Quote Originally Posted by EdMarx
My teacher told me that a c programmer NEVER uses scanf.
He does database stuff.
So if a lot of c programmers dont get user input, where do they get the input from.
Maybe the input is obtained by reading into a string (e.g., using fgets) which is then parsed in various ways, e.g., by using sscanf.
Maybe the input is a command line argument, which perhaps might be a file name upon which further input is read from file.
Maybe the input is through a GUI.
Or, just maybe, scanf is used because its pitfalls are deemed not particularly relevant for the given piece of code. (That is, "never" is too strong a word.)

Quote Originally Posted by EdMarx
Can I call and or control other programs with c?
Once you have the required knowledge, yes.

Quote Originally Posted by EdMarx
cant I create apps for mac and linux?
Once you have the required knowledge, yes.

Quote Originally Posted by EdMarx
And my main question for my teacher, which he said shouldn't be done with c, is GUI.
Why don't you ask him to explain why a GUI should not be done in C?

Quote Originally Posted by EdMarx
I just have a hard time wrapping my mind around programs that the user doesn't somehow interface with.
A GUI is certainly not the only possible user interface.

Quote Originally Posted by EdMarx
So is c usually all background programs?
I am not sure what you mean by "usually all background programs" as it sounds like an oxymoron. Do you mean to ask if the usual use of C is to write "background programs", or if "background programs" are usually written in C?

For the former, I would say no, but then "usual" is ambiguous; for the latter, it depends on what you mean by "background programs".

Quote Originally Posted by EdMarx
Is there generally never a GUI with c?
No, but generally C is not the best programming language in which to develop a GUI.