Perhaps I am asking a silly question, but I really don't know about it. Can anyone tell me the function for "sleep" kind of functionality in C language for Unix. I don't think any function with the name of sleep() exits in Unix's C language. or perhaps I am not known with the header file required for this. Can anyone guide me about the correct function to halt the program execution for a specified time? Do tell me the header file required for the function as well.