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Diffstat (limited to 'src/tools/qfile_unix.cpp')
| -rw-r--r-- | src/tools/qfile_unix.cpp | 746 |
1 files changed, 746 insertions, 0 deletions
diff --git a/src/tools/qfile_unix.cpp b/src/tools/qfile_unix.cpp new file mode 100644 index 0000000..b6da559 --- /dev/null +++ b/src/tools/qfile_unix.cpp @@ -0,0 +1,746 @@ +/**************************************************************************** +** +** Implementation of QFile class +** +** Created : 950628 +** +** 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 sales@trolltech.com. +** +** 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 +static inline int qt_open(const char *pathname, int flags, mode_t mode) +{ return ::open(pathname, flags, mode); } +#if defined(open) +# undef open +#endif + +// POSIX Large File Support redefines truncate -> truncate64 +#if defined(truncate) +# undef truncate +#endif + +#include "qfile.h" +#include <errno.h> +#include <limits.h> + +extern const char* qt_fileerr_read; + +bool qt_file_access( const QString& fn, int t ) +{ + if ( fn.isEmpty() ) + return FALSE; + return ::access( QFile::encodeName(fn), t ) == 0; +} + +/*! + \overload + Removes the file \a fileName. + Returns TRUE if successful, otherwise FALSE. +*/ + +bool QFile::remove( const QString &fileName ) +{ + if ( fileName.isEmpty() ) { +#if defined(QT_CHECK_NULL) + qWarning( "QFile::remove: Empty or null file name" ); +#endif + return FALSE; + } + return unlink( QFile::encodeName(fileName) ) == 0; +} + +#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 + +/*! + Opens the file specified by the file name currently set, using the + mode \a m. Returns TRUE if successful, otherwise FALSE. + + \keyword IO_Raw + \keyword IO_ReadOnly + \keyword IO_WriteOnly + \keyword IO_ReadWrite + \keyword IO_Append + \keyword IO_Truncate + \keyword IO_Translate + + The mode parameter \a m must be a combination of the following flags: + \table + \header \i Flag \i Meaning + \row \i IO_Raw + \i Raw (non-buffered) file access. + \row \i IO_ReadOnly + \i Opens the file in read-only mode. + \row \i IO_WriteOnly + \i Opens the file in write-only mode. If this flag is used + with another flag, e.g. \c IO_ReadOnly or \c IO_Raw or \c + IO_Append, the file is \e not truncated; but if used on + its own (or with \c IO_Truncate), the file is truncated. + \row \i IO_ReadWrite + \i Opens the file in read/write mode, equivalent to \c + (IO_ReadOnly | IO_WriteOnly). + \row \i IO_Append + \i Opens the file in append mode. (You must actually use \c + (IO_WriteOnly | IO_Append) to make the file writable and + to go into append mode.) This mode is very useful when you + want to write something to a log file. The file index is + set to the end of the file. Note that the result is + undefined if you position the file index manually using + at() in append mode. + \row \i IO_Truncate + \i Truncates the file. + \row \i IO_Translate + \i Enables carriage returns and linefeed translation for text + files under Windows. + \endtable + + The raw access mode is best when I/O is block-operated using a 4KB + block size or greater. Buffered access works better when reading + small portions of data at a time. + + \warning When working with buffered files, data may not be written + to the file at once. Call flush() to make sure that the data is + really written. + + \warning If you have a buffered file opened for both reading and + writing you must not perform an input operation immediately after + an output operation or vice versa. You should always call flush() + or a file positioning