QFileInfo Class Reference |
flags | PermissionSpec |
QFileInfo () | |
QFileInfo ( const QString & file ) | |
QFileInfo ( const QFile & file ) | |
QFileInfo ( const QDir & dir, const QString & file ) | |
QFileInfo ( const QFileInfo & fileinfo ) | |
~QFileInfo () | |
QDir | absoluteDir () const |
QString | absoluteFilePath () const |
QString | absolutePath () const |
QString | baseName () const |
QString | bundleName () const |
bool | caching () const |
QString | canonicalFilePath () const |
QString | canonicalPath () const |
QString | completeBaseName () const |
QString | completeSuffix () const |
QDateTime | created () const |
QDir | dir () const |
bool | exists () const |
QString | fileName () const |
QString | filePath () const |
QString | group () const |
uint | groupId () const |
bool | isAbsolute () const |
bool | isBundle () const |
bool | isDir () const |
bool | isExecutable () const |
bool | isFile () const |
bool | isHidden () const |
bool | isReadable () const |
bool | isRelative () const |
bool | isRoot () const |
bool | isSymLink () const |
bool | isWritable () const |
QDateTime | lastModified () const |
QDateTime | lastRead () const |
bool | makeAbsolute () |
QString | owner () const |
uint | ownerId () const |
QString | path () const |
bool | permission ( QFile::Permissions permissions ) const |
QFile::Permissions | permissions () const |
void | refresh () |
void | setCaching ( bool enable ) |
void | setFile ( const QString & file ) |
void | setFile ( const QFile & file ) |
void | setFile ( const QDir & dir, const QString & file ) |
qint64 | size () const |
QString | suffix () const |
QString | symLinkTarget () const |
bool | operator!= ( const QFileInfo & fileinfo ) |
bool | operator!= ( const QFileInfo & fileinfo ) const |
QFileInfo & | operator= ( const QFileInfo & fileinfo ) |
bool | operator== ( const QFileInfo & fileinfo ) |
bool | operator== ( const QFileInfo & fileinfo ) const |
typedef | QFileInfoList |
The QFileInfo class provides system-independent file information.
QFileInfo provides information about a file's name and position (path) in the file system, its access rights and whether it is a directory or symbolic link, etc. The file's size and last modified/read times are also available. QFileInfo can also be used to obtain information about a Qt resource.
A QFileInfo can point to a file with either a relative or an absolute file path. Absolute file paths begin with the directory separator "/" (or with a drive specification on Windows). Relative file names begin with a directory name or a file name and specify a path relative to the current working directory. An example of an absolute path is the string "/tmp/quartz". A relative path might look like "src/fatlib". You can use the function isRelative() to check whether a QFileInfo is using a relative or an absolute file path. You can call the function makeAbsolute() to convert a relative QFileInfo's path to an absolute path.
The file that the QFileInfo works on is set in the constructor or later with setFile(). Use exists() to see if the file exists and size() to get its size.
The file's type is obtained with isFile(), isDir() and isSymLink(). The symLinkTarget() function provides the name of the file the symlink points to.
On Unix (including Mac OS X), the symlink has the same size() has the file it points to, because Unix handles symlinks transparently; similarly, opening a symlink using QFile effectively opens the link's target. For example:
#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
On Windows, symlinks (shortcuts) are .lnk files. The reported size() is that of the symlink (not the link's target), and opening a symlink using QFile opens the .lnk file. For example:
#ifdef Q_OS_WIN QFileInfo info1("C:\\Documents and Settings\\Bob\\untabify.lnk"); info1.isSymLink(); // returns true info1.absoluteFilePath(); // returns "C:/Documents and Settings/Bob/untabify.lnk" info1.size(); // returns 743 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
Elements of the file's name can be extracted with path() and fileName(). The fileName()'s parts can be extracted with baseName(), suffix() or completeSuffix(). QFileInfo objects to directories created by Qt classes will not have a trailing file separator. If you wish to use trailing separators in your own file info objects, just append one to the file name given to the constructors or setFile().
The file's dates are returned by created(), lastModified() and lastRead(). Information about the file's access permissions is obtained with isReadable(), isWritable() and isExecutable(). The file's ownership is available from owner(), ownerId(), group() and groupId(). You can examine a file's permissions and ownership in a single statement using the permission() function.
Some of QFileInfo's functions query the file system, but for performance reasons, some functions only operate on the file name itself. For example: To return the absolute path of a relative file name, absolutePath() has to query the file system. The path() function, however, can work on the file name directly, and so it is faster.
Note: To speed up performance, QFileInfo caches information about the file.
To speed up performance, QFileInfo caches information about the file. Because files can be changed by other users or programs, or even by other parts of the same program, there is a function that refreshes the file information: refresh(). If you want to switch off a QFileInfo's caching and force it to access the file system every time you request information from it call setCaching(false).
