QFileInfo Class

 #ifdef Q_OS_UNIX

 QFileInfo info1("/home/bob/bin/untabify");
 info1.isSymLink();          // returns true
 info1.absoluteFilePath();   // returns "/home/bob/bin/untabify"
 info1.size();               // returns 56201
 info1.symLinkTarget();      // returns "/opt/pretty++/bin/untabify"

 QFileInfo info2(info1.symLinkTarget());
 info2.isSymLink();          // returns false
 info2.absoluteFilePath();   // returns "/opt/pretty++/bin/untabify"
 info2.size();               // returns 56201

 #endif

 #ifdef Q_OS_WIN

 QFileInfo info1("C:\\Users\\Bob\\untabify.lnk");
 info1.isSymLink();          // returns true
 info1.absoluteFilePath();   // returns "C:/Users/Bob/untabify.lnk"
 info1.size();               // returns 63942
 info1.symLinkTarget();      // returns "C:/Pretty++/untabify"

 QFileInfo info2(info1.symLinkTarget());
 info2.isSymLink();          // returns false
 info2.absoluteFilePath();   // returns "C:/Pretty++/untabify"
 info2.size();               // returns 63942

 #endif

 extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;

 qt_ntfs_permission_lookup++; // turn checking on
 qt_ntfs_permission_lookup--; // turn it off again

 void complexFunction()
 {
     QNtfsPermissionCheckGuard permissionGuard;  // check is enabled

     // do complex things here that need permission check enabled

 }   // as the guard goes out of scope the check is disabled

 qAreNtfsPermissionChecksEnabled();   // check status
 qEnableNtfsPermissionChecks();       // turn checking on
 qDisableNtfsPermissionChecks();      // turn it off again

Member Function Documentation

QFileInfo::QFileInfo()

Constructs an empty QFileInfo object that doesn't refer to any file system entry.

See also setFile().

[explicit] QFileInfo::QFileInfo(const QString &path)

Constructs a QFileInfo that gives information about a file system entry located at path that can be absolute or relative.

If path is relative, the QFileInfo will also have a relative path.

See also setFile(), isRelative(), QDir::setCurrent(), and QDir::isRelativePath().

[explicit] QFileInfo::QFileInfo(const QFileDevice &file)

Constructs a new QFileInfo that gives information about file file.

If the file has a relative path, the QFileInfo will also have a relative path.

See also isRelative().

[explicit] QFileInfo::QFileInfo(const QDir &dir, const QString &path)

Constructs a new QFileInfo that gives information about the given file system entry path that is relative to the directory dir.

If dir has a relative path, the QFileInfo will also have a relative path.

If path is absolute, then the directory specified by dir will be disregarded.

See also isRelative().

[since 6.0] QFileInfo::QFileInfo(const std::filesystem::path &file)

Constructs a new QFileInfo that gives information about the given file.

This function was introduced in Qt 6.0.

See also setFile(), isRelative(), QDir::setCurrent(), and QDir::isRelativePath().

[since 6.0] QFileInfo::QFileInfo(const QDir &dir, const std::filesystem::path &path)

Constructs a new QFileInfo that gives information about the file system entry at path that is relative to the directory dir.

If dir has a relative path, the QFileInfo will also have a relative path.

If path is absolute, then the directory specified by dir will be disregarded.

This function was introduced in Qt 6.0.

QFileInfo::QFileInfo(const QFileInfo &fileinfo)

Constructs a new QFileInfo that is a copy of the given fileinfo.

[noexcept] QFileInfo::~QFileInfo()

Destroys the QFileInfo and frees its resources.

QDir QFileInfo::absoluteDir() const

Returns a QDir object representing the absolute path of the parent directory of the file system entry that this QFileInfo refers to.

 // Given a current working directory of "/home/user/Documents/memos/"
 QFileInfo info1(u"relativeFile"_s);
 qDebug() << info1.absolutePath(); // "/home/user/Documents/memos/"
 qDebug() << info1.baseName(); // "relativeFile"
 qDebug() << info1.absoluteDir(); // QDir(u"/home/user/Documents/memos"_s)
 qDebug() << info1.absoluteDir().path(); // "/home/user/Documents/memos"

 // A QFileInfo on a dir
 QFileInfo info2(u"/home/user/Documents/memos"_s);
 qDebug() << info2.absolutePath(); // "/home/user/Documents"
 qDebug() << info2.baseName(); // "memos"
 qDebug() << info2.absoluteDir(); // QDir(u"/home/user/Documents"_s)
 qDebug() << info2.absoluteDir().path(); // "/home/user/Documents"

See also dir(), filePath(), fileName(), and isRelative().