operation, e.g. at(), between input and + output operations, otherwise the buffer may contain garbage. + + If the file does not exist and \c IO_WriteOnly or \c IO_ReadWrite + is specified, it is created. + + Example: + \code + QFile f1( "/tmp/data.bin" ); + f1.open( IO_Raw | IO_ReadWrite ); + + QFile f2( "readme.txt" ); + f2.open( IO_ReadOnly | IO_Translate ); + + QFile f3( "audit.log" ); + f3.open( IO_WriteOnly | IO_Append ); + \endcode + + \sa name(), close(), isOpen(), flush() +*/ + +bool QFile::open( int m ) +{ + if ( isOpen() ) { // file already open +#if defined(QT_CHECK_STATE) + qWarning( "QFile::open: File already open" ); +#endif + return FALSE; + } + if ( fn.isEmpty() ) { // no file name defined +#if defined(QT_CHECK_NULL) + qWarning( "QFile::open: No file name specified" ); +#endif + return FALSE; + } + init(); // reset params + setMode( m ); + if ( !(isReadable() || isWritable()) ) { +#if defined(QT_CHECK_RANGE) + qWarning( "QFile::open: File access not specified" ); +#endif + return FALSE; + } + bool ok = TRUE; + struct stat st; + if ( isRaw() ) { + int oflags = O_RDONLY; + if ( isReadable() && isWritable() ) + oflags = O_RDWR; + else if ( isWritable() ) + oflags = O_WRONLY; + if ( flags() & IO_Append ) { // append to end of file? + if ( flags() & IO_Truncate ) + oflags |= (O_CREAT | O_TRUNC); + else + oflags |= (O_APPEND | O_CREAT); + setFlags( flags() | IO_WriteOnly ); // append implies write + } else if ( isWritable() ) { // create/trunc if writable + if ( flags() & IO_Truncate ) + oflags |= (O_CREAT | O_TRUNC); + else + oflags |= O_CREAT; + } +#if defined(HAS_TEXT_FILEMODE) + if ( isTranslated() ) + oflags |= OPEN_TEXT; + else + oflags |= OPEN_BINARY; +#endif +#if defined(HAS_ASYNC_FILEMODE) + if ( isAsynchronous() ) + oflags |= OPEN_ASYNC; +#endif + fd = qt_open( QFile::encodeName(fn), oflags, 0666 ); + + if ( fd != -1 ) { // open successful + ::fstat( fd, &st ); // get the stat for later usage + } else { + ok = FALSE; + } + } else { // buffered file I/O + QCString perm; + char perm2[4]; + bool try_create = FALSE; + if ( flags() & IO_Append ) { // append to end of file? + setFlags( flags() | IO_WriteOnly ); // append implies write + perm = isReadable() ? "a+" : "a"; + } else { + if ( isReadWrite() ) { + if ( flags() & IO_Truncate ) { + perm = "w+"; + } else { + perm = "r+"; + try_create = TRUE; // try to create if not exists + } + } else if ( isReadable() ) { + perm = "r"; + } else if ( isWritable() ) { + perm = "w"; + } + } + qstrcpy( perm2, perm ); +#if defined(HAS_TEXT_FILEMODE) + if ( isTranslated() ) + strcat( perm2, "t" ); + else + strcat( perm2, "b" ); +#endif + for (;;) { // At most twice + + fh = fopen( QFile::encodeName(fn), perm2 ); + + if ( !fh && try_create ) { + perm2[0] = 'w'; // try "w+" instead of "r+" + try_create = FALSE; + } else { + break; + } + } + if ( fh ) { + ::fstat( fileno(fh), &st ); // get the stat for later usage + } else { + ok = FALSE; + } + } + if ( ok ) { + setState( IO_Open ); + // on successful open the file stat was got; now test what type + // of file we have + if ( (st.st_mode & S_IFMT) != S_IFREG ) { + // non-seekable + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } else { +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + length = st.st_size > UINT_MAX ? UINT_MAX : (Offset)st.st_size; +#else + length = (Offset)st.st_size; +#endif + ioIndex = (flags() & IO_Append) == 0 ? 0 : length; + if ( !