rtrim

Description

string rtrim ( string str [, string charlist] )

注: The second parameter was added in PHP 4.1.0

This function returns a string with whitespace stripped from the end of str. Without the second parameter, rtrim() will strip these characters:

" " (ASCII 32 (0x20)), an ordinary space.
"\t" (ASCII 9 (0x09)), a tab.
"\n" (ASCII 10 (0x0A)), a new line (line feed).
"\r" (ASCII 13 (0x0D)), a carriage return.
"\0" (ASCII 0 (0x00)), the NUL-byte.
"\x0B" (ASCII 11 (0x0B)), a vertical tab.

You can also specify the characters you want to strip, by means of the charlist parameter. Simply list all characters that you want to be stripped. With .. you can specify a range of characters.

例子 1. Usage example of rtrim()


<?php

$text = "\t\tThese are a few words :) ...  ";
$trimmed = rtrim($text);
// $trimmed = "\t\tThese are a few words :) ..."
$trimmed = rtrim($text, " \t.");
// $trimmed = "\t\tThese are a few words :)"
$clean = rtrim($binary, "\x00..\x1F");
// trim the ASCII control characters at the end of $binary 
// (from 0 to 31 inclusive)

?>

See also trim() and ltrim().

add a note User Contributed Notes

YAS
08-May-2006 09:01


To remove an unwanted character - example "." - if exist or not.



The example above doesn't include the case where there is no "."

If there is not "." at the example above the last word will be deleted.



Have fun with this code.



<?php

$text = "This string contains. some unwanted characters on the end .";

$text = trim($text);

$last = $text{strlen($text)-1};

if (!strcmp($last,"."))

{

  $text = rtrim($text, 'a..z');

  $text = rtrim($text, '.');

}

?>

gbelanger at exosecurity dot com
18-Feb-2006 06:31


True, the Perl chomp() will only trim newline characters. There is, however, the Perl chop() function which is pretty much identical to the PHP rtrim()



---



Here's a quick way to recursively trim every element of an array, useful after the file() function :



# Reads /etc/passwd file an trims newlines on each entry

$aFileContent = file("/etc/passwd");

foreach ($aFileContent as $sKey => $sValue) {

    $aFileContent[$sKey] = rtrim($sValue);

}



print_r($aFileContent);

Unimagined at UnaimaginedDesigns dot Com
16-Jan-2005 04:49


I needed a way to trim all white space and then a few chosen strings from the end of a string.  So I wrote this class to reuse when stuff needs to be trimmed.  



<?php



class cleaner {



function cleaner ($cuts,$pinfo) {

$ucut = "0";

$lcut = "0";

while ($cuts[$ucut]) {

$lcut++;

$ucut++;

}

$lcut = $lcut - 1;

$ucut = "0";

$rcut = "0";

$wiy = "start";



while ($wiy) {



if ($so) {

$ucut = "0";

$rcut = "0";

unset($so);

}



if (!$cuts[$ucut]) {

$so = "restart";

} else {

$pinfo = rtrim($pinfo);

$bpinfol = strlen($pinfo);

$tcut = $cuts[$ucut];

$pinfo = rtrim($pinfo,"$tcut");

$pinfol = strlen($pinfo);



    if ($bpinfol == $pinfol) {

    $rcut++;

    if ($rcut == $lcut) {

    unset($wiy);

    }

    $ucut++;

    } else {

    $so = "restart";

    }

}

}



$this->cleaner = $pinfo;

}



}



$pinfo = "Well... I'm really bored...<br /><br>&nbsp;    \n\t&nbsp;<br><br /><br>&nbsp;    \r\r&nbsp;<br>\r<br /><br>\r&nbsp;    &nbsp;\n<br>      <br />\t";



$cuts = array('\n','\r','\t',' ',' ','&nbsp;','<br />','<br>','<br/>');



$pinfo = new cleaner($cuts,$pinfo);

$pinfo = $pinfo->cleaner;



print $pinfo;



?>



That class will take any string that you put in the $cust array and remove it from the end of the $pinfo string.  It's useful for cleaning up comments, articles, or mail that users post to your site, making it so there's no extra blank space or blank lines.

todd at magnifisites dot com
20-Aug-2003 09:19


This shows how rtrim works when using the optional charlist parameter:

rtrim reads a character, one at a time, from the optional charlist parameter and compares it to the end of the str string. If the characters match, it trims it off and starts over again, looking at the "new" last character in the str string and compares it to the first character in the charlist again. If the characters do not match, it moves to the next character in the charlist parameter comparing once again. It continues until the charlist parameter has been completely processed, one at a time, and the str string no longer contains any matches. The newly "rtrimmed" string is returned.

<?php

  // Example 1:

  rtrim('This is a short short sentence', 'short sentence');

  // returns 'This is a'

  // If you were expecting the result to be 'This is a short ',

  // then you're wrong; the exact string, 'short sentence',

  // isn't matched.  Remember, character-by-character comparison!

  // Example 2:

  rtrim('This is a short short sentence', 'cents');

  // returns 'This is a short short '

?>

HW
06-Jun-2003 09:32


$text = "This string contains some unwanted characters on the end.";

$text1 = rtrim($text, 'a..z');

$text1 = rtrim($text1, '.');

echo $text1; // only the '.' is trimmed.

$text2 = rtrim($text, 'a..z.');

echo $text2; // The whole last word is trimmed.

icon-phpnet at phy dot duke dot edu
02-Apr-2002 02:00


Not entirely. Perl's "chomp" will only remove the newline character, while rtrim without the second parameter will remove ALL whitespace. E.g. chomp("blah \n") will return "blah ", while rtrim("blah \n") will return "blah".

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