Opening a txt file

James Sprinks

Hi All.

I am attempting to open a txt file in order to scrape data from it, line by line;

void logscrape::scrape()
{
    int size;

    QFile sedation("C:/PMPS/build-PMPSv1-Desktop_Qt_5_9_2_MSVC2017_64bit-Debug/SedationData/" + sedName);
    QFile log("C:/PMPS/build-PMPSv1-Desktop_Qt_5_9_2_MSVC2017_64bit-Debug/LogData/" + logName);
    QStringList csvtime;
    QStringList logtime;
    QStringList tcitarget;
    QStringList tciplasma;
    QStringList tcieffect;

    log.open(QIODevice::ReadOnly);

    while (!log.atEnd())
    {
        QByteArray logline = log.readLine();
        if (logline.contains("TCITAR"))
        {
            int timeindex = logline.indexOf("UTC");
            int targetindex = logline.indexOf("TCITAR");
            int plasmaindex = logline.indexOf("TCIPLA");
            int effectindex = logline.indexOf("TCIEEFF");

            logtime.append(logline.mid(timeindex - 9, 8));
            tcitarget.append(logline.mid(targetindex + 7, 4));
            tciplasma.append(logline.mid(plasmaindex + 7, 4));
            tcieffect.append(logline.mid(effectindex + 8, 4));

            size = logtime.size();

            qDebug() << logtime << tcieffect;
            qDebug() << size;
        }

    }

Everything works fine in terms of scraping the data - however the program just hangs after the line qDebug() << size. Any ideas?

James

VRonin

log.open(QIODevice::ReadOnly); should be opened in text mode log.open(QIODevice::ReadOnly | QIODevice::Text);
Use QTextStream when dealing with text, your method fails miserably with any non-ASCII encoded character. You can find an example in the docs
You should probably use a QRegularExpression to extract your data instead of indexOf+mid

hangs after the line qDebug() << size

The problem is not there

mrjj

Hi
I wondering how the input lines looks like?
Its not a CSV file but custom format ?

James Sprinks

@VRonin Hi

Thanks for the advice - however as I said it is scraping the data fine, this is not the cause of the hang.

James

James Sprinks

@mrjj Its a text file.

mrjj

@James-Sprinks
yes, that is very clear.
i mean how is each line saved ?
xx,yyy,444
or how does it look?

James Sprinks

Hi All

I solved the issue. I now have another one, I am trying to open a csv in readwrite mode, and get this error:

QIODevice::read (QFile, "C:\PMPS\build-PMPSv1-Desktop_Qt_5_9_2_MSVC2017_64bit-Debug\SedationData\logtest_sed.csv"): device not open

The path is correct... so why won't it open?

J

VRonin

You can find out using

if(!csvFile.open(QIODevice::ReadOnly | QIODevice::Text))
qDebug() << csvFile.errorString();

JonB

This post is deleted!