com.trolltech.qt.core
Class QFileInfo

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.core.QFileInfo
All Implemented Interfaces:
QtJambiInterface

public class QFileInfo
extends QtJambiObject

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.

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. By convention, QFileInfo interprets any path that ends with a slash '/' as a directory (e.g., "C:/WINDOWS/"), and those without a trailing slash (e.g., "C:/WINDOWS/hosts.txt") are treated as files.

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).

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());
    info1.isSymLink();          // returns false
    info1.absoluteFilePath();   // returns "/opt/pretty++/bin/untabify"
    info1.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());
    info1.isSymLink();          // returns false
    info1.absoluteFilePath();   // returns "C:/Pretty++/untabify"
    info1.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 and extension().

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.

See Also:
QDir, QFile

Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
Constructor Summary
QFileInfo()
          Constructs an empty QFileInfo object.
QFileInfo(QDir dir, java.lang.String file)
          Constructs a new QFileInfo that gives information about the given file in the directory dir.
QFileInfo(QFile file)
          Constructs a new QFileInfo that gives information about file file.
QFileInfo(QFileInfo fileinfo)
          Constructs a new QFileInfo that is a copy of the given fileinfo.
QFileInfo(java.lang.String file)
          Constructs a new QFileInfo that gives information about the given file.
 
Method Summary
 QDir absoluteDir()
          Returns the file's absolute path as a QDir object.
 java.lang.String absoluteFilePath()
          Returns the absolute path including the file name.
 java.lang.String absolutePath()
          Returns the file's path absolute path.
 java.lang.String baseName()
          Returns the base name of the file without the path.
 java.lang.String bundleName()
          Returns the name of the bundle.
 boolean caching()
          Returns true if caching is enabled; otherwise returns false.
 java.lang.String canonicalFilePath()
          Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.
 java.lang.String canonicalPath()
          Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.
 java.lang.String completeBaseName()
          Returns the complete base name of the file without the path.
 java.lang.String completeSuffix()
          Returns the complete suffix of the file.
 QDateTime created()
          Returns the date and time when the file was created.
 QDir dir()
          Returns the path of the object's parent directory as a QDir object.
 boolean equals(java.lang.Object other)
          
 boolean exists()
          Returns true if the file exists; otherwise returns false.
 java.lang.String fileName()
          Returns the name of the file, excluding the path.
 java.lang.String filePath()
          Returns the file name, including the path (which may be absolute or relative).
static QFileInfo fromNativePointer(QNativePointer nativePointer)
          This function returns the QFileInfo instance pointed to by nativePointer
 java.lang.String group()
          Returns the group of the file.
 int groupId()
          Returns the id of the group the file belongs to.
 boolean isAbsolute()
          Returns true if the file path name is absolute, otherwise returns false if the path is relative.
 boolean isBundle()
          Returns true if this object points to a bundle or to a symbolic link to a bundle on Mac OS X; otherwise returns false.
 boolean isDir()
          Returns true if this object points to a directory or to a symbolic link to a directory; otherwise returns false.
 boolean isExecutable()
          Returns true if the file is executable; otherwise returns false.
 boolean isFile()
          Returns true if this object points to a file or to a symbolic link to a file.
 boolean isHidden()
          Returns true if this is a `hidden' file; otherwise returns false.
 boolean isReadable()
          Returns true if the user can read the file; otherwise returns false.
 boolean isRelative()
          Returns true if the file path name is relative, otherwise returns false if the path is absolute (e.g. under Unix a path is absolute if it begins with a "/").
 boolean isRoot()
          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.
 boolean isSymLink()
          Returns true if this object points to a symbolic link (or to a shortcut on Windows); otherwise returns false.
 boolean isWritable()
          Returns true if the user can write to the file; otherwise returns false.
 QDateTime lastModified()
          Returns the date and time when the file was last modified.
 QDateTime lastRead()
          Returns the date and time when the file was last read (accessed).
 boolean makeAbsolute()
          Converts the file's path to an absolute path if it is not already in that form.
static QNativePointer nativePointerArray(QFileInfo[] array)
          This function returns a QNativePointer that is pointing to the specified QFileInfo array.
 java.lang.String owner()
          Returns the owner of the file.
 int ownerId()
          Returns the id of the owner of the file.
 java.lang.String path()
          Returns the file's path.
 boolean permission(QFile.Permission... permissions)
          Tests for file permissions.
 boolean permission(QFile.Permissions permissions)
          Tests for file permissions.
 QFile.Permissions permissions()
          Returns the complete OR-ed together combination of QFile::Permissions for the file.
 void refresh()
          Refreshes the information about the file, i.e. reads in information from the file system the next time a cached property is fetched.
 void setCaching(boolean on)
          If on is true, enables caching of file information.
 void setFile(QDir dir, java.lang.String file)
          Sets the file that the QFileInfo provides information about to file in directory dir.
 void setFile(QFile file)
          Sets the file that the QFileInfo provides information about to file.
 void setFile(java.lang.String file)
          Sets the file that the QFileInfo provides information about to file.
 long size()
          Returns the file size in bytes.
 java.lang.String suffix()
          Returns the suffix of the file.
 java.lang.String symLinkTarget()
          Returns the absolute path to the file or directory a symlink (or shortcut on Windows) points to, or a an empty string if the object isn't a symbolic link.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QFileInfo

