Cmsc 216(A+ Guaranteed answers)

format specifier for char correct answers %c format specifier for int correct answers %d format specifier for real correct answers %f What is object code? correct answers its machine code, but it is not executable! When is feof(stdin) true! correct answers when you've read to the end of...

Posix Thread correct answers Pthread to compile: gcc -lpthread Threads share correct answers Heap memory Global / static memory shared libraries virtual address space Threads have their own correct answers thread id -stack -stack pointer -frame pointer program counter -values of other...

Compiling a C Program correct answers C programs must be compiled to be executed • Use the gcc program to build your programs -g enables debugging -Wall warns about common things that may be problems -o filename places executable in filename -c only compiles to object file, don't link C...

30000 is of type ___, but 30000L is of type ____ 2.5 is of type _____, but 2.5f is of type _____ correct answers int, long double, float Two different types of scope correct answers Block scope- Variable declared inside a block is visible only within the block File scope- An identifier decla...

T/F array subscripting is equivalent to pointer arithmetic and vice versa correct answers true T/F In the scope where the array is declared, the compiler knows how big the array is but when you pass an array to a func, all it sees is a pointer to the first element so it does not know size correct...

The typedef keyword correct answers • You can give types new names • typedef existing-type new-name; typedef double Dollars; Dollars x, y = 1.25; x and y are double int *a, b -> only a is a pointer variable Structures Declarations correct answers - Like arrays, hold multiple ite...

Memory Hierarchy correct answers Smaller / faster / costlier at top Larger / slower / cheaper at bottom Lvl0. CPU Registers Lvl1. On chip l1 cache Lvl2. Off chip l2 cache Lvl3. Main memory Lvl4. Local secondary storage Lvl5. Remote secondary storage Operating System correct answers -Manag...

String Literals correct answers Constant, defined with double quotes Can you pass in String literals into string functions correct answers Yes, if you don't need to modify the parameter Can you compare two arrays directly correct answers No, as it compares the memory addresses of them Link...

Where does memory for a program's heap come from? correct answers - the memory allocation functions make calls to the OS - get big chunks of memory and hand out small regions when allocation requests occur Heap Manager Requirements correct answers - must be able to handle arbitrary sequences of...

Assembly language concepts correct answers • Registers - Fast-access locations that the CPU uses, rather than storing all variables in memory - In the code we'll be examining, these are named by three-letter codes, and begin with % %eax, %ebx - Y86 has 8 registers (shown in next slide) •...

What is the difference between a pointer and a pointer variable? correct answers A pointer is a memory address/reference A pointer variable is a variable whose value is an address What is a NULL pointer? correct answers • This is a pointer that points to the address 0, where nothing is allow...

What is a prototype? correct answers All identifiers in C need to be declared before they are used. This is true for functions as well as variables. For functions the declaration needs to be before the first call of the function. A full declaration includes the return type and the number and...

What is the difference between Big Endian and Little Endian? Suppose we have the value 0x. How would the value be represented using Big/Little Endian? correct answers Big Endian: Little Endian: (reverse of Big Endian) What is the purpose of the .align directive? correct answers The .align di...

x = y; x & y are scalar correct answers types can be different, larger, or smaller than each other x = y; x & y are arrays correct answers not allowed x = y; x & y are structs correct answers allowed, as long as they are of the same structure type NDEBUG correct answers if it's defined whe...