system command not executing with mpiicc -O

Hi,

I have intel Parallel studio XE cluster edition 2015 on my 10 Node server connected with infiniband band. I wrote my code in C. My code consists of system commands with sprintf commands like below

            printf("started \n");
            system("cp metis_input.txt $HOME/metis-4.0/.");
            sprintf(filename,"$HOME/metis-4.0/./partdmesh metis_input.txt %d",size-1);
            system(filename);
            sprintf(filename,"mv metis_input.txt.npart.%d nodes_proc.txt",size-1);
            system(filename);
            printf("completed \n");

when i compile my code n run it without any opmization flag it runs smoothly but when i compile my code with "mpiicc -O" the above lines dont even seem to b executed. I c that the above lines are being skipped. only the printf's r executed. Do i need to add anything extra in my code to get these system commands runnning for INTEL mpi compiler with -O ?