diff options
Diffstat (limited to 'src/tools/qfile.cpp')
| -rw-r--r-- | src/tools/qfile.cpp | 747 |
1 files changed, 747 insertions, 0 deletions
diff --git a/src/tools/qfile.cpp b/src/tools/qfile.cpp new file mode 100644 index 0000000..11e21d1 --- /dev/null +++ b/src/tools/qfile.cpp @@ -0,0 +1,747 @@ +/**************************************************************************** +** +** Implementation of QFile class +** +** Created : 930812 +** +** Copyright (C) 1992-2008 Trolltech ASA. All rights reserved. +** +** This file is part of the tools module of the Qt GUI Toolkit. +** +** This file may be used under the terms of the GNU General +** Public License versions 2.0 or 3.0 as published by the Free +** Software Foundation and appearing in the files LICENSE.GPL2 +** and LICENSE.GPL3 included in the packaging of this file. +** Alternatively you may (at your option) use any later version +** of the GNU General Public License if such license has been +** publicly approved by Trolltech ASA (or its successors, if any) +** and the KDE Free Qt Foundation. +** +** Please review the following information to ensure GNU General +** Public Licensing requirements will be met: +** http://trolltech.com/products/qt/licenses/licensing/opensource/. +** If you are unsure which license is appropriate for your use, please +** review the following information: +** http://trolltech.com/products/qt/licenses/licensing/licensingoverview +** or contact the sales department at [email protected]. +** +** This file may be used under the terms of the Q Public License as +** defined by Trolltech ASA and appearing in the file LICENSE.QPL +** included in the packaging of this file. Licensees holding valid Qt +** Commercial licenses may use this file in accordance with the Qt +** Commercial License Agreement provided with the Software. +** +** This file is provided "AS IS" with NO WARRANTY OF ANY KIND, +** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR +** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted +** herein. +** +**********************************************************************/ + +#include "qplatformdefs.h" + +// POSIX Large File Support redefines open -> open64 +#if defined(open) +# undef open +#endif + +// POSIX Large File Support redefines truncate -> truncate64 +#if defined(truncate) +# undef truncate +#endif + +#include "qfile.h" +#ifndef NO_ERRNO_H +#include <errno.h> +#endif + + +// Duplicated from qobject.h, but we cannot include qobject.h here since +// it causes qmake to not build on irix g++ +#define QT_TRANSLATE_NOOP(scope,x) (x) + +const char* qt_fileerr_unknown = QT_TRANSLATE_NOOP( "QFile", "Unknown error" ); +const char* qt_fileerr_read = QT_TRANSLATE_NOOP( "QFile", "Could not read from the file" ); +const char* qt_fileerr_write = QT_TRANSLATE_NOOP( "QFile", "Could not write to the file" ); + +#define QFILEERR_EACCES QT_TRANSLATE_NOOP( "QFile", "Permission denied" ) +#define QFILEERR_EMFILE QT_TRANSLATE_NOOP( "QFile", "Too many open files" ) +#define QFILEERR_ENOENT QT_TRANSLATE_NOOP( "QFile", "No such file or directory" ) +#define QFILEERR_ENOSPC QT_TRANSLATE_NOOP( "QFile", "No space left on device" ) + +class QFilePrivate +{ +public: + QString errorString; +}; + +extern bool qt_file_access( const QString& fn, int t ); + +/*! + \class QFile qfile.h + \reentrant + \brief The QFile class is an I/O device that operates on files. + + \ingroup io + \mainclass + + QFile is an I/O device for reading and writing binary and text + files. A QFile may be used by itself or more conveniently with a + QDataStream or QTextStream. + + The file name is usually passed in the constructor but can be + changed with setName(). You can check for a file's existence