highlight_file

(PHP 4, PHP 5)

highlight_file -- Syntax highlighting of a file

Description

mixed highlight_file ( string filename [, bool return] )

The highlight_file() function prints out a syntax highlighted version of the code contained in filename using the colors defined in the built-in syntax highlighter for PHP.

If the second parameter return is set to TRUE then highlight_file() will return the highlighted code as a string instead of printing it out. If the second parameter is not set to TRUE then highlight_file() will return TRUE on success, FALSE on failure.

注: The return parameter became available in PHP 4.2.0. Before this time it behaved like the default, which is FALSE

注: Since PHP 4.2.1 this function is also affected by safe_mode and open_basedir.

注意

Care should be taken when using the highlight_file() function to make sure that you do not inadvertently reveal sensitive information such as passwords or any other type of information that might create a potential security risk.

Many servers are configured to automatically highlight files with a phps extension. For example, example.phps when viewed will show the syntax highlighted source of the file. To enable this, add this line to the httpd.conf:

AddType application/x-httpd-php-source .phps

See also highlight_string().


add a note add a note User Contributed Notes
showsource at gmail dot com
08-Apr-2006 08:18
Please, be aware of just using marlon at mbwp dot nl example to show the sourcecode
Do as told in this manual, "CAUTION", do some check on what code to highlight.
Simply just using $_GET["file"] is very bad.
marlon at mbwp dot nl
05-Mar-2006 09:06
I use the folowing code to highlight a file with line numbers:

<?php
echo "<table bgcolor=#EEEEEE><tr><td width=30>";
for (
$i = 1; $i <= count(file($_GET['file'])); $i++) echo $i.".<br>";
echo
"</td><td>";
highlight_file($_GET['file']);
echo
"</td></tr></table>";
?>
msn at toolskyn dot nl
26-Feb-2006 05:18
I use this (simple and dirty) function in my tutorials to add linenumbers. I let all the linenumbers in one table cell so it is easier for people to copy and paste the code (so they don't have to remove all the linenumbers):

<?php
function highlight_with_linenum($file)
{
  
//open handle, set vars
  
$handle = fopen($file, "r");
  
$count = 1;
  
$lines = "";

  
//look line ends
  
while ($thisone = fread($handle, "1"))
   {
       if (
$thisone == "\n")
       {
          
//add number
          
$lines .= $count . "<br />";
          
$count++;
       }
   }   
  
//close handle
  
fclose($handle);

  
//highlight contents
  
$contents = highlight_file($file, TRUE);
      
  
//print output (you could as well return now)
  
print '<table><tr><td><code>' .
        
$lines . '</code></td><td>' .
        
$contents . '</td></tr></table>';   
}
?>

Maybe it's of use to someone
contact at soulpass dot com
30-Jan-2006 06:52
A couple side notes about my previous post regarding security:

When I previewed the post, one of the backslashes in the regular expression disappeared, so I escaped it with another backslash, and then it worked in the preview. When the note posted, both backslashes appeared. Hopefully it will work in this update. The correct regular expression should be:

(^/|\./)

Please change it if you use the suggestion in the post below.

Also, it would be a good idea to hide your valid_files.txt using .htaccess. The updated .htaccess is as follows:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule ^(.+).phps$ index.php?f=$1 [L]
</IfModule>

<Files valid_files.txt>
order allow,deny
deny from all
</Files>

Sorry for the confusion...
contact at soulpass dot com
30-Jan-2006 05:20
I wanted to have a provision for highlighting source files that I have written. I also wanted people to be able to see the highlighted files from links on my blog (i.e. - the general public would be exposed to this as well).

Using highlight_string() would require me to update a second file every time I update the original script, but using highlight_file() brings up a major security risk!

I made the following code that goes at the top of highlighting script. Note that if you want to enable highlighting of a particular file, you'll have to add its path to a text file, as described below.

<?php
if (!isset($_GET['f']) || !file_exists($_GET['f'] . '.php') ||
   !
in_array($_GET['f'], array_map('trim', file('valid_files.txt'))) ||
  
preg_match('(^/|\\./)', $_GET['f']) || $_GET['f'] == 'index') {
   exit(
'Message to malicious visitor.');
}
?>

This just serves to keep people from trying to highlight files below the current directory (in my case, /source/). After this snippet, you could put some simple highlighting code that highlights the file using highlight_file($_GET['f'] . '.php');

Since I have the highlighting script saved as "index.php," in my case the script is called with /source/index.php?f=path/to/file

Notice that there is no .php extension. With this script, it appends ".php" automatically, thus effectively disallowing any file other than a PHP file to be highlighted (i.e., no .htaccess file will be highlighted on accident). The script also aborts if it detects a leading forward slash (/), or a period followed by a forward slash (./) anywhere in the requested file. I couldn't think of a case where ./ would be a valid request, but I could be wrong there.

Also note that a file called "valid_files.txt" goes in the same directory as the highlighting script. The format of this file is as follows:

path/to/file1
path/to/file2

Note that there is no extension here either because PHP is assumed in the script.

