Why it is wrong to MapViewOfFile function returns a pointer to the pointer?-CodePudding

 for (int I=0; i<=2; I++) 
{
HANDLE fp=CreateFile (TEXT (" D://jyzhj2. Rar "),//input here need to copy the file SRC 
GENERIC_READ | GENERIC_WRITE, 
FILE_SHARE_READ, 
NULL, 
OPEN_EXISTING, 
FILE_FLAG_SEQUENTIAL_SCAN. 
NULL); 

If (fp==NULL) 
{
MessageBox (L "error"); 
} 

DWORD dwBytesInBlock=GetFileSize (fp, NULL);//file size 
HANDLE hFileMapping=CreateFileMapping (fp, 
NULL, 
PAGE_READWRITE, 
0,//(DWORD) (dwBytesInBlock & gt;> 16), 
DwBytesInBlock,//(DWORD) (dwBytesInBlock & amp; 0 x0000ffff), 
NULL); 

Int dwError=GetLastError (); 

//release the file the kernel object 
The CloseHandle (fp); 

//offset 
__int64 qwFileOffset=0; 

//the file data is mapped to the process's address space 
LPVOID pbFile=MapViewOfFile (hFileMapping, 
FILE_MAP_ALL_ACCESS, 
(DWORD) (qwFileOffset & gt;> 32), 
(DWORD) (qwFileOffset & amp; 0 XFFFFFFFF), 
DwBytesInBlock); 

HANDLE wp=CreateFile (TEXT (" D://xianjian 5. Rar "),//it need paste file DST 
GENERIC_READ | GENERIC_WRITE, 
FILE_SHARE_WRITE, 
NULL, 
CREATE_ALWAYS, 
FILE_FLAG_SEQUENTIAL_SCAN | FILE_FLAG_WRITE_THROUGH, 
NULL); 

HANDLE hFileMapping2=CreateFileMapping (wp, 
NULL, 
PAGE_READWRITE, 
0,//(DWORD) (dwBytesInBlock & gt;> 16), 
DwBytesInBlock,//(DWORD) (dwBytesInBlock & amp; 0 x0000ffff), 
NULL); 


The CloseHandle (wp); 

LPVOID pbFile2=MapViewOfFile (hFileMapping2, 
FILE_MAP_ALL_ACCESS, 
(DWORD) (qwFileOffset & gt;> 32), 
(DWORD) (qwFileOffset & amp; 0 XFFFFFFFF), 
DwBytesInBlock); 

Memcpy (pbFile2 pbFile, dwBytesInBlock); 

UnmapViewOfFile (pbFile2); 
UnmapViewOfFile (pbFile); 

The CloseHandle (hFileMapping2); 
The CloseHandle (hFileMapping); 
}

Have been memcpy (pbFile2 pbFile, dwBytesInBlock); Interrupt
Mapping. Exe of 0 x1023fde0 (msvcr90d. DLL) the most possible exceptions: 0 xc0000005: access conflict while reading position 0 x00000000
Mapping. Exe of 0 x1023fde0 (msvcr90d. DLL) an unhandled exception: 0 xc0000005: access conflict while reading position 0 x00000000

CodePudding user response:

A novice for guidance

CodePudding user response:

Check whether there is pbFile MapViewOfFile function of each parameter setting on

CodePudding user response:

Check the error code, etc., GetLastError

CodePudding user response:

reference 5 floor oyljerry reply:

check the error code, etc., GetLastError

Error code is 87, parameter error?

CodePudding user response:

What I want is to write the data of a file to another file, wireless, the bigger the better, what should I do

CodePudding user response:

Fread
fwrite

CodePudding user response:

caution is ten thousand ship!
Fyi:

 # include & lt; Sys/stat. H> 
#include  
#include  
#include  
#include  
#include  
#include  
#include  
# define MAX_CLU_BYTES 65536 
The FILE * fo; 
Int fh. 
__int64 offs, offs1; 
__int64 rvi64; 
Int the rv, WRV; 
Unsigned char buf [MAX_CLU_BYTES]; 
Char ofn [_MAX_PATH]; 
Char offstr [80]. 
Char drive [_MAX_DRIVE]; 
Char dir [_MAX_DIR]; 
Char fname [_MAX_FNAME]; 
Char ext [_MAX_EXT]; 
Char fullpath [_MAX_PATH]; 
Void strcpybutcomma (char * t, char * s) {
char c; 

While (1) {
C=* s++; 
If (', '! * t++=c=c); 
If (0==c) break; 
} 
} 
Int main (int arg c, char * * argv) {
If (argc<3) {
Printf (" Copy File Tail. \ n "); 
Usage: printf (" \ n "); 
Printf (" CFT is filename. Ext {Offset_Begin | - Offset_End | Offset_Begin - Offset_End} \ n "); 
Printf (" Copy filename. Ext {OB | - OE | OB - OE} to {OB | ~ OE | OB - OE} - filename. Ext \ n "); 
Printf (" Note: Byte at OE is NOT included. \ n "); 
Example: printf (" \ n "); 
Printf (" CFT is ABC. Rar 12345 \ n "); 
Printf (" Copy ABC. Rar offset 12345 - end to 12345 - ABC. Rar \ n "); 
Printf (" \ n CFT is ABC. Rar - 12345 "); 
Printf (" Copy ABC. Rar offset the to - 12345-12345 - end - ABC. Rar \ n "); 
Printf (" CFT is ABC. Rar, 123-12345 \ n "); 
Printf (" Copy ABC. Rar offset of 123-12345 to 123-12345 - ABC. Rar \ n "); 
Printf (" CFT is ABC. Rar xab 0-0 XCD \ n "); 
Printf (" Copy ABC. Rar offset 0 xab xab XCD 0 to 0-0 XCD - ABC. Rar \ n "); 
return 1; 
} 
Strcpybutcomma (offstr, argv [2]); 
The rv=sscanf (offstr, "% I64i - % I64i", & amp; Offs, & amp; Offs1); 
If (rv==0) {
Printf (" is not number offset % s \ n ", argv [2]). 
Return 2; 
} 
If (NULL==_fullpath (fullpath, argv [1], _MAX_PATH)) {
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