linux - php command works by running it static but not with a var between

Question

So my problem is this. When I try to run the following command nothing works, I get no error message and no output and and the file will not be transferred to the other device (here with the local host address as placeholder).

shell_exec('sshpass -p "'.$password.'" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1');

But if I pass the password in plain text in the command instead of using a variable (As shown below), it works as it should???

shell_exec('sshpass -p "Password" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1');

What I have already tried:

• I have tried to enter the password many times and it was always correct because I only had a simple one for testing purposes.
• And I have already tried first composing the command first, then saving it into another variable and then executing it

I have now tried a few things but somehow none of them works and I don't understand why because in the end these are 1:1 the same commands... Hopefully I will get smarter here

(The website runs on a Linux apache Server and I try to run this with php v. 7.3.19)

question from:https://stackoverflow.com/questions/65897549/php-command-works-by-running-it-static-but-not-with-a-var-between

Answer 1

So just look at the output of this code, it really will help you to debug

<?php

$password = "Password";

$commandOne = 'sshpass -p "'.$password.'" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1';
$commandTwo = 'sshpass -p "Password" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1';

echo $commandOne . PHP_EOL;
echo $commandTwo . PHP_EOL;

output

sshpass -p "Password" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1
sshpass -p "Password" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1

They are completly same when I use put "Pasword" in the password variable, so now just try to put your real pass and compare them, it will show you the problem
If you get the same result just try this in your code

<?php

$password = "Password";
$command = 'sshpass -p "'.$password.'" scp -o StrictHostKeyChecking=no /file.txt user@127.0.0.1:/home/user/ 2>&1';
shell_exec($command);