Displaying Process Information From task_struct?

I have to somehow retrieve process information from task_struct and display it in in the terminal, like ps does. However, I may also have to add my own code to the sched.c and sched.h files, so I can't simply use a system call that already exists in my program.

How might I go about this and what is the best way to access the task_struct information? I have already read numerous threads and web sites, none of which contain much detail. Any help would be appreciated!

each process has a task_struct; which processes do you want to access information for? I think usually only the kernel has access to this

process information is also available in the /proc filesystem, see the proc man page

I need to access some information from all of the processes of PID > 1024. Currently, I have used the /proc file-system to put together an array containing all of those process ID's. The code is as follows:

Code:

---

int main(int argc, char * argv[])

{
  char * path = "/proc/";
  struct task_struct *info;
  struct dirent **namelist;
  int i, x, y, procs = 0;
  int n = scandir(path, &namelist, 0, alphasort);
  int proclist[n];
  char * file_name;

  for( i = 0; i < n; i++ )
    {
        if(atoi(namelist[i]->d_name) >= 1024)
          {
            proclist[procs] = atoi(namelist[i]->d_name);
            procs++;
          }
    }

  printf("%d total processes.\n", procs);

  for(i = 0; i < procs; i++)
    {
      printf("%d\n", proclist[i]);
    }

  return 0;

}

---

Using the /proc file-system, how can I get information (possibly from "current"), such as PID, GID, running time, etc. about each process?

Is there some way to set a struct task_struct *current = /path/<pid>/attr/current?