Need a very simple word filter

[ntin0s]

Hello I am a student and new to web developing so i need your help,

I need to put a word filter to my chatbot so it will echo only what the user wrote after the echo. So if the user types "echo Hello" the bot will echo "Hello".
Here is my code
<?php
echo $_REQUEST['msg'];
?>

Thanks in advance

[Schmoopy]

Without a great knowledge of regexp I'd do it this way:

// Input string ($_REQUEST['msg'] in your case)
$str = 'echo Hello';

// Get the first 4 characters of the string
$sub = substr($str, 0, 4);

// If it matches then echo out the latter part of the string
if($sub == 'echo')
    echo substr($str, 4);

// Echoes "Hello" 

Probably better using regexp, this will work as long as your just using "echo". If you need it to do different things depending on what the user types, like special keywords, then please mention it.

[ntin0s]

It's not working. I just need the word echo not to be displayed if is written

[Schmoopy]

I don't understand, that's what the above code does, as long as "echo" is at the beginning of the string, it will echo everything after it.

Please try to clarify exactly what you want it to do, with a few examples if possible.

[ntin0s]

Ok i found the problem it was my mistake because im confused with so many files. Anyway the problem now is that if i type " echo something" it always echoes "Hello". So your code works but it always answers Hello. I need it to answer back what i wrote after echo

[Schmoopy]

Oh right, I was just using $str as an example, this should work for you:

$str = $_REQUEST['msg'];

// Get the first 4 characters of the string
$sub = substr($str, 0, 4);

// If it matches then echo out the latter part of the string
if($sub == 'echo')
    echo substr($str, 4); 

[ntin0s]

Thank you very much and sorry for not understanding. Now when i type "echo something" it answers back "something" as i wanted to but there is another problem now. If i type just "hi" without the echo at the beginning it gives no answer, just blank.

[Schmoopy]

What do you want it to say if "echo" is not at the beginning?

[ntin0s]

if "echo" is not at the beginning i want it to say what i wrote. For example :
User says: hello bot
Bot says: hello bot

if
User says:echo hello bot
Bot says: hello bot

The problem now is that if
User says: hello bot
Bot says:

[Schmoopy]

<?php

$str = $_REQUEST['msg'];

// Get the first 4 characters of the string
$sub = substr($str, 0, 4);

// If it matches then echo out the latter part of the string
if($sub == 'echo')
    echo substr($str, 4);
else
    echo $str;
    
?>