How to get response from 'apt remove' via shell_exec with PHP or Python?

Question

With the shell_exec command I can get an answer if the result of the executed command is a single text:

shel_exec('dpkg -l > list-softwares-dpkg.txt');

How to have the answer (in PHP or Python, you would need another command to have an answer ?) to execute a command when the answer is not a single text as in the example:

shel_exec('apt remove pacote_exemplo > removed-package.txt');

Obs In the example it executes and uninstalls, however I cannot know if the command was executed or not.

Answer 1

The popen other than exec and similar may interact similar to a Handler file I/O, probably with it will be able to catch the whole "exit", for example:

$response = '';
$handle = popen('apt-get remove ' . $package . ' 2>&1', 'r');

if ($handle) {
    while (feof($handle) === false) {
        $response .= fgets($handle); //Pega até encontrar uma quebra de linha
    }

    pclose($handle);
} else {
    die('Erro ao executar o programa');
}

if (empty($response)) {
    die('Resposta voltou vazia');
}

var_dump($response);

An example with ping (which is something that returns the output one by one):

<?php
$response = '';
$handle = popen('ping 127.0.0.1', 'r');

if ($handle) {
    while (feof($handle) === false) {
        $response .= fgets($handle); //Pega até encontrar uma quebra de linha
    }

    pclose($handle);
} else {
    die('Erro ao executar o programa');
}

if (empty($response)) {
    die('Resposta voltou vazia');
}

var_dump($response);

If you want to show the result directly in the output (output) do the echo within the while, thus:

<?php
$response = '';
$handle = popen('ping 127.0.0.1', 'r');

if ($handle) {
    while (feof($handle) === false) {
        echo fgets($handle); //Pega até encontrar uma quebra de linha
    }

    pclose($handle);
} else {
    die('Erro ao executar o programa');
}

The interesting thing in this way is that you can already pick up part of the answer and with a stripos or preg_match detect if the command is waiting type Y/N to confirm something and customize yourself for any situation you want, for example assuming you ran the apt-get remove and the terminal was displayed something like:

Do you want to continue [Y/N]

The while would catch in the fgets which contains this command and at this time you could use a fwrite, something like:

Note: changing the second parameter to a+, which opens for reading and writing; places the file pointer at the end of Handle.

$handle = popen('apt-get remove ' . $package . ' 2>&1', 'a+');

if ($handle) {
    while (feof($handle) === false) {
        $response = trim(fgets($handle));

        if (stripos($response, 'do you want to continue') !== false) {
            fwrite($handle, "Y\n");// O \n é para enviar a quebra de linha que creio ser necessária para disparar
        }
    }

    pclose($handle);
} else {
    die('Erro ao executar o programa');
}

Answer 2

The solution found was in PHP, using the class SSH2 package phplibsec to execute the command.

Following example:

    $input = 'apt-get remove ' . $package . ' -y';
    $ssh = new \phpseclib\Net\SSH2('localhost');
    if (!$ssh->login('user', 'pass')) {
        exit('Erro ao logar');
    }
    echo json_encode($ssh->exec($input));

In the example, connect to the ssh of the server (in case myself), and run the command, 'echo' prints the response that would come when running on the terminal.

Answer 3

Simple answer, go below.

shel_exec('apt remove pacote_exemplo > removed-package.txt'; echo $?);

the variable $? returns the return code of the last executed command. If the return code is different from 0 there is some problem in the command, then you should analyze the return code.