QFileInfo Class Reference

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

#include <qfileinfo.h>

Public Types
enum	PermissionSpec {   ReadUser = 0400, WriteUser = 0200, ExeUser = 0100, ReadGroup = 0040,   WriteGroup = 0020, ExeGroup = 0010, ReadOther = 0004, WriteOther = 0002,   ExeOther = 0001 }

Public Member Functions
	QFileInfo ()
	QFileInfo (const QString &file)
	QFileInfo (const QFile &)
	QFileInfo (const QDir &, const QString &fileName)
	QFileInfo (const QFileInfo &)
	~QFileInfo ()
QFileInfo &	operator= (const QFileInfo &)
void	setFile (const QString &file)
void	setFile (const QFile &)
void	setFile (const QDir &, const QString &fileName)
bool	exists () const
void	refresh () const
bool	caching () const
void	setCaching (bool)
QString	filePath () const
QString	fileName () const
QString	absFilePath () const
QString	baseName () const
QString	extension (bool complete=TRUE) const
QString	dirPath (bool absPath=FALSE) const
QDir	dir (bool absPath=FALSE) const
bool	isReadable () const
bool	isWritable () const
bool	isExecutable () const
bool	isRelative () const
bool	convertToAbs ()
bool	isFile () const
bool	isDir () const
bool	isSymLink () const
QString	readLink () const
QString	owner () const
uint	ownerId () const
QString	group () const
uint	groupId () const
bool	permission (int permissionSpec) const
uint	size () const
QDateTime	lastModified () const
QDateTime	lastRead () const

Private Member Functions
void	doStat () const

Static Private Member Functions
static void	slashify (QString &)
static void	makeAbs (QString &)

Private Attributes
QString	fn
QFileInfoCache *	fic
bool	cache

Detailed Description

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 a symbolic link. Its size and last modified/read times are also available.

To speed up performance QFileInfo caches information about the file. Since 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 would rather like a QFileInfo to access the file system every time you request information from it, you can call the function setCaching( FALSE ).

A QFileInfo can point to a file using either a relative or an absolute file path. Absolute file paths begin with the directory separator ('/') or a drive specification (not applicable to UNIX). Relative file names begin with a directory name or a file name and specify a path relative to the current 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 if a QFileInfo is using a relative or an absolute file path. You can call the function convertToAbs() to convert a relative QFileInfo to an absolute one.

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

Definition at line 51 of file qfileinfo.h.

Member Enumeration Documentation

enum QFileInfo::PermissionSpec

Enumerator
ReadUser
WriteUser
ExeUser
ReadGroup
WriteGroup
ExeGroup
ReadOther
WriteOther
ExeOther

Definition at line 54 of file qfileinfo.h.

                        {
        ReadUser  = 0400, WriteUser  = 0200, ExeUser  = 0100,
        ReadGroup = 0040, WriteGroup = 0020, ExeGroup = 0010,
        ReadOther = 0004, WriteOther = 0002, ExeOther = 0001 };

Constructor & Destructor Documentation

QFileInfo::QFileInfo

(

)

Constructs a new empty QFileInfo.

Definition at line 83 of file qfileinfo.cpp.

{
    fic   = 0;
    cache = TRUE;
}

QFileInfo::QFileInfo

(

const QString &

file

)

Constructs a new QFileInfo that gives information about the given file. The string given can be an absolute or a relative file path.

See also

bool setFile(QString ), isRelative(), QDir::setCurrent(), QDir::isRelativePath()

Definition at line 97 of file qfileinfo.cpp.

{
    fn    = file;
    slashify( fn );
    fic   = 0;
    cache = TRUE;
}

QFileInfo::QFileInfo

(

const QFile &

file

)

Constructs a new QFileInfo that gives information about file.

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

See also

isRelative()

Definition at line 113 of file qfileinfo.cpp.

{
    fn    = file.name();
    slashify( fn );
    fic   = 0;
    cache = TRUE;
}

QFileInfo::QFileInfo	(	const QDir &	d,
		const QString &	fileName
	)

Constructs a new QFileInfo that gives information about the file named fileName in the directory d.

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

See also

isRelative()

Definition at line 130 of file qfileinfo.cpp.

