linkers, loaders and libraries

Question 1

what is a library and what form do they come in

Answer 1

ready- compiled and tested programs that can be run when needed, they can come in the form of pre-built functions (.remainder)

Question 2

a DLL is a library that contains …

Answer 2

sub routines written to carry out a common task on the Windows OS (Save As)

Question 3

the benefits of libraries …(3)

Answer 3

• quick to implement into you own code
• pre-tested , so so you are sure that they are free from errors
• pre- compiled which means they are typically optimized

Question 4

drawbacks of libraries … (2)

Answer 4

• making specific tweaks can be difficult/impssible
• you have to trust that the developers will continue to maintain the library

Question 5

what is a linker

Answer 5

a piece of software that links external modules(code) and libraries within the code

Question 6

the two types of linkers are …

Answer 6

static linking
dynamic linking

Question 7

static liking works by including …

Answer 7

all the required code from libraries in the finished machine code

Question 8

dynamic linking(2)

Answer 8

• compiled versions of libraries are stored on the host computer
• the OS links the required code from the library as the program is running

Question 9

the advantage of dynamic linking is …

Answer 9

reduced size of compiled machine code

Question 10

the disadvantage of dynamic linking is if …

Answer 10

libraries change/don’t exist the program will stop working as it may try to call the subroutine in the wrong way

Question 11

a loader is a part of the OS that loads…

Answer 11

the executable program file(machine code) into memory (RAM) for execution