I need to include two variables inside the brackets below, whats the correct way to do this please?
//Needs two variables stated
listDebug();
The proper syntax for passing 2 variables to a function in PHP looks like this:
//Needs two variables stated
listDebug($var1, $var2);
Edit:
Judging by the comments, it looks like listDebug() is a library function that only accepts one argument and that you cannot edit. It logs information to a database and its single argument represents the string to be logged. In this case, you want to log the value of 2 separate values. The most straight forward approach would be simply concatenate them together like so:
listDebug($var1 . ' ' . $var2);
Is this what you are looking for?
listDebug($variable1,$variable2);
Will need more information if you are looking for more.
Seems like listDebug function implementation hasn't been written to accept more than one argument.
So you just cannot pass 2 arguments there. Call the function twice... or rewrite the function to respect second argument.
To get this to work instead I did listDebug($var1.$var2); Thanks for your replies and advice.
Related
I have the following code:
<?php
if(isset($_GET['function'])){
$_GET['function']();
}
?>
So if i entered this url:
http://localhost/?function=phpinfo
I will see the phpinfo function output on the screen.
can i have a way to concatenate 2 function in the url like this example:
http://localhost/?function=shell_exec('ls') AND phpinfo
So i want to see the first function output..
If you may asking why i need this, is because i am pen testing an web application with this situation..
Thanks for the help..
With your given code example it is not possible to do what you want. All your functions, so shellexec('ls') and phpinfo will be interpreted as one string, which is then called as a function in by calling it with added parenthis.
The only way that I can think of is using a variable parameter list, rather than just a single parameter. Get all the GET parameters in the function, and loop through them, executing each one.
This is my first question so please be patience.This question may sounds childish but I really want to know that what is a function in programming? How they are defined and how they are called to execute. I am just learning php. I have seen many functions like this
function myfunction () {
--------
--------
}
and another type function like this
function myfunction (some variables) {
------------
------------
}
I want to know what is the difference in between them? Any help and suggestions or any valuable link will be more appreciated. Before down voting this question any comments or any good learning link will be more helpful to me.
Those functions are exactly the same except for what they are provided (in terms of data). The first one requires no variables to be passed to it externally to run.
The second one has variables it does use that are passed from it externally, however, these may not be required as default values can be set for these variables.
A function in programming is used to perform a repetitive task, such as removing underscores from a string and making the first letter of each word a capital.
To define a variable, the simplest way is to do this:
function my_function () {
// Function code here
}
To call this function, you need to make sure it is accessible (e.g. included on the page), you simply do:
my_function();
That will execute the function and potentially return it's results.
You can also pass variables to functions as stated, but I recommend looking up tutorials on PHP functions.
https://www.google.co.uk/search?q=PHP+Functions ... lots of results for you :-)
This explanation is PHP specific, other languages may vary.
I've noticed a lot of PHP functions accept variables like this in any order.
<?php function_name('var8=hi, var2=hello'); ?>
Edit:
Like charles mentioned the string will actually look like this:
<?php function_name('var8=hi&var2=hello'); ?>
If I wanted to write a function like that, how would I do that?
You are just passing that function a string. For it to make any sense of that, it would have to parse the string to split up the key/value pairs. I'm not saying it's the best approach, but if you want to do that, you should use parse_str().
Note that this is not by any means a language feature of PHP, but I am just providing a means to handle what you've shown.
I am confused to as why you have your parameters in quotations.
When you create a function in php you are able to set default values by setting the variable, like so:
<?php
function foo($bar = 'pie')
{
return $bar;
}
echo foo(); // will echo pie
echo foo('bar'); //will output bar
?>
That's not quite a common idiom, but if there is a strong use case and makes your API more usable, why not. Short of using parse_str and the URL-encoded format, you could of course write a mini parser for that.
Pretty simple would also be abusing parse_ini_string for that:
function function_name($paramstr) {
extract(parse_ini_string(strtr($paramstr, ",", "\n")));
You'd probably still want default values; then also needs an array_merge etc.
(The reason this is not widely used is that you end up with only string scalars, and it prohibits the delimiters in the values as well. And not often are an arbitrary number of parameters really useful.)
This is stumping me.. I am writing components / library functions where it would be used for calling a lot of different functions, so I want it to make an array print out each variable to be passed into the function as an argument, like below but I am pretty sure that this isn't proper syntax.. thanks for any advice
$myfunction = function_name;
$myfunction (print_r($my_array));
You can use a built-in php function, reference from call-user-func-array
In addition to Bang Dao's answer:
If you need to get all function arguments as array, use func_get_args().
I'm trying to figure out how to know what has been done to a variable.
Here's an example:
function a($hello) {
$out .= strtoupper(ucwords(strtolower($hello)));
return $out;
}
echo function_trace('$hello') // returns array(strtoupper,ucwords,strtolower)
Thanks!
Matt
There's not really an easy way to do this, because variables don't store "state" or "history". Stack traces (where you probably got your inspiration from) are possible because they're generated from the existing execution stack, which is stored out of necessity to be able to properly unwind chains of function calls.
In addition, your example is trying to trace a function parameter - but that parameter variable is only defined within the scope of the function. Attempting to reference it outside of the function would result in the interpreter not knowing what variable you're trying to indicate - it'd think you're looking for a globally-scoped $hello, not the one used as an argument in the function.
There's no hook in PHP that does exactly what you want, but you can get a call stack with debug_backtrace():
http://php.net/manual/en/function.debug-backtrace.php
It's not possible to do exactly what you're asking for, but perhaps if you gave a bit more context about what you were hoping to do with that function trace, we could give some suggestions?