I have written the following function which executes a windows enumeration command for getting shared folders and store the result in a QString.
QProcess p;
p.setProgram("wmic");
p.setArguments({"share", "get", "name"});
p.start();
if (!p.waitForFinished()) {
return;
}
const QString output = p.readAllStandardOutput();
qDebug () << output;
const QString error = p.readAllStandardError();
if (!error.isEmpty()) {
qDebug () << error;
}
But the output has a lot of delimiters like "\n\r" ... so I wanted to strip all of those delimiters from my string output. In the next step, you consider we will have a result like the following one:
C$
D$
E$
IPC$
So I wanted to save these names in a QStringList, or something like a list which I can append those names in combo widget independently. How can I do that?
You could just use qstring split:
QStringList list = output.split("\n", QString::SkipEmptyParts);
If you need a more "intelligent" split that you can pass in a regex:
list = output.split(QRegExp("...some regex..."));
The skip empty parts just "removes"/ignores any values that would be empty - I don't think you need that in this case
Related
How can you skip folders with the QDirIterator?
I've tried it with:
QString nameFilter = "*.h";
QDirIterator dirIterator(folder, nameFilter, QDir::Files, QDirIterator::Subdirectories);
QString str("folder");
QStringList filenames;
while (dirIterator.hasNext())
{
if(dirIterator.next() == str) continue;
filenames.append(dirIterator.next());
}
but it only ignores the specific folder but not its subdirectories.
Any idea?
Bellow instruction working 100 percent :
This method QString QDirIterator::next() Advances the iterator to the next entry, and returns the "file path" of this new entry. If hasNext() returns false, this function does nothing, and returns a null QString.
If QDirIterator found a file with specific filter (based on const QStringList &nameFilters parameter) then QDirIterator::next() returns "file-path" and you cannot compare the whole "file-path" with "skiped-folder" to iterate!
Because of this i had to write a function as a directory parser as bellow :
QStringList Widget::getCurrDirsOfFile(const QFileInfo &file_info, const QString &default_folder)
{
QString file_path = file_info.filePath();
QString file_name = file_info.fileName();
file_path.truncate(file_path.lastIndexOf("/" + file_name));
file_path = file_path.mid(file_path.lastIndexOf("/") + 1);
return file_path;
}
This function get "file-path" and return last "folder-name's" of it like bellow :
input : /home/msi/Desktop/123/untitled/123/widget.h
output(list) : 123, 123
We have QString skiped_dir("untitled"); as skiped folders!
In this state when you got something excluding 123 "folder-name's", you can append that file to QStringList filenames :
if(folder_list.indexOf(QRegExp(skiped_dir)) == -1)
filenames.append(it.filePath());
So try this (notice in comments) :
void Widget::btn_iterate_clicked()
{
// folder to iterate
QString folder("/home/msi/Desktop/");
// folder-name you want to skip
QString skiped_dir("untitled");
// file-names which are match with .h filter stored in filenames list
QStringList filenames;
// this list used in QStringList getCurrDirsOfFile() method
QStringList folder_list;
// iterator
QDirIterator it(folder, QStringList() << "*.h" , QDir::Files, QDirIterator::Subdirectories);
while (it.hasNext()) // if next object exist for iterate
{
// we have the file with .h extension
it.next();
// get previous folders that exist in filepath address of it.fileInfo()
folder_list = getCurrDirsOfFile(it.fileInfo(), folder);
// if folder_list contained skiped folder then reject that or appent it
if(folder_list.indexOf(QRegExp(skiped_dir)) == -1)
filenames.append(it.filePath());
}
for(int i = 0;i < filenames.count();i++)
{
QMessageBox::information(this, "", filenames.at(i));
}
}
Suppose we have bellow tree (directories) :
This program just shows :
/home/msi/Desktop/build-untitled-Desktop_Qt_5_0_2_GCC_64bit-Debug/ui_widget.h
/home/msi/Desktop/1/1.h
I know this is a bit old, but your original code was close...there's two problems. First, the iterator covers every entry and what it returns is a full path and filename, not just the entry name within the current directory. Checking for an exact match is the problem rather than for containment. The second issue is that you have two calls to "next" without a call to "hasNext" between them, so it's possible you'll have a crash.
