);
}
else{
return -1;
}
}
?>
Shortens the filename and its expansion has seen.
<?php
$file = "Hellothisfilehasmorethan30charactersandthisfayl.exe";
function funclongwords($file)
{
if (strlen($file) > 30)
{
$vartypesf = strrchr($file,".");
$vartypesf_len = strlen($vartypesf);
$word_l_w = substr($file,0,15);
$word_r_w = substr($file,-15);
$word_r_a = substr($word_r_w,0,-$vartypesf_len);
return $word_l_w."...".$word_r_a.$vartypesf;
}
else
return $file;
}
// RETURN: Hellothisfileha...andthisfayl.exe
?>
Drop extensions of a file (even from a file location string)
<?php
$filename = "c:/some dir/abc defg. hi.jklmn";
echo substr($filename, 0, (strlen ($filename)) - (strlen (strrchr($filename,'.'))));
?>
output: c:/some dir/abc defg. hi
Hope it may help somebody like me.. (^_^)
And as always there is bound to be a bug:
<?php
function strlen_entities($text)
{
preg_match_all(
'/((?:&(?:#[0-9]{2,}|[a-z]{2,});)|(?:[^&])|'.
'(?:&(?!\w;)))s',$text,$textarray);
return count($textarray[0]);
}
function substr_entities($text,$start,$limit=0)
{
$return = '';
preg_match_all(
'/((?:&(?:#[0-9]{2,}|[a-z]{2,});)|(?:[^&])|'.
'(?:&(?!\w;)))s',$text,$textarray);
$textarray = $textarray[0];
$numchars = count($textarray)-1;
if ($start>=$numchars)
return false;
if ($start<0)
{
$start = ($numchars)+$start+1;
}
if ($start>=0)
{
if ($limit==0)
{
$end=$numchars;
}
elseif ($limit>0)
{
$end = $start+($limit-1);
}
else
{
$end = ($numchars)+$limit;
}
for ($i=$start;($i<=$end && isset($textarray[$i]));$i++)
{
$return .= $textarray[$i];
}
return $return;
}
}
?>
The javascript charAt equivalent in php of felipe has a little bug. It's necessary to compare the type (implicit) aswell or the function returns a wrong result:
<?php
function charAt($str,$pos) {
return (substr($str,$pos,1) !== false) ? substr($str,$pos,1) : -1;
}
?>
I've used the between, after, before, etc functions that biohazard put together for years and they work great. I've also added to it a new function that I use a lot and thought others might like it as well. It uses his before/after functions so they are required to use it.
<?php
$example_html = "<p>test1 Test2</p><title>hi there</title><p>Testing</p>";
$paragraph_text = multi_between('<p>', '</p>', $example_html);
//Prints an arry of:
//Array ( [1] => test1 Test2 [2] => Testing )
print_r($paragraph_text);
function multi_between($this, $that, $inthat)
{
$counter = 0;
while ($inthat)
{
$counter++;
$elements[$counter] = before($that, $inthat);
$elements[$counter] = after($this, $elements[$counter]);
$inthat = after($that, $inthat);
}
return $elements;
}
//Get the help functions from biohazard's post below.
?>
This returns the portion of str specified by the start and length parameters..
It can performs multi-byte safe on number of characters. like mb_strcut() ...
Note:
1.Use it like this bite_str(string str, int start, int length [,byte of on string]);
2.First character's position is 0. Second character position is 1, and so on...
3.$byte is one character length of your encoding, For example: utf-8 is "3", gb2312 and big5 is "2"...you can use the function strlen() get it...
Enjoy it :) ...
--- Bleakwind
QQ:940641
http://www.weaverdream.com
PS:I'm sorry my english is too poor... :(
<?php
// String intercept By Bleakwind
// utf-8:$byte=3 | gb2312:$byte=2 | big5:$byte=2
function bite_str($string, $start, $len, $byte=3)
{
$str = "";
$count = 0;
$str_len = strlen($string);
for ($i=0; $i<$str_len; $i++) {
if (($count+1-$start)>$len) {
$str .= "...";
break;
} elseif ((ord(substr($string,$i,1)) <= 128) && ($count < $start)) {
$count++;
} elseif ((ord(substr($string,$i,1)) > 128) && ($count < $start)) {
$count = $count+2;
$i = $i+$byte-1;
} elseif ((ord(substr($string,$i,1)) <= 128) && ($count >= $start)) {
$str .= substr($string,$i,1);
$count++;
} elseif ((ord(substr($string,$i,1)) > 128) && ($count >= $start)) {
$str .= substr($string,$i,$byte);
$count = $count+2;
$i = $i+$byte-1;
}
}
return $str;
}
// Test
$str = "123456���ֽ�123456�ַ���123456��ȡ����";
for($i=0;$i<30;$i++){
echo "<br>".bite_str($str,$i,20);
}
?>
<?php
/*
An advanced substr but without breaking words in the middle.
