How run bash script

Mihaill

Hi!
I have script :

sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/

How I can run this script? How I can run this script in QProcess?

JonB

@Mihaill
If you want to stick with using <<< you would have to run your command via bash -c "sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/".

If you don't want to invoke bash -c you would have to invoke sudo -S and then send the string 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/ via QProcess::write() so that it arrives at the sub-process's stdin.

To make it work as-is

QProcess p;
p.start("/bin/bash", { "-c", "sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/" } );

Untested, but the second way might work with

p.start("sudo", { "-S" });
p.write("1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/");  # string might need a terminating `\n`, I don't know

On a separate note, for my own interest. This whole use of sudo with a Here-document (the <<<) looks "odd" to me. In principle

command <<< some text

ought to be the same as

echo "some text" | command

But, for unknown/undocumented reason it is not for the sudo. sudo -S "password echo hello" works, but echo "password echo hello" | sudo -S gives a sudo "usage" error message. That implies to me that sudo behaves differently depending on whether stdin is or is not attached to a terminal....

UPDATE
I misunderstood how <<< works. Turns out, it only reads the next token, not the rest of the line, to present as stdin. So

command <<< some text

actually equates to echo some | command text. One would need command <<< "some text" to equate to echo "some text" | command.

As a result of this, my second "untested" proposal above would need to be changed to:

p.start("sudo", { "-S", "./live555ProxyServer", "-v", "rtsp://stream.com:554/Rz.32.02/" });
p.write("1qaz");  # string might need a terminating `\n`, I don't know

Mihaill

@JonB said in How run bash script:

p.start("/bin/bash", { "-c", "sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/" } );
p.start("sudo", { "-S" });
p.write("1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/"); #

I try use this, but when I try get output from console -> I get ""

p.readAll()  == "";

But errorString() == "Unknown error";
How I can get output from console?

JonB

@Mihaill
Now you need to look up how QProcess works. Your readAll() call is too early, the QProcess::start() has only just started the process.

The simplest for your case, if it suffices, is:

p.start("sudo", { "-S" });
p.write("1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/");  # string might need a terminating `\n`, I don't know
p.waitForFinished();
qDebug() << p.readAll();

Mihaill

@JonB I readAll() after 5 sec at start. I think that QProcess not work.

JonB

@Mihaill
QProcess works fine.

Why don't you try p.start("ls") or p.start("bash", { "-c", "ls" }) to see how that goes?

Whether (a) your command line, (b) your sudo -S and (c) your ./live555ProxyServer command all behave as desired is a different matter.

If you run sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/ on the command line, does it exit (i.e. immediately return to the shell prompt) or stay running (no return to shell prompt)?

Mihaill

This post is deleted!

Mihaill

@JonB I used m_proxyServerProcess.waitForFinished();
This code return normal result:

    m_proxyServerProcess.start("/bin/bash", {"-c","echo 'some text' "});
    m_proxyServerProcess.start("ls");
    m_proxyServerProcess.start("/bin/bash", { "-c", "ls" });

But it's return "" after 5 sec, but process not finished

m_proxyServerProcess.start("/bin/bash", {"-c",
            "sudo -S <<< 1qaz /home/osm/Downloads/live/proxyServer/live555ProxyServer -v rtsp://stream.lesohranitel.ru:554/RU.32.02/ "});

JonB

@Mihaill
If you want help answer questions asked. It's really not too hard. I last wrote:

If you run sudo -S <<< 1qaz ./live555ProxyServer -v rtsp://stream.com:554/Rz.32.02/ on the command line, does it exit (i.e. immediately return to the shell prompt) or stay running (no return to shell prompt)?

I asked that question because it is 100% vital to your question/behaviour/code. You know how your live555ProxyServer command behaves, how can I possibly know? Your ignoring it does not help either of us.

Mihaill

@JonB In command line it's running.
I check this code and code works, but readAll() == "". It's strange.
Thanks for help.

JonB

@Mihaill said in How run bash script:

@JonB In command line it's running.

I don't known what that means.

Do you mean that after typing sudo -S <<< 1qaz /home/osm/Downloads/live/proxyServer/live555ProxyServer -v rtsp://stream.lesohranitel.ru:554/RU.32.02/ in a terminal the command prompt does not appear again and live555ProxyServer keeps running? I would like to help you but it's so difficult to get the answers out from you! :)