php代码写为纯文本输出，为什么？

Question

I've installed apache server and php5 on linux, but am not able to get a simple php file executed and shown in browser. What I see in browser is this:

<?php echo 'hello';?>

Why is the php code not executed?

Here is the content of /etc/apache2/sites-available/default file:

<VirtualHost *:80>
    ServerAdmin webmaster@localhost

    DocumentRoot /var/www/public
    <Directory />
        Options FollowSymLinks
        AllowOverride All
    </Directory>
    <Directory /var/www/public>
        Options Indexes FollowSymLinks MultiViews
        AllowOverride All
        Order allow,deny
        allow from all
    </Directory>

    ScriptAlias /cgi-bin/ /usr/lib/cgi-bin/
    <Directory "/usr/lib/cgi-bin">
        AllowOverride All
        Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
        Order allow,deny
        Allow from all
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

And I have place my test php file in /var/www/public

Answer 1

Consider these:

• Is PHP installed?
• Is relevant apache module enabled (eg mod_php)?
• What is the file permission of PHP file? Can it be executed by the web server user?
• Is there any error message at apache or php error log?

Answer 2

Well you have the container missing for one,, here is a conditional with the echo call back.

if($result) {
       echo "success";
    }