QStorageInfo not giving mount path

[saber]

i have latest qt and i am in linux.

this is my code.

    QStringList result;
    const auto allMounted = QStorageInfo::mountedVolumes();
    result.reserve(allMounted.size());
    for(auto& singleMounted : allMounted)
    result << singleMounted.displayName();

    for(int i=0; i<result.count(); ++i ){
        QString l;
        l = result.at(i);
        QStorageInfo(l).rootPath();
        qDebug()<<QStorageInfo(l).rootPath();
    }

    qDebug()<< allMounted;
    qDebug()<< result;

here is the output

"/run"
"/"
"/tmp"
"/run/user/1000"
""
""
("/run", "/", "/tmp", "/run/user/1000", "Storage", "Fast")

why i am not getting last 2 storage mount path ?

i also want to remove ( "/run", "/tmp", "/run/user/1000") this three.

so please tell me how.

[mrjj]

Hi
You could just use
http://doc.qt.io/qt-5/qlist.html#removeAt
and remove from list ?

[saber]

and why i am not getting last 2 storage mount path ?

[mrjj]

@saber
no idea. If you look in the linux - what are they ?
maybe they dont have names at all and hence the empty strings.

[saber]

@mrjj

see the second debug output.

last two is the name("Storage", "Fast"). but when i put them in here (QStorageInfo(l).rootPath() ) as "l" ,i am not getting the root path.

[mrjj]

@saber
Maybe they are not rootPaths ?

[saber]

@mrjj i found the solution

QStringList result;
    const auto allMounted = QStorageInfo::mountedVolumes();
    result.reserve(allMounted.size());
    for(auto& singleMounted : allMounted)
    result << singleMounted.rootPath();

    for(int i=0; i<result.count(); ++i ){
        QString l = result.at(i);
        if((l == "/run/user/1000" )| l == "/tmp" | l == "/run"){
            result.removeAt(i);
        }
    }

output

("/", "/run/user/1000", "/run/media/shaber/Storage", "/run/media/shaber/Fast")

but this ("/run/user/1000") is not removed automatically .
why is it ? and how to do remove it?

[aha_1980]

@saber said in QStorageInfo not giving mount path:

if((l == "/run/user/1000" )| l == "/tmp" | l == "/run"){
result.removeAt(i);
}

What happens if you replace that with:

if (l == "/run/user/1000" || l == "/tmp" || l == "/run") {
  result.removeAt(i);
}

[saber]

@aha_1980
nothing changed

("/", "/run/user/1000", "/run/media/shaber/Storage")

same.

is there any way to get just the mounted REAL partition .

[aha_1980]

@saber: now I see it. if you use a debugger, you will notice the problem too.

you have a loop over x elements and compare element i against a pattern. if it matches, you remove the element.

But: therefore all following elements shift a position forward, which means you will miss the next element when the loop continues.

you can e.g. fix this by copying all wanted elements into a new list instead.

Regards

[JonB]

@aha_1980
Rather than copying to a new list, the simplest pattern to use when removing items from a list via a for () loop counter so as not to worry about shifting is always to count downward! :

for (int i = result.count() - 1; i >= 0; --i )
    if (...)
        result.removeAt(i);

will work :)

[aha_1980]

@JonB

Rather then removing elements from a list he could just add the elements he really wants, by adding the check here

for(auto& singleMounted : allMounted)
    result << singleMounted.rootPath();

Sorry, could not resist ;)

[JonB]

@aha_1980
Yes, but of course only works if you're copying/outputting the desired items somewhere. If you need to remove from a list, the downward pattern is worth knowing :)

[saber]

my final solution

 QStringList result;
    const auto allMounted = QStorageInfo::mountedVolumes();
    result.reserve(allMounted.size());
    for(auto& singleMounted : allMounted)
    result << singleMounted.rootPath();