///////////////////////////////////////////////////////////////////////////// // Name: file.h // Purpose: wxFile - encapsulates low-level "file descriptor" // wxTempFile - safely replace the old file // Author: Vadim Zeitlin // Modified by: // Created: 29/01/98 // RCS-ID: $Id$ // Copyright: (c) 1998 Vadim Zeitlin // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// #ifndef _WX_FILEH__ #define _WX_FILEH__ #include "wx/defs.h" #if wxUSE_FILE #include "wx/string.h" #include "wx/filefn.h" #include "wx/strconv.h" // ---------------------------------------------------------------------------- // constants // ---------------------------------------------------------------------------- // we redefine these constants here because S_IREAD &c are _not_ standard // however, we do assume that the values correspond to the Unix umask bits enum wxPosixPermissions { // standard Posix names for these permission flags: wxS_IRUSR = 00400, wxS_IWUSR = 00200, wxS_IXUSR = 00100, wxS_IRGRP = 00040, wxS_IWGRP = 00020, wxS_IXGRP = 00010, wxS_IROTH = 00004, wxS_IWOTH = 00002, wxS_IXOTH = 00001, // longer but more readable synonims for the constants above: wxPOSIX_USER_READ = wxS_IRUSR, wxPOSIX_USER_WRITE = wxS_IWUSR, wxPOSIX_USER_EXECUTE = wxS_IXUSR, wxPOSIX_GROUP_READ = wxS_IRGRP, wxPOSIX_GROUP_WRITE = wxS_IWGRP, wxPOSIX_GROUP_EXECUTE = wxS_IXGRP, wxPOSIX_OTHERS_READ = wxS_IROTH, wxPOSIX_OTHERS_WRITE = wxS_IWOTH, wxPOSIX_OTHERS_EXECUTE = wxS_IXOTH, // default mode for the new files: allow reading/writing them to everybody but // the effective file mode will be set after anding this value with umask and // so won't include wxS_IW{GRP,OTH} for the default 022 umask value wxS_DEFAULT = (wxPOSIX_USER_READ | wxPOSIX_USER_WRITE | \ wxPOSIX_GROUP_READ | wxPOSIX_GROUP_WRITE | \ wxPOSIX_OTHERS_READ | wxPOSIX_OTHERS_WRITE), // default mode for the new directories (see wxFileName::Mkdir): allow // reading/writing/executing them to everybody, but just like wxS_DEFAULT // the effective directory mode will be set after anding this value with umask wxS_DIR_DEFAULT = (wxPOSIX_USER_READ | wxPOSIX_USER_WRITE | wxPOSIX_USER_EXECUTE | \ wxPOSIX_GROUP_READ | wxPOSIX_GROUP_WRITE | wxPOSIX_GROUP_EXECUTE | \ wxPOSIX_OTHERS_READ | wxPOSIX_OTHERS_WRITE | wxPOSIX_OTHERS_EXECUTE) }; // ---------------------------------------------------------------------------- // class wxFile: raw file IO // // NB: for space efficiency this class has no virtual functions, including // dtor which is _not_ virtual, so it shouldn't be used as a base class. // ---------------------------------------------------------------------------- class WXDLLIMPEXP_BASE wxFile { public: // more file constants // ------------------- // opening mode enum OpenMode { read, write, read_write, write_append, write_excl }; // standard values for file descriptor enum { fd_invalid = -1, fd_stdin, fd_stdout, fd_stderr }; // static functions // ---------------- // check whether a regular file by this name exists static bool Exists(const wxString& name); // check whether we can access the given file in given mode // (only read and write make sense here) static bool Access(const wxString& name, OpenMode mode); // ctors // ----- // def ctor wxFile() { m_fd = fd_invalid; m_error = false; } // open specified file (may fail, use IsOpened()) wxFile(const wxString& fileName, OpenMode mode = read); // attach to (already opened) file wxFile(int lfd) { m_fd = lfd; m_error = false; } // open/close // create a new file (with the default value of bOverwrite, it will fail if // the file already exists, otherwise it will overwrite it and succeed) bool Create(const wxString& fileName, bool bOverwrite = false, int access = wxS_DEFAULT); bool Open(const wxString& fileName, OpenMode mode = read, int access = wxS_DEFAULT); bool