{
    fn    = d.filePath( fileName );
    slashify( fn );
    fic   = 0;
    cache = TRUE;
}

QFileInfo::QFileInfo

(

const QFileInfo &

fi

)

Constructs a new QFileInfo that is a copy of fi.

Definition at line 142 of file qfileinfo.cpp.

{
    fn = fi.fn;
    if ( fi.fic ) {
        fic = new QFileInfoCache;
        *fic = *fi.fic;
    } else {
        fic = 0;
    }
    cache = fi.cache;
}

QFileInfo::~QFileInfo

(

)

Destructs the QFileInfo.

Definition at line 158 of file qfileinfo.cpp.

{
    delete fic;
}

Member Function Documentation

QString QFileInfo::absFilePath

(

)

const

Returns the absolute path name.

The absolute path name is the file name including the absolute path. If the QFileInfo is absolute (i.e. not relative) this function will return the same string as filePath().

Note that this function can be time-consuming under UNIX. (in the order of milliseconds on a 486 DX2/66 running Linux).

See also

isRelative(), filePath()

Definition at line 410 of file qfileinfo_unix.cpp.

{
    if ( QDir::isRelativePath(fn) ) {
        QString tmp = QDir::currentDirPath();
        tmp += '/';
        tmp += fn;
        makeAbs( tmp );
        return QDir::cleanDirPath( tmp );
    } else {
        QString tmp = fn;
        makeAbs( tmp );
        return QDir::cleanDirPath( tmp );
    }

}

QString QFileInfo::baseName

(

)

const

Returns the base name of the file.

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

Example:

QFileInfo fi( "/tmp/abdomen.lower" );
QString base = fi.baseName();                // base = "abdomen"

See also

fileName(), extension()

Definition at line 341 of file qfileinfo.cpp.

{
    QString tmp = fileName();
    int pos = tmp.find( '.' );
    if ( pos == -1 )
        return tmp;
    else
        return tmp.left( pos );
}

bool QFileInfo::caching ( ) const

inline

Returns TRUE if caching is enabled.

See also

setCaching(), refresh()

Definition at line 132 of file qfileinfo.h.

{
    return cache;
}

bool QFileInfo::convertToAbs

(

)

Converts the file path name to an absolute path.

If it is already absolute nothing is done.

See also

filePath(), isRelative()

Definition at line 452 of file qfileinfo.cpp.

{
    if ( isRelative() )
        fn = absFilePath();
    return QDir::isRelativePath( fn );
}

QDir QFileInfo::dir

(

bool

absPath = FALSE

)

const

Returns the directory path of the file.

If the QFileInfo is relative and absPath is FALSE, the QDir will be relative, otherwise it will be absolute.

See also

dirPath(), filePath(), fileName(), isRelative()

Definition at line 393 of file qfileinfo.cpp.

{
    return QDir( dirPath(absPath) );
}

QString QFileInfo::dirPath

(

bool

absPath = FALSE

)

const

Returns the directory path of the file.

If absPath is TRUE an absolute path is always returned.

See also

dir(), filePath(), fileName(), isRelative()

Definition at line 358 of file qfileinfo_unix.cpp.

{
    QString s;
    if ( absPath )
        s = absFilePath();
    else
        s = fn;
    int pos = s.findRev( '/' );
    if ( pos == -1 ) {
        return QString::fromLatin1(".");
    } else {
        if ( pos == 0 )
            return QString::fromLatin1( "/" );
        return s.left( pos );
    }
}

void QFileInfo::doStat ( ) const

private

Definition at line 324 of file qfileinfo_unix.cpp.

{
    QFileInfo *that = ((QFileInfo*)this);       // mutable function
    if ( !that->fic )
        that->fic = new QFileInfoCache;
    STATBUF *b = &that->fic->st;
    that->fic->isSymLink = FALSE;

#if defined(_OS_UNIX_) && defined(S_IFLNK)
    if ( ::lstat(QFile::encodeName(fn),b) == 0 ) {
        if ( S_ISLNK( b->st_mode ) )
            that->fic->isSymLink = TRUE;
        else
            return;
    }
#endif
    int r;

    r = STAT( QFile::encodeName(fn), b );

    if ( r != 0 ) {
        delete that->fic;
        that->fic = 0;
    }
}

bool QFileInfo::exists

(

)

const

Returns TRUE if the file pointed to exists, otherwise FALSE.

