dispatch root command

main.cpp

#include <cstdio>
#include <cstring>

int main()
{
  FILE* const sudo = popen("sudo -H -s", "r+");

  fprintf(sudo, "echo login_test\n");
  fflush(sudo);

  char line[256];
  char* const fgets_ret = fgets(line, sizeof(line), sudo);

  if(fgets_ret==NULL) {
    fprintf(stderr, "failed!\n");
  } else {
    fprintf(stderr, "%s\n", line);
    if(strcmp(line, "login_test\n")==0) {
      fprintf(stderr, "success!\n");
      fprintf(sudo, "echo logined! >&2\n");      
    }
  }

  fclose(sudo);
  return 0;
}