with + exists() and remove a file with remove(). + + The file is opened with open(), closed with close() and flushed + with flush(). Data is usually read and written using QDataStream + or QTextStream, but you can read with readBlock() and readLine() + and write with writeBlock(). QFile also supports getch(), + ungetch() and putch(). + + The size of the file is returned by size(). You can get the + current file position or move to a new file position using the + at() functions. If you've reached the end of the file, atEnd() + returns TRUE. The file handle is returned by handle(). + + Here is a code fragment that uses QTextStream to read a text file + line by line. It prints each line with a line number. + \code + QStringList lines; + QFile file( "file.txt" ); + if ( file.open( IO_ReadOnly ) ) { + QTextStream stream( &file ); + QString line; + int i = 1; + while ( !stream.atEnd() ) { + line = stream.readLine(); // line of text excluding '\n' + printf( "%3d: %s\n", i++, line.latin1() ); + lines += line; + } + file.close(); + } + \endcode + + Writing text is just as easy. The following example shows how to + write the data we read into the string list from the previous + example: + \code + QFile file( "file.txt" ); + if ( file.open( IO_WriteOnly ) ) { + QTextStream stream( &file ); + for ( QStringList::Iterator it = lines.begin(); it != lines.end(); ++it ) + stream << *it << "\n"; + file.close(); + } + \endcode + + The QFileInfo class holds detailed information about a file, such + as access permissions, file dates and file types. + + The QDir class manages directories and lists of file names. + + Qt uses Unicode file names. If you want to do your own I/O on Unix + systems you may want to use encodeName() (and decodeName()) to + convert the file name into the local encoding. + + \important readAll() at() + + \sa QDataStream, QTextStream +*/ + +/*! + \fn Q_LONG QFile::writeBlock( const QByteArray& data ) + + \overload +*/ + + +/*! + Constructs a QFile with no name. +*/ + +QFile::QFile() +: d(0) +{ + init(); +} + +/*! + Constructs a QFile with a file name \a name. + + \sa setName() +*/ + +QFile::QFile( const QString &name ) + : fn(name), d(0) +{ + init(); +} + + +/*! + Destroys a QFile. Calls close(). +*/ + +QFile::~QFile() +{ + close(); + delete d; +} + + +/*! + \internal + Initialize internal data. +*/ + +void QFile::init() +{ + delete d; + d = new QFilePrivate; + setFlags( IO_Direct ); + setStatus( IO_Ok ); + setErrorString( qt_fileerr_unknown ); + fh = 0; + fd = 0; + length = 0; + ioIndex = 0; + ext_f = FALSE; // not an external file handle +} + + +/*! + \fn QString QFile::name() const + + Returns the name set by setName(). + + \sa setName(), QFileInfo::fileName() +*/ + +/*! + Sets the name of the file to \a name. The name can have no path, a + relative path or an absolute absolute path. + + Do not call this function if the file has already been opened. + + If the file name has no path or a relative path, the path used + will be whatever the application's current directory path is + \e{at the time of the open()} call. + + Example: + \code + QFile file; + QDir::setCurrent( "/tmp" ); + file.setName( "readme.txt" ); + QDir::setCurrent( "/home" ); + file.open( IO_ReadOnly ); // opens "/home/readme.txt" under Unix + \endcode + + Note that the directory separator "/" works for all operating + systems supported by Qt. + + \sa name(), QFileInfo, QDir +*/ + +void QFile::setName( const QString &name ) +{ + if ( isOpen() ) { +#if defined(QT_CHECK_STATE) + qWarning( "QFile::setName: File is open" ); +#endif + close(); + } + fn = name; +} + +/*! + \overload + + Returns TRUE if this file exists; otherwise returns FALSE. + + \sa name() +*/ + +bool QFile::exists() const +{ + return qt_file_access( fn, F_OK ); +} + +/*! + Returns TRUE if the file given by \a fileName exists; otherwise + returns FALSE. +*/ + +bool QFile::exists( const QString &fileName ) +{ + return qt_file_access( fileName, F_OK ); +} + + +/*! + Removes the file specified by the file name currently set. Returns + TRUE if successful; otherwise returns FALSE. + + The file is closed before it is removed. +*/ + +bool QFile::remove() +{ + close(); + return remove( fn ); +} + +#if defined(Q_OS_MAC) || defined(Q_OS_MSDOS) || defined(Q_OS_WIN32) || defined(Q_OS_OS2) +# define HAS_TEXT_FILEMODE // has translate/text filemode +#endif +#if defined(O_NONBLOCK) +# define HAS_ASYNC_FILEMODE +# define OPEN_ASYNC O_NONBLOCK +#elif defined(O_NDELAY) +# define HAS_ASYNC_FILEMODE +# define OPEN_ASYNC O_NDELAY +#endif + +/*! + Flushes the file buffer to the disk. + + close() also flushes the file buffer. +*/ + +void QFile::flush() +{ + if ( isOpen() && fh ) { // can only flush open/buffered file + if ( fflush( fh ) ) { // write error + if ( errno == ENOSPC ) // disk is full + setStatus( IO_ResourceError ); + else + setStatus( IO_WriteError ); + setErrorStringErrno( errno ); + } + } +} + +/*! \reimp + \fn QIODevice::Offset QFile::at() const +*/ + +/*! + Returns TRUE if the end of file has been reached; otherwise returns FALSE. + If QFile has not been open()'d, then the behavior is undefined. + + \sa size() +*/ + +bool QFile::atEnd() const +{ + if ( !isOpen() ) { +#if defined(QT_CHECK_STATE) + qWarning( "QFile::atEnd: File is not open" ); +#endif + return FALSE; + } + if ( isDirectAccess() && !isTranslated() ) { + if ( at() < size() ) + return FALSE; + } + const QString errorString = d->errorString; + const bool ret = QIODevice::atEnd(); + if (errorString != d->errorString) + d->errorString = errorString; + return ret; +} + +/*! + Reads a line of text. + + Reads bytes from the file into the char* \a p, until end-of-line + or \a maxlen bytes have been read, whichever occurs first. Returns + the number of bytes read, or -1 if there was an error. Any + terminating newline is not stripped. + + This function is only efficient for buffered files. Avoid + readLine() for files that have been opened with the \c IO_Raw + flag. + + \sa readBlock(), QTextStream::readLine() +*/ + +Q_LONG QFile::readLine( char *p, Q_ULONG maxlen ) +{ + if ( maxlen == 0 ) // application bug? + return 0; +#if defined(QT_CHECK_STATE) + Q_CHECK_PTR( p ); + if ( !isOpen() ) { // file not open + qWarning( "QFile::readLine: File not open" ); + return -1; + } + if ( !isReadable() ) { // reading not permitted + qWarning( "QFile::readLine: Read operation not permitted" ); + return -1; + } +#endif + Q_LONG nread; // number of bytes read + if ( isRaw() ) { // raw file + nread = QIODevice::readLine( p, maxlen ); + } else { // buffered file + p = fgets( p, maxlen, fh ); + if ( p ) { + nread = qstrlen( p ); + if ( !isSequentialAccess() ) + ioIndex += nread; + } else { + nread = -1; + setStatus(IO_ReadError); + setErrorString( qt_fileerr_read ); + } + } + return nread; +} + + +/*! + \overload + + Reads a line of text. + + Reads bytes from the file into string \a s, until end-of-line or + \a maxlen bytes have been read, whichever occurs first. Returns + the number of bytes read, or -1 if there was an error, e.g. end of + file. Any terminating newline is not stripped. + + This function is only efficient for buffered files. Avoid using + readLine() for files that have been opened with the \c IO_Raw + flag. + + Note that the string is read as plain Latin1 bytes, not Unicode. + + \sa readBlock(), QTextStream::readLine() +*/ + +Q_LONG QFile::readLine( QString& s, Q_ULONG maxlen ) +{ + QByteArray ba(maxlen); + Q_LONG l = readLine(ba.data(),maxlen); + if ( l >= 0 ) { + ba.truncate(l); + s = QString(ba); + } + return l; +} + + +/*! + Reads a single byte/character from the file. + + Returns the byte/character read, or -1 if the end of the file has + been reached. + + \sa putch(), ungetch() +*/ + +int QFile::getch() +{ +#if defined(QT_CHECK_STATE) + if ( !isOpen() ) { // file not open + qWarning( "QFile::getch: File not open" ); + return EOF; + } + if ( !isReadable() ) { // reading not permitted + qWarning( "QFile::getch: Read operation not permitted" ); + return EOF; + } +#endif + + int ch; + + if ( !ungetchBuffer.isEmpty() ) { + int len = ungetchBuffer.length(); + ch = ungetchBuffer[ len-1 ]; + ungetchBuffer.truncate( len - 1 ); + return ch; + } + + if ( isRaw() ) { // raw file (inefficient) + char buf[1]; + ch = readBlock( buf, 1 ) == 1 ? buf[0] : EOF; + } else { // buffered file + if ( (ch = getc( fh )) != EOF ) { + if ( !isSequentialAccess() ) + ioIndex++; + } else { + setStatus(IO_ReadError); + setErrorString( qt_fileerr_read ); + } + } + return ch; +} + +/*! + Writes the character \a ch to the file. + + Returns \a ch, or -1 if some error occurred. + + \sa getch(), ungetch() +*/ + +int QFile::putch( int ch ) +{ +#if defined(QT_CHECK_STATE) + if ( !isOpen() ) { // file not open + qWarning( "QFile::putch: File not open" ); + return EOF; + } + if ( !isWritable() ) { // writing not permitted + qWarning( "QFile::putch: Write operation not permitted" ); + return EOF; + } +#endif + if ( isRaw() ) { // raw file (inefficient) + char buf[1]; + buf[0] = ch; + ch = writeBlock( buf, 1 ) == 1 ? ch : EOF; + } else { // buffered file + if ( (ch = putc( ch, fh )) != EOF ) { + if ( !isSequentialAccess() ) + ioIndex++; + if ( ioIndex > length ) // update file length + length = ioIndex; + } else { + setStatus(IO_WriteError); + setErrorString( qt_fileerr_write ); + } + } + return ch; +} + +/*! + Puts the character \a ch back into the file and decrements the + index if it is not zero. + + This function is normally called to "undo" a getch() operation. + + Returns \a ch, or -1 if an error occurred. + + \sa getch(), putch() +*/ + +int QFile::ungetch( int ch ) +{ +#if defined(QT_CHECK_STATE) + if ( !isOpen() ) { // file not open + qWarning( "QFile::ungetch: File not open" ); + return EOF; + } + if ( !isReadable() ) { // reading not permitted + qWarning( "QFile::ungetch: Read operation not permitted" ); + return EOF; + } +#endif + if ( ch == EOF ) // cannot unget EOF + return ch; + + if ( isSequentialAccess() && !fh) { + // pipe or similar => we cannot ungetch, so do it manually + ungetchBuffer += QChar(ch); + return ch; + } + + if ( isRaw() ) { // raw file (very inefficient) + char buf[1]; + at( ioIndex-1 ); + buf[0] = ch; + if ( writeBlock(buf, 1) == 1 ) + at ( ioIndex-1 ); + else + ch = EOF; + } else { // buffered file + if ( (ch = ungetc(ch, fh)) != EOF ) { + if ( !isSequentialAccess() ) + ioIndex--; + } else { + setStatus( IO_ReadError ); + setErrorString( qt_fileerr_read ); + } + } + return ch; +} + + +static QCString locale_encoder( const QString &fileName ) +{ + return fileName.local8Bit(); +} + + +static QFile::EncoderFn encoder = locale_encoder; + +/*! + When you use QFile, QFileInfo, and QDir to access the file system + with Qt, you can use Unicode file names. On Unix, these file names + are converted to an 8-bit encoding. If you want to do your own + file I/O on Unix, you should convert the file name using this + function. On Windows NT/2000, Unicode file names are supported + directly in the file system and this function should be avoided. + On Windows 95, non-Latin1 locales are not supported. + + By default, this function converts \a fileName to the local 8-bit + encoding determined by the