getchar() in C on Unix

**Underclocker** · 08-14-2007, 11:44 PM

Hi, I'm trying to write a portion of a program that outputs error when characters other than A, B and S are inputted with the use of getchar() then end, except I can't get it to work. Currently it looks like this:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main( void ) {

  int ch;

  printf( "Input characters:\n" );
  
  while ( ch != '\n' ) {

    ch = getchar();
    if( ch != 'A' || ch != 'B' || ch != 'S' ) {

      printf( "\nError: Please only input A, B and S.\n" );
      return 0;
      
    }

  }

return 0;

}

Can someone please tell me what I'm doing wrong?

**Underclocker** · 08-15-2007, 06:41 PM

Nevermind, I figured out what's wrong...

08-14-2007, 11:44 PM	#1 (permalink)
Underclocker Just passing by. Join Date: Aug 2007 Location: Sydney, Australia Posts: 824 OS: XP Pro SP3 x86 My System	getchar() in C on Unix Hi, I'm trying to write a portion of a program that outputs error when characters other than A, B and S are inputted with the use of getchar() then end, except I can't get it to work. Currently it looks like this: Code: #include <stdio.h> #include <stdlib.h> #include <math.h> int main( void ) { int ch; printf( "Input characters:\n" ); while ( ch != '\n' ) { ch = getchar(); if( ch != 'A' \|\| ch != 'B' \|\| ch != 'S' ) { printf( "\nError: Please only input A, B and S.\n" ); return 0; } } return 0; } Can someone please tell me what I'm doing wrong?

08-15-2007, 06:41 PM	#2 (permalink)
Underclocker Just passing by. Join Date: Aug 2007 Location: Sydney, Australia Posts: 824 OS: XP Pro SP3 x86 My System	Re: getchar() in C on Unix Nevermind, I figured out what's wrong...