i have used system call to copy different files one by one using system for close to 68 files.

system("Cp -cf source destination");
the calls return with "-1"  which i could lookup from QNX help as couldnt load shell.
where as i am able to open a shell through terminal at the same time.

Are there any other specific reason when the system calls returns -1. or why it couldnt load a shell ??