* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
static char sccsid
[] = "@(#)tgoto.c 5.1 (Berkeley) %G%";
#define CTRL(c) ('c' & 037)
* Routine to perform cursor addressing.
* CM is a string containing printf type escapes to allow
* cursor addressing. We start out ready to print the destination
* line, and switch each time we print row or column.
* The following escapes are defined for substituting row/column:
* %. gives %c hacking special case characters
* %+x like %c but adding x first
* The codes below affect the state but don't use up a value.
* %>xy if value > x add y
* %i increments row/column (for one origin indexing)
* %B BCD (2 decimal digits encoded in one byte)
* %D Delta Data (backwards bcd)
* all other characters are ``self-inserting''.
tgoto(CM
, destcol
, destline
)
static char result
[MAXRETURNSIZE
];
register char *dp
= result
;
register int which
= destline
;
* ``We don't do that under BOZO's big top''
*dp
++ = (which
/ 100) | '0';
*dp
++ = which
/ 10 | '0';
*dp
++ = which
% 10 | '0';
which
= oncol
? destcol
: destline
;
* This code is worth scratching your head at for a
* while. The idea is that various weird things can
* happen to nulls, EOT's, tabs, and newlines by the
* tty driver, arpanet, and so on, so we don't send
* them if we can help it.
* Tab is taken out to get Ann Arbors to work, otherwise
* when they go to column 9 we increment which is wrong
* because bcd isn't continuous. We should take out
* the rest too, or run the thing through more than
* once until it doesn't make any of these, but that
* would make termlib (and hence pdp-11 ex) bigger,
* and also somewhat slower. This requires all
* programs which use termlib to stty tabs so they
* don't get expanded. They should do this anyway
* because some terminals use ^I for other things,
* like nondestructive space.
if (which
== 0 || which
== CTRL(d
) || /* which == '\t' || */ which
== '\n') {
if (oncol
|| UP
) /* Assumption: backspace works */
* Loop needed because newline happens
* to be the successor of tab.
strcat(added
, oncol
? (BC
? BC
: "\b") : UP
);
which
= (which
/10 << 4) + which
%10;
which
= which
- 2 * (which
%16);