I''m having the following code in one of my functions : FILE *file; file=fopen(filename,"rb"); Now my problem, in my reference book I found nothing about getting the filesize of the given file. Can anybody help me? Everything is possible ... ... at least I think so.

you could use the unix way:

#include
...
struct stat sb;
stat (filename,&sb)
printf("File size is: %d\n",sb.st_size);


or the windows way:

#include <windows.h>
...
HANDLE h = CreateFile( ... )
DWORD highDWord, lowDWord;

lowDWord = GetFileSize(h, &highDWord);
printf("filesize is: %d\n", lowDWord); // fails for files > 4gig

or the "stdio" way:

#include <stdio.h>

FILE *fh = fopen(fn,"rb");

int old_pos = ftell(fh);
lseek(fh,0,SEEK_END);
long pos = ftell(fh);
printf("filesize is: %d\n", pos);
fseek(fh,old_pos,SEEK_SET);


Hope that helps...


-- Pryankster
(Check out my game, a work in progress: DigiBot)

Edited by - Pryankster on June 4, 2000 1:12:45 PM

The stdio way is slightly wrong. ftell() returns a long, not an int. I also recommend using fseek() instead of lseek(), since fseek() is ANSI compatible, which lseek() isn't. This is how it should be:

#include < stdio.h>

FILE *fh = fopen(fn,"rb");

long old_pos = ftell(fh);
fseek(fh,0,SEEK_END);
long pos = ftell(fh);
printf("Filesize is: %ld\n", pos);
fseek(fh,old_pos,SEEK_SET);

/. Muzzafarath
Mad House Software

Edited by - Muzzafarath on June 4, 2000 1:44:09 PM

Edited by - Muzzafarath on June 4, 2000 1:45:16 PM

There is a small problem, nobody here is checking the return value of "fopen()". By not checking it you risk using a NULL pointer!

This is a better way to use "fopen()".

FILE *fp;

if((fp=fopen(filename, "r+b"))!=NULL) {
rewind(fp);
//do other stuff here
fclose(fp);
}
else {
//display error messages
}

Bah. You''re right ... fseek, not lseek (blame it on all those years using file-descriptor I/O on unix, instead of stdio ;-)

And I forgot to add "error checking elided for clarity" ;-)

Hey, thanks guys. That''s the stuff I was looking for.

Everything is possible ...
... at least I think so.