chr

add a note User Contributed Notes

jasonwiener.com
23-Sep-2006 01:58


In re: to Mike's post on converting int to alpha.  



http://us3.php.net/manual/en/function.chr.php#54256



I'm using it to build an A-Z index and wanted to drive it using ints via a for loop.  The prob was it only produced a-y when i started @ 1 and incremeneted to 27.  Made a couple changes and it works great now.  Thanks Mike for doing the heavy lifting.



J.



---start code---

    function convertIntToAlphabet($int_wert) {

        if($int_wert%27>=1) {

           $alpha_string=chr(($int_wert%27)+64).$alpha_string;

           $alpha_string=convertIntToAlphabet($int_wert/27).$alpha_string;

       }

       return $alpha_string;

    }

---finish code---

jdavid at skynet dot be
05-Sep-2006 07:33


To elaborate on JasonLauDotBiz's piece of code and also schafer at robandger dot com:



for ($i = 0; $i < 10; $i++) {

    $randnum = mt_rand(0,61);

    if ($randnum < 10)

        $randstr .= $randnum;

    else if ($randnum < 36)

        $randstr .= chr($randnum+55);

    else

        $randstr .= chr($randnum+61);

}

echo $randstr;



This will give you a 10 character string consisting of [A-Za-z0-9]. Usefull for passwords or other random strings.

mwgamera at gmail dot com
22-Aug-2006 11:20


Unicode version of chr() using mbstring

<?php

  function unichr($u) {

    return mb_convert_encoding(pack("N",$u), mb_internal_encoding(), 'UCS-4BE');

  }

?>

It returns a string in internal encoding (possibly more than one byte).

JasonLauDotBiz
17-Feb-2006 11:34


I didn't see it here, so here's simple random string generation using char.



for($i=0; $i<7; $i++){

$random_string .= chr(rand(0,25)+65);

}

echo $random_string;

sgaston at mercy corps dot ()rg
14-Feb-2006 06:52


I found this function useful as a way to detect and to replace Microsoft Smart Quotes when desplaying info on a webpage.



The following lines seem to do the trick:



<?php

$text = "string containing Microsoft Smart Quotes...";

$chrs = array (chr(150), chr(147), chr(148), chr(146));

$repl = array ("-", "\"", "\"", "'");

$text = str_replace($chrs, $repl, $text);

?>

plugwash at p10link dot net
15-Jan-2006 04:41


bear in mind that php doesn't really care about character sets. php strings are just arbitary byte sequences thier meaning (especailly when you go beyond code 127) depends entirely on whats interpreting the data (in the case of a browser the charset specified in the http headers).

admin at icstrategy dot midgetforhire dot com
09-Jan-2006 02:51


I made a password generator with this function...



<?php

$passlength = 8;

$pass = "";

$i = 0;

while($i <= $passlength)

    {

    $pass .= chr(rand(33,126));

    $i++;

    }

echo $pass;

?>



Ofcourse you can change passlength.



Example of an 8-char password:

AFJ\)t'u}



I realise it isn't compatible for all sites, but most will accept :)

bg at ms dot com
16-Oct-2005 02:20


"If anyone can shed some light on what the difference is, please do."



This is what happens when you give bright young people new power but without old understanding.



A line feed

...........does this.



A carriage return

does this.



The "carriage" is the typewriter (or teletypewriter's) strikehead mechanism.  The "return" means return to leftmost margin; whereas, linefeed means just go down one line but remain at unaltered horizontal position.

php at elijahtech dot com
26-Aug-2005 11:52


Based on Mike's code, here are some handy functions to convert integer numbers into an alphanumeric form based on a custom character set.  Meaning, the array $chrs can include anything, and as long as the same $chrs is used in the decoding, it will always work.  I am using it a condense a generated ID that gets displayed.



e.g., g5 = 997, 10000093 = FXtP -- Much shorter!