(flags()&IO_Truncate) && length == 0 && isReadable() ) { + // try if you can read from it (if you can, it's a sequential + // device; e.g. a file in the /proc filesystem) + int c = getch(); + if ( c != -1 ) { + ungetch(c); + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } + resetStatus(); + } + } + } else { + init(); + if ( errno == EMFILE ) // no more file handles/descrs + setStatus( IO_ResourceError ); + else + setStatus( IO_OpenError ); + setErrorStringErrno( errno ); + } + return ok; +} + +/*! + \overload + Opens a file in the mode \a m using an existing file handle \a f. + Returns TRUE if successful, otherwise FALSE. + + Example: + \code + #include <stdio.h> + + void printError( const char* msg ) + { + QFile f; + f.open( IO_WriteOnly, stderr ); + f.writeBlock( msg, qstrlen(msg) ); // write to stderr + f.close(); + } + \endcode + + When a QFile is opened using this function, close() does not actually + close the file, only flushes it. + + \warning If \a f is \c stdin, \c stdout, \c stderr, you may not + be able to seek. See QIODevice::isSequentialAccess() for more + information. + + \sa close() +*/ + +bool QFile::open( int m, FILE *f ) +{ + if ( isOpen() ) { +#if defined(QT_CHECK_RANGE) + qWarning( "QFile::open: File already open" ); +#endif + return FALSE; + } + init(); + setMode( m &~IO_Raw ); + setState( IO_Open ); + fh = f; + ext_f = TRUE; + struct stat st; + ::fstat( fileno(fh), &st ); +#if defined(QT_LARGEFILE_SUPPORT) +#if !defined(QT_ABI_QT4) + off_t tmp = ftello( fh ); + ioIndex = tmp > UINT_MAX ? UINT_MAX : (Offset)tmp; +#else + ioIndex = (Offset)ftello( fh ); +#endif +#else + ioIndex = (Offset)ftell( fh ); +#endif + if ( (st.st_mode & S_IFMT) != S_IFREG || f == stdin ) { //stdin is non seekable + // non-seekable + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } else { +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + length = st.st_size > UINT_MAX ? UINT_MAX : (Offset)st.st_size; +#else + length = (Offset)st.st_size; +#endif + if ( !(flags()&IO_Truncate) && length == 0 && isReadable() ) { + // try if you can read from it (if you can, it's a sequential + // device; e.g. a file in the /proc filesystem) + int c = getch(); + if ( c != -1 ) { + ungetch(c); + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } + resetStatus(); + } + } + return TRUE; +} + +/*! + \overload + Opens a file in the mode \a m using an existing file descriptor \a f. + Returns TRUE if successful, otherwise FALSE. + + When a QFile is opened using this function, close() does not actually + close the file. + + The QFile that is opened using this function, is automatically set to be in + raw mode; this means that the file input/output functions are slow. If you + run into performance issues, you should try to use one of the other open + functions. + + \warning If \a f is one of 0 (stdin), 1 (stdout) or 2 (stderr), you may not + be able to seek. size() is set to \c INT_MAX (in limits.h). + + \sa close() +*/ + + +bool QFile::open( int m, int f ) +{ + if ( isOpen() ) { +#if defined(QT_CHECK_RANGE) + qWarning( "QFile::open: File already open" ); +#endif + return FALSE; + } + init(); + setMode( m |IO_Raw ); + setState( IO_Open ); + fd = f; + ext_f = TRUE; + struct stat st; + ::fstat( fd, &st ); +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + off_t tmp = ::lseek(fd, 0, SEEK_CUR); + ioIndex = tmp > UINT_MAX ? UINT_MAX : (Offset)tmp; +#else + ioIndex = (Offset)::lseek(fd, 0, SEEK_CUR); +#endif + if ( (st.st_mode & S_IFMT) != S_IFREG || f == 0 ) { // stdin is not seekable... + // non-seekable + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } else { +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + length = st.st_size > UINT_MAX ? UINT_MAX : (Offset)st.st_size; +#else + length = (Offset)st.st_size; +#endif + if ( length == 0 && isReadable() ) { + // try if you can read from it (if you can, it's a sequential + // device; e.g. a file in the /proc filesystem) + int c = getch(); + if ( c != -1 ) { + ungetch(c); + setType( IO_Sequential ); + length = INT_MAX; + ioIndex = 0; + } + resetStatus(); + } + } + return TRUE; +} + +/*! + Returns the file size. + \sa at() +*/ + +QIODevice::Offset QFile::size() const +{ + struct stat st; + int ret = 0; + if ( isOpen() ) { + ret = ::fstat( fh ? fileno(fh) : fd, &st ); + } else { + ret = ::stat( QFile::encodeName(fn), &st ); + } + if ( ret == -1 ) + return 0; +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + return (uint)st.st_size > UINT_MAX ? UINT_MAX : (Offset)st.st_size; +#else + return st.st_size; +#endif +} + + +/*! + \overload + + Sets the file index to \a pos. Returns TRUE if successful; + otherwise returns FALSE. + + Example: + \code + QFile f( "data.bin" ); + f.open( IO_ReadOnly ); // index set to 0 + f.at( 100 ); // set index to 100 + f.at( f.at()+50 ); // set index to 150 + f.at( f.size()-80 ); // set index to 80 before EOF + f.close(); + \endcode + + Use \c at() without arguments to retrieve the file offset. + + \warning The result is undefined if the file was open()'ed using + the \c IO_Append specifier. + + \sa size(), open() +*/ + +bool QFile::at( Offset pos ) +{ + if ( !isOpen() ) { +#if defined(QT_CHECK_STATE) + qWarning( "QFile::at: File is not open" ); +#endif + return FALSE; + } + if ( isSequentialAccess() ) + return FALSE; + bool ok; + if ( isRaw() ) { + off_t l = ::lseek( fd, pos, SEEK_SET ); + ok = ( l != -1 ); + pos = (Offset)l; + } else { // buffered file +#if defined(QT_LARGEFILE_SUPPORT) + ok = ( ::fseeko(fh, pos, SEEK_SET) == 0 ); +#else + ok = ( ::fseek(fh, pos, SEEK_SET) == 0 ); +#endif + } + if ( ok ) +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + ioIndex = pos > UINT_MAX ? UINT_MAX : (Offset)pos; +#else + ioIndex = (Offset)pos; +#endif +#if defined(QT_CHECK_RANGE) + else +#if defined(QT_ABI_QT4) + qWarning( "QFile::at: Cannot set file position %lld", pos ); +#else + qWarning( "QFile::at: Cannot set file position %lu", pos ); +#endif +#endif + return ok; +} + +/*! + \reimp + + \warning We have experienced problems with some C libraries when a buffered + file is opened for both reading and writing. If a read operation takes place + immediately after a write operation, the read buffer contains garbage data. + Worse, the same garbage is written to the file. Calling flush() before + readBlock() solved this problem. +*/ + +Q_LONG QFile::readBlock( char *p, Q_ULONG len ) +{ + if ( !len ) // nothing to do + return 0; + +#if defined(QT_CHECK_NULL) + if ( !p ) + qWarning( "QFile::readBlock: Null pointer error" ); +#endif +#if defined(QT_CHECK_STATE) + if ( !isOpen() ) { + qWarning( "QFile::readBlock: File not open" ); + return -1; + } + if ( !isReadable() ) { + qWarning( "QFile::readBlock: Read operation not permitted" ); + return -1; + } +#endif + Q_ULONG nread = 0; // number of bytes read + if ( !ungetchBuffer.isEmpty() ) { + // need to add these to the returned string. + uint l = ungetchBuffer.length(); + while( nread < l ) { + *p = ungetchBuffer.at( l - nread - 1 ); + p++; + nread++; + } + ungetchBuffer.truncate( l - nread ); + } + + if ( nread < len ) { + if ( isRaw() ) { // raw file + nread += ::read( fd, p, len-nread ); + if ( len && nread <= 0 ) { + nread = 0; + setStatus(IO_ReadError); + setErrorStringErrno( errno ); + } + } else { // buffered file + nread += fread( p, 1, len-nread, fh ); + if ( (uint)nread != len ) { + if ( ferror( fh ) || nread==0 ) { + setStatus(IO_ReadError); + setErrorString( qt_fileerr_read ); + } + } + } + } + if ( !isSequentialAccess() ) + ioIndex += nread; + return nread; +} + + +/*! \reimp + + Writes \a len bytes from \a p to the file and returns the number of + bytes actually written. + + Returns -1 if a serious error occurred. + + \warning When working with buffered files, data may not be written + to the file at once. Call flush() to make sure the data is really + written. + + \sa readBlock() +*/ + +Q_LONG QFile::writeBlock( const char *p, Q_ULONG len ) +{ + if ( !len ) // nothing to do + return 0; + +#if defined(QT_CHECK_NULL) + if ( p == 0 && len != 0 ) + qWarning( "QFile::writeBlock: Null pointer error" ); +#endif +#if defined(QT_CHECK_STATE) + if ( !isOpen() ) { // file not open + qWarning( "QFile::writeBlock: File not open" ); + return -1; + } + if ( !isWritable() ) { // writing not permitted + qWarning( "QFile::writeBlock: Write operation not permitted" ); + return -1; + } +#endif + Q_ULONG nwritten; // number of bytes written + if ( isRaw() ) // raw file + nwritten = ::write( fd, (void *)p, len ); + else // buffered file + nwritten = fwrite( p, 1, len, fh ); + if ( nwritten != len ) { // write error + if ( errno == ENOSPC ) // disk is full + setStatus( IO_ResourceError ); + else + setStatus( IO_WriteError ); + setErrorStringErrno( errno ); + if ( !isSequentialAccess() ) { + if ( isRaw() ) { // recalc file position +#if defined(QT_LARGEFILE_SUPPORT) && !defined(QT_ABI_QT4) + off_t tmp = ::lseek( fd, 0, SEEK_CUR ); + ioIndex = tmp > UINT_MAX ? UINT_MAX : (Offset)tmp; +#else + ioIndex = (Offset)::lseek( fd, 0, SEEK_CUR ); +#endif + } else { +#if defined(QT_LARGEFILE_SUPPORT) +#if !defined(QT_ABI_QT4) + off_t tmp = (Offset)::fseeko( fh, 0, SEEK_CUR ); + ioIndex = tmp > UINT_MAX ? UINT_MAX : (Offset)tmp; +#else + ioIndex = (Offset)::fseeko( fh, 0, SEEK_CUR ); +#endif +#else + ioIndex = (Offset)::fseek( fh, 0, SEEK_CUR ); +#endif + } + } + } else { + if ( !isSequentialAccess() ) + ioIndex += nwritten; + } + if ( ioIndex > length ) // update file length + length = ioIndex; + return nwritten; +} + +/*! + Returns the file handle of the file. + + This is a small positive integer, suitable for use with C library + functions such as fdopen() and fcntl(). On systems that use file + descriptors for sockets (ie. Unix systems, but not Windows) the handle + can be used with QSocketNotifier as well. + + If the file is not open or there is an error, handle() returns -1. + + \sa QSocketNotifier +*/ + +int QFile::handle() const +{ + if ( !isOpen() ) + return -1; + else if ( fh ) + return fileno( fh ); + else + return fd; +} + +/*! + Closes an open file. + + The file is not closed if it was opened with an existing file handle. + If the existing file handle is a \c FILE*, the file is flushed. + If the existing file handle is an \c int file descriptor, nothing + is done to the file. + + Some "write-behind" filesystems may report an unspecified error on + closing the file. These errors only indicate that something may + have gone wrong since the previous open(). In such a case status() + reports IO_UnspecifiedError after close(), otherwise IO_Ok. + + \sa open(), flush() +*/ + + +void QFile::close() +{ + bool ok = FALSE; + if ( isOpen() ) { // file is not open + if ( fh ) { // buffered file + if ( ext_f ) + ok = fflush( fh ) != -1; // flush instead of closing + else + ok = fclose( fh ) != -1; + } else { // raw file + if ( ext_f ) + ok = TRUE; // cannot close + else + ok = ::close( fd ) != -1; + } + init(); // restore internal state + } + if (!ok) { + setStatus( IO_UnspecifiedError ); + setErrorStringErrno( errno ); + } +} |