/****************************************************************************
** $Id$
**
** Implementation of QFileInfo class
**
** Created : 950628
**
** Copyright (C) 1992-2002 Trolltech AS.  All rights reserved.
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** This file is part of the tools module of the Qt GUI Toolkit.
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** LICENSE.QPL included in the packaging of this file.
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** This file may be distributed and/or modified under the terms of the
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** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
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** licenses may use this file in accordance with the Qt Commercial License
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**   information about Qt Commercial License Agreements.
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#include "qplatformdefs.h"

#include "qfileinfo.h"
#include "qdatetime.h"
#include "qdir.h"
#include "qfiledefs_p.h"


extern bool qt_file_access( const QString& fn, int t );

/*!
  \class QFileInfo
  \brief The QFileInfo class provides system-independent file information.

  \ingroup io

  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.

  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 a drive specification (except on Unix).
  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 convertToAbs() 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.

  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 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 QDir class.
*/

/*!
    \enum QFileInfo::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.

    \value ReadUser The file is readable by the user.
    \value WriteUser The file is writable by the user.
    \value ExeUser The file is executable by the user.
    \value ReadGroup The file is readable by the group.
    \value WriteGroup The file is writable by the group.
    \value ExeGroup The file is executable by the group.
    \value ReadOther The file is readable by anyone.
    \value WriteOther The file is writable by anyone.
    \value ExeOther The file is executable by anyone.
*/


/*!
  Constructs a new empty QFileInfo.
*/

QFileInfo::QFileInfo()
{
    fic	  = 0;
    cache = TRUE;
#if defined(Q_OS_UNIX)
    symLink = FALSE;
#endif
}

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

  \sa setFile(), isRelative(), QDir::setCurrent(), QDir::isRelativePath()
*/

QFileInfo::QFileInfo( const QString &file )
{
    fn	  = file;
    slashify( fn );
    fic	  = 0;
    cache = TRUE;
#if defined(Q_OS_UNIX)
    symLink = FALSE;
#endif
}

/*!
  Constructs a new QFileInfo that gives information about file \a file.

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

  \sa isRelative()
*/

QFileInfo::QFileInfo( const QFile &file )
{
    fn	  = file.name();
    slashify( fn );
    fic	  = 0;
    cache = TRUE;
#if defined(Q_OS_UNIX)
    symLink = FALSE;
#endif
}

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

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

  \sa isRelative()
*/
#ifndef QT_NO_DIR
QFileInfo::QFileInfo( const QDir &d, const QString &fileName )
{
    fn	  = d.filePath( fileName );
    slashify( fn );
    fic	  = 0;
    cache = TRUE;
#if defined(Q_OS_UNIX)
    symLink = FALSE;
#endif
}
#endif
/*!
  Constructs a new QFileInfo that is a copy of \a fi.
*/

QFileInfo::QFileInfo( const QFileInfo &fi )
{
    fn = fi.fn;
    if ( fi.fic ) {
	fic = new QFileInfoCache;
	*fic = *fi.fic;
    } else {
	fic = 0;
    }
    cache = fi.cache;
#if defined(Q_OS_UNIX)
    symLink = fi.symLink;
#endif
}

/*!
  Destroys the QFileInfo and frees its resources.
*/

QFileInfo::~QFileInfo()
{
    delete fic;
}


/*!
  Makes a copy of \a fi and assigns it to this QFileInfo.
*/

QFileInfo &QFileInfo::operator=( const QFileInfo &fi )
{
    fn = fi.fn;
    if ( !fi.fic ) {
	delete fic;
	fic = 0;
    } else {
	if ( !fic ) {
	    fic = new QFileInfoCache;
	    Q_CHECK_PTR( fic );
	}
	*fic = *fi.fic;
    }
    cache = fi.cache;
#if defined(Q_OS_UNIX)
    symLink = fi.symLink;
#endif
    return *this;
}


/*!
  Sets the file that the QFileInfo provides information about to \a file.

  The string given can be an absolute or a relative file path. Absolute
  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:
  \code
    QString absolute = "/local/bin";
    QString relative = "local/bin";
    QFileInfo absFile( absolute );
    QFileInfo relFile( relative );

    QDir::setCurrent( QDir::rootDirPath() );
    // 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"
  \endcode

  \sa isRelative(), QDir::setCurrent(), QDir::isRelativePath()
*/

void QFileInfo::setFile( const QString &file )
{
    fn = file;
    slashify( fn );
    delete fic;
    fic = 0;
}

/*!
    \overload
  Sets the file that the QFileInfo provides information about to \a file.

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

  \sa isRelative()
*/

void QFileInfo::setFile( const QFile &file )
{
    fn	= file.name();
    slashify( fn );
    delete fic;
    fic = 0;
}

/*!
    \overload
  Sets the file that the QFileInfo provides information about to \a
  fileName in directory \a d.

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

  \sa isRelative()
*/
#ifndef QT_NO_DIR
void QFileInfo::setFile( const QDir &d, const QString &fileName )
{
    fn	= d.filePath( fileName );
    slashify( fn );
    delete fic;
    fic = 0;
}
#endif

/*!
  Returns TRUE if the file exists; otherwise returns FALSE.
*/

bool QFileInfo::exists() const
{
    return qt_file_access( fn, F_OK );
}

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

  \sa setCaching()
*/

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

/*!
  \fn bool QFileInfo::caching() const
  Returns TRUE if caching is enabled; otherwise returns FALSE.
  \sa setCaching(), refresh()
*/

/*!
  If \a enable is TRUE, enables caching of file information. If \a
  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.