Comes in 3 flavours, one gets up to length chars as a maximum, the other with length chars as a minimum up to the next word, and the other considers removing final dots, commas and etcteteras for the sake of beauty (hahaha).
This functions were posted by me some years ago, in the middle of the ages I had to use them in some corporations incorporated, with the luck to find them in some php not up to date mirrors. These mirrors are rarely being more not up to date till the end of the world... Well, may be am I the only person that finds usef not t bre word in th middl?
Than! (ks)
This is the calling syntax:
snippet(phrase,[max length],[phrase tail])
snippetgreedy(phrase,[max length before next space],[phrase tail])
*/
function snippet($text,$length=64,$tail="...") {
$text = trim($text);
$txtl = strlen($text);
if($txtl > $length) {
for($i=1;$text[$length-$i]!=" ";$i++) {
if($i == $length) {
return substr($text,0,$length) . $tail;
}
}
$text = substr($text,0,$length-$i+1) . $tail;
}
return $text;
}
// It behaves greedy, gets length characters ore goes for more
function snippetgreedy($text,$length=64,$tail="...") {
$text = trim($text);
if(strlen($text) > $length) {
for($i=0;$text[$length+$i]!=" ";$i++) {
if(!$text[$length+$i]) {
return $text;
}
}
$text = substr($text,0,$length+$i) . $tail;
}
return $text;
}
// The same as the snippet but removing latest low punctuation chars,
// if they exist (dots and commas). It performs a later suffixal trim of spaces
function snippetwop($text,$length=64,$tail="...") {
$text = trim($text);
$txtl = strlen($text);
if($txtl > $length) {
for($i=1;$text[$length-$i]!=" ";$i++) {
if($i == $length) {
return substr($text,0,$length) . $tail;
}
}
for(;$text[$length-$i]=="," || $text[$length-$i]=="." || $text[$length-$i]==" ";$i++) {;}
$text = substr($text,0,$length-$i+1) . $tail;
}
return $text;
}
/*
echo(snippet("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea") . "<br>");
echo(snippetwop("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea") . "<br>");
echo(snippetgreedy("this is not too long to run on the column on the left, perhaps, or perhaps yes, no idea"));
*/
?>
Here is also a nice (but a bit slow) alternative for colorizing an true color image:
<?php
// $colorize = hexadecimal code in String format, f.e. "10ffa2"
// $im = the image that have to be computed
$red = hexdec(substr($colorize, 0, 2));
$green = hexdec(substr($colorize, 2, 2));
$blue = hexdec(substr($colorize, 4, 2));
$lum_c = floor(($red*299 + $green*587 + $blue*144) / 1000);
for ($i = 0; $i < $lum_c; $i++)
{
$r = $red * $i / $lum_c;
$g = $green * $i / $lum_c;
$b = $blue * $i / $lum_c;
$pal[$i] = $r<<16 | $g<<8 | $b;
}
$pal[$lum_c] = $red<<16 | $green<<8 | $blue;
for ($i = $lum_c+1; $i < 255; $i++)
{
$r = $red + (255-$red) * ($i-$lum_c) / (255-$lum_c);
$g = $green + (255-$green) * ($i-$lum_c) / (255-$lum_c);
$b = $blue + (255-$blue) * ($i-$lum_c) / (255-$lum_c);
$pal[$i] = $r<<16 | $g<<8 | $b;
}
$sy = imagesy($im);
$sx = imagesx($im);
for($y=0;$y<$sy;$y++)
{
for($x=0;$x<$sx;$x++)
{
$rgba = imagecolorat($im, $x, $y);
$a = ($rgba & 0x7F000000) >> 24;
$r = ($rgba & 0xFF0000) >> 16;
$g = ($rgba & 0x00FF00) >> 8;
$b = ($rgba & 0x0000FF);
$lum = floor(($r*299+$g*587+$b*144)/1000);
imagesetpixel($im, $x, $y, $a<<24 | $pal[$lum]);
}
}
?>
This function can replace substr() in some situations you don't want to cut right in the middle of a word. strtrim will cut between words when it is possible choosing the closest possible final string len to return. the maxoverflow parameter lets you choose how many characters can overflow past the maxlen parameter.
