input string of unknown length in c

is it even possible to write a program in c that prints out string input if unknown length to output only using getchar() and putchar()?

Do you mean like this?

Code:

---

#include <stdio.h>
#include <ctype.h>

int main() {
    int ch;
    while ((ch = getchar()) != EOF) {
        if (islower(ch))
            ch = toupper(ch);
        putchar(ch);
    }
    return 0;
}

---

hi thx for your answer

in my assignment it says that I can only use the std library <stdio.h>

I have been trying for over an hour and I can't get it. I have no Idea how it should work .

I didn't realize something so basic could be an "assignment". But the answer's there. It just has more than you need.

sry just ignore my first reply

and no thats the beginning of the assignment