I suspect we are saying the same thing. C is defined as an int (as Larry also showed), not an unsigned char (and frankly if you had done that, most modern compilers will give you a warning). IIRC you are correct that the Ritchie compiler would not catch that error.

But, the truth is I know few C (experienced) programmers that would define c as anything but an int; particularly in the modern era with compiler warnings as good as they are.

Clem

On Fri, May 15, 2020 at 4:18 PM <ron@ronnatalie.com> wrote:

EOF is defined to be -1.
getchar() returns int, but c is a unsigned char, the value of (c = getchar()) will be 255. This will never compare equal to -1.

Ron,

Hmmm... getchar/getc are defined as returning int in the man page and C is traditionally defined as an int in this code..

On Fri, May 15, 2020 at 4:02 PM <ron@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 */