可执行文件在通过linux命令行执行时运行良好——在通过c++ system()命令调用时运行错误

I have a watershed model executable in linux that when executed, reads from a number of input text files. When I find that executable via shell and execute it (without root), everything works fine. However, I'm writing a c++ program that needs to call the executable and so thought I'd simply use system(). When I do, the model executes but then returns an "end-of-file" runtime error associated with one of the primary input text files. I have no idea why the program would execute fine when I execute manually via shell but return an error when executed via the system() command. I have a watershed model executable in linux th