Technical Questions

9. What’s a signal? What do I use signals for? A signal is an exceptional condition that occurs during the execution of your program. It might be the result of …

7. What is a “locale”? A locale is a description of certain conventions your program might be expected to follow under certain circumstances. It’s mostly helpful to internationalize your program. …

6. How do I determine whether a character is numeric, alphabetic, and so on? The header file ctype.h defines various functions for determining what class a character belongs to. These …

4. What is the difference between a free-standing and a hosted environment? Not all C programmers write database management systems and word processors. Some write code for embedded systems, such …

3. How can I write functions that take a variable number of arguments? Use <stdarg.h>. This defines some macros that let your program deal with variable numbers of arguments. There’s …

1. Why should I use standard library functions instead of writing my own? The standard library functions have three advantages: they work, they’re efficient, and they’re portable. They work: Your …

25. How does free() know how much memory to release? There’s no standard way. It can vary from compiler to compiler, even from version to version of the same compiler. …

23. What is a “null pointer assignment” error? What are bus errors, memory faults, and core dumps? These are all serious errors, symptoms of a wild pointer or subscript. Null …

21. What happens if you free a pointer twice? If you free a pointer, use it to allocate memory again, and free it again, of course it’s safe If you …

19. What is the stack? A “stack trace” is a list of which functions have been called, based on this information. When you start using a debugger, one of the …