Finally, the script does not allow _itself_ to be highlighted. That's where "|| $_GET['f'] == 'index'" comes in. In case a security risk has not been covered here, we don't want anyone to see the measures, or lack thereof, that have been covered.

If you want to use an .htaccess file to clean up the URL, here's an idea for that:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteRule ^(.+).phps$ index.php?f=$1 [L]
</IfModule>

The .htaccess file goes in the same directory as the highlighting script (again, in my case, /source/). With it, the script may be called with this URI: /source/path/to/file.phps

This also adds another security benefit, as people may now see that the files appears to be ending in .phps.

I know it's a bit messy, but it's also a big deal to have the script as secure as possible. If anyone has any suggestions, please post them.
ganchev at design dot bg
13-Jan-2006 04:40
here's a simple way to add line numbers and
optionally highlight the one that has error on it.
just pass file and line arguments as GET variables

<?php

$f
= fopen($_GET['file'], "r");
$count = 1;
$line = "";
echo
"<table>";
while (
$c = fread($f, "1")) {
 
$line .= $c;
  if (
$c == "\n") {
   echo
"<tr style='background: " . (($_GET['line'] == $count) ? "#eedddd" : "#ffffff") . "'><td width='10%'>$count.</td><td>" . highlight_string($line, TRUE) . "</td></tr>\n";
  
$line = "";
  
$count++;
  }
}
echo
"</table>";
fclose($f);

?>
dtroi50 at gmail dot com
10-Jan-2006 06:39
If you run a site that has PHP script examples and you want to show the source, instead of a phps file, just add the following code to the top of the script.

<?php
if(count($_GET)) {
highlight_file(__FILE__);
}
?>

Then to make a source link use this:

<?php
print'<a href="?source">Show source</a>';
?>

Note that you don't have to use souce. If any get variables are set, it'll work.

-Tom
venski at gmail dot com
06-Jan-2006 09:21
I think it will be better if the variable contains the files that are allowed to be viewed. There can always befound a way to pass the name of a forbiddedn file that is not in the prohibited array.

Thus the code will be:

<?php
//array with files to allow
$allowed = array('index.php', 'menu.php', 'about.php');

// get the filename
$file = $_GET[file];
if(
file_Exists($file)){
   if(
in_array($file, $allowed)){
      
// check if it is part of the allowed list
      
highlight_file($file); //highlight file
  
}
   else{
      
// not allowed. just die. do not warn ;)
      
die("");
   }
}
else{
  
// file doesnt exist
  
echo "The file does not exist.";     
}
?>
trukin at gmail dot com
09-Dec-2005 11:46
this function can be a high security risk. use something like in_array to check if a file is prohibited to be shown on screen.

<?
$ar
= array('config.php', 'index.php', 'functions.php');    //array with files to denie
$file = $_GET[file];                    // iniziate the variable
if(file_Exists($file)){
   if(!
in_array($file, $ar)){    // check if it is prohibited
      
highlight_file($file); //highlight file
  
}else{    // prohibited file
      
echo "You do not have permision to see the ".$file." file.";
   }
}else{   
// file doesnt exist
  
echo "That file does not exist.";       
}
?>
Michael Newton (http://mike.eire.ca/)
07-Dec-2005 01:48
To print out the current file:

<?php highlight_file( __FILE__ ); ?>

Useful to add this as a header to all scripts (during development only, of course!)

<?php
if ($_GET['debug']) {
  
highlight_file( __FILE__ );
   exit;
}
?>
Vlad Alexa Mancini valexa at nextcode dot org
22-Feb-2005 03:19
Here is a small bash script that you can type at the console to make recursive symbolic .phps links for all your .php files starting at your curent directory

for f in `find -name '*.php'`; do ln -s `basename $f` $f's'; done

NOTE: You doubtedly want to do this at / as it will make such symlinks for all the php files on your filesystem

NOTE: This places the symlinks in the same directory as the php file that they are simlinking

And a simpler one that is not recursive and does the same thing but only for the php files in your current directory

for f in *.php; do ln -s $f $f's'; done
aidan at php dot net
26-Sep-2004 11:29
To add line numbers to source code, with optional function linking, use the below function:

http://aidan.dotgeek.org/lib/?file=function.highlight_file_linenum.php

A much more thorough and smarter, though slower version is here:

http://aidan.dotgeek.org/lib/?file=PHP_Highlight.php
csst0266 at cs dot uoi dot gr
14-Aug-2004 12:42
Here is a simple, yet useful, tip... Issuing the following command under a Unix-like OS:

ln -s your_script.php your_script.phps

Will result in the creation of a symbolic link (called your_script.phps) to the source code (your_script.php). This way you have (apart from the source code .php) the highlighted version of your script (.phps) accessible via your web browser.
zan at stargeek dot com
09-Jan-2003 02:24
here's how to use highlight_file to create a browseable archive of php scripts http://www.stargeek.com/scripts.php?script=7&cat=blog