Elijah

-----------------------------------------------------------

$chrs = array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S' ,'T', 'U', 'V', 'W', 'X', 'Y', 'Z');



function int_to_alph($int, $chrs)

{

  $base = sizeof($chrs);

  do {

    $alph = $chrs[($int % $base)] . $alph;

  } while($int = intval($int / $base));

  return $alph;

}



function alph_to_int($alph, $chrs)

{

  $base = sizeof($chrs);

  for($i = 0, $int = 0; $i < strlen($alph); $i++)

  {

    $int += intval(array_search(substr($alph, strlen($alph) - $i - 1, 1), $chrs)) * pow($base, $i);

  }

  return $int;

}

grey - greywyvern - com
19-Aug-2005 10:55


I spent hours looking for a function which would take a numeric HTML entity value and output the appropriate UTF-8 bytes.  I found this at another site and only had to modify it slightly; so I don't take credit for this.



<?php function unichr($dec) { 

  if ($dec < 128) { 

    $utf = chr($dec); 

  } else if ($dec < 2048) { 

    $utf = chr(192 + (($dec - ($dec % 64)) / 64)); 

    $utf .= chr(128 + ($dec % 64)); 

  } else { 

    $utf = chr(224 + (($dec - ($dec % 4096)) / 4096)); 

    $utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64)); 

    $utf .= chr(128 + ($dec % 64)); 

  } 

  return $utf;

} ?>



So for example:



<?php



  $str = "Chinese: &#20013;&#25991;";

  $str = preg_replace("/&#(\d{2,5});/e", "unichr($1);", $str);



?>

Mike
28-Jun-2005 10:43


Hi out there!



Here are two usefull functions to convert ordinal values to int value and back (unlimited length).



For Example:

'A' = 1

'B' = 2

'C' = 3

'AA' = 27

'ABC' = 731



Convert ordinal value to INT:



function convertAlphabetToInt($alpha_string) {

    $int_wert=0;

    $potenzcounter=0;

    for ($i=strlen($alpha_string);$i>0;$i--) {

        $ordinalwert=(ord(substr($alpha_string,$i-1,1))-64);

        $int_wert+=$ordinalwert*pow(26,$potenzcounter);

        $potenzcounter++;

    }

    return $int_wert;

}



And back from INT to ordinal:



function convertIntToAlphabet($int_wert) {

    if($int_wert%26>=1) {

        $alpha_string=chr(($int_wert%26)+64).$alpha_string;

        $alpha_string=convertIntToAlphabet($int_wert/26).$alpha_string;

    }

    return $alpha_string;

}



This functions will return for example:

convertAlphabetToInt("ABCD") => Output: 19010

convertIntToAlphabet(19010) = Output: "ABCD"



I hope someone can use it :)

Greetings,

Mike

24-May-2005 10:15


If you want to increment your letter, which is stored as a string, you have to convert it back to an integer first.



<?php

    $letter=strtolower($_GET['letter']);    //You wanted this originally, but not decided you want the previous letter

    $letter=ord($letter);            //Convert to an integer

    $letter=chr($letter-1);            //Convert back to a string, but the previous letter (naturally won't work with A or a)

?>

mike at go dot online dot pt
12-Mar-2005 04:18


In addition to what mcusack wrote about new lines in text files under Windows:



<?php

$text = "First line\r\n";

$text .= "Second line";

echo $text;

?>

Will output:

First lineSecond line



<?php

$text = "First line" . chr(13) . chr(10);

$text .= "Second line";

echo $text;

?>

Will output:

First line

Second line

sarabas at itstudio dot pl
17-Feb-2005 08:26


The following function helped me to generate ascii-only usernames from firstname/lastname containing iso-8859-2 characters. The convertion array was based on contents of 'man iso-8859-2'.



Example: iso2ascii("b&#322;a&#380;ej.&#378;d&#378;b&#322;o") returns "blazej.zdzblo"



