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)
(PHP 4, PHP 5, PHP 7, PHP 8)
chr — Gera uma string de um byte a partir de um número
Retorna uma string de um caractere contendo o caractere especificado
pela interpretação do parâmetro codepoint
como um inteiro sem sinal.
Esta função pode ser usada para criar uma string de um caracteres em uma codificação de 1-byte como ASCII, ISO-8859, ou Windows 1252, passando-se a posição do caractere desejado na tabela de mapeamento da codificação. Entretanto, observe que esta função não tem ciência de codificação de strings e, em particular, não pode receber um valor de ponto de código Unicode para gerar uma string em uma codificação multi-byte como UTF-8 ou UTF-16.
Esta função é complementar à função ord().
codepoint
Um inteiro entre 0 e 255.
Valores fora do intervalo válido (0..255) sofrerão operação binária AND com o valor 255, o que é equivalente ao algoritmo a seguir:
while ($bytevalue < 0) {
$bytevalue += 256;
}
$bytevalue %= 256;
Uma string de um caractere contendo o byte especificado.
Versão | Descrição |
---|---|
7.4.0 |
A função não mais aceita silenciosamente códigos não suportados no parâmetro codepoint ,
convertendo-os para 0 .
|
Exemplo #1 Exemplo de chr()
<?php
// Assume que a string será usada como codificação ASCII ou compatível
$str = "A string termina com ESC: ";
$str .= chr(27); /* adiciona um caractere ESC ao final de $str */
/* Frequentement isto é mais útil: */
$str = sprintf("A string termina com ESC: %c", 27);
?>
Exemplo #2 Comportamento com parâmetro fora dos limites
<?php
echo chr(-159), chr(833), PHP_EOL;
?>
O exemplo acima produzirá:
aA
Exemplo #3 Construindo uma string UTF-8 a partir de bytes individuais
<?php
$str = chr(240) . chr(159) . chr(144) . chr(152);
echo $str;
?>
O exemplo acima produzirá:
%c
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)
Another quick and short function to get unicode char by its code.
<?php
/**
* Return unicode char by its code
*
* @param int $u
* @return char
*/
function unichr($u) {
return mb_convert_encoding('&#' . intval($u) . ';', 'UTF-8', 'HTML-ENTITIES');
}
?>
I spent hours looking for a function which would take a numeric HTML entity value and output the appropriate UTF-8 bytes. I found this at another site and only had to modify it slightly; so I don't take credit for this.
<?php function unichr($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: 中文";
$str = preg_replace("/&#(\d{2,5});/e", "unichr($1);", $str);
?>
Here is a sample of encoding and decoding using "chr" and "ord".
<?php
function Encode($txtData,$Level){
for ($j = 0;$j<$Level;$j++){
$tmpStr = '';
for ($i = 0;$i<strlen($txtData);$i++)
$tmpStr .= ord(substr(strtoupper($txtData), $i, 1));
$txtData = $tmpStr;
}
return (strlen($Level)).$Level.$txtData;
}
function Decode($txtData){
$intLevel = substr($txtData, 1, substr($txtData, 0, 1));
$startStr = substr($txtData, substr($txtData, 0, 1)+1, strlen($txtData));
for ($j = 0;$j<$intLevel;$j++){
for ($i = 0;$i<strlen($startStr);$i+=2)
$tmpStr .= chr(intval(substr($startStr, $i, 2)));
$startStr = $tmpStr;
$tmpStr = "";
}
return $startStr;
}
echo Encode('123',4).'<br>';
echo Decode(Encode('123',5));
?>
<?php
for ($i = 128; $i <= 191; $i++) {
$str = chr(240) . chr(159) . chr(144) . chr($i);
echo $str;
}
?>
// rivencodec 1.0
// encode riverse ascii 1 simple function can encode/decode
// can use it for secure source with speed encode text
<?php
function rivencodec($ch,$a=0) {
while((@$b = $ch[$a++])) { $ch[$a-1] = chr(255-ord($b)); }
return $ch;
}
$zz = rivencodec("abcdefghijklmn");
echo 'encode: ',$zz,'<br/>',PHP_EOL;
$yy = rivencodec($zz);
echo 'decode: ',$yy,'<br/>',PHP_EOL;
?>
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");
?>
to remove the ASCII control characters (except "line feed" and "tab") :
$tab_chr = array() ;
for($control = 0; $control < 32; $control++) {
if ($control != 9 && $control != 10) {
$tab_chr[]= chr($control) ;
}
}
$tab_chr[]= chr(127) ;
$string = str_replace($tab_chr, '', $string);
When having to deal with parsing an IIS4 or IIS5 metabase dump I wrote a simple function for converting those MS hexidecimal values into their ascii counter parts. Hopefully someone will find use for it.
