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PHP : Function Reference : Miscellaneous Functions : php_strip_whitespace


Return source with stripped comments and whitespace (PHP 5)
string php_strip_whitespace ( string filename )

Returns the PHP source code in filename with PHP comments and whitespace removed. This may be useful for determining the amount of actual code in your scripts compared with the amount of comments. This is similar to using php -w from the commandline.



Path to the PHP file.

Return Values

The stripped source code will be returned on success, or an empty string on failure.


This function works as described as of PHP 5.0.1. Before this it would only return an empty string. For more information on this bug and its prior behavior, see bug report » #29606.


Example 1361. php_strip_whitespace() example

// PHP comment here

* Another PHP comment

echo        php_strip_whitespace(__FILE__);
// Newlines are considered whitespace, and are removed too:

The above example will output:

echo php_strip_whitespace(__FILE__); do_nothing(); ?>

Notice the PHP comments are gone, as are the whitespace and newline after the first echo statement.

Code Examples / Notes » php_strip_whitespace


With newlines stripped your HEREDOCs won't work.


This function can not be used to strip comments outside <?php ... ?>
// this comment will not be removed
// this comment will be removed


Notice: In my last comment for this function I failed to add some important parts of the function. So I have re-added it here. Feel free to delete my earlier comment. Thanks!
To use php_strip_whitespace in (PHP 4 >= 4.2.0) you could try the function below. This function also helps solve the issues with php_strip_whitespace not fully removing new lines and extra whitespace's in HTML when embedded with PHP.
if (!defined ('T_ML_COMMENT'))
if (!defined ('T_DOC_COMMENT'))
   define ('T_DOC_COMMENT', T_ML_COMMENT);
function StripWhitespace($sFileName)
   if ( !is_file($sFileName) )
       return false;
   $sContent = implode('', file($sFileName));
   $aTokens = token_get_all($sContent);
   $bLast = false;
   $sStr = '';
   for ( $i = 0, $j = count($aTokens); $i < $j; $i++ )
       if ( is_string($aTokens[$i]) )
           $bLast = false;
           $sStr .= $aTokens[$i];
           switch ( $aTokens[$i][0] )
               case T_COMMENT:
               case T_ML_COMMENT:
               case T_DOC_COMMENT:
               case T_WHITESPACE:
               if (!$bLast)
                   $sStr .= ' ';
                   $bLast = true;
                    $bLast = false;
                   $sStr .= $aTokens[$i][1];
   $sStr = trim($sStr);
   $sStr = str_replace("\n", "", $sStr);
   $sStr = str_replace("\r", "", $sStr);
   return $sStr;


Not only can this be used for JavaScript files, but also for:
* Java source code
* CSS (Style Sheets)
* Any file with C-style comments.


If you wish to just remove excess whitespace from a string, see the example "Strip whitespace" in the preg_replace documentation (

zvjezdan patz

I was given a report that was separated by spaces and asked to make graphs from it.  I needed to turn the report data into a csv in memory so I could manipulate it further.  
First needed to see the report, then need to strip out the whitespace, but leave one space between each item that I could convert to a column.
There were lots of complicated ways to do this.  I stumbled on something simple.
Say the report looks like this:
Monday    Tuesday    Wednesday    Thursday   Friday   Saturday   Sunday
1               5               7                    8               10         7              8        
7               15             4                    0               21         4              12
9               5               7                    9               0           9              43
The report is using spaces and not tabs to separate everything.  Assume it's a file called data.txt you can use the following to strip out the spaces and make it comma delimited:
$handle = @fopen("data.txt", "r");
if ($handle)
 while (!feof($handle))
   $buffer = fgets($handle, 4096);
   // this will search for 5 spaces and replace with 1, then 4, then 3, then 2
   // then only one will be left.  Replace that one space with a comma
   // then output with nl2br so you can see the line breaks
   print nl2br(str_replace(" ", ",",ereg_replace( '  ', ' ',ereg_replace( '   ', ' ', ereg_replace( '    ', ' ', ereg_replace( '     ',' ',$buffer ))))));
Hope that helps someone else.


