capturing echo into a variable

Question

I am calling functions using dynamic function names (something like this)

$unsafeFunctionName = $_POST[\'function_name\'];
$safeFunctionName   = safe($unsafe         


        

Answer 1

In order to use the output value, if present, or the return value if not, you could simply modify your code like this:

ob_start();
$return_val = $safeFunctionName();
$echo_val = ob_get_clean();
$result = "<return_value>" . (strlen($echo_val) ? $echo_val : $return_val) . "</return_value>";

Answer 2

PHP: ob_get_contents

ob_start(); //Start output buffer
echo "abc123";
$output = ob_get_contents(); //Grab output
ob_end_clean(); //Discard output buffer

Answer 3

Let me preface this by saying:

Be careful with that custom function calling business. I am assuming you know how dangerous this can be which is why you're cleaning it somehow.

Past that, what you want is known as output buffering:

function hello() {
    print "Hello World";
}
ob_start();
hello();
$output = ob_get_clean();
print "--" . $output . "--";

(I added the dashes to show it's not being printed at first)

The above will output --Hello World--