how to get file size in c++

[chiwing]

I need to write a dll which include a function that return file size


would any one help me to finish the part between /*** and **/

/***
bool Check_file_size ()
{
int Size_1 = GetSize("myself.dll") ;
int Size_2 = GetSize("upper_folder\serial.txt") ;
int Size_3 = GetSize("upper_folder\happy.fcv") ;

if (Szie_1 != default_1 ) return(false);
if (Size_2 != default_2 ) return(false);
if (Size_3 != default_3 ) return(false);
}

int Get_Size(string path);
{
....
....
return(Size);
}

**/

let's give an example of what upper_folder means

as above mentioned, there is a "myself.dll" in C:\Programs File\Success\libraries\

then the "serial.txt" and "happy.fcv" is in C:\Programs File\Success\


I am a beginner of programming ^^

big thanks

[writetonsharma]

fopen();
fseek(seek to the end of the file)
ftell(get the file size in bytes)
fseek(again come to the begining of the file if you want to traverse the file)

[Duthomhas]

On Windows, you can also use the GetFileSizeEx() or GetFileSize() function ( http://www.google.com/search?btnI=1&q=msdn+GetFileSizeEx ).

You'll have to have an open HANDLE to the file to use it.

Hope this helps.

[kbw]

Windows/*NIX (and probably most conventional OS') support stat function.

[Duthomhas]

Oh, zap, how did I forget that one?

#include <iostream>
using namespace std;

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int main( int argc, char** argv )
  {
  if (argc != 2)
    {
    cerr << "usage:\n"
            "  filesize FILENAME\n\n";
    return 1;
    }

  struct stat filestatus;
  stat( argv[ 1 ], &filestatus );

  cout << filestatus.st_size << " bytes\n";

  return 0;
  }

See http://linux.die.net/man/2/stat

;->

[writetonsharma]

hehehehe... me too... :P

infact replied to someone about stat...

[chiwing]

Duoas
Oh, zap, how did I forget that one?
#include <iostream>
using namespace std;

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

int main( int argc, char** argv )
{
if (argc != 2)
{
cerr << "usage:\n"
" filesize FILENAME\n\n";
return 1;
}

struct stat filestatus;
stat( argv[ 1 ], &filestatus );

cout << filestatus.st_size << " bytes\n";

return 0;
}

See http://linux.die.net/man/2/stat

;->

thanks all of the people giving help
but do this compatible on windows xp,vista?
thanks again

[kbw]

Yes.

[chiwing]

Duoas
On Windows, you can also use the GetFileSizeEx() or GetFileSize() function ( http://www.google.com/search?btnI=1&q=msdn+GetFileSizeEx ).

You'll have to have an open HANDLE to the file to use it.

how the program know which file i want to get ? filename ??

[chiwing]

i have find the answer on internet already

handle=FileOpen("filename", FILE_CSV|FILE_WRITE, ';');
if(handle>0)
{
FileWrite(handle, Close[0], Open[0], High[0], Low[0], TimeToStr(orderOpen));
FileClose(handle);
}

i don't know what is handle before..

[chiwing]

below site say that when handle = 0, then it means no error , it opposite to when i have learn in the ticket = XXX

http://msdn.microsoft.com/en-us/library/z5hh6ee9(VS.80).aspx

just soliloquize, don't need to reply anything, thanks :)

[chiwing]

if a file is reading by another process, and i want to get the size of this file, which is better for getting it's size? GetFileSize or Ftell ?

[decoupling]

int Get_Size( string path )
{
// #include <fstream>
FILE *pFile = NULL;

// get the file stream
fopen_s( &pFile, path.c_str(), "rb" );

// set the file pointer to end of file
fseek( pFile, 0, SEEK_END );

// get the file size
int Size = ftell( pFile );

// return the file pointer to begin of file if you want to read it
// rewind( pFile );

// close stream and release buffer
fclose( pFile );

return Size;
}

[jsmith]

It would be better to use off_t (or loff_t) than int.

[chiwing]

off_t (or loff_t) than int.

off_t Size = ftell( pFile );

right?