<?php
function hex_decode($string) {
for ($i=0; $i < strlen($string); $i) {
$decoded .= chr(hexdec(substr($string,$i,2)));
$i = (float)($i)+2;
}
return $decoded;
}
?>
In addition to replacing Microsoft Windows smart quotes, as sgaston demonstrated on 2006-02-13, I replace all other Microsoft Windows characters using suggestions[1] published by character code specialist[2] Jukka Korpela.
<?php
$str = str_replace(chr(130), ',', $str); // baseline single quote
$str = str_replace(chr(131), 'NLG', $str); // florin
$str = str_replace(chr(132), '"', $str); // baseline double quote
$str = str_replace(chr(133), '...', $str); // ellipsis
$str = str_replace(chr(134), '**', $str); // dagger (a second footnote)
$str = str_replace(chr(135), '***', $str); // double dagger (a third footnote)
$str = str_replace(chr(136), '^', $str); // circumflex accent
$str = str_replace(chr(137), 'o/oo', $str); // permile
$str = str_replace(chr(138), 'Sh', $str); // S Hacek
$str = str_replace(chr(139), '<', $str); // left single guillemet
$str = str_replace(chr(140), 'OE', $str); // OE ligature
$str = str_replace(chr(145), "'", $str); // left single quote
$str = str_replace(chr(146), "'", $str); // right single quote
$str = str_replace(chr(147), '"', $str); // left double quote
$str = str_replace(chr(148), '"', $str); // right double quote
$str = str_replace(chr(149), '-', $str); // bullet
$str = str_replace(chr(150), '-', $str); // endash
$str = str_replace(chr(151), '--', $str); // emdash
$str = str_replace(chr(152), '~', $str); // tilde accent
$str = str_replace(chr(153), '(TM)', $str); // trademark ligature
$str = str_replace(chr(154), 'sh', $str); // s Hacek
$str = str_replace(chr(155), '>', $str); // right single guillemet
$str = str_replace(chr(156), 'oe', $str); // oe ligature
$str = str_replace(chr(159), 'Y', $str); // Y Dieresis
?>
[1] On the use of some MS Windows characters in HTML
http://www.cs.tut.fi/~jkorpela/www/windows-chars.html
[2] Unicode Explained by Jukka Korpela
http://www.amazon.com/dp/059610121X/
Secure password generator with a variable maximum amount of symbols.
<?php
function passwdGen($minLength = 8, $maxLength = 12, $maxSymbols = 2)
{
$symbolCount = 0;
srand((double)microtime() * 1000003);
for ($i = 0; $i < rand($minLength, $maxLength); $i++)
{
do
{
$char = rand(33, 126);
$symbolCount += $isSymbol = (!in_array($char, range(48, 57)) && !in_array($char, range(65, 90)) && !in_array($char, range(97, 122)));
if ($symbolCount <= $maxSymbols || !$isSymbol)
{
break;
}
}
while (true);
$passwd = sprintf('%s%c', isset($passwd) ? $passwd : NULL, $char);
}
return $passwd;
}
?>
Here is a function that's help me find what chr(number) outputs what character quicker than typing out 256 echo tags.
