How to clear input buffer in C?

Question

I have the following program:

int main(int argc, char *argv[])
{
  char ch1, ch2;
  printf(\"Input the first character:\"); // Line 1
  scanf(\"%c\", &ch         


        

Answer 1

A portable way to clear up to the end of a line that you've already tried to read partially is:

int c;

while ( (c = getchar()) != '\n' && c != EOF ) { }

This reads and discards characters until it gets \n which signals the end of the file. It also checks against EOF in case the input stream gets closed before the end of the line. The type of c must be int (or larger) in order to be able to hold the value EOF.

There is no portable way to find out if there are any more lines after the current line (if there aren't, then getchar will block for input).