chunk_split()

(PHP 4, PHP 5, PHP 7)

将字符串分割成小块

说明

chunk_split(string $body[,int $chunklen= 76[,string $end= "rn"]]) : string

使用此函数将字符串分割成小块非常有用。例如将base64_encode()的输出转换成符合 RFC 2045 语义的字符串。它会在每$chunklen个字符后边插入$end。

参数

$body

要分割的字符。

$chunklen

分割的尺寸。

$end

行尾序列符号。

返回值

返回分割后的字符。

范例

Example #1chunk_split()例子

<?php
// 使用 RFC 2045 语义格式化 $data
$new_string = chunk_split(base64_encode($data));
?>

参见

• str_split()将字符串转换为数组
• explode()使用一个字符串分割另一个字符串
• split() 用正则表达式将字符串分割到数组中
• wordwrap()打断字符串为指定数量的字串
• » RFC 2045

An alternative for unicode strings;
<?php
function chunk_split_unicode($str, $l = 76, $e = "\r\n") {
  $tmp = array_chunk(
    preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY), $l);
  $str = "";
  foreach ($tmp as $t) {
    $str .= join("", $t) . $e;
  }
  return $str;
}
$str = "Yarım kilo çay, yarım kilo şeker";
echo chunk_split($str, 4) ."\n";
echo chunk_split_unicode($str, 4);
?>
Yar�
�m k
ilo 
çay
, ya
rım
 kil
o ş
eker
Yarı
m ki
lo ç
ay, 
yarı
m ki
lo ş
eker

As an alternative for qeremy [atta] gmail [dotta] com
There is much shorter way for binarysafe chunking of multibyte string:
<?php
function word_chunk($str, $len = 76, $end = "\n") {
  $pattern = '~.{1,' . $len . '}~u'; // like "~.{1,76}~u"
  $str = preg_replace($pattern, '$0' . $end, $str);
  return rtrim($str, $end);
}
$str = 'русский';
echo chunk_split($str, 3) ."\n";
echo word_chunk($str, 3) . "\n";
?>
р�
�с
с�
�и
й
рус
ски
й

I'm not sure what versions this also occurs in but the output of chunk_split() in PHP 5.0.4 does not match the output in other versions of PHP.
In all versions of PHP I have used, apart from 5.0.4 chunk_split() adds the separator (\r\n) to the end of the string. But in PHP 5.0.4 this does not happen. This had a fairly serious impact on a library I maintain so it may also affect others who are not aware of this.

The description of the function is slightly inaccurate. A trailing $end is also added.

the best way to solve the problem with the last string added by chunk_split() is:
<?php
$string = '1234';
substr(chunk_split($string, 2, ':'), 0, -1);
// will return 12:34
?>

If you are using UTF-8 charset you will face a problem with Arabic language
to solve this problem i used this function
<?php
function chunk_split_($text,$length,$string_end)
{
  $text = iconv("UTF-8","windows-1256",$text);
  $text = str_split($text);
  foreach($text as $val)
  {
    if($a !== $val)
    {
      $a = $val;
      $x = 0;
    }else{
      $a = $val;
      $x++;
    }
    if($x > $length)
    {
      $new_text .= $val.$string_end;
      $x = 0;
    }else
    {
       $new_text .= $val;
    }
    
  }
  $new_text = iconv("windows-1256","UTF-8",$new_text);
  return $new_text;
}
?>

Not quite completely obvious, but... 
you can un_chunk_split() by:
$long_str = str_replace( "\r\n", "", $chunked_str );

"version" of chunk_split for cyrillic characters in UTF-8
public function UTFChunk($Text,$Len = 10,$End = "\r\n")
{
  if(mb_detect_encoding($Text) == "UTF-8")
  {
    return mb_convert_encoding(
        chunk_split(
          mb_convert_encoding($Text, "KOI8-R","UTF-8"), $Len,$End
        ),
        "UTF-8", "KOI8-R"
      );
  } else
  {
    return chunk_split($Text,$Len,$End);
  }
}
this is example for russian language

another way to group thousands in a number, which is much simpler, is built into PHP :)
www.php.net/number_format

Important note is the maximum line length and the recommended one. The standard says:
"Lines in a message MUST be a maximum of 998 characters excluding the CRLF, but it is RECOMMENDED that lines be limited to 78 characters excluding the CRLF. "
See PHP manual for chunk_split() Which is set to 76 characters long chunk and "\r\n" at the end of line by default.