Definition at line 265 of file qfileinfo.cpp.

{
    return qt_file_access( fn, F_OK );
}

QString QFileInfo::extension

(

bool

complete = TRUE

)

const

Returns the extension name of the file.

If complete is TRUE (the default), extension() returns the string of all characters in the file name after (but not including) the first '.' character. For a file named "archive.tar.gz" this returns "tar.gz".

If complete is FALSE, extension() returns the string of all characters in the file name after (but not including) the last '.' character. For a file named "archive.tar.gz" this returns "gz".

Example:

QFileInfo fi( "lex.yy.c" );
QString ext = fi.extension();                // ext = "yy.c"
QString ext = fi.extension( FALSE ); // ext = "c"

See also

fileName(), baseName()

Definition at line 374 of file qfileinfo.cpp.

{
    QString s = fileName();
    int pos = complete ? s.find( '.' ) : s.findRev( '.' );
    if ( pos < 0 )
        return QString::fromLatin1( "" );
    else
        return s.right( s.length() - pos - 1 );
}

QString QFileInfo::fileName

(

)

const

Returns the name of the file, the file path is not included.

Example:

QFileInfo fi( "/tmp/abdomen.lower" );
QString name = fi.fileName();                // name = "abdomen.lower"

See also

isRelative(), filePath(), baseName(), extension()

Definition at line 387 of file qfileinfo_unix.cpp.

{
    int p = fn.findRev( '/' );
    if ( p == -1 ) {
        return fn;
    } else {
        return fn.mid(p+1);
    }
}

QString QFileInfo::filePath

(

)

const

Returns the name, i.e. the file name including the path (which can be absolute or relative).

See also

isRelative(), absFilePath()

Definition at line 321 of file qfileinfo.cpp.

{
    return fn;
}

QString QFileInfo::group

(

)

const

Returns the group the file belongs to.

On systems where files do not have groups this function always returns 0.

Note that this function can be time-consuming under UNIX (in the order of milliseconds on a 486 DX2/66 running Linux).

See also

groupId(), owner(), ownerId()

Definition at line 187 of file qfileinfo_unix.cpp.

{
    struct group *gr = getgrgid( groupId() );
    if ( gr )
        return QFile::decodeName( gr->gr_name );
    return QString::null;
}

uint QFileInfo::groupId

(

)

const

Returns the id of the group the file belongs to.

On systems where files do not have groups this function always returns ((uind) -2).

See also

group(), owner(), ownerId()

Definition at line 204 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    if ( fic )
        return fic->st.st_gid;
    return nobodyID;
}

bool QFileInfo::isDir

(

)

const

Returns TRUE if we are pointing to a directory or a symbolic link to a directory.

See also

isFile(), isSymLink()

Definition at line 88 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    return fic ? (fic->st.st_mode & STAT_MASK) == STAT_DIR : FALSE;
}

bool QFileInfo::isExecutable

(

)

const

Returns TRUE if the file is executable.

See also

isReadable(), isWritable(), permission()

Definition at line 425 of file qfileinfo.cpp.

{
    return qt_file_access( fn, X_OK );
}

bool QFileInfo::isFile

(

)

const

Returns TRUE if we are pointing to a real file.

See also

isDir(), isSymLink()

Definition at line 75 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    return fic ? (fic->st.st_mode & STAT_MASK) == STAT_REG : FALSE;
}

bool QFileInfo::isReadable

(

)

const

Returns TRUE if the file is readable.

See also

isWritable(), isExecutable(), permission()

Definition at line 405 of file qfileinfo.cpp.

{
    return qt_file_access( fn, R_OK );
}

bool QFileInfo::isRelative

(

)

const

Returns TRUE if the file path name is relative to the current directory, FALSE if the path is absolute (e.g. under UNIX a path is relative if it does not start with a '/').

According to Einstein this function should always return TRUE.

Definition at line 439 of file qfileinfo.cpp.