<?php
function strtrim($str, $maxlen=100, $elli=NULL, $maxoverflow=15) {
global $CONF;
if (strlen($str) > $maxlen) {
if ($CONF["BODY_TRIM_METHOD_STRLEN"]) {
return substr($str, 0, $maxlen);
}
$output = NULL;
$body = explode(" ", $str);
$body_count = count($body);
$i=0;
do {
$output .= $body[$i]." ";
$thisLen = strlen($output);
$cycle = ($thisLen < $maxlen && $i < $body_count-1 && ($thisLen+strlen($body[$i+1])) < $maxlen+$maxoverflow?true:false);
$i++;
} while ($cycle);
return $output.$elli;
}
else return $str;
}
?>
Here's a little addon to the html_substr function posted by fox.
Now it counts only chars outside of tags, and doesn't cut words.
Note: this will only work in xhtml strict/transitional due to the checking of "/>" tags and the requirement of quotations in every value of a tag. It's also only been tested with the presence of br, img, and a tags, but it should work with the presence of any tag.
<?php
function html_substr($posttext, $minimum_length = 200, $length_offset = 20, $cut_words = FALSE, $dots = TRUE) {
// $minimum_length:
// The approximate length you want the concatenated text to be
// $length_offset:
// The variation in how long the text can be in this example text
// length will be between 200 and 200-20=180 characters and the
// character where the last tag ends
// Reset tag counter & quote checker
$tag_counter = 0;
$quotes_on = FALSE;
// Check if the text is too long
if (strlen($posttext) > $minimum_length) {
// Reset the tag_counter and pass through (part of) the entire text
$c = 0;
for ($i = 0; $i < strlen($posttext); $i++) {
// Load the current character and the next one
// if the string has not arrived at the last character
$current_char = substr($posttext,$i,1);
if ($i < strlen($posttext) - 1) {
$next_char = substr($posttext,$i + 1,1);
}
else {
$next_char = "";
}
// First check if quotes are on
if (!$quotes_on) {
// Check if it's a tag
// On a "<" add 3 if it's an opening tag (like <a href...)
// or add only 1 if it's an ending tag (like </a>)
if ($current_char == '<') {
if ($next_char == '/') {
$tag_counter += 1;
}
else {
$tag_counter += 3;
}
}
// Slash signifies an ending (like </a> or ... />)
// substract 2
if ($current_char == '/' && $tag_counter <> 0) $tag_counter -= 2;
// On a ">" substract 1
if ($current_char == '>') $tag_counter -= 1;
// If quotes are encountered, start ignoring the tags
// (for directory slashes)
if ($current_char == '"') $quotes_on = TRUE;
}
else {
// IF quotes are encountered again, turn it back off
if ($current_char == '"') $quotes_on = FALSE;
}
// Count only the chars outside html tags
if($tag_counter == 2 || $tag_counter == 0){
$c++;
}
// Check if the counter has reached the minimum length yet,
// then wait for the tag_counter to become 0, and chop the string there
if ($c > $minimum_length - $length_offset && $tag_counter == 0 && ($next_char == ' ' || $cut_words == TRUE)) {
$posttext = substr($posttext,0,$i + 1);
if($dots){
$posttext .= '...';
}
return $posttext;
}
}
}
return $posttext;
}
?>
I needed to cut a string after x chars at a html converted utf-8 text (for example Japanese text like 嬰謰弰脰欰罏).
The problem was, the different length of the signs, so I wrote the following function to handle that.
Perhaps it helps.
<?php
function html_cutstr ($str, $len)
{
if (!preg_match('/\&#[0-9]*;.*/i', $str))
{
$rVal = strlen($str, $len);
break;
}
$chars = 0;
$start = 0;
for($i=0; $i < strlen($str); $i++)
{
if ($chars >= $len)
break;
$str_tmp = substr($str, $start, $i-$start);
if (preg_match('/\&#[0-9]*;.*/i', $str_tmp))
{
$chars++;
$start = $i;
}
}
$rVal = substr($str, 0, $start);
if (strlen($str) > $start)
$rVal .= " ...";
return $rVal;
}
?>
All the references to "curly braces" on this page appear to be obsolete.
