View the PHP opcode steps with PHP extension vld

First download the latest version of the vld extension:

 
~/public_html/php-5.3.13/ext> wget http://pecl.php.net/get/vld-0.11.2.tgz 
~/public_html/php-5.3.13/ext> tar zxvf vld-0.11.2.tgz 
~/public_html/php-5.3.13/ext> cd vld-0.11.2/ 

Next, compile and install the vld extension:

 
~/public_html/php-5.3.13/ext/vld-0.11.2> phpize 
~/public_html/php-5.3.13/ext/vld-0.11.2> ./configure --with-php-config=/usr/local/services/php/bin/php-config --enable-vld 
~/public_html/php-5.3.13/ext/vld-0.11.2> make 
~/public_html/php-5.3.13/ext/vld-0.11.2> sudo make install 
Installing shared extensions: /usr/local/services/php/lib/php/extensions/no-debug-non-zts-20090626/ 

Finally, copy the generated vld.so into the extension_dir directory:

 
~/public_html/php-5.3.13/ext/vld-0.11.2> cd /usr/local/services/php/lib/php/extensions/no-debug-non-zts-20090626/ 
/usr/local/services/php/lib/php/extensions/no-debug-non-zts-20090626> sudo cp vld.so /usr/local/services/php/extensions/ 

Then modify the php.ini file to add the following configuration:

 
extension=vld.so 

Next create the test.php file:

 
<?php 
$a = "hello world"; 
echo $a . PHP_EOL; 

To execute using cli, see the opcode generated:

 
~/public_html> php -dvld.active=1 test.php 
Finding entry points 
Branch analysis from position: 0 
Return found 
filename: /home/zhanhailiang/public_html/test.php 
function name: (null) 
number of ops: 4 
compiled vars: !0 = $a 
line # * op fetch ext return operands 
--------------------------------------------------------------------------------- 
3 0 > ASSIGN !0, 'hello+world' 
5 1 CONCAT ~1 !0, '%0A' 
2 ECHO ~1 
6 3 > RETURN 1 
branch: # 0; line: 3- 6; sop: 0; eop: 3 
path #1: 0, 
hello world