How do I get my program to wait for a keypress?

Code:

---

#include <stdio.h>

void myflush ( FILE *in )
{
  int ch;

  do
    ch = fgetc ( in );
  while ( ch != EOF && ch != '\n' );

  clearerr ( in );
}

void mypause ( void )
{
  printf ( "Press [Enter] to continue . . ." );
  fflush ( stdout );
  getchar();
}

int main ( void )
{
  int number;

  // Test with an empty stream
  printf ( "Hello, world!\n" );
  mypause();

  // Leave extra input in the stream
  printf ( "Enter more than one character" );

  myflush ( stdin );
  mypause();

  return 0;
}

---

What is the function of "fflush ( stdout );" and "clearerr ( in );" in this code?

Have you looked in the manual pages for those functions?
What did it say?

fflush(stdout); flushes the output stream (stdout) to ensure no chars are in the stream that could echo, 'myflush' is used to eat all chars in the input stream that could potentially automatically trigger getchar(); to return prematurely.

And clearerr(stream); resets all the errors/EOFs set for that specific stream, see http://www.cplusplus.com/reference/c.../clearerr.html

Yes, I looked in the manual pages for those functions, and I always do a research before posting a thread.
http://www.space.unibe.ch/comp_doc/c...MAN/fflush.htm
the question I should be asking is why we do use "fflush ( stdout );" and "clearerr ( in );" here?
because I get the same result without this 2 lines.
Obviously we use it to avoid something which I want to know about.

ffs, read my post.

you NEVER EVER flush st.... oh

um, yes you can flush stdout ;)