Constructs an empty QFileInfo object.
Note that an empty QFileInfo object contain no file reference.
See also setFile().
Constructs a new QFileInfo that gives information about the given file. The file can also include an absolute or relative path.
See also setFile(), isRelative(), QDir::setCurrent(), and QDir::isRelativePath().
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().
Constructs a new QFileInfo that gives information about the given file in the directory dir.
If dir has a relative path, the QFileInfo will also have a relative path.
If file is an absolute path, then the directory specified by dir will be disregarded.
See also isRelative().
Constructs a new QFileInfo that is a copy of the given fileinfo.
Destroys the QFileInfo and frees its resources.
Returns the file's absolute path as a QDir object.
See also dir(), filePath(), fileName(), and isRelative().
Returns an absolute path including the file name.
The absolute path name consists of the full path and the file name. On Unix this will always begin with the root, '/', directory. On Windows this will always begin 'D:/' where D is a drive letter, except for network shares that are not mapped to a drive letter, in which case the path will begin '//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.
If the QFileInfo is empty it returns QDir::currentPath().
See also filePath(), canonicalFilePath(), and isRelative().
Returns a file's path absolute path. This doesn't include the file name.
On Unix the absolute path will always begin with the root, '/', directory. On Windows this will always begin 'D:/' where D is a drive letter, except for network shares that are not mapped to a drive letter, in which case the path will begin '//sharename/'.
In contrast to canonicalPath() symbolic links or redundant "." or ".." elements are not necessarily removed.
Warning: If the QFileInfo object was created with an empty QString, the behavior of this function is undefined.
See also absoluteFilePath(), path(), canonicalPath(), fileName(), and isRelative().
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().
Returns the name of the bundle.
On Mac OS X 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"
This function was introduced in Qt 4.3.
See also isBundle(), filePath(), baseName(), and extension().
Returns true if caching is enabled; otherwise returns false.
See also setCaching() and refresh().
Returns the canonical path including the file name, i.e. an absolute path without symbolic links or redundant "." or ".." elements.
If the file does not exist, canonicalFilePath() returns an empty string.
See also filePath(), absoluteFilePath(), and dir().
Returns the file's path canonical path (excluding the file name), i.e. an absolute path without symbolic links or redundant "." or ".." elements.
If the file does not exist, canonicalPath() returns an empty string.
See also path() and absolutePath().
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().
Returns the complete suffix 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().
Returns the date and time when the file was created.
On most Unix systems, this function returns the time of the last status change. A status change occurs when the file is created, but it also occurs whenever the user writes or sets inode information (for example, changing the file permissions).
If neither creation time nor "last status change" time are not available, returns the same as lastModified().
See also lastModified() and lastRead().
Returns the path of the object's parent directory as a QDir object.
Note: The QDir returned always corresponds to the object's parent directory, even if the QFileInfo represents a directory.
For each of the follwing, dir() returns a QDir for "~/examples/191697".
QFileInfo fileInfo1("~/examples/191697/."); QFileInfo fileInfo2("~/examples/191697/.."); QFileInfo fileInfo3("~/examples/191697/main.cpp");
For each of the follwing, dir() returns a QDir for ".".
QFileInfo fileInfo4("."); QFileInfo fileInfo5(".."); QFileInfo fileInfo6("main.cpp");
See also absolutePath(), filePath(), fileName(), isRelative(), and absoluteDir().
Returns true if the file exists; otherwise returns false.
Note: If the file is a symlink that points to a non existing file, false is returned.
Returns the name of the file, excluding the path.
Example:
QFileInfo fi("/tmp/archive.tar.gz"); QString name = fi.fileName(); // name = "archive.tar.gz"
Note that, if this QFileInfo object is given a path ending in a slash, the name of the file is considered empty.
See also isRelative(), filePath(), baseName(), and extension().
Returns the file name, including the path (which may be absolute or relative).
See also absoluteFilePath(), canonicalFilePath(), and isRelative().
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).
See also groupId(), owner(), and ownerId().
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.
See also group(), owner(), and ownerId().
Returns true if the file path name is absolute, otherwise returns false if the path is relative.
See also isRelative().
Returns true if this object points to a bundle or to a symbolic link to a bundle on Mac OS X; otherwise returns false.
This function was introduced in Qt 4.3.
See also isDir(), isSymLink(), and isFile().
Returns true if this object points to a directory or to a symbolic link to a directory; otherwise returns false.
See also isFile(), isSymLink(), and isBundle().
Returns true if the file is executable; otherwise returns false.
See also isReadable(), isWritable(), and permission().
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 which isn't a file, such as a directory.
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