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Comment by rll | Hacker News Reader

Yup, people often miss that PHP is modal and that the default mode is simply to output. So if you put Hello World in a file it actually compiles to these opcodes:

    ECHO      'Hello+World%0A'
    RETURN    1

Which is identical to the opcodes produced by putting <?php echo "Hello World"; ?> into a file.

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No, it's not identical.

    $ echo -n "<?php echo 'Hello World'; ?>" > hello.php
    $ php -d vld.active=1 -d vld.execute=0 -f hello.php
    line     # *  op                           fetch          ext  return  operands
    ---------------------------------------------------------------------------------
    1     0  >   ECHO                                                     'Hello+World'
          1    > RETURN                                                   1

    $ echo -n "Hello World" > hello.php
    $ php -d vld.active=1 -d vld.execute=0 -f hello.php
    1     0  >   ECHO                                                     'Hello+World'
          1    > RETURN                                                   1

    $ echo "<?php echo 'Hello World'; ?>" > hello.php 
    $ php -d vld.active=1 -d vld.execute=0 -f hello.php
    1     0  >   ECHO                                                     'Hello+World'
    2     1    > RETURN                                                   1

    $ echo "Hello World" > hello.php 
    $ php -d vld.active=1 -d vld.execute=0 -f hello.php
    2     0  >   ECHO                                                     'Hello+World%0A'
          1    > RETURN                                                   1

PHP 5.3.10-1ubuntu3.6 / Zend Engine v2.3.0 / vld-0.11.2

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