QString QFileInfo::absoluteFilePath() const

Returns the absolute full path to the file system entry this QFileInfo refers to, including the entry's name.

On Unix, absolute paths begin with the directory separator '/'. On Windows, absolute paths begin with a drive specification (for example, D:/).

On Windows, the paths of network shares that are not mapped to a drive letter begin with //sharename/.

QFileInfo will uppercase drive letters. Note that QDir does not do this. The code snippet below shows this.

     QFileInfo fi("c:/temp/foo"); => fi.absoluteFilePath() => "C:/temp/foo"

This function returns the same as filePath(), unless isRelative() is true. In contrast to canonicalFilePath(), symbolic links or redundant "." or ".." elements are not necessarily removed.

See also filePath(), canonicalFilePath(), and isRelative().

QString QFileInfo::absolutePath() const

Returns the absolute path of the file system entry this QFileInfo refers to, excluding the entry's name.

On Unix, absolute paths begin with the directory separator '/'. On Windows, absolute paths begin with a drive specification (for example, D:/).

On Windows, the paths of network shares that are not mapped to a drive letter begin with //sharename/.

In contrast to canonicalPath() symbolic links or redundant "." or ".." elements are not necessarily removed.

See also absoluteFilePath(), path(), canonicalPath(), fileName(), and isRelative().

QString QFileInfo::baseName() const

Returns the base name of the file without the path.

The base name consists of all characters in the file up to (but not including) the first '.' character.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 QString base = fi.baseName();  // base = "archive"

The base name of a file is computed equally on all platforms, independent of file naming conventions (e.g., ".bashrc" on Unix has an empty base name, and the suffix is "bashrc").

See also fileName(), suffix(), completeSuffix(), and completeBaseName().

QDateTime QFileInfo::birthTime() const

Returns the date and time when the file was created (born), in local time.

If the file birth time is not available, this function returns an invalid QDateTime.

If the file is a symlink, this function returns information about the target, not the symlink.

This function overloads QFileInfo::birthTime(const QTimeZone &tz), and returns the same as birthTime(QTimeZone::LocalTime).

See also lastModified(), lastRead(), metadataChangeTime(), and fileTime().

[since 6.6] QDateTime QFileInfo::birthTime(const QTimeZone &tz) const

Returns the date and time when the file was created (born).

The returned time is in the time zone specified by tz. For example, you can use QTimeZone::LocalTime or QTimeZone::UTC to get the time in the Local time zone or UTC, respectively. Since native file system API typically uses UTC, using QTimeZone::UTC is often faster, as it does not require any conversions.

If the file birth time is not available, this function returns an invalid QDateTime.

If the file is a symlink, this function returns information about the target, not the symlink.

This function was introduced in Qt 6.6.

See also lastModified(const QTimeZone &), lastRead(const QTimeZone &), metadataChangeTime(const QTimeZone &), and fileTime(QFileDevice::FileTime, const QTimeZone &).

QString QFileInfo::bundleName() const

Returns the name of the bundle.

On macOS and iOS this returns the proper localized name for a bundle if the path isBundle(). On all other platforms an empty QString is returned.

Example:

 QFileInfo fi("/Applications/Safari.app");
 QString bundle = fi.bundleName();                // name = "Safari"

See also isBundle(), filePath(), baseName(), and suffix().

bool QFileInfo::caching() const

Returns true if caching is enabled; otherwise returns false.

See also setCaching() and refresh().

QString QFileInfo::canonicalFilePath() const

Returns the file system entry's canonical path, including the entry's name, that is, an absolute path without symbolic links or redundant '.' or '..' elements.

If the entry does not exist, canonicalFilePath() returns an empty string.

See also filePath(), absoluteFilePath(), and dir().

QString QFileInfo::canonicalPath() const

Returns the file system entry's canonical path (excluding the entry's name), i.e. an absolute path without symbolic links or redundant "." or ".." elements.

If the entry does not exist, this method returns an empty string.