According to http://us.php.net/manual/en/language.types.string.php
"Using square array-brackets is preferred because the {braces} style is deprecated as of PHP 6."
Robert Chapin
Chapin Information Services
Hi there here is a little function i wrote to limit the number of lines in a string, i could not find anything else like it out there
<?php
function lineLimiter ($string = "", $max_lines = 1) {
$string = ereg_replace("\n", "##", $string);
$totalLines = (substr_count($string, '##') + 1);
$string = strrev($string);
$stringLength = strlen($string);
while ($totalLines > $max_lines) {
$pos = 0;
$pos = strpos ( $string, "##") + 2;
//$pos = $pos - $stringLength;
$string = substr($string, $pos);
$totalLines--;
}
$string = strrev($string);
$string = ereg_replace("##", "\n", $string);
return $string;
}
?>
Because i didnt see a function that would cut a phrase from a text (article or whatever) no matter where, front/middle/end and add ... + keeping the words intact, i wrote this:
Usage:
- The parameter $value if array will need the whole text and the portion you want to start from, a string. EG: cuttext(array($text, $string), 20). If the string is "have" and is near the beginning of the text, the function will cut like "I have a car ...", if the string is in the middle somewhere it will cut like "... if you want to have your own car ..." and if its somewhere near the end it will cut like "... and you will have one."
- The $length parameter is self explanatory.
Note: if you have just a string "127hh43h2h52312453jfks2" and you want to cut it, just use the function like so: cuttext($string, 10) and it will cut it like "127hh43h2h..."
<?php
////////////////////////////////////////////////////////
// Function: cuttext
// Description: Cuts a string and adds ...
function cuttext($value, $length)
{
if(is_array($value)) list($string, $match_to) = $value;
else { $string = $value; $match_to = $value{0}; }
$match_start = stristr($string, $match_to);
$match_compute = strlen($string) - strlen($match_start);
if (strlen($string) > $length)
{
if ($match_compute < ($length - strlen($match_to)))
{
$pre_string = substr($string, 0, $length);
$pos_end = strrpos($pre_string, " ");
if($pos_end === false) $string = $pre_string."...";
else $string = substr($pre_string, 0, $pos_end)."...";
}
else if ($match_compute > (strlen($string) - ($length - strlen($match_to))))
{
$pre_string = substr($string, (strlen($string) - ($length - strlen($match_to))));
$pos_start = strpos($pre_string, " ");
$string = "...".substr($pre_string, $pos_start);
if($pos_start === false) $string = "...".$pre_string;
else $string = "...".substr($pre_string, $pos_start);
}
else
{
$pre_string = substr($string, ($match_compute - round(($length / 3))), $length);
$pos_start = strpos($pre_string, " "); $pos_end = strrpos($pre_string, " ");
$string = "...".substr($pre_string, $pos_start, $pos_end)."...";
if($pos_start === false && $pos_end === false) $string = "...".$pre_string."...";
else $string = "...".substr($pre_string, $pos_start, $pos_end)."...";
}
$match_start = stristr($string, $match_to);
$match_compute = strlen($string) - strlen($match_start);
}
return $string;
}
?>
<?php
$a = 'abc';
$php = 'ok123';
$str = microtime(TRUE);
for($i=0;$i<=1000000;$i++)
$a = substr($php,1,1);
echo microtime(true)-$str,"\n";
$str = microtime(TRUE);
for($i=0;$i<=1000000;$i++)
$a = $php[1];
echo microtime(true)-$str;
?>
output:
0.26694822311401
0.10447096824646
If you need to parse utf-8 strings char by char, try this one:
<?php
$utf8marker=chr(128);
$count=0;
while(isset($string{$count})){
if($string{$count}>=$utf8marker) {
$parsechar=substr($string,$count,2);
$count+=2;
} else {
$parsechar=$string{$count};
$count++;
}
/* do what you like with parsechar ... , eg.:*/ echo $parsechar."<BR>\r\n";
}
?>
- it works without mb_substr
- it is fast, because it grabs characters based on indexes when possible and avoids any count and split functions
<?php
function insert_substr($str, $pos, $substr) {
$part1 = substr($str, 0, -$pos);
$part2 = substr($str, -$pos);
return $part1.$substr.$part2;
}
?>
I wrote this simple function to limit the middle characters of a string to a specified length.
