[nologik@localhost ~]$ cat upxme.c
#include <stdio.h>

int main(void) {




printf ("\nhello\n");

return 1;

}


[nologik@localhost ~]$ gcc -o up upxme.c
[nologik@localhost ~]$ upx -9 up
                       Ultimate Packer for eXecutables
    Copyright (C) 1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006
UPX 2.02        Markus Oberhumer, Laszlo Molnar & John Reiser   Aug 13th 2006

        File size         Ratio      Format      Name
   --------------------   ------   -----------   -----------
upx: up: NotCompressibleException

Packed 1 file: 0 ok, 1 error.
[nologik@localhost ~]$