[TUHS] v7 K&R C

Paul Winalski paul.winalski at gmail.com
Sun May 17 02:28:01 AEST 2020


> On Fri, May 15, 2020 at 4:02 PM <ron at ronnatalie.com> wrote:
>
>Unfortunately, if c is char on a machine with unsigned chars, or it’s of
>type unsigned char, the EOF will never be detected.
>
>    - while ((c = getchar()) != EOF) if (c == '\n') { /* entire record is now there */

The function prototype for getchar() is:    int getchar(void);

It returns an int, not a char.  In all likelihood this is specifically
*because* EOF is defined as -1.  The above code works fine if c is an
int.  One always has to be very careful when doing a typecast of a
function return value.

-Paul W.


More information about the TUHS mailing list