Remove all string from double dash onward in php

Question

Let's assume i have this 3 php variables

 $var1 = 'my:command --no-question --dry-run=false';
 $var2 = 'another:command create somefile';
 $var3 = 'third-command --simulate=true';

How can I clean up the variable containing double dash without affecting $var2.

If i use substr, it will remove dash from $var1 and $var3 but $var2 will become empty

>>> preg_replace('/[ \=\-]/', '_', substr($var1, 0, strpos($var1, " --")))
=> "my:command"
>>> preg_replace('/[ \=\-]/', '_', substr($var2, 0, strpos($var2, " --")))
=> ""
>>> preg_replace('/[ \=\-]/', '_', substr($var3, 0, strpos($var3, " --")))
=> "third-command"

Expected result:

>>> $var1
=>  "my:command"

>>> $var2
=>  "another:command_create_somefile"

>>> $var3
=>  "third_command"

Answer 1

No need for regex:

<?php
$arr = [
    'my:command --no-question --dry-run=false',
    'another:command create somefile',
    'third-command --simulate=true'
];

foreach( $arr as $command )
{
    echo str_replace( ' ', '_', trim( explode( '--', $command )[ 0 ] ) ).PHP_EOL;
}

Output:

my:command
another:command_create_somefile
third-command