Close(); // Close is a NOP if not opened // assign an existing file descriptor and get it back from wxFile object void Attach(int lfd) { Close(); m_fd = lfd; m_error = false; } void Detach() { m_fd = fd_invalid; } int fd() const { return m_fd; } // read/write (unbuffered) // returns number of bytes read or wxInvalidOffset on error ssize_t Read(void *pBuf, size_t nCount); // returns the number of bytes written size_t Write(const void *pBuf, size_t nCount); // returns true on success bool Write(const wxString& s, const wxMBConv& conv = wxMBConvUTF8()); // flush data not yet written bool Flush(); // file pointer operations (return wxInvalidOffset on failure) // move ptr ofs bytes related to start/current offset/end of file wxFileOffset Seek(wxFileOffset ofs, wxSeekMode mode = wxFromStart); // move ptr to ofs bytes before the end wxFileOffset SeekEnd(wxFileOffset ofs = 0) { return Seek(ofs, wxFromEnd); } // get current offset wxFileOffset Tell() const; // get current file length wxFileOffset Length() const; // simple accessors // is file opened? bool IsOpened() const { return m_fd != fd_invalid; } // is end of file reached? bool Eof() const; // has an error occurred? bool Error() const { return m_error; } // type such as disk or pipe wxFileKind GetKind() const { return wxGetFileKind(m_fd); } // dtor closes the file if opened ~wxFile() { Close(); } private: // copy ctor and assignment operator are private because // it doesn't make sense to copy files this way: // attempt to do it will provoke a compile-time error. wxFile(const wxFile&); wxFile& operator=(const wxFile&); int m_fd; // file descriptor or INVALID_FD if not opened bool m_error; // error memory }; // ---------------------------------------------------------------------------- // class wxTempFile: if you want to replace another file, create an instance // of wxTempFile passing the name of the file to be replaced to the ctor. Then // you can write to wxTempFile and call Commit() function to replace the old // file (and close this one) or call Discard() to cancel the modification. If // you call neither of them, dtor will call Discard(). // ---------------------------------------------------------------------------- class WXDLLIMPEXP_BASE wxTempFile { public: // ctors // default wxTempFile() { } // associates the temp file with the file to be replaced and opens it wxTempFile(const wxString& strName); // open the temp file (strName is the name of file to be replaced) bool Open(const wxString& strName); // is the file opened? bool IsOpened() const { return m_file.IsOpened(); } // get current file length wxFileOffset Length() const { return m_file.Length(); } // move ptr ofs bytes related to start/current offset/end of file wxFileOffset Seek(wxFileOffset ofs, wxSeekMode mode = wxFromStart) { return m_file.Seek(ofs, mode); } // get current offset wxFileOffset Tell() const { return m_file.Tell(); } // I/O (both functions return true on success, false on failure) bool Write(const void *p, size_t n) { return m_file.Write(p, n) == n; } bool Write(const wxString& str, const wxMBConv& conv = wxMBConvUTF8()) { return m_file.Write(str, conv); } // flush data: can be called before closing file to ensure that data was // correctly written out bool Flush() { return m_file.Flush(); } // different ways to close the file // validate changes and delete the old file of name m_strName bool Commit(); // discard changes void Discard(); // dtor calls Discard() if file is still opened ~wxTempFile(); private: // no copy ctor/assignment operator wxTempFile(const wxTempFile&); wxTempFile& operator=(const wxTempFile&); wxString m_strName, // name of the file to replace in Commit() m_strTemp; // temporary file name wxFile m_file; // the temporary file }; #endif // wxUSE_FILE #endif // _WX_FILEH__