{
    return QDir::isRelativePath( fn );
}

bool QFileInfo::isSymLink

(

)

const

Returns TRUE if we are pointing to a symbolic link.

See also

isFile(), isDir(), readLink()

Definition at line 100 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    return fic ? fic->isSymLink : FALSE;
}

bool QFileInfo::isWritable

(

)

const

Returns TRUE if the file is writable.

See also

isReadable(), isExecutable(), permission()

Definition at line 415 of file qfileinfo.cpp.

{
    return qt_file_access( fn, W_OK );
}

QDateTime QFileInfo::lastModified

(

)

const

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

See also

lastRead()

Definition at line 294 of file qfileinfo_unix.cpp.

{
    QDateTime dt;
    if ( !fic || !cache )
        doStat();
    if ( fic )
        dt.setTime_t( (uint)fic->st.st_mtime );
    return dt;
}

QDateTime QFileInfo::lastRead

(

)

const

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

On systems that do not support last read times, the modification time is returned.

See also

lastModified()

Definition at line 313 of file qfileinfo_unix.cpp.

{
    QDateTime dt;
    if ( !fic || !cache )
        doStat();
    if ( fic )
        dt.setTime_t( (uint)fic->st.st_atime );
    return dt;
}

void QFileInfo::makeAbs ( QString &  )

staticprivate

Definition at line 64 of file qfileinfo_unix.cpp.

{
    return;
}

QFileInfo & QFileInfo::operator=

(

const QFileInfo &

fi

)

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

Definition at line 168 of file qfileinfo.cpp.

{
    fn = fi.fn;
    if ( !fi.fic ) {
        delete fic;
        fic = 0;
    } else {
        if ( !fic ) {
            fic = new QFileInfoCache;
            CHECK_PTR( fic );
        }
        *fic = *fi.fic;
    }
    cache = fi.cache;
    return *this;
}

QString QFileInfo::owner

(

)

const

Returns the owner of the file.

On systems where files do not have owners this function returns 0.

Note that this function can be time-consuming under UNIX. (in the order of milliseconds on a 486 DX2/66 running Linux).

See also

ownerId(), group(), groupId()

Returns the owner of the file.

On systems where files do not have owners this function returns a null string.

Note that this function can be time-consuming under UNIX. (in the order of milliseconds on a 486 DX2/66 running Linux).

See also

ownerId(), group(), groupId()

Definition at line 150 of file qfileinfo_unix.cpp.

{
    passwd *pw = getpwuid( ownerId() );
    if ( pw )
        return QFile::decodeName( pw->pw_name );
    return QString::null;
}

uint QFileInfo::ownerId

(

)

const

Returns the id of the owner of the file.

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

See also

owner(), group(), groupId()

Definition at line 166 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    if ( fic )
        return fic->st.st_uid;
    return nobodyID;
}

bool QFileInfo::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:

QFileInfo fi( "/tmp/tonsils" );
if ( fi.permission( QFileInfo::WriteUser | QFileInfo::ReadGroup ) )
    qWarning( "Tonsils can be changed by me, and the group can read them.");
if ( fi.permission( QFileInfo::WriteGroup | QFileInfo::WriteOther ) )
    qWarning( "Danger! Tonsils can be changed by the group or others!" );

See also

isReadable(), isWritable(), isExecutable()

Definition at line 236 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    if ( fic ) {
        uint mask = 0;
        if ( permissionSpec & ReadUser)
            mask |= S_IRUSR;
        if ( permissionSpec & WriteUser)
            mask |= S_IWUSR;
        if ( permissionSpec & ExeUser)
            mask |= S_IXUSR;
        if ( permissionSpec & ReadGroup)
            mask |= S_IRGRP;
        if ( permissionSpec & WriteGroup)
            mask |= S_IWGRP;
        if ( permissionSpec & ExeGroup)
            mask |= S_IXGRP;
        if ( permissionSpec & ReadOther)
            mask |= S_IROTH;
        if ( permissionSpec & WriteOther)
            mask |= S_IWOTH;
        if ( permissionSpec & ExeOther)
            mask |= S_IXOTH;
        if ( mask ) {
           return (fic->st.st_mode & mask) == mask;
        } else {
#if defined(CHECK_NULL)
           qWarning( "QFileInfo::permission: permissionSpec is 0" );
#endif
           return TRUE;
        }
    } else {
        return FALSE;
    }
}

QString QFileInfo::readLink

(

)

const

Returns the name a symlink points to, or a null QString if the object does not refer to 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()

Definition at line 119 of file qfileinfo_unix.cpp.

