深入理解PHP原理之执行周期分析

[root@localhost software]# tar zxvf vld-0.9.1.tgz.gz
[root@localhost vld-0.9.1]# /usr/local/php/bin/phpize
[root@localhost vld-0.9.1]# ./configure --with-php-config=/usr/local/php/bin/php-config
[root@localhost vld-0.9.1]# make install //不需要make

<?php
  echo 'hello, world.';
?>

[root@localhost html]# /usr/local/php/bin/php -dvld.active=1 hello.php
Branch analysis from position: 0
Return found
filename:    /var//html/hello.php
function name: (null)
number of ops: 3
piled vars: none
line   # op              fetch     ext return operands
-------------------------------------------------------------------------------
  2   0 ECHO                           'hello%2C+world.'
  4   1 RETURN                          1
     2 ZEND_HANDLE_EXCEPTION
hello, world.

[root@localhost html]# vi vld.php
<?php
  $i = "This is a string";
  //I am ments
  echo $i. ' that has been echoed on screen';
?>

[root@localhost html]# /usr/local/php/bin/php -dvld.active=1 vld.php
Branch analysis from position: 0
Return found
filename:    /var//html/vld.php
function name: (null)
number of ops: 5
piled vars: !0 = $i
line   # op              fetch     ext return operands
-------------------------------------------------------------------------------
  3   0 ASSIGN                          !0, 'This+is+a+string'
  7   1 CONCAT                      ~1  !0, '+that+has+been+echoed+on+screen'
     2 ECHO                           ~1
 10  3 RETURN                          1
     4 ZEND_HANDLE_EXCEPTION
This is a string that has been echoed on screen