Get the size of an HD in Linux 1

[666cartman]

I finally found the solution:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/fs.h>
#include <sys/ioctl.h>
#include <linux/hdreg.h>

void main ()

{
int fd;
int sector_size = 1;
long sectors;
long size;
struct hd_big_geometry g;
fd=open(&quot;/dev/hda&quot;,O_RDONLY);
if (ioctl(fd, HDIO_GETGEO_BIG_RAW, &g))return -1;
if (ioctl(fd, BLKGETSIZE, &sectors))return -1;
if (ioctl(fd, BLKSSZGET, &sector_size))return -1;

printf(&quot;sectorsize: %d sectors:
%ld\n&quot;,sector_size,sectors);
size=sectors/(1024/sector_size);

printf(&quot;size: %ld\n&quot;,size);

}


the Code is not perfect but it works, notice that it gets the real size of an hd from the driver. Of course it only works if you are root.

 

[jamisar]

OK, on exit C will close all opened fd's
but is not good practice to left them opened!!
you could get problems.
give for flexibility, the /dev/???? as params to main.
i see no problems, setting root-setuid to a WELL written and
COMPILED exec, chmod 4511 <name>; chown 0 <name>
so everybody can get the infos.

 

[666cartman]

sorry, i just forgot to enter the close in the post it is in my real prog, also are the params, i just posted a real slim code fragment, sorryy anout that

 

[Laopang]

I think you may add :
close(fd);
before the application exit.

 

[Laopang]

if (ioctl(fd, BLKGETSIZE, ¡±ors))return -1;
if (ioctl(fd, BLKSSZGET, ¡±or_size))return -1;

may be:
if (ioctl(fd, BLKGETSIZE,&sectors))
return ;
if (ioctl(fd, BLKSSZGET,&sector_size))
return ;