  \sa refresh(), caching()
*/

void QFileInfo::setCaching( bool enable )
{
    if ( cache == enable )
	return;
    cache = enable;
    if ( cache ) {
	delete fic;
	fic = 0;
    }
}


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

  \sa isRelative(), absFilePath()
*/

QString QFileInfo::filePath() const
{
    return fn;
}

/*!
  Returns the base name of the file.

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

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

  The path is not included in either case.

  Example:
  \code
     QFileInfo fi( "/tmp/archive.tar.gz" );
     QString base = fi.baseName();  // base = "archive"
     base = fi.baseName( TRUE );    // base = "archive.tar"
  \endcode

  \sa fileName(), extension()
*/

QString QFileInfo::baseName( bool complete ) const
{
    QString tmp = fileName();
    int pos = complete ? tmp.findRev( '.' ) : tmp.find( '.' );
    if ( pos == -1 )
	return tmp;
    else
	return tmp.left( pos );
}

/*!
  Returns the file's extension name.

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

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

  Example:
  \code
     QFileInfo fi( "/tmp/archive.tar.gz" );
     QString ext = fi.extension();  // ext = "tar.gz"
     ext = fi.extension( FALSE );   // ext = "gz"
  \endcode

  \sa fileName(), baseName()

*/

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

/*!
  Returns the directory path of the file.

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

  \sa dirPath(), filePath(), fileName(), isRelative()
*/
#ifndef QT_NO_DIR
QDir QFileInfo::dir( bool absPath ) const
{
    return QDir( dirPath(absPath) );
}
#endif


/*!
  Returns TRUE if the file is readable; otherwise returns FALSE.
  \sa isWritable(), isExecutable(), permission()
*/

bool QFileInfo::isReadable() const
{
    return qt_file_access( fn, R_OK );
}

/*!
  Returns TRUE if the file is writable; otherwise returns FALSE.
  \sa isReadable(), isExecutable(), permission()
*/

bool QFileInfo::isWritable() const
{
    return qt_file_access( fn, W_OK ) && permission( WriteUser );
}

/*!
  Returns TRUE if the file is executable; otherwise returns FALSE.
  \sa isReadable(), isWritable(), permission()
*/

bool QFileInfo::isExecutable() const
{
    return qt_file_access( fn, X_OK );
}


/*!
  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 "/").
*/
#ifndef QT_NO_DIR
bool QFileInfo::isRelative() const
{
    return QDir::isRelativePath( fn );
}

/*!
  Converts the file path name to an absolute path.

  If it is already absolute, nothing is done.

  \sa filePath(), isRelative()
*/

bool QFileInfo::convertToAbs()
{
    if ( isRelative() )
	fn = absFilePath();
    return QDir::isRelativePath( fn );
}
#endif

/*!
  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.

  \sa isDir(), isSymLink()
*/
bool QFileInfo::isFile() const
{
    if ( !fic || !cache )
	doStat();
    return fic ? (fic->st.st_mode & QT_STAT_MASK) == QT_STAT_REG : FALSE;
}

/*!
  Returns TRUE if this object points to a directory or to a symbolic
  link to a directory; otherwise returns FALSE.
  \sa isFile(), isSymLink()
*/
bool QFileInfo::isDir() const
{
    if ( !fic || !cache )
	doStat();
    return fic ? (fic->st.st_mode & QT_STAT_MASK) == QT_STAT_DIR : FALSE;
}

/*!
  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.
*/
#if (QT_VERSION-0 >= 400)
#error "QFileInfo::size() should return QIODevice::Offset instead of uint"
#endif
uint QFileInfo::size() const
{
    if ( !fic || !cache )
	doStat();
    if ( fic )
	return (uint)fic->st.st_size;
    else
	return 0;
}

/*!
  Returns the date and time when the file was created.

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

  \sa created() lastModified() lastRead()
*/

QDateTime QFileInfo::created() const
{
    QDateTime dt;
    if ( !fic || !cache )
	doStat();
    if ( fic && fic->st.st_ctime != 0 ) {
	dt.setTime_t( fic->st.st_ctime );
	return dt;
    } else {
	return lastModified();
    }
}

/*!
  Returns the date and time when the file was last modified.

  \sa created() lastModified() lastRead()
*/

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

/*!
  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().

  \sa created() lastModified() lastRead()
*/

QDateTime QFileInfo::lastRead() const
{
    QDateTime dt;
    if ( !fic || !cache )
	doStat();
    if ( fic && fic->st.st_atime != 0 ) {
	dt.setTime_t( fic->st.st_atime );
	return dt;
    } else {
	return lastModified();
    }
}

#ifndef QT_NO_DIR

/*!
  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.

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

  \sa isRelative(), filePath()
*/
QString QFileInfo::absFilePath() const
{
    QString tmp;
    if ( QDir::isRelativePath(fn)
#if defined(Q_OS_WIN32) || defined(Q_OS_WIN64)
	 && fn[1] != ':'
#endif
	 ) {
	tmp = QDir::currentDirPath();
	tmp += '/';
    }
    tmp += fn;
    makeAbs( tmp );
    return QDir::cleanDirPath( tmp );
}

#endif
