posix_spawn, returns 1

[SPlatten]

@jsulm , I wasn't aware of it or I forgot...I will certain look for it now and an example.

[jsulm]

@SPlatten said in posix_spawn, returns 1:

what does a return of 1 mean with a pid ?

"The posix_spawn() and posix_spawnp() functions fail only in the case
where the underlying fork(2), vfork(2) or clone(2) call fails; in
these cases, these functions return an error number, which will be
one of the errors described for fork(2), vfork(2) or clone(2)."
https://man7.org/linux/man-pages/man3/posix_spawn.3.html

[SPlatten]

@jsulm , I'm not sure if what I'm doing is correct?

bool clsMainWnd::blnLaunch(QString strApp, QStringList& slstArgs, qint64& int64PID) {
    Q_ASSERT_X(clsMainWnd::mspobjProcess!=nullptr, "blnLaunch", "mspobjProcess is null!");
    int intLastSep = strApp.lastIndexOf(QDir::separator());
    int64PID = 0;
    if ( intLastSep > 0 ) {
        QString strName = strApp.mid(intLastSep + 1)
               ,strPath = strApp.mid(0, intLastSep + 1);
        if ( mspobjProcess->startDetached(strName, slstArgs, strPath, &int64PID) == true
          && int64PID > 0 ) {
            return true;
        }
    }
    return false;
}

In the above, strApp:

~/XMLMPAM/config/modules/mdFileIO

slstArgs <2 items>:

"8123"
"8124"

It doesn't seem to be working as I get no valid PID back.

[jsulm]

@SPlatten Then please check what https://doc.qt.io/qt-5/qprocess.html#error and https://doc.qt.io/qt-5/qiodevice.html#errorString return

[SPlatten]

@jsulm , I've modified the function:

bool clsMainWnd::blnLaunch(QString strApp, QStringList& slstArgs, qint64& int64PID) {
    Q_ASSERT_X(clsMainWnd::mspobjProcess!=nullptr, "blnLaunch", "mspobjProcess is null!");
    int intLastSep = strApp.lastIndexOf(QDir::separator());
    int64PID = 0;
    if ( intLastSep > 0 ) {
        QString strName = strApp.mid(intLastSep + 1)
               ,strPath = strApp.mid(0, intLastSep + 1);
        if ( mspobjProcess->startDetached(strName, slstArgs, strPath, &int64PID) == true
          && int64PID > 0 ) {
            return true;
        }
        qDebug() << mspobjProcess->error();
    }
    return false;
}

The result is:

QProcess::UnknownError

Not terribly helpful.

[jsulm]

@SPlatten said in posix_spawn, returns 1:

strName

What does it contain when you call startDetached? Did you try with absolute path to the executable?

[SPlatten]

@jsulm strName contains:

mdFileIO

I just tried calling the function with the absolute path:

bool clsMainWnd::blnLaunch(QString strApp, QStringList& slstArgs, qint64& int64PID) {
    Q_ASSERT_X(clsMainWnd::mspobjProcess!=nullptr, "blnLaunch", "mspobjProcess is null!");
    int intLastSep = strApp.lastIndexOf(QDir::separator());
    int64PID = 0;
    if ( intLastSep > 0 ) {
        QString strName = strApp.mid(intLastSep + 1)
               ,strPath = strApp.mid(0, intLastSep + 1);
        if ( mspobjProcess->startDetached(strApp, slstArgs, strPath, &int64PID) == true
          && int64PID > 0 ) {
            return true;
        }
        qDebug() << mspobjProcess->error();
    }
    return false;
}

Where strApp contains:

~/XMLMPAM/config/modules/mdFileIO

Same result.

[jsulm]

@SPlatten said in posix_spawn, returns 1:

~/XMLMPAM/config/modules/mdFileIO

Try with whole path, without ~ as ~ is resolved by the shell as far as I know.

[SPlatten]

@jsulm , still having problems:

bool clsMainWnd::blnLaunch(QString strApp, QStringList& slstArgs, qint64& int64PID) {
    Q_ASSERT_X(clsMainWnd::mspobjProcess!=nullptr, "blnLaunch", "mspobjProcess is null!");
    QString strUserProfile("~");

    if ( strApp.contains(strUserProfile) == true ) {
    //Application path contains user proflie reference, replace with actual folder
        QString strUserFolder(clsDebugService::strGetUserFolder(strUserProfile));

        if ( strUserFolder.endsWith(QDir::separator()) == true ) {
            strUserFolder = strUserFolder.left(strUserFolder.length() - 1);
        }
        strApp = strApp.replace(strUserProfile, strUserFolder);
    }
    int intLastSep = strApp.lastIndexOf(QDir::separator());
    int64PID = 0;
    if ( intLastSep > 0 ) {
        QString strName = strApp.mid(intLastSep + 1)
               ,strPath = strApp.mid(0, intLastSep + 1);
        if ( mspobjProcess->startDetached(strApp, slstArgs, strPath, &int64PID) == true
          && int64PID > 0 ) {
            return true;
        }
        qDebug() << mspobjProcess->error();
    }
    return false;
}

After replacing "~" strApp now contains:

"/Users/simonplatten/XMLMPAM/config/modules/mdFileIO"

Although I get exactly the same results.

QProcess::UnknownError

[Edit] I just copied the path and app name and pasted into a terminal, I get:

Last login: Mon Sep 28 09:04:18 on ttys001
You have new mail.
simonplatten@Simons-iMac ~ % /Users/simonplatten/XMLMPAM/config/modules/mdFileIO 
zsh: operation not permitted: /Users/simonplatten/XMLMPAM/config/modules/mdFileIO

[JonB]

@SPlatten
What is your question? If you cannot execute /Users/simonplatten/XMLMPAM/config/modules/mdFileIO, e.g. from zsh, then you cannot execute it, and Qt QProcess won't solve that.

From what very little I know (I'm not Mac), have you tried Googling for zsh: operation not permitted? You get hits telling you why this happens under various MacOS incarnations and what you are supposed to do about it to allow it to run. [Looks like it's some Mac addition for "security" purposes.]

[SPlatten]

@JonB , I will look into it, thank you...its very odd, I am an Amin on the system.

[SPlatten]

@JonB ,@jsulm , got it I think, the application created by Qt Creator is not actually a file, but instead a folder:

drwxr-xr-x  3 simonplatten  staff     96 28 Sep 07:29 mdFileIO.app

If I then go into this folder the actual executable is located in:

/Users/simonplatten/build-mdFileIO-Desktop_Qt_5_14_2_clang_64bit-Release/mdFileIO.app/Contents/MacOS/mdFileIO

ls -l:

-rwxr-xr-x  1 simonplatten  staff  81280 28 Sep 07:29 mdFileIO

I can run this application.

[SPlatten]

@JonB , @jsulm So I simplified my application, commenting out the entire content of main and replacing with just:

printf("Hello World\n");
return 0;

This worked without fault, so now I've put back the original and will investigate what exactly is causing the problems.

[SPlatten]

It makes 0 sense to me, I've put it back exactly the way it was, in fact all I did was undo until it was as it was...rebuilt and now it works!