user's locale. This is sufficient for + file names that the user chooses. File names hard-coded into the + application should only use 7-bit ASCII filename characters. + + The conversion scheme can be changed using setEncodingFunction(). + This might be useful if you wish to give the user an option to + store file names in UTF-8, etc., but be aware that such file names + would probably then be unrecognizable when seen by other programs. + + \sa decodeName() +*/ + +QCString QFile::encodeName( const QString &fileName ) +{ + return (*encoder)(fileName); +} + +/*! + \enum QFile::EncoderFn + + This is used by QFile::setEncodingFunction(). +*/ + +/*! + \nonreentrant + + Sets the function for encoding Unicode file names to \a f. The + default encodes in the locale-specific 8-bit encoding. + + \sa encodeName() +*/ +void QFile::setEncodingFunction( EncoderFn f ) +{ + encoder = f; +} + +static +QString locale_decoder( const QCString &localFileName ) +{ +#ifndef Q_WS_MAC + return QString::fromLocal8Bit(localFileName); +#else + extern QString qt_mac_precomposeFileName(const QString &); // qglobal.cpp + return qt_mac_precomposeFileName(QString::fromLocal8Bit(localFileName)); +#endif +} + +static QFile::DecoderFn decoder = locale_decoder; + +/*! + This does the reverse of QFile::encodeName() using \a localFileName. + + \sa setDecodingFunction() +*/ +QString QFile::decodeName( const QCString &localFileName ) +{ + return (*decoder)(localFileName); +} + +/*! + \enum QFile::DecoderFn + + This is used by QFile::setDecodingFunction(). +*/ + +/*! + \nonreentrant + + Sets the function for decoding 8-bit file names to \a f. The + default uses the locale-specific 8-bit encoding. + + \sa encodeName(), decodeName() +*/ + +void QFile::setDecodingFunction( DecoderFn f ) +{ + decoder = f; +} + +/*! + Returns a human-readable description of the reason of an error that occurred + on the device. The error described by the string corresponds to changes of + QIODevice::status(). If the status is reset, the error string is also reset. + + The returned strings are not translated with the QObject::tr() or + QApplication::translate() functions. They are marked as translatable + strings in the "QFile" context. Before you show the string to the user you + should translate it first, for example: + + \code + QFile f( "address.dat" ); + if ( !f.open( IO_ReadOnly ) { + QMessageBox::critical( + this, + tr("Open failed"), + tr("Could not open file for reading: %1").arg( qApp->translate("QFile",f.errorString()) ) + ); + return; + } + \endcode + + \sa QIODevice::status(), QIODevice::resetStatus(), setErrorString() +*/ + +QString QFile::errorString() const +{ + if ( status() == IO_Ok ) + return qt_fileerr_unknown; + return d->errorString; +} + +/*! + \nonreentrant + + Sets the error string returned by the errorString() function to \a str. + + \sa errorString(), QIODevice::status() +*/ + +void QFile::setErrorString( const QString& str ) +{ + d->errorString = str; +} + +void QFile::setErrorStringErrno( int errnum ) +{ + switch ( errnum ) { + case EACCES: + d->errorString = QFILEERR_EACCES; + break; + case EMFILE: + d->errorString = QFILEERR_EMFILE; + break; + case ENOENT: + d->errorString = QFILEERR_ENOENT; + break; + case ENOSPC: + d->errorString = QFILEERR_ENOSPC; + break; + default: +#ifndef Q_OS_TEMP + d->errorString = QString::fromLocal8Bit( strerror( errnum ) ); +#else + { + unsigned short *string; + FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER|FORMAT_MESSAGE_FROM_SYSTEM, + NULL, + errnum, + MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), + (LPTSTR)&string, + 0, + NULL ); + d->errorString = QString::fromUcs2( string ); + LocalFree( (HLOCAL)string ); + } +#endif + break; + } +} |