Linux: unable to retrieve process name from pid via ioctl - linux

Question

I'm trying to retrieve retrieve process name from pid via ioctl, this is the C code:
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <dirent.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/signal.h>
#include <sys/syscall.h>
#include <sys/procfs.h>
#include <stdio.h>
#include <signal.h>
#include <elf.h>
#include <stdlib.h>
#include <errno.h>
int main(int argc, char **argv) {
char ProcID[50]="/proc/";
int fd;
prpsinfo_t ProcessInfo;
int ioctlResult;
if ( argc != 2 ) {
printf("usage: %s <pid>\n", argv[0]);
return 0;
}
strcat(ProcID,argv[1]);
fd = open(ProcID, O_RDONLY, 0);
if (fd == -1) {
printf("open error: [%d] [%s]\n",errno, strerror(errno));
return 0;
}
ioctlResult = ioctl(fd, NT_PRPSINFO, &ProcessInfo);
if (ioctlResult == -1)
{
printf("Error ioctl: [%d] [%s]\n",errno, strerror(errno));
} else {
printf("Process name: %s\n",ProcessInfo.pr_fname);
}
close(fd);
return 0;
}
When I try to execute it I obtain errno 25 (Inappropriate ioctl for device). I think the file descriptor open on "/proc/" isn't correct; is there another path to consider ?