VT100 terminfo problem

[Guy Harris]

> >>The *ONLY* time "raw" mode should be used for "full-screen" interactive
> >>applications are those times when:
> >
> >Add another one:
> >	5) keys must not generate signals.
> >
> 
> No - keyboard signals are not a reason to avoid CBREAK.

We all agree, but they *are* a reason to avoid "raw" mode, since it doesn't
support keyboard signals.  The list given was a list of conditions, all of
which should be true before you use "raw" mode.  Even if they are true, CBREAK
mode may still be appropriate; if one of them is not true, RAW mode is
inappropriate.

> Traditionally this is handled in BSD by setting CBREAK and disabling all
> special characters.  I concede this would have been true in V7, but special
> characters have been settable since 3BSD.

Careful what you concede; V7 let you set the special characters.

> I'm not sure the 8-bit argument for using RAW is valid either.

Given that the argument was "if you DON'T want an 8-bit data path, DON'T use
raw mode", it is valid.  The converse, of course, doesn't follow; if you want
an 8-bit data path, you need not necessarily use raw mode.

> Also, be aware that using PASS8 makes quoting input characters
> impossible (either literal next or '\').  In fact, trying to quote
> a character will just succeed in setting its 8-th bit.  This is a
> bug without a one-line fix - luckily the next release of BSD fixes this.

SunOS 4.0 also handles this correctly.

> No argument here, however i still can't believe the ISIG and ICANON
> flags are in the *l*flag element.  And considering these flags are
> bit masks which can't be type-checked at compile time, this is a real
> blunder.  I can see lots of new termio(s) programmers thinking ISIG
> and ICANON belong in the iflag...

I think I know of one program - perhaps even one distributed with S3 - where it
*was* stting either the ISIG or ICANON bit in "c_iflag".  The names are
somewhat bogus....