Qt 5.6 | Qt Core | C++ Classes | QTemporaryDir

Qt 5.6.2 Reference Documentation

# QTemporaryDir Class

The QTemporaryDir class creates a unique directory for temporary use. More...

Header: | #include <QTemporaryDir>
qmake: | QT += core

- List of all members, including inherited members

Note: All functions in this class are reentrant.

## Public Functions

| QTemporaryDir()
| QTemporaryDir(const QString &templatePath)
| ~QTemporaryDir()
bool | autoRemove() const
QString | errorString() const
bool | isValid() const
QString | path() const
bool | remove()
void | setAutoRemove(bool b)

## Detailed Description

The QTemporaryDir class creates a unique directory for temporary use.

QTemporaryDir is used to create unique temporary dirs safely. The dir itself is created by the constructor. The name of the temporary directory is guaranteed to be unique (i.e., you are guaranteed to not overwrite an existing dir), and the directory will subsequently be removed upon destruction of the QTemporaryDir object. The directory name is either auto-generated, or created based on a template, which is passed to QTemporaryDir's constructor.

Example:

          // Within a function/method...

          QTemporaryDir dir;
          if (dir.isValid()) {
              // dir.path() returns the unique directory path
          }

          // The QTemporaryDir destructor removes the temporary directory
          // as it goes out of scope.

It is very important to test that the temporary directory could be created, using isValid(). Do not use exists(), since a default-constructed QDir represents the current directory, which exists.

The path to the temporary dir can be found by calling path().

A temporary directory will have some static part of the name and some part that is calculated to be unique. The default path will be determined from QCoreApplication::applicationName() (otherwise `qt_temp`) and will be placed into the temporary path as returned by QDir::tempPath(). If you specify your own path, a relative path will not be placed in the temporary directory by default, but be relative to the current working directory. In all cases, a random string will be appended to the path in order to make it unique.

See also QDir::tempPath(), QDir, and QTemporaryFile.

## Member Function Documentation

### QTemporaryDir::QTemporaryDir()

Constructs a QTemporaryDir using as template the application name returned by QCoreApplication::applicationName() (otherwise `qt_temp`). The directory is stored in the system's temporary directory, QDir::tempPath().

See also QDir::tempPath().

### QTemporaryDir::QTemporaryDir(const QString &templatePath)

Constructs a QTemporaryDir with a template of templatePath.

If templatePath is a relative path, the path will be relative to the current working directory. You can use QDir::tempPath() to construct templatePath if you want use the system's temporary directory.

If the templatePath ends with XXXXXX it will be used as the dynamic portion of the directory name, otherwise it will be appended. Unlike QTemporaryFile, XXXXXX in the middle of the template string is not supported.

See also QDir::tempPath().

### QTemporaryDir::~QTemporaryDir()

Destroys the temporary directory object. If auto remove mode was set, it will automatically delete the directory including all its contents.

See also autoRemove().

### bool QTemporaryDir::autoRemove() const

Returns `true` if the QTemporaryDir is in auto remove mode. Auto-remove mode will automatically delete the directory from disk upon destruction. This makes it very easy to create your QTemporaryDir object on the stack, fill it with files, do something with the files, and finally on function return it will automatically clean up after itself.

Auto-remove is on by default.

See also setAutoRemove() and remove().

### QString QTemporaryDir::errorString() const

If isValid() returns `false`, this function returns the error string that explains why the creation of the temporary directory failed. Otherwise, this function return an empty string.

This function was introduced in Qt 5.6.

### bool QTemporaryDir::isValid() const

Returns `true` if the QTemporaryDir was created successfully.

### QString QTemporaryDir::path() const

Returns the path to the temporary directory. Empty if the QTemporaryDir could not be created.

### bool QTemporaryDir::remove()

Removes the temporary directory, including all its contents.

Returns `true` if removing was successful.

### void QTemporaryDir::setAutoRemove(bool b)

Sets the QTemporaryDir into auto-remove mode if b is true.

Auto-remove is on by default.

See also autoRemove() and remove().