public QFileInfo(QDir dir,
                 java.lang.String file)

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.

See Also:
isRelative

QFileInfo

public QFileInfo(QFile 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

QFileInfo

public QFileInfo(QFileInfo fileinfo)

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


QFileInfo

public QFileInfo(java.lang.String file)

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, QDir::isRelativePath

QFileInfo

public QFileInfo()

Constructs an empty QFileInfo object.

Note that an empty QFileInfo object contain no file reference.

See Also:
setFile
Method Detail

absoluteDir

public final QDir absoluteDir()

Returns the file's absolute path as a QDir object.

See Also:
filePath, fileName, isRelative, dir

absoluteFilePath

public final java.lang.String absoluteFilePath()

Returns the 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/'.

This function returns the same as filePath, unless isRelative is true.

If the QFileInfo is empty it returns QDir::currentPath().

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

See Also:
isRelative, filePath

absolutePath

public final java.lang.String absolutePath()

Returns the file's path absolute path. This doesn't include the file name.

See Also:
dir, filePath, fileName, isRelative, path

baseName

public final java.lang.String baseName()

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, completeBaseName

bundleName

public final java.lang.String bundleName()

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"

See Also:
isBundle, filePath, baseName, extension

caching

public final boolean caching()

Returns true if caching is enabled; otherwise returns false.

See Also:
setCaching, refresh

canonicalFilePath

public final java.lang.String canonicalFilePath()

Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.

On systems that do not have symbolic links this function will always return the same string that absoluteFilePath returns. If the canonical path does not exist (normally due to dangling symbolic links) canonicalFilePath returns an empty string.

See Also:
filePath, absoluteFilePath

canonicalPath

public final java.lang.String canonicalPath()

Returns the canonical path, i.e. a path without symbolic links or redundant "." or ".." elements.

On systems that do not have symbolic links this function will always return the same string that absolutePath returns. If the canonical path does not exist (normally due to dangling symbolic links) canonicalPath returns an empty string.

See Also:
absolutePath

completeBaseName

public final java.lang.String completeBaseName()

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, baseName

completeSuffix

public final java.lang.String completeSuffix()

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, completeBaseName

created

public final QDateTime created()

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, lastRead

dir

public final QDir dir()

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.

See Also:
dirPath, filePath, fileName, isRelative, absoluteDir

exists

public final boolean exists()

Returns true if the file exists; otherwise returns false.


fileName

public final java.lang.String fileName()

Returns the name of the file, excluding the path.

Example:

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

See Also:
isRelative, filePath, baseName, extension

filePath

public final java.lang.String filePath()

Returns the file name, including the path (which may be absolute or relative).

See Also:
isRelative, absoluteFilePath

group

public final java.lang.String group()

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, ownerId

groupId

public final int groupId()

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, ownerId

isAbsolute

public final boolean isAbsolute()

Returns true if the file path name is absolute, otherwise returns false if the path is relative.

See Also:
isRelative

isBundle

public final boolean isBundle()

Returns true if this object points to a bundle or to a symbolic link to a bundle on Mac OS X; otherwise returns false.

See Also:
isDir, isSymLink, isFile

isDir

public final boolean isDir()

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

See Also:
isFile, isSymLink, isBundle

isExecutable

public final boolean isExecutable()

Returns true if the file is executable; otherwise returns false.