See also path() and absolutePath().

QString QFileInfo::completeBaseName() const

Returns the complete base name of the file without the path.

The complete base name consists of all characters in the file up to (but not including) the last '.' character.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 QString base = fi.completeBaseName();  // base = "archive.tar"

See also fileName(), suffix(), completeSuffix(), and baseName().

QString QFileInfo::completeSuffix() const

Returns the complete suffix (extension) of the file.

The complete suffix consists of all characters in the file after (but not including) the first '.'.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 QString ext = fi.completeSuffix();  // ext = "tar.gz"

See also fileName(), suffix(), baseName(), and completeBaseName().

QDir QFileInfo::dir() const

Returns a QDir object representing the path of the parent directory of the file system entry that this QFileInfo refers to.

For each of the following, dir() returns the QDir "~/examples/191697".

     QFileInfo fileInfo1("~/examples/191697/.");
     QFileInfo fileInfo2("~/examples/191697/..");
     QFileInfo fileInfo3("~/examples/191697/main.cpp");

For each of the following, dir() returns the QDir ".".

     QFileInfo fileInfo4(".");
     QFileInfo fileInfo5("..");
     QFileInfo fileInfo6("main.cpp");

See also absolutePath(), filePath(), fileName(), isRelative(), and absoluteDir().

bool QFileInfo::exists() const

Returns true if the file system entry this QFileInfo refers to exists; otherwise returns false.

[static] bool QFileInfo::exists(const QString &path)

Returns true if the file system entry path exists; otherwise returns false.

QString QFileInfo::fileName() const

Returns the name of the file system entry this QFileInfo refers to, excluding the path.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 QString name = fi.fileName();                // name = "archive.tar.gz"

See also isRelative(), filePath(), baseName(), and suffix().

QString QFileInfo::filePath() const

Returns the path of the file system entry this QFileInfo refers to; the path may be absolute or relative.

See also absoluteFilePath(), canonicalFilePath(), and isRelative().

QDateTime QFileInfo::fileTime(QFileDevice::FileTime time) const

Returns the file time specified by time.

If the time cannot be determined, an invalid date time is returned.

If the file is a symlink, this function returns information about the target, not the symlink.

This function overloads QFileInfo::fileTime(QFileDevice::FileTime, const QTimeZone &), and returns the same as fileTime(time, QTimeZone::LocalTime).

See also birthTime(), lastModified(), lastRead(), and metadataChangeTime().

[since 6.6] QDateTime QFileInfo::fileTime(QFileDevice::FileTime time, const QTimeZone &tz) const

Returns the file time specified by time.

The returned time is in the time zone specified by tz. For example, you can use QTimeZone::LocalTime or QTimeZone::UTC to get the time in the Local time zone or UTC, respectively. Since native file system API typically uses UTC, using QTimeZone::UTC is often faster, as it does not require any conversions.

If the time cannot be determined, an invalid date time is returned.

If the file is a symlink, this function returns information about the target, not the symlink.

This function was introduced in Qt 6.6.

See also birthTime(const QTimeZone &), lastModified(const QTimeZone &), lastRead(const QTimeZone &), metadataChangeTime(const QTimeZone &), and QDateTime::isValid().

[since 6.0] std::filesystem::path QFileInfo::filesystemAbsoluteFilePath() const

Returns absoluteFilePath() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also absoluteFilePath().

[since 6.0] std::filesystem::path QFileInfo::filesystemAbsolutePath() const

Returns absolutePath() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also absolutePath().

[since 6.0] std::filesystem::path QFileInfo::filesystemCanonicalFilePath() const

Returns canonicalFilePath() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also canonicalFilePath().

[since 6.0] std::filesystem::path QFileInfo::filesystemCanonicalPath() const

Returns canonicalPath() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also canonicalPath().

[since 6.0] std::filesystem::path QFileInfo::filesystemFilePath() const

Returns filePath() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also filePath().

[since 6.2] std::filesystem::path QFileInfo::filesystemJunctionTarget() const

Returns junctionTarget() as a std::filesystem::path.

This function was introduced in Qt 6.2.

See also junctionTarget().

[since 6.0] std::filesystem::path QFileInfo::filesystemPath() const

Returns path() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also path().

