Re: "stty discard undef" fails under Mac OS X

[Jim Meyering]

Vincent Lefevre <address@hidden> wrote:
> Under Mac OS X:
>
> prunille:~> /usr/local/bin/stty --version
> stty (GNU coreutils) 6.7
> [...]
> prunille:~> /usr/local/bin/stty discard undef
> /usr/local/bin/stty: invalid argument `discard'
> Try `/usr/local/bin/stty --help' for more information.
> zsh: exit 1     /usr/local/bin/stty discard undef
>
> But with the stty provided by Mac OS X, "/bin/stty discard undef"
> works as expected:
>
> prunille% /bin/stty -a | grep discard
> cchars: discard = ^O; dsusp = ^Y; eof = ^D; eol = <undef>;
> prunille% /bin/stty discard undef
> prunille% /bin/stty -a | grep discard
> cchars: discard = <undef>; dsusp = ^Y; eof = ^D; eol = <undef>;
>
> It seems that "stty flush undef" does the same thing and works
> with the coreutils, but it isn't described in the coreutils stty(1)
> man page and in the "stty --help" output:
>
> prunille:~> /usr/local/bin/stty --help | grep flush
>  * dsusp CHAR    CHAR will send a terminal stop signal once input flushed
>  * [-]imaxbel    beep and do not flush a full input buffer on a character
>    [-]noflsh     disable flushing after interrupt and quit special characters

Thanks for the report.
I hesitate to document "flush", but might add an alias "discard",
and perhaps "stflush", since the latter is what Solaris 10 calls it.
I'm inclined not to document "flush" since it's not specified by POSIX,
and people might think it is the opposite of "noflsh".

If someone does a survey of what other vendor-provided versions of
stty do (and summarizes here), that might accelerate the process.
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