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TQFileInfo Class Reference

The TQFileInfo class provides system-independent file information. More...

All the functions in this class are reentrant when TQt is built with thread support.

#include <qfileinfo.h>

List of all member functions.

Public Members


Detailed Description

The TQFileInfo class provides system-independent file information.

TQFileInfo 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.

A TQFileInfo 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 TQFileInfo is using a relative or an absolute file path. You can call the function convertToAbs() to convert a relative TQFileInfo's path to an absolute path.

The file that the TQFileInfo 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.

To speed up performance, TQFileInfo 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 TQFileInfo'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 readLink() function provides the name of the file the symlink points to.

Elements of the file's name can be extracted with dirPath() 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.

If you need to read and traverse directories, see the TQDir class.

See also Input/Output and Networking.


Member Type Documentation

TQFileInfo::PermissionSpec

This enum is used by the permission() function to report the permissions and ownership of a file. The values may be OR-ed together to test multiple permissions and ownership values.

Warning: The semantics of ReadUser, WriteUser and ExeUser are unfortunately not platform independent: on Unix, the rights of the owner of the file are returned and on Windows the rights of the current user are returned. This behavior might change in a future TQt version. If you want to find the rights of the owner of the file, you should use the flags ReadOwner, WriteOwner and ExeOwner. If you want to find out the rights of the current user, you should use isReadable(), isWritable() and isExecutable().


Member Function Documentation

TQFileInfo::TQFileInfo ()

Constructs a new empty TQFileInfo.

TQFileInfo::TQFileInfo ( const TQString & file )

Constructs a new TQFileInfo that gives information about the given file. The file can also include an absolute or relative path.

Warning: Some functions might behave in a counter-intuitive way if file has a trailing directory separator.

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

TQFileInfo::TQFileInfo ( const TQFile & file )

Constructs a new TQFileInfo that gives information about file file.

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

See also isRelative().

TQFileInfo::TQFileInfo ( const TQDir & d, const TQString & fileName )

Constructs a new TQFileInfo that gives information about the file called fileName in the directory d.

If d has a relative path, the TQFileInfo will also have a relative path.

See also isRelative().

TQFileInfo::TQFileInfo ( const TQFileInfo & fi )

Constructs a new TQFileInfo that is a copy of fi.

TQFileInfo::~TQFileInfo ()

Destroys the TQFileInfo and frees its resources.

TQString TQFileInfo::absFilePath () const

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 TQFileInfo is empty it returns TQDir::currentDirPath().

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

See also isRelative() and filePath().

Examples: biff/biff.cpp and fileiconview/qfileiconview.cpp.

TQString TQFileInfo::baseName ( bool complete = FALSE ) const

Returns the base name of the file.

If complete is FALSE (the default) the base name consists of all characters in the file name up to (but not including) the first '.' character.

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

The path is not included in either case.

Example:

        TQFileInfo fi( "/tmp/archive.tar.gz" );
        TQString base = fi.baseName();  // base = "archive"
        base = fi.baseName( TRUE );    // base = "archive.tar"
    

See also fileName() and extension().

bool TQFileInfo::caching () const

Returns TRUE if caching is enabled; otherwise returns FALSE.

See also setCaching() and refresh().

bool TQFileInfo::convertToAbs ()

Converts the file's path to an absolute path.

If it is already absolute, nothing is done.

See also filePath() and isRelative().

TQDateTime TQFileInfo::created () const

Returns the date and time when the file was created.

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

See also lastModified() and lastRead().

TQDir TQFileInfo::dir ( bool absPath = FALSE ) const

Returns the file's path as a TQDir object.

If the TQFileInfo is relative and absPath is FALSE, the TQDir will be relative; otherwise it will be absolute.

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

Example: fileiconview/qfileiconview.cpp.

TQString TQFileInfo::dirPath ( bool absPath = FALSE ) const

Returns the file's path.

If absPath is TRUE an absolute path is returned.

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

Example: fileiconview/qfileiconview.cpp.

bool TQFileInfo::exists () const

Returns TRUE if the file exists; otherwise returns FALSE.

Examples: biff/biff.cpp, distributor/distributor.ui.h, and i18n/main.cpp.

TQString TQFileInfo::extension ( bool complete = TRUE ) const

Returns the file's extension name.

If complete is TRUE (the default), extension() returns the string of all characters in the file name after (but not including) the first '.' character.

If complete is FALSE, extension() returns the string of all characters in the file name after (but not including) the last '.' character.