See Also:
isReadable, isWritable, permission

isFile

public final boolean isFile()

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.

See Also:
isDir, isSymLink, isBundle

isHidden

public final boolean isHidden()

Returns true if this is a `hidden' file; otherwise returns false.

Note: This function returns true for the special entries "." and ".." on Unix, even though QDir::entryList threats them as shown.


isReadable

public final boolean isReadable()

Returns true if the user can read the file; otherwise returns false.

See Also:
isWritable, isExecutable, permission

isRelative

public final boolean isRelative()

Returns true if the file path name is relative, otherwise returns false if the path is absolute (e.g. under Unix a path is absolute if it begins with a "/").

See Also:
isAbsolute

isRoot

public final boolean isRoot()

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.


isSymLink

public final boolean isSymLink()

Returns true if this object points to a symbolic link (or to a shortcut on Windows); otherwise returns false.

On Unix (including Mac OS X), opening a symlink effectively opens the link's target. On Windows, it opens the .lnk file itself.

Example:

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

See Also:
isFile, isDir, symLinkTarget

isWritable

public final boolean isWritable()

Returns true if the user can write to the file; otherwise returns false.

See Also:
isReadable, isExecutable, permission

lastModified

public final QDateTime lastModified()

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

See Also:
created, lastRead

lastRead

public final QDateTime lastRead()

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

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

See Also:
created, lastModified

makeAbsolute

public final boolean makeAbsolute()

Converts the file's path to an absolute path if it is not already in that form. Returns true to indicate that the path was converted; otherwise returns false to indicate that the path was already absolute.

See Also:
filePath, isRelative

owner

public final java.lang.String owner()

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).

See Also:
ownerId, group, groupId

ownerId

public final int ownerId()

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).

See Also:
owner, group, groupId

path

public final java.lang.String path()

Returns the file's path. This doesn't include the file name.

See Also:
dir, filePath, fileName, isRelative, absolutePath

permission

public final boolean permission(QFile.Permission... permissions)

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");

See Also:
isReadable, isWritable, isExecutable

permission

public final boolean permission(QFile.Permissions permissions)

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");

See Also:
isReadable, isWritable, isExecutable

permissions

public final QFile.Permissions permissions()

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


refresh

public final void refresh()

Refreshes the information about the file, i.e. reads in information from the file system the next time a cached property is fetched.


setCaching

public final void setCaching(boolean on)

If on is true, enables caching of file information. If on 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, caching

setFile

public final void setFile(QDir dir,
                          java.lang.String file)

Sets the file that the QFileInfo provides information about to file in directory dir.

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

See Also:
isRelative

setFile

public final void setFile(java.lang.String file)

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

The file can also include an absolute or relative file path. Absolute paths begin with the directory separator (e.g. "/" under Unix) or a drive specification (under Windows). Relative file names begin with a directory name or a file name and specify a path relative to the current directory.

Example:

    QString absolute = "/local/bin";
    QString relative = "local/bin";
    QFileInfo absFile(absolute);
    QFileInfo relFile(relative);

    QDir::setCurrent(QDir::rootPath());
    // absFile and relFile now point to the same file

    QDir::setCurrent("/tmp");
    // absFile now points to "/local/bin",
    // while relFile points to "/tmp/local/bin"

See Also:
isRelative, QDir::setCurrent, QDir::isRelativePath

setFile

public final void setFile(QFile file)

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:
isFile, isRelative

size

public final long size()

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

See Also:
exists

suffix

public final java.lang.String suffix()

Returns the suffix 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, completeBaseName

symLinkTarget

public final java.lang.String symLinkTarget()

Returns the absolute path to the file or directory a symlink (or shortcut on Windows) points to, or a an empty string if the object isn't a symbolic link.

This name may not represent an existing file; it is only a string. QFileInfo::exists() returns true if the symlink points to an existing file.

See Also:
exists, isSymLink, isDir, isFile

fromNativePointer

public static QFileInfo fromNativePointer(QNativePointer nativePointer)
This function returns the QFileInfo instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

nativePointerArray

public static QNativePointer nativePointerArray(QFileInfo[] array)
This function returns a QNativePointer that is pointing to the specified QFileInfo array.

Parameters:
array - the array that the returned pointer will point to.
Returns:
a QNativePointer that is pointing to the specified array.

equals

public boolean equals(java.lang.Object other)

Overrides:
equals in class java.lang.Object