[since 6.6] std::filesystem::path QFileInfo::filesystemReadSymLink() const

Returns readSymLink() as a std::filesystem::path.

This function was introduced in Qt 6.6.

See also readSymLink().

[since 6.0] std::filesystem::path QFileInfo::filesystemSymLinkTarget() const

Returns symLinkTarget() as a std::filesystem::path.

This function was introduced in Qt 6.0.

See also symLinkTarget().

QString QFileInfo::group() const

Returns the group of the file. On Windows, on systems where files do not have groups, or if an error occurs, an empty string is returned.

This function can be time consuming under Unix (in the order of milliseconds).

If the file is a symlink, this function returns information about the target, not the symlink.

See also groupId(), owner(), and ownerId().

uint QFileInfo::groupId() const

Returns the id of the group the file belongs to.

On Windows and on systems where files do not have groups this function always returns (uint) -2.

If the file is a symlink, this function returns information about the target, not the symlink.

See also group(), owner(), and ownerId().

bool QFileInfo::isAbsolute() const

Returns true if the file system entry's path is absolute, otherwise returns false (that is, the path is relative).

See also isRelative().

[since 6.4] bool QFileInfo::isAlias() const

Returns true if this object points to an alias; otherwise returns false.

Aliases only exist on macOS. They are treated as regular files, so opening an alias will open the file itself. In order to open the file or directory an alias references use symLinkTarget().

This function was introduced in Qt 6.4.

See also isFile(), isDir(), isSymLink(), and symLinkTarget().

bool QFileInfo::isBundle() const

Returns true if this object points to a bundle or to a symbolic link to a bundle on macOS and iOS; otherwise returns false.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isDir(), isSymLink(), and isFile().

bool QFileInfo::isDir() const

Returns true if this object points to a directory or to a symbolic link to a directory. Returns false if the object points to something that is not a directory (such as a file) or that does not exist.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isFile(), isSymLink(), and isBundle().

bool QFileInfo::isExecutable() const

Returns true if the file system entry this QFileInfo refers to is executable; otherwise returns false.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isReadable(), isWritable(), and permission().

bool QFileInfo::isFile() const

Returns true if this object points to a file or to a symbolic link to a file. Returns false if the object points to something that is not a file (such as a directory) or that does not exist.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isDir(), isSymLink(), and isBundle().

bool QFileInfo::isHidden() const

Returns true if the file system entry this QFileInfo refers to is `hidden'; otherwise returns false.

Note: This function returns true for the special entries "." and ".." on Unix, even though QDir::entryList treats them as shown. And note that, since this function inspects the file name, on Unix it will inspect the name of the symlink, if this file is a symlink, not the target's name.

On Windows, this function returns true if the target file is hidden (not the symlink).

bool QFileInfo::isJunction() const

Returns true if the object points to a junction; otherwise returns false.

Junctions only exist on Windows' NTFS file system, and are typically created by the mklink command. They can be thought of as symlinks for directories, and can only be created for absolute paths on the local volume.

bool QFileInfo::isNativePath() const

Returns true if the file path can be used directly with native APIs. Returns false if the file is otherwise supported by a virtual file system inside Qt, such as the Qt Resource System.

Note: Native paths may still require conversion of path separators and character encoding, depending on platform and input requirements of the native API.

See also QDir::toNativeSeparators(), QFile::encodeName(), filePath(), absoluteFilePath(), and canonicalFilePath().

bool QFileInfo::isReadable() const

Returns true if the user can read the file system entry this QFileInfo refers to; otherwise returns false.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isWritable(), isExecutable(), and permission().

bool QFileInfo::isRelative() const

Returns true if the file system entry's path is relative, otherwise returns false (that is, the path is absolute).

On Unix, absolute paths begin with the directory separator '/'. On Windows, absolute paths begin with a drive specification (for example, D:/).

See also isAbsolute().

bool QFileInfo::isRoot() const

Returns true if the object points to a directory or to a symbolic link to a directory, and that directory is the root directory; otherwise returns false.

bool QFileInfo::isShortcut() const

Returns true if this object points to a shortcut; otherwise returns false.

Shortcuts only exist on Windows and are typically .lnk files. For instance, true will be returned for shortcuts (*.lnk files) on Windows, but false will be returned on Unix (including macOS and iOS).

