Depending on the build process you selected, you should either end up
with a new PHP binary to be linked into your Web server (or run as CGI), or with an .so (shared object) file. If you compiled the
example file first_module.c as a shared object, your result file
should be first_module.so. To use it, you first have to copy
it to a place from which it's accessible to PHP. For a simple test procedure,
you can copy it to your htdocs directory and try it with
the source in Example 46-3.
If you compiled it into the PHP binary,
omit the call to dl(), as the module's
functionality is instantly available to your scripts.
For security reasons, you should not put your
dynamic modules into publicly accessible directories. Even though it can be
done and it simplifies testing, you should put them into a separate directory
in production environments.
Example 46-3. A test file for first_module.so.
// remove next comment if necessary
$param = 2;
$return = first_module($param);
print("We sent '$param' and got '$return'");
Calling this PHP file should output the following:
We sent '2' and got '2'
If required, the dynamic loadable module is loaded by calling the
dl() function. This function looks for the
specified shared object, loads it, and makes its functions
available to PHP. The module exports the function
first_module(), which accepts a single
parameter, converts it to an integer, and returns the result of the
If you've gotten this far, congratulations! You just built your
first extension to PHP.