function iso2ascii($str) {

 $arr=array(

  chr(161)=>'A', chr(163)=>'L', chr(165)=>'L', chr(166)=>'S', chr(169)=>'S',

  chr(170)=>'S', chr(171)=>'T', chr(172)=>'Z', chr(174)=>'Z', chr(175)=>'Z',

  chr(177)=>'a', chr(179)=>'l', chr(181)=>'l', chr(182)=>'s', chr(185)=>'s',

  chr(186)=>'s', chr(187)=>'t', chr(188)=>'z', chr(190)=>'z', chr(191)=>'z',

  chr(192)=>'R', chr(193)=>'A', chr(194)=>'A', chr(195)=>'A', chr(196)=>'A',

  chr(197)=>'L', chr(198)=>'C', chr(199)=>'C', chr(200)=>'C', chr(201)=>'E',

  chr(202)=>'E', chr(203)=>'E', chr(204)=>'E', chr(205)=>'I', chr(206)=>'I',

  chr(207)=>'D', chr(208)=>'D', chr(209)=>'N', chr(210)=>'N', chr(211)=>'O',

  chr(212)=>'O', chr(213)=>'O', chr(214)=>'O', chr(216)=>'R', chr(217)=>'U',

  chr(218)=>'U', chr(219)=>'U', chr(220)=>'U', chr(221)=>'Y', chr(222)=>'T',

  chr(223)=>'s', chr(224)=>'r', chr(225)=>'a', chr(226)=>'a', chr(227)=>'a',

  chr(228)=>'a', chr(229)=>'l', chr(230)=>'c', chr(231)=>'c', chr(232)=>'c',

  chr(233)=>'e', chr(234)=>'e', chr(235)=>'e', chr(236)=>'e', chr(237)=>'i',

  chr(238)=>'i', chr(239)=>'d', chr(240)=>'d', chr(241)=>'n', chr(242)=>'n',

  chr(243)=>'o', chr(244)=>'o', chr(245)=>'o', chr(246)=>'o', chr(248)=>'r',

  chr(249)=>'u', chr(250)=>'u', chr(251)=>'u', chr(252)=>'u', chr(253)=>'y',

  chr(254)=>'t'

 );

 return strtr($str,$arr);

}

16-Dec-2004 02:04


Same function as suggested by tippy2k/jmartin. tippy2k's code seems to have a syntax error in the function declaration; jmartin's code throws a notice. 

So here's yet another version, without temporary variables and loops:



<?

// 1 <= $a <= 702

function col2str($a) {

 return ($a-->26?chr(($a/26+25)%26+ord('A')):'').chr($a%26+ord('A'));

}



// Example

$colname = col2str(1) // returns "A"

$colname = col2str(27) // returns "AA"

$colname = col2str(702) // returns "ZZ"

?>

jon
15-Sep-2004 07:11


in response to jcokos's function for catching non-Ascii values when converting to entitites for XML. 



I have found it better to use htmlspecialchars rather than htmlentities because htmlentities does convert some non-Ascii characters to entitities, for example the copyright symbol. To be fully compliant with XML, the numeric entity should be used, rather than the symbolic version used in htmlentities.



<?php

   function strictify ( $string ) {



       $fixed = htmlspecialchars( $string, ENT_QUOTES );



       $trans_array = array();

       for ($i=127; $i<255; $i++) {

           $trans_array[chr($i)] = "&#" . $i . ";";

       }



       $really_fixed = strtr($fixed, $trans_array);



       return $really_fixed;



   }

?>

tenyou at gmail dot com
15-Jul-2004 02:05


When having to deal with parsing an IIS4 or IIS5 metabase dump I wrote a simple function for converting those MS hexidecimal values into their ascii counter parts. Hopefully someone will find use for it.





<?php


function hex_decode($string)  {


        for ($i=0; $i < strlen($string); $i)  {


        $decoded .= chr(hexdec(substr($string,$i,2)));


        $i = (float)($i)+2;


        }


return $decoded;


}


?>

tippy2k
14-May-2004 10:27


Working on the same thing as jmartin today.  701 is the limit of the script, 'ZZ'.  This should work a little faster.  Hope it helps.



<?

function SSkey($xkey+1) {

    $prefix = chr(floor($xkey+1 / 26)+64);

    if($prefix == chr(64)) unset($prefix);

    $suffix = chr($xkey+1 - (floor($xkey+1 / 26)*26) +64);

    if($suffix == chr(64)) {

        $prefix = chr( ord($prefix) -1);

        if($prefix == chr(64)) unset($prefix);

        $suffix = 'Z';

    } 

    $sskey = "$prefix$suffix"; 

    return $sskey;

}

?>

jmartin at prescientsoftware dot com
14-Apr-2004 05:42


Here is a function that will convert column numbers in to a letters for use in a spreadsheet.  It is limited up to 'ZZ' but can easliy by modifed.





