7 Nov
2017
7 Nov
'17
2:55 p.m.
On 11/7/17 3:07 AM, Dennis Boone wrote:
Thanks for the note. I thought about it and tried it out even though I
don't see the ^H (my cursor backs up a space).
After typing echo "\^H" | od -c, here's what it looks like:
$ echo "" | od -c
0000000 \b \n
0000002
So, sure enough there's a backspace in there and my code "sees" it too:
$ echo "" | 1-8
<<BACKSPACE>>
$
--
GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF
I'm not
looking for code review, but the code is intended to replace
the tabs and backspaces with \t and \b respectively, but I haven't
been able to test it because I can't seem to make a backspace
character appear in input. In later unices, ^V followed by the
backspace would work, but that's not part of v7. Backspace itself is
my erase character, so anytime I just type it, it backspaces :).
This bit from the middle of sys/dev/tty.c seems to indicate that you
escape it with \:
} else {
mc = maptab[c];
if (c==tp->t_erase || c==tp->t_kill)
mc = c;
if (mc && (mc==c || (tp->t_flags&LCASE))) {
if (bp[-2] != '\\')
c = mc;
bp--;
}
}
On my test v7 system if I type backslash control-h:
# stty
speed 0 baud
erase = '^H'; kill = '^U'
even -nl echo -tabs
# echo \^H | od -c
0000000 \b \n
0000002
#
De