astro@princeton.UUCP (06/15/83)
While we are on the subject of tty drivers ... one of my complaints with both the BSD and System III tty drivers is that there is no way to turn off the echoing of carriage return/line feeds. The most general case is where the new-line is supplied by the program. For example, suppose if one wanted the computer's response to a question to appear on the same line after the question. I have written Forth compilers for both PDP11 and VAX Unix, and have an atavistic liking for the traditional OK prompt at the end of the line. I have usually had to mung the terminal driver to get this. 4.1 BSD has a normally unused provision for an alternate end-of-line character tbrk_c. This would do the job if set to <CR> and tested for before the test for CRMOD if this character was not echoed. Alas, however, it is echoed. As I have said above, not echoing this character would have been more general, as a program using this feature which desired it to be echoed could have echoed it itself. William L. Sebok Princeton Univ. Observatory Peyton Hall Princeton N.J 08544 ..!allegra!princeton!astrovax!wls
guy@rlgvax.UUCP (06/15/83)
Actually, t_brkc goes back to V7 (as do several other things in 4.1BSD), and
the USG driver has an equivalent; both of them echo the character, however.
If it weren't echoed, you could also set it to ESC and use it for TENEX-style
command completion and for TECO...
Why not add another ECHO? bit to the USG driver; it already has 4 of them.
Unfortunately, ECHONL doesn't mean "don't echo NL if it's off", but means
"echo an NL even if ECHO is off".
Guy Harris
RLG Corporation
{seismo,mcnc,we13,brl-bmd,allegra}!rlgvax!guy