user-0 提问: 运行后有出乱码

回复:
user: user-1
content: 赵4老师都回复了，我只能接分了。 我是谁？

user: user-0
content: 没有‘\0’的原因，那怎么解决啊

user: user-1
content: _chsize Changes the file size.  int _chsize( int handle, long size );  Routine Required Header Optional Headers Compatibility  _chsize <io.h> <errno.h> Win 95, Win NT    For additional compatibility information, see Compatibility in the Introduction.  Libraries  LIBC.LIB Single thread static library, retail version  LIBCMT.LIB Multithread static library, retail version  MSVCRT.LIB Import library for MSVCRT.DLL, retail version    Return Value  _chsize returns the value 0 if the file size is successfully changed. A return value of –1 indicates an error: errno is set to EACCES if the specified file is locked against access, to EBADF if the specified file is read-only or the handle is invalid, or to ENOSPC if no space is left on the device.  Parameters  handle  Handle referring to open file  size  New length of file in bytes  Remarks  The _chsize function extends or truncates the file associated with handle to the length specified by size. The file must be open in a mode that permits writing. Null characters ('\0') are appended if the file is extended. If the file is truncated, all data from the end of the shortened file to the original length of the file is lost.  Example   /* CHSIZE.C: This program uses _filelength to report the size  * of a file before and after modifying it with _chsize.  */  #include <io.h> #include <fcntl.h> #include <sys/types.h> #include <sys/stat.h> #include <stdio.h>  void main( void ) {    int fh, result;    unsigned int nbytes = BUFSIZ;     /* Open a file */    if( (fh = _open( "data", _O_RDWR | _O_CREAT, _S_IREAD                     | _S_IWRITE ))  != -1 )    {       printf( "File length before: %ld\n", _filelength( fh ) );       if( ( result = _chsize( fh, 329678 ) ) == 0 )          printf( "Size successfully changed\n" );       else          printf( "Problem in changing the size\n" );       printf( "File length after:  %ld\n", _filelength( fh ) );       _close( fh );    } }   Output  File length before: 0 Size successfully changed File length after:  329678     File Handling Routines  See Also   _close, _creat, _open  _fileno Gets the file handle associated with a stream.  int _fileno( FILE *stream );  Function Required Header Compatibility  _fileno <stdio.h> Win 95, Win NT    For additional compatibility information, see Compatibility in the Introduction.  Libraries  LIBC.LIB Single thread static library, retail version  LIBCMT.LIB Multithread static library, retail version  MSVCRT.LIB Import library for MSVCRT.DLL, retail version    Return Value  _fileno returns the file handle. There is no error return. The result is undefined if stream does not specify an open file.  Parameter  stream  Pointer to FILE structure  Remarks  The _fileno routine returns the file handle currently associated with stream. This routine is implemented both as a function and as a macro. For details on choosing either implementation, see Choosing Between Functions and Macros.  Example   /* FILENO.C: This program uses _fileno to obtain  * the file handle for some standard C streams.  */  #include <stdio.h>  void main( void ) {    printf( "The file handle for stdin is %d\n", _fileno( stdin ) );    printf( "The file handle for stdout is %d\n", _fileno( stdout ) );    printf( "The file handle for stderr is %d\n", _fileno( stderr ) ); }   Output  The file handle for stdin is 0 The file handle for stdout is 1 The file handle for stderr is 2   Stream I/O Routines  See Also   _fdopen, _filelength, fopen, freopen