The shortcut (.lnk) files are treated as regular files. Opening those will open the .lnk file itself. In order to open the file a shortcut references to, it must uses symLinkTarget() on a shortcut.

See also isFile(), isDir(), isSymbolicLink(), and symLinkTarget().

bool QFileInfo::isSymLink() const

Returns true if this object points to a symbolic link, shortcut, or alias; otherwise returns false.

Symbolic links exist on Unix (including macOS and iOS) and Windows and are typically created by the ln -s or mklink commands, respectively. Opening a symbolic link effectively opens the link's target.

In addition, true will be returned for shortcuts (*.lnk files) on Windows, and aliases on macOS. This behavior is deprecated and will likely change in a future version of Qt. Opening a shortcut or alias will open the .lnk or alias file itself.

Example:

 QFileInfo info(fileName);
 if (info.isSymLink())
     fileName = info.symLinkTarget();

See also isFile(), isDir(), and symLinkTarget().

bool QFileInfo::isSymbolicLink() const

Returns true if this object points to a symbolic link; otherwise returns false.

Symbolic links exist on Unix (including macOS and iOS) and Windows (NTFS-symlink) and are typically created by the ln -s or mklink commands, respectively.

Unix handles symlinks transparently. Opening a symbolic link effectively opens the link's target.

In contrast to isSymLink(), false will be returned for shortcuts (*.lnk files) on Windows and aliases on macOS. Use QFileInfo::isShortcut() and QFileInfo::isAlias() instead.

See also isFile(), isDir(), isShortcut(), and symLinkTarget().

bool QFileInfo::isWritable() const

Returns true if the user can write to the file system entry this QFileInfo refers to; otherwise returns false.

If the file is a symlink, this function returns information about the target, not the symlink.

See also isReadable(), isExecutable(), and permission().

[since 6.2] QString QFileInfo::junctionTarget() const

Resolves an NTFS junction to the path it references.

Returns the absolute path to the directory an NTFS junction points to, or an empty string if the object is not an NTFS junction.

There is no guarantee that the directory named by the NTFS junction actually exists.

This function was introduced in Qt 6.2.

See also isJunction(), isFile(), isDir(), isSymLink(), isSymbolicLink(), and isShortcut().

QDateTime QFileInfo::lastModified() const

Returns the date and time when the file was last modified.

If the file is a symlink, this function returns information about the target, not the symlink.

This function overloads QFileInfo::lastModified(const QTimeZone &), and returns the same as lastModified(QTimeZone::LocalTime).

See also birthTime(), lastRead(), metadataChangeTime(), and fileTime().

[since 6.6] QDateTime QFileInfo::lastModified(const QTimeZone &tz) const

Returns the date and time when the file was last modified.

The returned time is in the time zone specified by tz. For example, you can use QTimeZone::LocalTime or QTimeZone::UTC to get the time in the Local time zone or UTC, respectively. Since native file system API typically uses UTC, using QTimeZone::UTC is often faster, as it does not require any conversions.

If the file is a symlink, this function returns information about the target, not the symlink.

This function was introduced in Qt 6.6.

See also birthTime(const QTimeZone &), lastRead(const QTimeZone &), metadataChangeTime(const QTimeZone &), and fileTime(QFileDevice::FileTime, const QTimeZone &).

QDateTime QFileInfo::lastRead() const

Returns the date and time when the file was last read (accessed).

On platforms where this information is not available, returns the same time as lastModified().

If the file is a symlink, this function returns information about the target, not the symlink.

This function overloads QFileInfo::lastRead(const QTimeZone &), and returns the same as lastRead(QTimeZone::LocalTime).

See also birthTime(), lastModified(), metadataChangeTime(), and fileTime().

[since 6.6] QDateTime QFileInfo::lastRead(const QTimeZone &tz) const

Returns the date and time when the file was last read (accessed).

The returned time is in the time zone specified by tz. For example, you can use QTimeZone::LocalTime or QTimeZone::UTC to get the time in the Local time zone or UTC, respectively. Since native file system API typically uses UTC, using QTimeZone::UTC is often faster, as it does not require any conversions.

On platforms where this information is not available, returns the same time as lastModified().

If the file is a symlink, this function returns information about the target, not the symlink.

This function was introduced in Qt 6.6.