Here's a version of Chunk Split I wrote that will not split html entities. Useful if you need to inject something in html (in my case, <wbr/> tags to allow for long text wrapping).
<?php
function HtmlEntitySafeSplit($html,$size,$delim)
{
 $pos=0;
 for($i=0;$i<strlen($html);$i++)
 {
  if($pos >= $size && !$unsafe)
  {
   $out.=$delim;
   $unsafe=0;
   $pos=0;
  }
  $c=substr($html,$i,1);
  if($c == "&")
   $unsafe=1;
  elseif($c == ";")
   $unsafe=0;
  $out.=$c;
  $pos++;
 }
 return $out;
}
?>

>> chunk_split will also add the break _after_ the last occurence.
this should be not the problem 
substr(chunk_split('FF99FF', 2, ':'),0,8);
will return FF:99:FF

I've found this quite useful for simulating various kinds of shuffles with cards. It is humorous but can imitate multiple deck cuts and other (imperfectly) random events.
<?php
function truffle_shuffle($body, $chunklen = 76, $end = "\r\n")
{
   $chunk = chunk_split($body, $chunklen, "-=blender=-");
   $truffle = explode("-=blender=-",$chunk);
   $shuffle = shuffle($truffle);
   $huknc = implode($end,$shuffle);
   return $huknc;
}
?>

When using ssmtp for simple command line mailing:
$mail_to = "destination@emailbox.com";
$msg = "this would be an actual base64_encoded gzip msg";
$date = date(r);
$mail = "X-FROM: root@sender.org \n";
$mail .= "X-TO: ".$mail_to. " \n";
$mail .= "To: ".$mail_to. " \n";
$mail .= "Date: $date \n";
$mail .= "From: root@sender.org \n";
$mail .= "Subject: lifecheck \n";
$mail .= $msg." \n";
exec("echo '$mail'  |  /usr/sbin/ssmtp ".$mail_to);
be sure to invoke chunk_split() on your message body - ssmtp becomes unhappy with long lines and will subsequently trash your message.

In reply to "adrian at zhp dot inet dot pl" digit grouping function:
<?php
  $number = strrev(chunk_split (strrev($number), 3,' '));
  //If $number is '1234567', result is '1 234 567'.
?>
There is a much more simple way of doing this, by using the built-in number_format() function. 
<?php 
  $number = number_format($number,2,"."," ");
  //This will round $number to 2 decimals, use the dot (".")
  //as decimal point, and the space (" ") as thousand sepparator.
?>

This function is very simple and many other functions make this on PHP 5 and even some ones in 4 the good think about this one is that work on php 3.0.6 and 4 
function split_hjms_chars($xstr, $xlenint, $xlaststr)
{
  $texttoshow = chunk_split($xstr,$xlenint,"\r\n"); 
  $texttoshow = split("\r\n",$texttoshow);
  $texttoshow = $texttoshow[0].$xlaststr;
  return $texttoshow;
}
// For use 
echo split_hjms_chars("This is your text",6,"...");
// Will return
This i...
It is useful to cut long text on preview lists and if the server it's old.
Hope it helps some one. Hans Svane

Well I have been having issues with a shoutbox I am coding it would keep expanding the <TD> if there were large words in it but I fixed it with this:
function PadString($String){
  $Exploded = explode(" ", $String);
  $Max_Parts = count($Exploded);
  
  $CurArray = 0;
  $OutString = '';
  while($CurArray<=$Max_Parts)
  {
    $Peice_Size = strlen($Exploded[$CurArray]);
    if($Peice_Size>15)
    {
      $OutString .= chunk_split($Exploded[$CurArray], 12, " ");
      $CurArray++;
    } else {
      $OutString .= " ".$Exploded[$CurArray];
      $CurArray++;
    }
  }
  
  return $OutString;
}

@Royce
I think this is better, since you can still use the ampersand in your text:
<?php
function HtmlEntitySafeSplit($html,$size,$delim)
{
 $pos=0;
 for($i=0;$i<strlen($html);$i++)
 {
  if($pos >= $size && !$unsafe)
  {
   $out.=$delim;
   $unsafe=0;
   $pos=0;
  }
  $c=substr($html,$i,1);
  if($c == "&")
   $unsafe=1;
  elseif($c == ";")
   $unsafe=0;
  elseif($c == " ")
   $unsafe=0;
  $out.=$c;
  $pos++;
 }
 return $out;
}
?>

chunk_split() is not multibyte safe. If you ever run into needing the function that is multibyte safe, here you go:
<?php
function mbStringToArray ($str) {
  if (empty($str)) return false;
  $len = mb_strlen($str);
  $array = array();
  for ($i = 0; $i < $len; $i++) {
    $array[] = mb_substr($str, $i, 1);
  }
  return $array;
}
function mb_chunk_split($str, $len, $glue) {
  if (empty($str)) return false;
  $array = mbStringToArray ($str);
  $n = 0;
  $new = '';
  foreach ($array as $char) {
    if ($n < $len) $new .= $char;
    elseif ($n == $len) {
      $new .= $glue . $char;
      $n = 0;
    }
    $n++;
  }
  return $new;
}
?>

To phpkid:
This is a much simpler solution.
<?php
function longWordWrap($string) {
  $string = str_replace("\n", "\n ", $string); // add a space after newline characters, so that 2 words only seperated by \n are not considered as 1 word
  $words = explode(" ", $string); // now split by space
  foreach ($words as $word) {
    $outstring .= chunk_split($word, 12, " ") . " ";
  }
  return $outstring;
}
?>