{
    QString r;

#if defined(_OS_UNIX_) && !defined(_OS_OS2EMX_)
    char s[PATH_MAX+1];
    if ( !isSymLink() )
        return QString();
    int len = (int)readlink( QFile::encodeName(fn).data(), s, PATH_MAX );
    if ( len >= 0 ) {
        s[len] = '\0';
        r = QFile::decodeName(s);
    }
#endif

    return r;
}

void QFileInfo::refresh

(

)

const

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

See also

setCaching()

Definition at line 277 of file qfileinfo.cpp.

{
    QFileInfo *that = (QFileInfo*)this;         // Mutable function
    delete that->fic;
    that->fic = 0;
}

void QFileInfo::setCaching

(

bool

enable

)

Enables caching of file information if enable is TRUE, or disables it if enable is FALSE.

When caching is enabled, QFileInfo reads the file information the first time

Caching is enabled by default.

See also

refresh(), caching()

Definition at line 302 of file qfileinfo.cpp.

{
    if ( cache == enable )
        return;
    cache = enable;
    if ( cache ) {
        delete fic;
        fic = 0;
    }
}

void QFileInfo::setFile

(

const QString &

file

)

Sets the file to obtain information about.

The string given can be an absolute or a relative file path. Absolute file paths begin with the directory separator (e.g. '/' under UNIX) or a drive specification (not applicable to UNIX). Relative file names begin with a directory name or a file name and specify a path relative to the current directory.

Example:

#include <qfileinfo.h>
#include <qdir.h>

void test()
{
    QString absolute = "/liver/aorta";
    QString relative = "liver/aorta";
    QFileInfo fi1( absolute );
    QFileInfo fi2( relative );

    QDir::setCurrent( QDir::rootDirPath() );
                      // fi1 and fi2 now point to the same file

    QDir::setCurrent( "/tmp" );
                      // fi1 now points to "/liver/aorta",
                      // while fi2 points to "/tmp/liver/aorta"
}

See also

isRelative(), QDir::setCurrent(), QDir::isRelativePath()

Definition at line 219 of file qfileinfo.cpp.

{
    fn = file;
    slashify( fn );
    delete fic;
    fic = 0;
}

void QFileInfo::setFile

(

const QFile &

file

)

Sets the file to obtain information about.

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

See also

isRelative()

Definition at line 235 of file qfileinfo.cpp.

{
    fn  = file.name();
    slashify( fn );
    delete fic;
    fic = 0;
}

void QFileInfo::setFile	(	const QDir &	d,
		const QString &	fileName
	)

Sets the file to obtains information about to fileName in the directory d.

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

See also

isRelative()

Definition at line 252 of file qfileinfo.cpp.

{
    fn  = d.filePath( fileName );
    slashify( fn );
    delete fic;
    fic = 0;
}

uint QFileInfo::size

(

)

const

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

Definition at line 278 of file qfileinfo_unix.cpp.

{
    if ( !fic || !cache )
        doStat();
    if ( fic )
        return (uint)fic->st.st_size;
    else
        return 0;
}

void QFileInfo::slashify ( QString &  n )

staticprivate

Definition at line 58 of file qfileinfo_unix.cpp.

{
    return;
}

Member Data Documentation

bool QFileInfo::cache

private

Definition at line 128 of file qfileinfo.h.

QFileInfoCache* QFileInfo::fic

private

Definition at line 127 of file qfileinfo.h.

QString QFileInfo::fn

private

Definition at line 126 of file qfileinfo.h.

---

The documentation for this class was generated from the following files:

• doxygen-1.8.11/qtools/qfileinfo.h
• doxygen-1.8.11/qtools/qfileinfo.cpp
• doxygen-1.8.11/qtools/qfileinfo_unix.cpp
• doxygen-1.8.11/qtools/qfileinfo_win32.cpp