<?php
$input = "hello world"
echo(limitchrmid($imput,10)) // hel ... rld
//limit chars middle
function limitchrmid($value,$lenght){
if (strlen($value) >= $lenght ){
$lenght_max = ($lenght/2)-3;
$start = strlen($value)- $lenght_max;
$limited = substr($value,0,$lenght_max);
$limited.= " ... ";
$limited.= substr($value,$start,$lenght_max);
}
else{
$limited = $value;
}
return $limited;
}
?>
If you want to substring the middle of a string with another and keep the words intact:
<?php
/**
* Reduce a string by the middle, keeps whole words together
*
* @param string $string
* @param int $max (default 50)
* @param string $replacement (default [...])
* @return string
* @author david at ethinkn dot com
* @author loic at xhtml dot ne
* @author arne dot hartherz at gmx dot net
*/
function strMiddleReduceWordSensitive ($string, $max = 50, $rep = '[...]') {
$strlen = strlen($string);
if ($strlen <= $max)
return $string;
$lengthtokeep = $max - strlen($rep);
$start = 0;
$end = 0;
if (($lengthtokeep % 2) == 0) {
$start = $lengthtokeep / 2;
$end = $start;
} else {
$start = intval($lengthtokeep / 2);
$end = $start + 1;
}
$i = $start;
$tmp_string = $string;
while ($i < $strlen) {
if ($tmp_string[$i] == ' ') {
$tmp_string = substr($tmp_string, 0, $i) . $rep;
$return = $tmp_string;
}
$i++;
}
$i = $end;
$tmp_string = strrev ($string);
while ($i < $strlen) {
if ($tmp_string[$i] == ' ') {
$tmp_string = substr($tmp_string, 0, $i);
$return .= strrev ($tmp_string);
}
$i++;
}
return $return;
return substr($string, 0, $start) . $rep . substr($string, - $end);
}
echo strMiddleReduceWordSensitive ('ABCDEEF GHIJK LLKJHKHKJHKL HGHFK sdfasdfsdafsdf sadf asdf sadf sad s', 30) . "\n";
// Returns: ABCDEEF GHIJK[...]asdf sadf sad s (33 chrs)
echo strMiddleReduceWordSensitive ('ABCDEEF GHIJK LLKJHKHKJHKL HGHFK sdfasdfsdafsdf sadf asdf sadf sad s', 30, '...') . "\n";
// Returns: ABCDEEF GHIJK...asdf sadf sad s (32 chrs)
?>
Here is a recursion function to get parts of passed string which are in a char. Func looks pretty, and works fast, tell me please if you find more opt way.
<?php
$s = "info= &make&,endvcc &new& &another&info";
echo str_cut($s,"&",",");
//output:
//make,new,another
function str_cut($s,$a,$d="")
{
$f=strpos($s,$a)+1;
$l=strpos($s,$a,$f);
$out= substr($s,$f,$l-$f);
if
(strpos($s,$a,$l+1)!==false)
{$s=substr($s,$l+1);$out.=$d.str_cut($s,$a,$d);}
return $out;
}
?>
it is possible to output in array, you have to returns a var as an array.
Also you can add an extra needle, which would be compare with the end of strings :
replace to
$l=strpos($s,$b,$f)-$f;
and dont forget to pass into recursion call $b value, but i did like that
$b=func_get_arg(func_num_args()-1);
care! the last argument should be $a, because $b getting last arg. like that:
function str_cut($s,$d="",$a)
but i think this method of getting $b not the best way for perfomance.
Sorry for my English.
Simple use of substr to determine possession:
<?php
function possessive ($word) {
return $word.(substr($word, -1) == 's' ? "'" : "'s");
}
// Davis => Davis'
// Paul => Paul's
?>
<?php
$string="NanheKumar";
echo substr($string,0,5); //Nanhe
echo substr($string,5); //Kumar
echo substr($string,-4); //umar
echo substr($string,-4,2); //um
echo substr($string,2,6); //umnheKum
?>
If you need a word-sensitive and also html-tags aware version of substr, this one should do the job. It works fine for me
<?php
/**
* word-sensitive substring function with html tags awareness
* @param text The text to cut
* @param len The maximum length of the cut string
* @returns string
**/
function substrws( $text, $len=180 ) {
if( (strlen($text) > $len) ) {
$whitespaceposition = strpos($text," ",$len)-1;
if( $whitespaceposition > 0 )
$text = substr($text, 0, ($whitespaceposition+1));
// close unclosed html tags
if( preg_match_all("|<([a-zA-Z]+)>|",$text,$aBuffer) ) {
if( !empty($aBuffer[1]) ) {
preg_match_all("|</([a-zA-Z]+)>|",$text,$aBuffer2);
if( count($aBuffer[1]) != count($aBuffer2[1]) ) {
foreach( $aBuffer[1] as $index => $tag ) {
if( empty($aBuffer2[1][$index]) || $aBuffer2[1][$index] != $tag)
$text .= '</'.$tag.'>';
}
}
}
}
}
return $text;
}
?>
I noticed a slight issue when parsing out long strings using the substr function.
