First, you need to read the man page on system(3). The return value is of the format returned by wait(2). Thus, you need to feed that into the WEXITSTATUS macro to get the actual return value.

Second, you are not returning a value from your main function. The 2 is just a value left over on the stack.

Here's a quick cut at correcting your program (I'm not at a Linux system at the moment so I can't check it):

Code:

#include <stdio.h>
main ( int argc, char* argv[] )
{
  char *cmd=argv[1];
  int rt=system(cmd);
  int actual_exit = -1, actual_signal = -1;
  if (WIFEXITED(rt)) actual_exit = WEXITSTATUS(rt);
  else actual_signal = WTERMSIG(rt);
  printf ("\n executed command: %s\n RETURN: %d or SIGNAL: %d\n", 
    cmd, actual_exit, actual_signal);
  return actual_exit;
}

I took care of handling the case where the child process gets a signal though the program exit status won't reflect it correctly.

See if that helps.