If you wish to just remove excess whitespace from a string, see the example "Strip whitespace" in the preg_replace documentation (http://www.php.net/manual/en/function.preg-replace.php).
(PHP 5, PHP 7)
php_strip_whitespace — Return source with stripped comments and whitespace
$filename
)
Returns the PHP source code in filename with
PHP comments and whitespace removed. This may be useful for determining the
amount of actual code in your scripts compared with the amount of comments.
This is similar to using php -w from the
commandline.
filenamePath to the PHP file.
The stripped source code will be returned on success, or an empty string on failure.
Note:
This function works as described as of PHP 5.0.1. Before this it would only return an empty string. For more information on this bug and its prior behavior, see bug report » #29606.
Example #1 php_strip_whitespace() example
<?php
// PHP comment here
/*
* Another PHP comment
*/
echo php_strip_whitespace(__FILE__);
// Newlines are considered whitespace, and are removed too:
do_nothing();
?>
The above example will output:
<?php echo php_strip_whitespace(__FILE__); do_nothing(); ?>
Notice the PHP comments are gone, as are the whitespace and newline after the first echo statement.
If you wish to just remove excess whitespace from a string, see the example "Strip whitespace" in the preg_replace documentation (http://www.php.net/manual/en/function.preg-replace.php).
With this function You can compress Your PHP source code.
<?php
function compress_php_src($src) {
// Whitespaces left and right from this signs can be ignored
static $IW = array(
T_CONCAT_EQUAL, // .=
T_DOUBLE_ARROW, // =>
T_BOOLEAN_AND, // &&
T_BOOLEAN_OR, // ||
T_IS_EQUAL, // ==
T_IS_NOT_EQUAL, // != or <>
T_IS_SMALLER_OR_EQUAL, // <=
T_IS_GREATER_OR_EQUAL, // >=
T_INC, // ++
T_DEC, // --
T_PLUS_EQUAL, // +=
T_MINUS_EQUAL, // -=
T_MUL_EQUAL, // *=
T_DIV_EQUAL, // /=
T_IS_IDENTICAL, // ===
T_IS_NOT_IDENTICAL, // !==
T_DOUBLE_COLON, // ::
T_PAAMAYIM_NEKUDOTAYIM, // ::
T_OBJECT_OPERATOR, // ->
T_DOLLAR_OPEN_CURLY_BRACES, // ${
T_AND_EQUAL, // &=
T_MOD_EQUAL, // %=
T_XOR_EQUAL, // ^=
T_OR_EQUAL, // |=
T_SL, // <<
T_SR, // >>
T_SL_EQUAL, // <<=
T_SR_EQUAL, // >>=
);
if(is_file($src)) {
if(!$src = file_get_contents($src)) {
return false;
}
}
$tokens = token_get_all($src);
$new = "";
$c = sizeof($tokens);
$iw = false; // ignore whitespace
$ih = false; // in HEREDOC
$ls = ""; // last sign
$ot = null; // open tag
for($i = 0; $i < $c; $i++) {
$token = $tokens[$i];
if(is_array($token)) {
list($tn, $ts) = $token; // tokens: number, string, line
$tname = token_name($tn);
if($tn == T_INLINE_HTML) {
$new .= $ts;
$iw = false;
} else {
if($tn == T_OPEN_TAG) {
if(strpos($ts, " ") || strpos($ts, "\n") || strpos($ts, "\t") || strpos($ts, "\r")) {
$ts = rtrim($ts);
}
$ts .= " ";
$new .= $ts;
$ot = T_OPEN_TAG;
$iw = true;
} elseif($tn == T_OPEN_TAG_WITH_ECHO) {
$new .= $ts;
$ot = T_OPEN_TAG_WITH_ECHO;
$iw = true;
} elseif($tn == T_CLOSE_TAG) {
if($ot == T_OPEN_TAG_WITH_ECHO) {
$new = rtrim($new, "; ");
} else {
$ts = " ".$ts;
}
$new .= $ts;
$ot = null;
$iw = false;
} elseif(in_array($tn, $IW)) {
$new .= $ts;
$iw = true;
} elseif($tn == T_CONSTANT_ENCAPSED_STRING
|| $tn == T_ENCAPSED_AND_WHITESPACE)