See also birthTime(const QTimeZone &), lastModified(const QTimeZone &), metadataChangeTime(const QTimeZone &), and fileTime(QFileDevice::FileTime, const QTimeZone &).

bool QFileInfo::makeAbsolute()

If the file system entry's path is relative, this method converts it to an absolute path and returns true; if the path is already absolute, this method returns false.

See also filePath() and isRelative().

QDateTime QFileInfo::metadataChangeTime() const

Returns the date and time when the file's metadata was last changed, in local time.

A metadata change occurs when the file is first created, but it also occurs whenever the user writes or sets inode information (for example, changing the file permissions).

If the file is a symlink, this function returns information about the target, not the symlink.

This function overloads QFileInfo::metadataChangeTime(const QTimeZone &tz), and returns the same as metadataChangeTime(QTimeZone::LocalTime).

See also birthTime(), lastModified(), lastRead(), and fileTime().

[since 6.6] QDateTime QFileInfo::metadataChangeTime(const QTimeZone &tz) const

Returns the date and time when the file's metadata was last changed. A metadata change occurs when the file is first created, but it also occurs whenever the user writes or sets inode information (for example, changing the file permissions).

The returned time is in the time zone specified by tz. For example, you can use QTimeZone::LocalTime or QTimeZone::UTC to get the time in the Local time zone or UTC, respectively. Since native file system API typically uses UTC, using QTimeZone::UTC is often faster, as it does not require any conversions.

If the file is a symlink, this function returns information about the target, not the symlink.

This function was introduced in Qt 6.6.

See also birthTime(const QTimeZone &), lastModified(const QTimeZone &), lastRead(const QTimeZone &), and fileTime(QFileDevice::FileTime time, const QTimeZone &).

QString QFileInfo::owner() const

Returns the owner of the file. On systems where files do not have owners, or if an error occurs, an empty string is returned.

This function can be time consuming under Unix (in the order of milliseconds). On Windows, it will return an empty string unless the NTFS permissions check has been enabled.

If the file is a symlink, this function returns information about the target, not the symlink.

See also ownerId(), group(), and groupId().

uint QFileInfo::ownerId() const

Returns the id of the owner of the file.

On Windows and on systems where files do not have owners this function returns ((uint) -2).

If the file is a symlink, this function returns information about the target, not the symlink.

See also owner(), group(), and groupId().

QString QFileInfo::path() const

Returns the path of the file system entry this QFileInfo refers to, excluding the entry's name.

See also filePath(), absolutePath(), canonicalPath(), dir(), fileName(), and isRelative().

bool QFileInfo::permission(QFileDevice::Permissions permissions) const

Tests for file permissions. The permissions argument can be several flags of type QFile::Permissions OR-ed together to check for permission combinations.

On systems where files do not have permissions this function always returns true.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 if (fi.permission(QFile::WriteUser | QFile::ReadGroup))
     qWarning("I can change the file; my group can read the file");
 if (fi.permission(QFile::WriteGroup | QFile::WriteOther))
     qWarning("The group or others can change the file");

If the file is a symlink, this function returns information about the target, not the symlink.

See also isReadable(), isWritable(), and isExecutable().

QFileDevice::Permissions QFileInfo::permissions() const

Returns the complete OR-ed together combination of QFile::Permissions for the file.

If the file is a symlink, this function returns information about the target, not the symlink.

[since 6.6] QString QFileInfo::readSymLink() const

Read the path the symlink references.

Returns the raw path referenced by the symbolic link, without resolving a relative path relative to the directory containing the symbolic link. The returned string will only be an absolute path if the symbolic link actually references it as such. Returns an empty string if the object is not a symbolic link.

This function was introduced in Qt 6.6.

See also symLinkTarget(), exists(), isSymLink(), isDir(), and isFile().

void QFileInfo::refresh()

Refreshes the information about the file system entry this QFileInfo refers to, that is, reads in information from the file system the next time a cached property is fetched.

void QFileInfo::setCaching(bool enable)

If enable is true, enables caching of file information. If enable is false caching is disabled.

When caching is enabled, QFileInfo reads the file information from the file system the first time it's needed, but generally not later.

Caching is enabled by default.

See also refresh() and caching().

void QFileInfo::setFile(const QString &path)

Sets the path of the file system entry that this QFileInfo provides information about to path that can be absolute or relative.

