PHP Questions

The Apache configuration file is called httpd.conf.

include()
The include() function takes all the content in a specified file and includes it in the current file. If an error occurs, the include() function generates a warning, but the script will continue execution.

include_once()
File will not be included more than once. If we want to include a file once only and further calling of the file will be ignored then we have to use the PHP function include_once().

require()
The require() function is identical to include(), except that it handles errors differently. The require() generates a fatal error, and the script will stop.

require_once()
The required file is called only once when a page is open and further calling of the file will be ignored.

Permissions in PHP are very similar to UNIX. Each file has three types of permissions – Read, write and execute. Permissions can be changed using the change mode or CHMOD command. CHMOD is followed by 3 digit number specifying the permission type. CHMOD 777 is for Read, Write and execute.

Unnecessary permissions can be stripped off using UNMASK command.

Unmask (777);

$result = mysql_query($sql, $db_link);
$num_rows = mysql_num_rows($result);
echo "$num_rows rows found";