Re: [Groff] Re: backspace and Unicode in terminals

[Jim Reid]

>>>>> "Andries" == Andries Brouwer <address@hidden> writes:

    >> Doing so I wonder how is the backspace character (U+0008, \b)
    >> handled in TTYs?  Is there any documentation for it?

    Andries> There are many types of TTY. A termcap/terminfo entry
    Andries> would tell you what escape sequence causes the cursor to
    Andries> move left one position.  (In termcap the boolean bs will
    Andries> tell you whether it is 010, backspace.)

    Andries> Such cursor movement is entirely independent of the text
    Andries> present on the screen.

IIRC, termcap and terminfo entries can also indicate whether the tty
-- essentially any character-oriented display -- does overstriking or
not. In the good old days of daisywheel printers, this was sometimes
used to get underlining or emulation of non-ASCII characters.

BTW Werner, termcap and terminfo were developed so applications could
manipulate any tty display without having prior knowledge of the
escape codes for the device it was driving. The curses library
built on top of that to enable stuff like line deletion and insertion,
arbitrary cursor movement, etc, etc in a portable (non tty-specific)
way.