k&r(7.1): Standard Input and Output

/* k&r(7.1): Standard Input and Output
   created on Mar 27, 2011
   */
#include    "stdio.h"
#include    "ctype.h"

main() /* lower: convert input to lower case */
{
    int c;

    while ((c = getchar()) != EOF)
      putchar(tolower(c));
    return 0;
}