{
if($ts[0] == '"') {
$ts = addcslashes($ts, "\n\t\r");
}
$new .= $ts;
$iw = true;
} elseif($tn == T_WHITESPACE) {
$nt = @$tokens[$i+1];
if(!$iw && (!is_string($nt) || $nt == '$') && !in_array($nt[0], $IW)) {
$new .= " ";
}
$iw = false;
} elseif($tn == T_START_HEREDOC) {
$new .= "<<<S\n";
$iw = false;
$ih = true; // in HEREDOC
} elseif($tn == T_END_HEREDOC) {
$new .= "S;";
$iw = true;
$ih = false; // in HEREDOC
for($j = $i+1; $j < $c; $j++) {
if(is_string($tokens[$j]) && $tokens[$j] == ";") {
$i = $j;
break;
} else if($tokens[$j][0] == T_CLOSE_TAG) {
break;
}
}
} elseif($tn == T_COMMENT || $tn == T_DOC_COMMENT) {
$iw = true;
} else {
if(!$ih) {
$ts = strtolower($ts);
}
$new .= $ts;
$iw = false;
}
}
$ls = "";
} else {
if(($token != ";" && $token != ":") || $ls != $token) {
$new .= $token;
$ls = $token;
}
$iw = true;
}
}
return $new;
}
?>
For example:
<?php
$src = <<<EOT
<?php
// some comment
for ( $i = 0; $i < 99; $i ++ ) {
echo "i=${ i }\n";
/* ... */
}
/** ... */
function abc() {
return "abc";
};
abc();
?>
<h1><?= "Some text " . str_repeat("_-x-_ ", 32);;; ?></h1>
EOT;
var_dump(compress_php_src($src));
?>
And the result is:
string(125) "<?php for(=0;<99;++){echo "i=\n";}function abc(){return "abc";};abc(); ?>
<h1><?="Some text ".str_repeat("_-x-_ ",32)?></h1>"
It should be pointed out that this function does not work on files that make use of the short tag notation (<?).
Beware that this function uses the output buffering mechanism.
If you give a 'stream wrapped' path as argument, anything echoed by the stream wrapper during this call (e.g. trace messages) won't be displayed to the screen but will be inserted in php_strip_whitespace's result.
If you execute this stripped code later, it will display the messages which should have been output during php_strip_whitespace's execution !
I was looking earlier for a way to strip php comments from my source files but didn't come up with much. I wrote the following function to do the trick using the tokenizer. I've tested in on an entire phpMyAdmin install and it worked fine afterward... so it should be good to go. You may also specify any number of tokens to strip such as T_WHITESPACE rather the default of T_COMMENT and T_DOC_COMMENT.
Hopefully someone finds it useful.
<?php
function strip_tokens($code) {
$args = func_get_args();
$arg_count = count($args);
// if no tokens to strip have been specified then strip comments by default
if( $arg_count === 1 ) {
$args[1] = T_COMMENT;
$args[2] = T_DOC_COMMENT;
}
// build a keyed array of tokens to strip
for( $i = 1; $i < $arg_count; ++$i )
$strip[ $args[$i] ] = true;
// set a keyed array of newline characters used to preserve line numbering
$newlines = array("\n" => true, "\r" => true);
$tokens = token_get_all($code);
reset($tokens);
$return = '';
$token = current($tokens);
while( $token ) {
if( !is_array($token) )
$return.= $token;
elseif( !isset($strip[ $token[0] ]) )
$return.= $token[1];
else {
// return only the token's newline characters to preserve line numbering
for( $i = 0, $token_length = strlen($token[1]); $i < $token_length; ++$i )
if( isset($newlines[ $token[1][$i] ]) )
$return.= $token[1][$i];
}
$token = next($tokens);
} // while more tokens
return $return;
} // function
?>