[tz] Re: 2025c zic.c calls fflush(3) on read only file pointer.

Dec. 18, 2025

      does anyone implement the ungetc() part or am i misunderstanding what
that's trying to say?

#include <stdio.h>
int main() {
 FILE* fp = fopen("/tmp/x.c", "r");
 ungetc('x', fp);
 printf("%c\n", fgetc(fp));
 fclose(fp);

 fp = fopen("/tmp/x.c", "r");
 ungetc('x', fp);
 fflush(fp);
 printf("%c\n", fgetc(fp));
 fclose(fp);

 return 0;
}

where this file is /tmp/x.c gives me x and # whether or not the flush
is there, for both glibc and macOS.

On Thu, Dec 18, 2025 at 12:24 PM Paul Eggert via tz <tz@iana.org> wrote:
...
Thanks for reporting the bug and the POSIX versions. zic should work
even on POSIX.1-2001 platforms, so I installed the attached. This should
let zic work even on unmodified NetBSD.

[tz] Re: 2025c zic.c calls fflush(3) on read only file pointer.

enh