Weird behavior of QProcess and multiple qoutes

[jsulm]

@Manta-Ray
Then just do

arguments << "set_network" << "0" << "psk" << "\"" + pwd + "\"";

[Manta Ray]

@jsulm
Ok, added

    arguments.clear();
    arguments << "set_network" << "0" << "psk" << "'\"" << pwd << "\"'";
    qDebug() << arguments;
    wpacli->execute(program, arguments);

and got the same result:

("set_network", "0", "psk", "'\"", "12345678", "\"'")
Selected interface 'wlan0'
FAIL

[jsulm]

@Manta-Ray Please read again what I wrote and compare it to what you did.

[Manta Ray]

Wow!
It works! Thanks a lot!
Thanks!
Thanks!
Thanks!

Can you, please, explain me, what's the magic is going here?

[Konstantin Tokarev]

@Manta-Ray You need to pass 4 arguments to wpa_cli:

set_network, 0, psk, "12345678"

instead you passed 6

set_network, 0, psk, ", 12345678, "

[jsulm]

@Manta-Ray No magic. You simply put both " as own parameters:

arguments << "set_network" << "0" << "psk" << "'\"" << pwd << "\"'";

see here:

("set_network", "0", "psk", "'\"", "12345678", "\"'")

Instead you need to put your password as one string with leading and trailing ", like here:

arguments << "set_network" << "0" << "psk" << "\"" + pwd + "\"";

[Manta Ray]

Ahaaaa, Thanks you guys a lot!!!!!!
I really appreciate you!!!!

[Guanhong]

@Manta-Ray
I met the same issue and it failed.
Could you show me your codes or tell me what's wrong with my codes following, thanks

            QString strSSID = "12345678"
            QString program = "wpa_cli";
            QStringList arguments;      
            arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << "'\"" << strSSID << "\"'";  
            QProcess prcsWlan4;
            prcsWlan4.start(program, arguments);
            prcsWlan4.waitForFinished(-1);  
            QString strResult4 = prcsWlan4.readAllStandardOutput();

the result strResult4 is FAIL

[Christian Ehrlicher]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

<< "'"" << strSSID << ""'";

Why do you quote this? It's not needed at all - every value in the QStringList is passed as one parameter to your app. That's the reason why you should not use the other call - to avoid useless and wrong quotes.

[Guanhong]

@Christian-Ehrlicher
thank you for your swift reply

actually in my project, strSSID is a variable, it is delivered by other parameters, here I just made it a constant for convenience.

I changed
arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << "'"" << strSSID << ""'";
to
arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << "'"" + strSSID + ""'";

it still FAILed.
could you help me?

[jsulm]

@Guanhong Please read once more what @Christian-Ehrlicher wrote. Your change is NOT what he wrote...

[Guanhong]

@jsulm thank you.
I think quotes are necessary, because there is a single quote outside a double quote.
I need to process the following command by QProcess, could you show me how?
pa_cli -i wlan0 set_network 1 ssid '"hima24g"'

[Christian Ehrlicher]

Again: there is no need to quote an argument when using QProcess::start() with QStringList - they are only needed on the command line so bash/cmd.exe/whatever knows what a single argument is! Your ssid is hima24g and not "hima24g" or 'hima24g' ... or?

[Guanhong]

@Christian-Ehrlicher
Even if there are single quotes and double quotes in the command, is there no need to add quotes? I looked at earlier replies, it seems that quotes are need.

I just removed quotes and changed my codes to
arguments << "-i" << "wlan0" << "set_network" << "0"<< "ssid" << strSSID ;
FAILed too.

[jsulm]

@Guanhong Then add proper error handling and also read from std error of your process to see whether it prints any errors.

[Guanhong]

@jsulm
QString strResult4 = prcsWlan4.readAllStandardOutput();
strResult4 is FAIL

[jsulm]

@Guanhong said in Weird behavior of QProcess and multiple qoutes:

readAllStandardOutput()

I was talking about std ERROR (https://doc.qt.io/qt-5/qprocess.html#readAllStandardError)...

[Christian Ehrlicher]

Please run it on the command line. Maybe you don't have the proper privileges.

[Guanhong]

@Christian-Ehrlicher
I have run it on the command line, it is no problem.

[Christian Ehrlicher]

@Guanhong Please show how you run it on the command line