<?php


 function col2chr($a){


        if($a<27){


            return strtoupper(chr($a+96));    


        }else{


            while($a > 26){


                $b++;


                $a = $a-26;                


            }                   


            $b = strtoupper(chr($b+96));    


            $a = strtoupper(chr($a+96));                


            return $b.$a;


        }


    }


?>

perrodin at laposte dot net
12-Apr-2004 07:20


Note that if the number is higher than 256, it will return the number mod 256.

For example :

chr(321)=A because A=65(256)

goffrie at somewhere dot ca
06-Apr-2004 08:06


ASCII 7 makes a beep.

so

print chr(7);

is useful in long scripts (like ones that download big files) when you want to get the user's attention after a long time of waiting.

---------------------

Me:)

---------------------

mcusack at fastlanecompanies dot com
26-Mar-2004 08:46


when working with output to a windows system i.e. a textfile the end of line "\n" will not return a valid newline that windows will understand (this is due to a lack of standards accross OS types) this is because windows reads new lines as carriage return and an additional char the linefeed the traditional "\n" so in short use the following to produce a new line under a windows text environment "\r\n"





// not tested but this should work in most cases (i think....)





<?php


function win_nl2br($stringtext) {


return str_replace("\r\n", "<br>", $stringtext);


}





function win_br2nl($stringtext) {


return str_replace("<br>", "\r\n", $stringtext);


}


?>





Hope this is as informative to you as it was to me ......

loremaster
09-Sep-2003 04:27


Re: Kristin: Line feed vs carriage return



I may be wrong, it's been a while since I cared about the difference.



Line feeds add a new line below the current carriage position and moves the carriage to it.

Carriage return brings the carriage (or cursor, if you like) to the beginning of the line.



Most mutliline text fields, when you press Enter, you get both a line feed (new line) and a carriage return (return).  Typically I use the strtr function and replace "\n\r" rather than searching for ascii 13 and 10.  There are many ways, of course, so your mileage may vary.

jgray at triangle dash solutions dot com
26-Jul-2003 01:20


Lowercase alphabet:

for($a=97;$a<(97+26);$a++){ echo chr($a); }

infoserv at chollian dot net
25-Jun-2003 11:16


Cutting Korean(2Byte)-String





<?php


function cutStr($str,$len){


    if(strlen($str) > $len){


        $str = substr($str,0,$len - 2);


        if(strlen(substr(strrchr($str," "),1)) % 2)


            $str = substr($str,0,strlen($str) - 1);


        $str .= "..";


    }


    return $str;


}


?>

jcokos
27-Mar-2003 10:12


A quick function that I use to make strings "XML" compliant, changing every special character into their #$... equivalent.





htmlentities doesn't get all of the chars above 127, so the second part of this (which I stole from one of the comments above) finishes the process, returning a nice, xml happy string.





<?php


    function strictify ( $string ) {





        $fixed = htmlentities( $string, ENT_QUOTES );





        $trans_array = array();


        for ($i=127; $i<255; $i++) {


           $trans_array[chr($i)] = "&#" . $i . ";";


        }





        $really_fixed = strtr($fixed, $trans_array);





        return $really_fixed;





    }


?>





HTH

avenger at php dot net
22-Mar-2003 05:26


I usally used this code to test a Chinese string:





<?php


$chinese_str = "";


if (preg_match("/^[".chr(0xa1)."-".chr(0xff)."_-]+$/",$chinese_str) {


    echo 'This is a Chinese word..';


} else {


    echo 'This is not a Chinese word..';


}


?>

Kristin
07-Mar-2003 12:19


Note that chr(10) is a 'line feed' and chr(13) is a 'carriage return' and they are not the same thing! I found this out while attempting to parse text from forms and text files for inclusion as HTML by replacing all the carriage returns with <BR>'s only to find after many head-scratchings that I should have been looking for line feeds. If anyone can shed some light on what the difference is, please do.





If you're planning on saving text from a form into a database for later display, you'll need to apply the following function so that it gets saved with the proper HTML tags.





<?php


$text = str_replace ( chr(10), "<BR>", $text );


?>





When you want to plug it back into that form for editing you need to convert it back.





<?php


$text = str_replace ( "<BR>", chr(10), $text)


?>





Hope this saves somebody some trouble. :)

joeldegan AT yahoo.com
15-Dec-2002 06:53


Want terminal colors in command line php scripts?