Here is my string: $merge = "UPDATE AssistanceRequest SET RequestorID = '4301' WHERE RequestorID IN ( '4535','6222','4865','5137','4893')"
To parse out the WHERE portion I used:
$whereClause = substr($merge, strpos($merge,'WHERE', (strlen($merge) - strpos($merge,'WHERE'))));
Normally the function returned: $whereClause = "WHERE RequestorID IN ( '4535','6222','4865','5137','4893')"
This $whereClause gives me the WHERE clause to modify the MSSQL database records being manipulated. So that when I used $whereClause as the WHERE clause to create subsequent SQL, I used the following syntax: $setDeleteFlag = "UPDATE AssistanceRequestor SET bIsDirty = 'DELETE' " . $whereClause;
This should have returned: $setDeleteFlag = "UPDATE AssistanceRequestor SET bIsDirty = 'DELETE' WHERE RequestorID IN ( '4535','6222','4865','5137','4893')"
As long as the length of the original $merge string was less than 104 characters, the $setDeleteFlag sql came out correctly. However, when the length of the original $merge string exceeded 104 characters, I got this returned:
$setDeleteFlag = "UPDATE AssistanceRequestor SET bIsDirty = 'DELETE' UPDATE AssistanceRequestor SET bIsDirty = 'DELETE' WHERE RequestorID IN ( '4535','6222','4865','5137','4893')"
The result was that the bIsDirty field for every record in the database was set to 'DELETE'. I fixed it by breaking apart the substr to create the original $whereClause so that it looked like this:
$wherePosition = strpos($merge,'WHERE');
$whereClause = substr($merge, $wherePosition, strlen($merge) - $wherePosition);
$setDeleteFlag = "UPDATE AssistanceRequestor SET bIsDirty = 'DELETE' " . $whereClause;
I do have to note that I run PHP 5.x on my development server, while I think the production host is still on 4.x. I did not seem to have an issue in development, but I don't think I tested strings longer than 104 characters. Maybe this issue has been corrected in version 5.x.
Be careful when comparing the return value of substr to FALSE. FALSE may be returned even if the output is a valid string.
substr("0", 0); // equals "0", comparision with FALSE evaluates to true, because "0" == 0 == FALSE
I've seen numerous requests over the years from people trying to put together templating systems using XML parsers or regular expressions - you can create a simple template system with the following class. It could easily be expanded to take advantage of parameters, conditionals, etc.
<?php
class Template
{
const OPEN_BRACKET = "{";
const CLOSE_BRACKET = "}";
public static function inject(array $source, $template)
{
$ob_size = strlen(self::OPEN_BRACKET);
$cb_size = strlen(self::CLOSE_BRACKET);
$pos = 0;
$end = strlen($template);
while($pos <= $end)
{
if($pos_1 = strpos($template, self::OPEN_BRACKET, $pos))
{
if($pos_1)
{
$pos_2 = strpos($template, self::CLOSE_BRACKET, $pos_1);
if($pos_2)
{
$return_length = ($pos_2-$cb_size) - $pos_1;
$var = substr($template, $pos_1+$ob_size, $return_length);
$template = str_replace(self::OPEN_BRACKET.$var.self::CLOSE_BRACKET, $source[$var], $template);
$pos = $pos_2 + $cb_size;
}
else
{
throw new exception("Incorrectly formed template - missing closing bracket. Please check your syntax.");
break;
}
}
}
else
{
//exit the loop
break;
}
}
return $template;
}
}
//array of values to inject into the template
$array = array("NAME" => "John Doe",
"DOB" => "12/21/1986",
"ACL" => "Super Administrator");
//template using '{' and '}' to signify variables
$template = "This is your template, {NAME}. You were born on {DOB} and you are a {ACL} on this system.";
echo Template::inject($array, $template);
?>