while (dirIterator.hasNext())
{
QString fname = dirIterator.next ();
if (fname.contains (str)) continue;
filenames.append (fname);
}
Note that you may need to be more specific with the value of "str". Any filename could contain the word "folder", so you'll probably want to check for str.endsWith ("/folder") as well as str.contains ("/folder/").
If you inspect the values returned from "next", you'll better see how to compare what you're excluding to the current entry, so just tweak the string comparison to get what you want.
The data of my file.txt is as below:
Student_ID=0001
Student_Name=joseph
Student_GradeLevel=2
How do I get the value, let say I want to get the Student_ID using Qt.
Thanks.
Take a look at this function, it can be used to find any value you want in your input file, where all lines are in the format you've posted above (key=value). If the key is not found, it returns an empty QString() object.
QString findValueInFile(QString key, QString filename) {
QFile file(filename);
if(file.open(QIODevice::ReadOnly)) {
QTextStream txtStr(&file);
QStringList fileContent = txtStr.readAll().split('\n');
for(auto &&line : fileContent) {
if(line.contains(key)) return line.split(QChar('='))[1];
}
file.close();
}
return QString(); // not found
}
Now you call it somewhere, e.g.:
qDebug() << findValueInFile("Student_ID", "file.txt");
qDebug() << findValueInFile("Student_Name", "file.txt");
This function can be easily modified if you replace your = sign with other delimiter e.g. => or sth else. However for key=value format there is a special QSettings class (mentioned by sebastian) that can allow you to read those values even easier:
QSettings file("file.txt", QSettings::IniFormat);
qDebug() << file.value("Student_Name").toString(); // et voila!
You can probably also use QSettings, as they are able to read ini files.
There are some caveats though regarding backslashes which might be important to you (though they aren't for the example you posted): http://doc.qt.io/qt-4.8/qsettings.html#Format-enum
QSettings iniFile("myfile.txt", QSettings::IniFormat);
// now get the values by their key
auto studentId = iniFile.value("Student_ID").toString().toInt();
I'm more of a PyQt user, so: apologies if I got some C++ specifics wrong...
I am working on VS2015 with qt framework. In my source code, I have a function for printing in the GUI screen.
This function is called each time something needs to be printed.
It goes like this.
void Trial::Print_MessageBox(QString string)
{
ui.MessagesScreen->appendPlainText(string);
Cursor_Messagebox.movePosition(QTextCursor::End);
ui.MessagesScreen->setTextCursor(Cursor_Messagebox);
ui.MessagesScreen->ensureCursorVisible();
}
// Output in MessageBox
void Trial::Print_MessageBox(QFlags<QNetworkInterface::InterfaceFlag> flags)
{
QString str = QString("Flag %1").arg(flags);
ui.MessagesScreen->appendPlainText(str);
}
The above function has no problems and running well.
Now I am trying to read a text file. This has set of values in no order or size. An example for this:
231, 54, 4 \n
47777, 2211, 676, 9790, 34236, 7898\n
1, 3\n
Objective is to convert these into integers (line by line) and print them in the GUI and also send them (line by line) to other system. So I tried to do it with the following.
void Trial::ReadFile_Data()
{
QFile file("input.txt");
if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
{
Print_MessageBox("Error in reading File");
return;
}
QTextStream in(&file);
while (!in.atEnd())
{
QString line = in.readLine();
Print_MessageBox(line);
int conv = line.toInt();
QString str = QString("%1 %2").arg("Values are: ").arg(conv);
Print_MessageBox(str);
QStringList fields = line.split(",");
}
file.close();
}
When I print the "line", it is just printing the same values as in the file. When I do the conversion and printing, I get an error (which is expected) Now I try to remove "," with the help of split then I get QstringList which I cannot use as I have the Qstring function to print(this cant be changed)
I am not getting any pointers from here. Please help me out as this is bugging me since long time.
