# calling a script function via call_user_function

- Thread: https://externals.io/message/37027
- Original archive: https://news-web.php.net/php.internals/37027
- Started by Marshall Greenblatt on 2008-04-15T15:37:17+00:00
- Messages: 3
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## #37027 — Marshall Greenblatt — 2008-04-15T15:37:17+00:00

URL: https://externals.io/message/37027#37027

Hi All,

I'm building an embedded application that uses PHP scripting for internal
data processing.  It behaves as follows:

1. Provide arbitrary application-specified input parameters.
2. Execute a PHP script that manipulates those input parameters.
3. Retrieve the resulting return value.

I've attempted three possible approaches for achieving this goal.   Please
bear with me as I explain each of these approaches -- it's necessary in
order to understand the question :-)


Approach A:

Parse a script containing a PHP function, and then call that PHP function.

On the PHP side:

// some arbitrary user-defined PHP function
function myfunction( $pArg ) { return strtoupper( $pArg ); }

On the application side:

// do something to parse "myfunction" and cause it to be available via
call_user_function()
php_lint_script(&file_handle TSRMLS_CC);

zval funcname, retval;
zval *args[1];

INIT_ZVAL(retval);
INIT_ZVAL(funcname);

MAKE_STD_ZVAL(args[1]);
ZVAL_STRING(args[1], "the string to make uppercase", 0);

ZVAL_STRING(&funcname, "myfunction", 0);

// call the user function
if(call_user_function(EG(function_table), NULL, &funcname, &retval, 1, args
TSRMLS_CC) != FAILURE)
{
   // it worked
}

My problem with Approach A is that "php_lint_script", "php_execute_script",
etc, do not add the PHP function "myfunction" to the EG(function_table)
hash, so call_user_function() always fails.


Approach B:

Execute a PHP script and retrieve the return value without calling a
particular PHP function.

On the PHP side:

return strtoupper( $GLOBAL_VARIABLE );

On the application side:

php_register_variable("GLOBAL_VARIABLE", "the string to make uppercase",
 `NULL` TSRMLS_CC);

zval *retval;
php_execute_simple_script(&file_handle, &retval TSRMLS_CC);

My problem with Approach B is that the return zval from the
php_execute_simple_script() function always contains a true/false value
instead of whatever was returned using the 'return' construct from the code.


Approach C:

Similar to approach B, except call a module function to record the result.

On the PHP side:

record_return( strtoupper( $GLOBAL_VARIABLE ) );

On the application side, create a module that provides the "record_return"
function to record the return value for later usage.  This approach works.
However, if at all possible, I would prefer to use the PHP language 'return'
construct and somehow retrieve the resulting value.


Does anyone have any suggestions on how I could get either approach A or
approach B working?  Any input would be greatly appreciated.

I'm currently using PHP 5.2.4 for development -- I can upgrade to a newer
version if that would be beneficial.

Thanks,
Marshall

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## #37029 — Marshall Greenblatt — 2008-04-15T18:04:51+00:00

URL: https://externals.io/message/37027#37029 · In reply to: #37027

Hi All,

A correction to my earlier email.

On Tue, Apr 15, 2008 at 11:37 AM, Marshall Greenblatt <
magreenblatt@gmail.com> wrote:

>
> Approach B:
>
> Execute a PHP script and retrieve the return value without calling a
> particular PHP function.
>
> On the PHP side:
>
> return strtoupper( $GLOBAL_VARIABLE );
>
> On the application side:
>
> php_register_variable("GLOBAL_VARIABLE", "the string to make uppercase",
> `NULL` TSRMLS_CC);
>
> zval *retval;
> php_execute_simple_script(&file_handle, &retval TSRMLS_CC);
>
> My problem with Approach B is that the return zval from the
> php_execute_simple_script() function always contains a true/false value
> instead of whatever was returned using the 'return' construct from the code.
>
>
This approach does actually work as advertised.  I had a bug in my test code
:-).

However, that still leaves the original question -- how to call a function
defined in a PHP script using call_user_function() or similar?

Thanks,
Marshall

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## #37031 — Marshall Greenblatt — 2008-04-15T18:23:21+00:00

URL: https://externals.io/message/37027#37031 · In reply to: #37027

Hi All,

Pardon the noise.  All functions, including call_user_function(), now work
as expected.

Thanks,
Mashall