This should take care of that.


<?





$_colors = array(


        'LIGHT_RED'      => "[1;31m",


        'LIGHT_GREEN'     => "[1;32m",


        'YELLOW'     => "[1;33m",


        'LIGHT_BLUE'     => "[1;34m",


        'MAGENTA'     => "[1;35m",


        'LIGHT_CYAN'     => "[1;36m",


        'WHITE'     => "[1;37m",


        'NORMAL'     => "[0m",


        'BLACK'     => "[0;30m",


        'RED'         => "[0;31m",


        'GREEN'     => "[0;32m",


        'BROWN'     => "[0;33m",


        'BLUE'         => "[0;34m",


        'CYAN'         => "[0;36m",


        'BOLD'         => "[1m",


        'UNDERSCORE'     => "[4m",


        'REVERSE'     => "[7m",





);





function termcolored($text, $color="NORMAL", $back=1){


    global $_colors;


    $out = $_colors["$color"];


    if($out == ""){ $out = "[0m"; }


    if($back){


        return chr(27)."$out$text".chr(27).chr(27)."[0m".chr(27);


    }else{


        echo chr(27)."$out$text".chr(27).chr(27)."[0m".chr(27);


    }//fi


}// end function





echo termcolored("test\n", "BLUE");


?>

gschafer at robandger dot com
09-Nov-2002 08:17


Here's a small function I wrote up to generate random passwords using the chr() function.





<?php


function randPass($len)


{


 $pw = ''; //intialize to be blank


 for($i=0;$i<$len;$i++)


 {


   switch(rand(1,3))


   {


     case 1: $pw.=chr(rand(48,57));  break; //0-9


     case 2: $pw.=chr(rand(65,90));  break; //A-Z


     case 3: $pw.=chr(rand(97,122)); break; //a-z


   }


 }


 return $pw;


}


?>





Example:





<?php


 $password = randPass(10); //assigns 10-character password


?>





I found this useful in my early coding days... I'm sure someone else will too :D

29-Jun-2002 11:05


This bit of code will convert all those lovely tilde,umlaut etc. etc. characters into safe character codes:





<?php


    $trans_array = array();


    for ($i=127; $i<255; $i++) {


        $trans_array[chr($i)] = "&#" . $i . ";";


    }


    $outtext = strtr($intext, $trans_array);


?>

webmaster at project-enigma dot net
14-Apr-2002 03:51


\n == &#13;

Usefull if u want to display multi-line-alt-strings

e.g. <img src="/gifs/php_logo.gif" alt="Here u can see the&#13;PHPLogo&#13;3rd line">

happyevil(at)1218.org
27-Mar-2001 11:31


Here is a function that's help me find what chr(number) outputs what character quicker than typing out 256 echo tags.





<?php


 function listChr(){


  for ($i = 0; $i < 256; ++$i) {


  static $genNum;


  $genNum++;


  echo "chr($genNum) will output '";


  echo (chr($genNum));


  echo "'< br>\n";


  }


}


listChr();


?>





Another helpful chr is #9, being a tab.  Quite using when making error logs.





 $tab = (chr(9));


 echo "<pre>error{$tab}date{$tab}time</pre>";





 -- HappyEvil

ddawsonNOSPAM at execpc dot com
10-May-2000 07:59


[Editor's note:





%c is defined as: "Print the character belonging to the ascii code given"





chr() just gives a string, so you need to use %s, even if the string consists of only one character. This is consistent with other languages.


--Jeroen@php.net]








Learn from my mistake:


Do not expect this to work!





<?php


$c_question = chr(63);


$v_out = sprintf("<%cphp\n", $c_question);


//... more stuff being sprintf'd into v_out here ...


$v_out = sprintf("%s%c>\n", $v_out, $c_question);


$v_fp = fopen("foofile", "w");


if ($v_fp)


{


     fwrite($v_fp, $v_out, strlen($v_out));


     fclose($v_fp);


}


?>





When I did this, foofile contained <NUL NUL NUL NUL NUL>.


I spun my wheels quite awhile looking at fputs, fwrite to verify I was calling those functions correctly.


My mistake was using $c_question = chr(63) instead of


$c_question = 63 (correct).  Then everything worked fine.

add a note

chr

描述