Example:

        TQFileInfo fi( "/tmp/archive.tar.gz" );
        TQString ext = fi.extension();  // ext = "tar.gz"
        ext = fi.extension( FALSE );   // ext = "gz"
    

See also fileName() and baseName().

Example: qdir/qdir.cpp.

TQString TQFileInfo::fileName () const

Returns the name of the file, excluding the path.

Example:

        TQFileInfo fi( "/tmp/archive.tar.gz" );
        TQString name = fi.fileName();           // name = "archive.tar.gz"
    

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

Examples: dirview/dirview.cpp, fileiconview/qfileiconview.cpp, and network/ftpclient/ftpmainwindow.ui.h.

TQString TQFileInfo::filePath () const

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

See also isRelative() and absFilePath().

Examples: dirview/main.cpp and fileiconview/qfileiconview.cpp.

TQString TQFileInfo::group () const

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

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

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

uint TQFileInfo::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.

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

bool TQFileInfo::isDir () const

Returns TRUE if this object points to a directory or to a symbolic link to a directory; otherwise returns FALSE.

See also isFile() and isSymLink().

Examples: dirview/dirview.cpp and fileiconview/qfileiconview.cpp.

bool TQFileInfo::isExecutable () const

Returns TRUE if the file is executable; otherwise returns FALSE.

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

bool TQFileInfo::isFile () const

Returns TRUE if this object points to a file. Returns FALSE if the object points to something which isn't a file, e.g. a directory or a symlink.

See also isDir() and isSymLink().

Examples: dirview/dirview.cpp, distributor/distributor.ui.h, fileiconview/qfileiconview.cpp, and qdir/qdir.cpp.

bool TQFileInfo::isHidden () const

Returns TRUE if the file is hidden; otherwise returns FALSE.

On Unix-like operating systems, including Mac OS X, a file is hidden if its name begins with ".". On Windows a file is hidden if its hidden attribute is set.

bool TQFileInfo::isReadable () const

Returns TRUE if the file is readable; otherwise returns FALSE.

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

Example: distributor/distributor.ui.h.

bool TQFileInfo::isRelative () const

Returns TRUE if the file path name is relative. Returns FALSE if the path is absolute (e.g. under Unix a path is absolute if it begins with a "/").

bool TQFileInfo::isSymLink () const

Returns TRUE if this object points to a symbolic link (or to a shortcut on Windows, or an alias on Mac OS X); otherwise returns FALSE.

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

Examples: dirview/dirview.cpp, distributor/distributor.ui.h, and fileiconview/qfileiconview.cpp.

bool TQFileInfo::isWritable () const

Returns TRUE if the file is writable; otherwise returns FALSE.

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

Example: distributor/distributor.ui.h.

TQDateTime TQFileInfo::lastModified () const

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

See also created() and lastRead().

Example: biff/biff.cpp.

TQDateTime TQFileInfo::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 as lastModified().

See also created() and lastModified().

Example: biff/biff.cpp.

TQFileInfo & TQFileInfo::operator= ( const TQFileInfo & fi )

Makes a copy of fi and assigns it to this TQFileInfo.

TQString TQFileInfo::owner () const

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

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

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

uint TQFileInfo::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).

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

bool TQFileInfo::permission ( int permissionSpec ) const

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

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

Example:

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

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

TQString TQFileInfo::readLink () const

Returns the name a symlink (or shortcut on Windows) points to, or a TQString::null if the object isn't a symbolic link.

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

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

void TQFileInfo::refresh () const

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

See also setCaching().

void TQFileInfo::setCaching ( bool enable )

If enable is TRUE, enables caching of file information. If enable is FALSE caching is disabled.

When caching is enabled, TQFileInfo 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 TQFileInfo::setFile ( const TQString & file )

Sets the file that the TQFileInfo 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:

    TQString absolute = "/local/bin";
    TQString relative = "local/bin";
    TQFileInfo absFile( absolute );
    TQFileInfo relFile( relative );

    TQDir::setCurrent( TQDir::rootDirPath() );
    // absFile and relFile now point to the same file

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

See also isRelative(), TQDir::setCurrent(), and TQDir::isRelativePath().

Example: biff/biff.cpp.

void TQFileInfo::setFile ( const TQFile & file )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

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

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

See also isRelative().

void TQFileInfo::setFile ( const TQDir & d, const TQString & fileName )

This is an overloaded member function, provided for convenience. It behaves essentially like the above function.

Sets the file that the TQFileInfo provides information about to fileName in directory d.

If fileName includes a relative path, the TQFileInfo will also have a relative path.

See also isRelative().

uint TQFileInfo::size () const

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

Example: qdir/qdir.cpp.


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