Just simple...
QStringList::const_iterator constIterator;
for (constIterator = fonts.constBegin(); constIterator != fonts.constEnd();
++constIterator) {
cout << (*constIterator).toLocal8Bit().constData() << endl;
}
where fonts is your QStringlist
Your question reduces to "How do I iterate over a QStringList".
Like this:
// C++11
for (auto field : fields) Print_messageBox(field);
// C++98
foreach (QString field, fields) Print_messageBox(field);
See here for information about how foreach a.k.a Q_FOREACH was implemented.
I am using QSettings to parse an ini file: QSettings cfg(path, QSettings::IniFormat);
When I obtain a value QVariant qv = cfg.value("title"); containing a comma the variant contains a QStringList instead of a QString
title=foo => QString
title=foo,bar => QStringList
How can I always get strings, or at least obtain the original line ( title=foo,bar ) ?
You have at least two ways to address this issue, all of them presented below:
test.ini
title="foo,bar"
title_unquoted=foo,bar
main.cpp
#include <QSettings>
#include <QDebug>
int main()
{
QSettings settings("test.ini", QSettings::IniFormat);
// Original issue
qDebug() << settings.value("title_unquoted");
// 1st solution: join the strings
qDebug() << settings.value("title").toStringList().join(',');
// 2nd solution: use quotes in the ini file
qDebug() << settings.value("title");
return 0;
}
main.pro
TEMPLATE = app
TARGET = main
QT = core
SOURCES += main.cpp
Build and Run
qmake && make && ./main
Output
QVariant(QStringList, ("foo", "bar"))
"foo,bar"
QVariant(QString, "foo,bar")
In other words, use quotes for strings with special characters or join the strings manually in the list. The former is far better if it is under your control as you usually ought to aim for proper quoting when using "special" characters in strings.
I'm using Qt to get a file name from the user:
QString fileName = QFileDialog::getOpenFileName(this,tr("Select an image file"),"d:\\",tr("Image files(*.tiff *.tif )"));
It works, but I need the file name without its extension, is it possible in Qt??
whenn I try :
QString f = QFileInfo(fileName).fileName();
f is like "filename.tif", but I want it to be "filename".
QFileInfo has two functions for this:
QString QFileInfo::completeBaseName () const
Returns file name with shortest extension removed (file.tar.gz -> file.tar)
QString QFileInfo::baseName () const
Returns file name with longest extension removed (file.tar.gz -> file)
To cope with filenames containing multiple dots, look for the last one and take the substring until that one.
int lastPoint = fileName.lastIndexOf(".");
QString fileNameNoExt = fileName.left(lastPoint);
Of course this can (and should) be written as a helper function for reuse:
inline QString withoutExtension(const QString & fileName) {
return fileName.left(fileName.lastIndexOf("."));
}
You can split fileName with "." as separator like this:
QString croped_fileName=fileName.split(".",QString::SkipEmptyParts).at(0);
or use section function of QString to take the first part before "." like this:
QString croped_fileName=fileName.section(".",0,0);
You can use QString::split and use the . as the place where to split it.
QStringList list1 = str.split(".");
That will return a QStringList with {"filename", "extenstion"}. Now you can get your filename without the extension.
To get absolute path without extension for QFileInfo fileInfo("/a/path/to/foo.tar.gz") you can use:
QDir(file_info.absolutePath()).filePath(file_info.baseName());
to get "/a/path/to/foo" or
QDir(file_info.absolutePath()).filePath(file_info.completeBaseName());
to get "/a/path/to/foo.tar"