<?php
function listChr(){
for ($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{$tab}time</pre>";
-- HappyEvil
I needed to generate an invalid UTF-8 character for testing with JSON. This did the trick:
<?php
echo 'Bogus UTF-8 character at end' . chr(0xC6) ;
Another quick function to get unicode char by its code.
<?php
function unichr($dec)
{
if ($dec < 0x80)
{
$utf = chr($dec);
}
else if ($dec < 0x0800)
{
$utf = chr(0xC0 + ($dec >> 6));
$utf .= chr(0x80 + ($dec & 0x3f));
}
else if ($dec < 0x010000)
{
$utf = chr(0xE0 + ($dec >> 12));
$utf .= chr(0x80 + (($dec >> 6) & 0x3f));
$utf .= chr(0x80 + ($dec & 0x3f));
}
else if ($dec < 0x200000)
{
$utf = chr(0xF0 + ($dec >> 18));
$utf .= chr(0x80 + (($dec >> 12) & 0x3f));
$utf .= chr(0x80 + (($dec >> 6) & 0x3f));
$utf .= chr(0x80 + ($dec & 0x3f));
}
else
{
die("UTF-8 character size is more than 4 bytes");
}
return $utf;
}
echo unichr(0x263A);
?>
Simple password generation function using sprintf and the %c type specifier; which is the same as chr().
function genPass($len = 8) {
for ($i=0;$i<=$len;$i++) {
$passwd = sprintf('%s%c', isset($passwd) ? $passwd : NULL, rand(48, 122));
}
return $passwd;
}
[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.
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. :)
argument is automatically converted to integer, so chr('65') and chr(65) would both output the letter A
string mb_chr ( int $cp [, string $encoding ] )
Parameter List:
cp - character code (in decimal notation)
encoding - encoding (UTF-8, ASCII and so on)
We get the letter 'Ж' from the encoding UTF-8:
$sim = mb_chr(0x0416, 'UTF-8');
echo $sim; // Ж
Get the character '}' from the encoding ASCII:
$sim = mb_chr(125, 'ASCII');
echo $sim ; // }
It seems that php uses the table from here: http://ascii-code.com/
(and not from here: http://www.asciitable.com/ as suggested in the documentation) for codes from 128 to 255.
<?php
for ($i = 32; $i <= 255; $i++) {
echo chr($i);
}
?>
chr() with unicode support
<?php
function uchr ($codes) {
if (is_scalar($codes)) $codes= func_get_args();
$str= '';
foreach ($codes as $code) $str.= html_entity_decode('&#'.$code.';',ENT_NOQUOTES,'UTF-8');
return $str;
}
echo uchr(23383); echo '<br/>';
echo uchr(23383,215,23383); echo '<br/>';
echo uchr(array(23383,215,23383,215,23383)); echo '<br/>';
?>
I was looking for a simple method to construct excel like column identifiers e.g: A B .... AA AB AC etc, using chr() and modulo, but there is magic...
https://www.php.net/manual/en/language.operators.increment.php
So, this also works
<?php
$p = chr(65); // or simply $p = 'A';
for ($i = 1; $i < 53; $i++){
echo $p++ . " - ";
if ($i % 10 == 0) echo '</br>';
}
?>
Gives
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 - AA - AB - AC - AD -
AE - AF - AG - AH - AI - AJ - AK - AL - AM - AN -
AO - AP - AQ - AR - AS - AT - AU - AV - AW - AX -
AY - AZ -
The function chr() also accepts negative numbers as an ascii code, so chr(-number) is equal to chr((number%256)+256).
And for ascii code higher than 255 is chr(number%256)
We can test with a little script
<?php
for($i=-300; $i<300; $i++){
echo "Ascii $i\t" . ord(chr($i)) . "\n";
}
?>