On Sat, Jul 30, 2022 at 05:23:37PM -0600, Todd C. Miller wrote:
> On Sat, 30 Jul 2022 18:19:02 -0500, Scott Cheloha wrote:
>
> > Bump. The standard's error cases for fflush(3) are identical to those
> > for fclose(3):
> >
> > https://pubs.opengroup.org/onlinepubs/9699919799/functions/fflush.html
> > https://pubs.opengroup.org/onlinepubs/9699919799/functions/fclose.html
> >
> > Is the fact that our fclose(3) can succeed even if the error flag is
> > set a bug?
>
> As far as I can tell, neither fflush() nor fclose() check the status
> of the error flag, though they may set it of course. That is why
> I was suggesting an explicit ferror() call at the end.
I'm sorry, I'm having a dumb moment, I don't quite understand what
you're looking for.
Please tweak my patch so it's the way you want it, with the ferror(3)
call in the right spot.
We're sorta-kinda circling around adding the missing (?) stdio error
checking to other utilities in bin/ and usr.bin/, no? I want to be
sure I understand how to do the next patch, because if we do that it
will probably be a bunch of programs all at once.
Index: echo.c
===================================================================
RCS file: /cvs/src/bin/echo/echo.c,v
retrieving revision 1.10
diff -u -p -r1.10 echo.c
--- echo.c 9 Oct 2015 01:37:06 -0000 1.10
+++ echo.c 10 Aug 2022 18:00:12 -0000
@@ -53,12 +53,15 @@ main(int argc, char *argv[])
nflag = 0;
while (*argv) {
- (void)fputs(*argv, stdout);
- if (*++argv)
- putchar(' ');
+ if (fputs(*argv, stdout) == EOF)
+ err(1, "stdout");
+ if (*++argv && putchar(' ') == EOF)
+ err(1, "stdout");
}
- if (!nflag)
- putchar('\n');
+ if (!nflag && putchar('\n') == EOF)
+ err(1, "stdout");
+ if (fflush(stdout) == EOF || ferror(stdout) || fclose(stdout) == EOF)
+ err(1, "stdout");
return 0;
}
