How to parse console command strings in PHP with quotes - php

Question

For my game I'm coding a console that sends messages via AJAX and then receives output from the server.
For example, an input would be:
/testmessage Hello!
However, I would also need to parse the quotes e.g.:
/testmessage "Hello World!"
However, since I am simply exploding the string with spaces, PHP sees "Hello and World!" as separate parameters. How do I make PHP think that "Hello World!" is one parameter?
Right now I'm using the following code to parse the command:
// Suppose $inputstring = '/testmessage "Hello World!"';
$inputstring = substr($inputstring, 1);
$parameters = explode(" ", $inputstring);
$command = strtolower($parameters[0]);
switch ($command) {
case "testmessage":
ConsoleDie($parameters[1]);
break;
}
Thank you in advance.

Answer 1

This code will do what you want:
$params = preg_split('/(".*?")/', '/testmessage "Hello World!" 1 2 3', -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
$realParams = array();
foreach($params as $param)
{
$param = trim($param);
if ($param == '')
continue;
if (strpos($param, '"') === 0)
$realParams = array_merge($realParams, array(trim($param, '"')));
else
$realParams = array_merge($realParams, explode(' ', $param));
}
unset($params);
print_r($realParams);
that print:
array(5) {
[0]=>
string(12) "/testmessage"
[1]=>
string(14) "Hello World!"
[2]=>
string(1) "1"
[3]=>
string(1) "2"
[4]=>
string(1) "3"
}
Note: As you can see the first parameter is the command

Answer 2

Hope this code is more 'understandable'
$input = $inputstring = '/testmessage "Hello World!" "single phrase" level two';
// find the parameters surrounded with quotes, grab only the value (remove "s)
preg_match_all('/"(.*?)"/', $inputstring, $quotes);
// for each parameters with quotes, put a 'placeholder' like {{1}}, {{2}}
foreach ($quotes[1] as $key => $value) {
$inputstring = str_replace($value, "{{{$key}}}", $inputstring);
}
// then separate by space
$parameters = explode(" ", $inputstring);
// replace the placeholders {{1}} with the original value
foreach ($parameters as $key => $value) {
if (preg_match('{{(\d+)}}', $value, $matches)) {
$parameters[$key] = $quotes[1][$matches[1]];
}
}
// here you go
print_r($parameters);

Answer 3

I may not have understood you fully, but if you are assuming that the first word is always a command word, and anything following is 'one parameter' you could do the following
$inputstring = substr($inputstring, 1);
$parameters = explode(" ", $inputstring);
// shift the first element off the array i.e. the command
$command = strtolower(array_shift($parameters));
// Glue the rest of the array together
$input_message = implode($parameters);
switch ($command) {
case "testmessage":
ConsoleDie($input_message);
break;
}

Answer 4

You can use the Symfony Console Component which offers a secure and clean way to get console inputs.
For your use case you should do:
use Symfony\Component\Console\Input\ArgvInput;
use Symfony\Component\Console\Input\InputDefinition;
use Symfony\Component\Console\Input\InputArgument;
$input = new ArgvInput(null, new InputDefinition(array(
new InputArgument('message', InputArgument::REQUIRED)
)));
$parameters = $input->getArguments(); // $parameters['message'] contains the first argument