On Unix, absolute paths begin with the directory separator '/'. On Windows, absolute paths begin with a drive specification (for example, D:/).

Relative paths begin with a directory name or a regular file name and specify a file system entry's path relative to the current working directory.

Example:

 QFileInfo info("/usr/bin/env");

 QString path = info.absolutePath(); // path = /usr/bin
 QString base = info.baseName(); // base = env

 info.setFile("/etc/hosts");

 path = info.absolutePath(); // path = /etc
 base = info.baseName(); // base = hosts

See also isFile(), isRelative(), QDir::setCurrent(), and QDir::isRelativePath().

void QFileInfo::setFile(const QFileDevice &file)

This is an overloaded function.

Sets the file that the QFileInfo provides information about to file.

If file includes a relative path, the QFileInfo will also have a relative path.

See also isRelative().

void QFileInfo::setFile(const QDir &dir, const QString &path)

This is an overloaded function.

Sets the path of the file system entry that this QFileInfo provides information about to path in directory dir.

If dir has a relative path, the QFileInfo will also have a relative path.

If path is absolute, then the directory specified by dir will be disregarded.

See also isRelative().

[since 6.0] void QFileInfo::setFile(const std::filesystem::path &path)

Sets the path of file system entry that this QFileInfo provides information about to path.

If path is relative, the QFileInfo will also have a relative path.

This function was introduced in Qt 6.0.

qint64 QFileInfo::size() const

Returns the file size in bytes. If the file does not exist or cannot be fetched, 0 is returned.

If the file is a symlink, this function returns information about the target, not the symlink.

See also exists().

[since 6.0] void QFileInfo::stat()

Reads all attributes from the file system.

This is useful when information about the file system is collected in a worker thread, and then passed to the UI in the form of caching QFileInfo instances.

This function was introduced in Qt 6.0.

See also setCaching() and refresh().

QString QFileInfo::suffix() const

Returns the suffix (extension) of the file.

The suffix consists of all characters in the file after (but not including) the last '.'.

Example:

 QFileInfo fi("/tmp/archive.tar.gz");
 QString ext = fi.suffix();  // ext = "gz"

The suffix of a file is computed equally on all platforms, independent of file naming conventions (e.g., ".bashrc" on Unix has an empty base name, and the suffix is "bashrc").

See also fileName(), completeSuffix(), baseName(), and completeBaseName().

[noexcept] void QFileInfo::swap(QFileInfo &other)

Swaps this file info with other. This function is very fast and never fails.

QString QFileInfo::symLinkTarget() const

Returns the absolute path to the file or directory a symbolic link points to, or an empty string if the object isn't a symbolic link.

This name may not represent an existing file; it is only a string.

See also exists(), isSymLink(), isDir(), and isFile().

bool QFileInfo::operator!=(const QFileInfo &fileinfo) const

Returns true if this QFileInfo refers to a different file system entry than the one referred to by fileinfo; otherwise returns false.

See also operator==().

QFileInfo &QFileInfo::operator=(const QFileInfo &fileinfo)

Makes a copy of the given fileinfo and assigns it to this QFileInfo.

[noexcept] QFileInfo &QFileInfo::operator=(QFileInfo &&other)

Move-assigns other to this QFileInfo instance.

bool QFileInfo::operator==(const QFileInfo &fileinfo) const

Returns true if this QFileInfo and fileinfo refer to the same entry on the file system; otherwise returns false.

Note that the result of comparing two empty QFileInfo objects, containing no file system entry references (paths that do not exist or are empty), is undefined.

See also operator!=().

 QDirIterator it(dir);
 while (it.hasNext()) {
     // Implicit conversion from QString (returned by it.next()):
     // may create unnecessary data structures and cause additional
     // accesses to the file system. Unless this macro is defined,
     // this line does not compile.

     QFileInfo fi = it.next();

     ~~~
 }

 QDirIterator it(dir);
 while (it.hasNext()) {
     // Extract the QFileInfo from the iterator directly:
     QFileInfo fi = it.nextFileInfo();

     ~~~
 }

 QFileInfo fi1 = some_string; // Does not compile unless this macro is defined
 QFileInfo fi2(some_string);  // OK
 QFileInfo fi3{some_string};  // Possibly better, avoids the risk of the Most Vexing Parse
 auto fi4 = QFileInfo(some_string); // OK