Improve resizewin(1).

[trasz]

Summary

The patch does two things: it improves the way the utility reports
warnings and errors, and minimizes the chance for "unable to parse
response" error which happens when you type too fast for the machine
you're running it on (or for the serial link, not sure).

Plan is to commit those two things separately.

[cem]

usr.bin/resizewin/resizewin.c

98 ↗

(On Diff #28102)

Is there any guarantee data is nul-terminated? Maybe "%.*s", (int)cnt, data?

[darius-dons.net.au]

usr.bin/resizewin/resizewin.c

98 ↗

(On Diff #28102)

Doubtful, there's probably not any point printing it (and wasn't before) except I was using it to debug when I wrote it originally.

i.e. I think you can just replace it with a single warnx("\n\ntimeout reading from terminal");

I think the \n's are worthwhile because the terminal might eat the message otherwise.

[trasz]

usr.bin/resizewin/resizewin.c

98 ↗

(On Diff #28102)

I don't think we can add '\n's like that; warn(3) prefixes the output with the command line and it would look weird. Also, I've experimented a bit and it still displayed properly.