(PHP 5 <= 5.0.4)
php_check_syntax — Check the PHP syntax of (and execute) the specified file
$filename
   [, string &$error_message
  ] )
   Performs a syntax (lint) check on the specified 
   filename testing for scripting errors.
  
   This is similar to using php -l from the commandline except that this
   function will execute (but not output) the checked
   filename.
  
   For example, if a function is defined in filename,
   this defined function will be available to the file that executed 
   php_check_syntax(), but output from 
   filename will be suppressed.
  
Note:
For technical reasons, this function is deprecated and removed from PHP. Instead, use php -l somefile.php from the commandline.
filenameThe name of the file being checked.
error_message
       If the error_message parameter is used, it will
       contain the error message generated by the syntax check. 
       error_message is passed by 
       reference.
      
   Returns TRUE if the lint check passed, and FALSE if the link check
   failed or if filename cannot be opened.
  
| Version | Description | 
|---|---|
| 5.0.5 | This function was removed from PHP. | 
| 5.0.3 | Calling exit() after php_check_syntax() resulted in a Segfault. | 
| 5.0.1 | error_messageis passed by reference. | 
php -l somefile.php
The above example will output something similar to:
PHP Parse error: unexpected T_STRING in /tmp/somefile.php on line 81