I thought this was a nice function until I realised it wouldnt strip down html. As i'd been reading an article on compressing output to speed up delivery.
So I wrote a little one to do that for me. Here its is, incase people were looking for a html version. It may need tweaking, like with existing &nbsp;'s.
function strip_html($data)
// strip unecessary comments and characters from a webpages text
// all line comments, multi-line comments \\r \\n \\t multi-spaces that make a script readable.
// it also safeguards enquoted values and values within textareas, as these are required
$data=preg_replace_callback("/>[^<]*<\\/textarea/i", "harden_characters", $data);
$data=preg_replace_callback("/\\"[^\\"<>]+\\"/", "harden_characters", $data);
$data=preg_replace("/(\\/\\/.*\\n)/","",$data); // remove single line comments, like this, from // to \\n
$data=preg_replace("/(\\t|\\r|\\n)/","",$data);  // remove new lines \\n, tabs and \\r
$data=preg_replace("/(\\/\\*.*\\*\\/)/","",$data);  // remove multi-line comments /* */
$data=preg_replace("/(<![^>]*>)/","",$data);  // remove multi-line comments <!-- -->
$data=preg_replace('/(\\s+)/', ' ',$data); // replace multi spaces with singles
$data=preg_replace('/>\\s</', '><',$data);
$data=preg_replace_callback("/\\"[^\\"<>]+\\"/", "unharden_characters", $data);
$data=preg_replace_callback("/>[^<]*<\\/textarea/", "unharden_characters", $data);
return $data;
function harden_characters($array)
$safe=preg_replace('/\\n/', "%0A", $safe);
$safe=preg_replace('/\\t/', "%09", $safe);
$safe=preg_replace('/\\s/', "&nbsp;", $safe);
return $safe;
function unharden_characters($array)
$safe=preg_replace('/%0A/', "\\n", $safe);
$safe=preg_replace('/%09/', "\\t", $safe);
$safe=preg_replace('/&nbsp;/', " ", $safe);
return $safe;
The article code was similar to this, which shouldn't work as php_strip_whitespace takes a filename as input:-
// ob_start(); and output here
header('Content-Encoding: gzip');
echo $data;


Here's one for CSS:
function css_strip_whitespace($css)
 $replace = array(
   "#/\*.*?\*/#s" => "",  // Strip C style comments.
   "#\s\s+#"      => " ", // Strip excess whitespace.
 $search = array_keys($replace);
 $css = preg_replace($search, $replace, $css);
 $replace = array(
   ": "  => ":",
   "; "  => ";",
   " {"  => "{",
   " }"  => "}",
   ", "  => ",",
   "{ "  => "{",
   ";}"  => "}", // Strip optional semicolons.
   ",\n" => ",", // Don't wrap multiple selectors.
   "\n}" => "}", // Don't wrap closing braces.
   "} "  => "}\n", // Put each rule on it's own line.
 $search = array_keys($replace);
 $css = str_replace($search, $replace, $css);
 return trim($css);
A word on the first regular expression, since it took me a while.
It strips C style comments. /* Like this. */
^         ^
The pound signs at either end quote the regex. They don't match anything.
The s at the very end sets the PCRE_DOTALL modifier. More info here:
#  /\*  .*?  \*/  #s
   1    2    3
The expression itself consists of 3 parts:
1. the opening comment sequence, represented by     /\*
2. everything in the middle, represented by         .*?
3. and the closing comment sequence, represented by \*/
  ^    ^
The comment asterisks are escaped. If I had used the more common / for PCRE quoting I would've had to escape those too.
The ? prevents the regex from being greedy. See halfway down this page:


Beware that this function uses the output buffering mechanism.
If you give a 'stream wrapped' path as argument, anything echoed by the stream wrapper during this call (e.g. trace messages) won't be displayed to the screen but will be inserted in php_strip_whitespace's result.
If you execute this stripped code later, it will display the messages which should have been output during php_strip_whitespace's execution !


@Zvjezdan Patz
Your script is quite the strain on the server. You might just want to do this (just the print line):
print preg_replace("/[ ]{1,}/", ",", trim($str));

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