user: user-1
content: fopen, _wfopen Open a file.  FILE *fopen( const char *filename, const char *mode );  FILE *_wfopen( const wchar_t *filename, const wchar_t *mode );  Function Required Header Compatibility  fopen <stdio.h> ANSI, Win 95, Win NT  _wfopen <stdio.h> or <wchar.h> Win NT    For additional compatibility information, see Compatibility in the Introduction.  Libraries  LIBC.LIB Single thread static library, retail version  LIBCMT.LIB Multithread static library, retail version  MSVCRT.LIB Import library for MSVCRT.DLL, retail version    The c, n, and t mode options are Microsoft extensions for fopen and _fdopen and should not be used where ANSI portability is desired.  Return Value  Each of these functions returns a pointer to the open file. A null pointer value indicates an error.   Parameters  filename  Filename  mode  Type of access permitted  Remarks  The fopen function opens the file specified by filename. _wfopen is a wide-character version of fopen; the arguments to _wfopen are wide-character strings. _wfopen and fopen behave identically otherwise.  Generic-Text Routine Mappings  TCHAR.H Routine  _UNICODE & _MBCS Not Defined _MBCS Defined _UNICODE Defined  _tfopen fopen fopen _wfopen    The character string mode specifies the type of access requested for the file, as follows:  "r"  Opens for reading. If the file does not exist or cannot be found, the fopen call fails.  "w"  Opens an empty file for writing. If the given file exists, its contents are destroyed.  "a"  Opens for writing at the end of the file (appending) without removing the EOF marker before writing new data to the file; creates the file first if it doesn’t exist.  "r+"  Opens for both reading and writing. (The file must exist.)  "w+"  Opens an empty file for both reading and writing. If the given file exists, its contents are destroyed.  "a+"  Opens for reading and appending; the appending operation includes the removal of the EOF marker before new data is written to the file and the EOF marker is restored after writing is complete; creates the file first if it doesn’t exist.  When a file is opened with the "a" or "a+" access type, all write operations occur at the end of the file. The file pointer can be repositioned using fseek or rewind, but is always moved back to the end of the file before any write operation is carried out. Thus, existing data cannot be overwritten.  The "a" mode does not remove the EOF marker before appending to the file. After appending has occurred, the MS-DOS TYPE command only shows data up to the original EOF marker and not any data appended to the file. The "a+" mode does remove the EOF marker before appending to the file. After appending, the MS-DOS TYPE command shows all data in the file. The "a+" mode is required for appending to a stream file that is terminated with the CTRL+Z EOF marker.  When the "r+", "w+", or "a+" access type is specified, both reading and writing are allowed (the file is said to be open for “update”). However, when you switch between reading and writing, there must be an intervening fflush, fsetpos, fseek, or rewind operation. The current position can be specified for the fsetpos or fseek operation, if desired.  In addition to the above values, the following characters can be included in mode to specify the translation mode for newline characters:  t  Open in text (translated) mode. In this mode, CTRL+Z is interpreted as an end-of-file character on input. In files opened for reading/writing with "a+", fopen checks for a CTRL+Z at the end of the file and removes it, if possible. This is done because using fseek and ftell to move within a file that ends with a CTRL+Z, may cause fseek to behave improperly near the end of the file.   Also, in text mode, carriage return–linefeed combinations are translated into single linefeeds on input, and linefeed characters are translated to carriage return–linefeed combinations on output. When a Unicode stream-I/O function operates in text mode (the default), the source or destination stream is assumed to be a sequence of multibyte characters. Therefore, the Unicode stream-input functions convert multibyte characters to wide characters (as if by a call to the mbtowc function). For the same reason, the Unicode stream-output functions convert wide characters to multibyte characters (as if by a call to the wctomb function).  b  Open in binary (untranslated) mode; translations involving carriage-return and linefeed characters are suppressed.   If t or b is not given in mode, the default translation mode is defined by the global variable _fmode. If t or b is prefixed to the argument, the function fails and returns NULL.   For more information about using text and binary modes in Unicode and multibyte stream-I/O, see Text and Binary Mode File I/O and Unicode Stream I/O in Text and Binary Modes.  c  Enable the commit flag for the associated filename so that the contents of the file buffer are written directly to disk if either fflush or _flushall is called.  n  Reset the commit flag for the associated filename to “no-commit.” This is the default. It also overrides the global commit flag if you link your program with COMMODE.OBJ. The global commit flag default is “no-commit” unless you explicitly link your program with COMMODE.OBJ.  Valid characters for the mode string used in fopen and _fdopen correspond to oflag arguments used in _open and _sopen, as follows.  Characters in mode String Equivalent oflag Value for _open/_sopen   a _O_WRONLY | _O_APPEND (usually _O_WRONLY | _O_CREAT | _O_APPEND)  a+ _O_RDWR | _O_APPEND (usually _O_RDWR | _O_APPEND | _O_CREAT )  r _O_RDONLY  r+ _O_RDWR  w _O_WRONLY (usually _O_WRONLY | _O_CREAT | _O_TRUNC)  w+ _O_RDWR (usually _O_RDWR | _O_CREAT | _O_TRUNC)  b _O_BINARY  t _O_TEXT  c None  n None    Example  /* FOPEN.C: This program opens files named "data"  * and "data2".It  uses fclose to close "data" and  * _fcloseall to close all remaining files.  */  #include <stdio.h>  FILE *stream, *stream2;  void main( void ) {    int numclosed;     /* Open for read (will fail if file "data" does not exist) */    if( (stream  = fopen( "data", "r" )) == NULL )       printf( "The file 'data' was not opened\n" );    else       printf( "The file 'data' was opened\n" );     /* Open for write */    if( (stream2 = fopen( "data2", "w+" )) == NULL )       printf( "The file 'data2' was not opened\n" );    else       printf( "The file 'data2' was opened\n" );     /* Close stream */    if( fclose( stream ) )       printf( "The file 'data' was not closed\n" );     /* All other files are closed: */    numclosed = _fcloseall( );    printf( "Number of files closed by _fcloseall: %u\n", numclosed ); }   Output  The file 'data' was opened The file 'data2' was opened Number of files closed by _fcloseall: 1   Stream I/O Routines  See Also   fclose, _fdopen, ferror, _fileno, freopen, _open, _setmode

user: user-1
content: #include <stdio.h> #include <io.h> int main() {     FILE *fp;     char text[1024]={0};     if ((fp=fopen("D:\\123.txt","rb+"))==NULL)     {         fp=fopen("D:\\123.txt","wb");     }     fprintf(fp,"%s","D:\\123\\VD.exe\r\nF:\\123\\video");     fflush(fp);     _chsize(_fileno(fp),ftell(fp));     rewind(fp);     while (fgets(text,1024,fp)!=NULL)     {         puts(text);     }     fclose(fp);     return 0;  } //D:\123\VD.exe // //F:\123\video //

user: user-2
content: 没有‘\0’的原因

user: user-0
content: 不要沉啊，求大神