///////////////////////////////////////////////////////////////////////////// // 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 license ///////////////////////////////////////////////////////////////////////////// #ifndef _WX_FILEH__ #define _WX_FILEH__ #ifdef __GNUG__ #pragma interface "file.h" #endif #ifndef WX_PRECOMP #include "wx/string.h" #include "wx/filefn.h" #endif #if wxUSE_FILE // ---------------------------------------------------------------------------- // 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 #define wxS_IRUSR 00400 #define wxS_IWUSR 00200 #define wxS_IXUSR 00100 #define wxS_IRGRP 00040 #define wxS_IWGRP 00020 #define wxS_IXGRP 00010 #define wxS_IROTH 00004 #define wxS_IWOTH 00002 #define wxS_IXOTH 00001 // default mode for the new files: corresponds to umask 022 #define wxS_DEFAULT (wxS_IRUSR | wxS_IWUSR | wxS_IRGRP | wxS_IWGRP |\ wxS_IROTH | wxS_IWOTH) // ---------------------------------------------------------------------------- // 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 WXDLLEXPORT 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 wxChar *name); // check whetther we can access the given file in given mode // (only read and write make sense here) static bool Access(const wxChar *name, OpenMode mode); // ctors // ----- // def ctor wxFile() { m_fd = fd_invalid; } // open specified file (may fail, use IsOpened()) wxFile(const wxChar *szFileName, OpenMode mode = read); // attach to (already opened) file wxFile(int fd) { m_fd = fd; } // 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 wxChar *szFileName, bool bOverwrite = FALSE, int access = wxS_DEFAULT); bool Open(const wxChar *szFileName, 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 fd) { Close(); m_fd = fd; } void Detach() { m_fd = fd_invalid; } int fd() const { return m_fd; } // read/write (unbuffered) // returns number of bytes read or ofsInvalid on error off_t Read(void *pBuf, off_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, wxMBConv& conv = wxConvLibc) { const wxWX2MBbuf buf = s.mb_str(conv); size_t size = strlen(buf); return Write((const char *) buf, size) == size; } // flush data not yet written bool Flush(); // file pointer operations (return ofsInvalid on failure) // move ptr ofs bytes related to start/current off_t/end of file off_t Seek(off_t ofs, wxSeekMode mode = wxFromStart); // move ptr to ofs bytes before the end off_t SeekEnd(off_t ofs = 0) { return Seek(ofs, wxFromEnd); } // get current off_t off_t Tell() const; // get current file length off_t 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 occured? bool Error() const { return m_error; } // 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 WXDLLEXPORT 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(); } // 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) != 0; } bool Write(const wxString& str, wxMBConv& conv = wxConvLibc) { return m_file.Write(str, conv); } // 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__