/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
#ifndef lint
static char sccsid[] = "@(#)tgoto.c 5.1 (Berkeley) 6/5/85";
#endif not lint
#define CTRL(c) ('c' & 037)
#define MAXRETURNSIZE 64
char *UP;
char *BC;
/*
* 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:
*
* %d as in printf
* %2 like %2d
* %3 like %3d
* %. 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
* %r reverses row/column
* %i increments row/column (for one origin indexing)
* %% gives %
* %B BCD (2 decimal digits encoded in one byte)
* %D Delta Data (backwards bcd)
*
* all other characters are ``self-inserting''.
*/
char *
tgoto(CM, destcol, destline)
char *CM;
int destcol, destline;
{
static char result[MAXRETURNSIZE];
static char added[10];
char *cp = CM;
register char *dp = result;
register int c;
int oncol = 0;
register int which = destline;
if (cp == 0) {
toohard:
/*
* ``We don't do that under BOZO's big top''
*/
return ("OOPS");
}
added[0] = 0;
while (c = *cp++) {
if (c != '%') {
*dp++ = c;
continue;
}
switch (c = *cp++) {
#ifdef CM_N
case 'n':
destcol ^= 0140;
destline ^= 0140;
goto setwhich;
#endif
case 'd':
if (which < 10)
goto one;
if (which < 100)
goto two;
/* fall into... */
case '3':
*dp++ = (which / 100) | '0';
which %= 100;
/* fall into... */
case '2':
two:
*dp++ = which / 10 | '0';
one:
*dp++ = which % 10 | '0';
swap:
oncol = 1 - oncol;
setwhich:
which = oncol ? destcol : destline;
continue;
#ifdef CM_GT
case '>':
if (which > *cp++)
which += *cp++;
else
cp++;
continue;
#endif
case '+':
which += *cp++;
/* fall into... */
case '.':
casedot:
/*
* 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.
*/
do {
strcat(added, oncol ? (BC ? BC : "\b") : UP);
which++;
} while (which == '\n');
}
*dp++ = which;
goto swap;
case 'r':
oncol = 1;
goto setwhich;
case 'i':
destcol++;
destline++;
which++;
continue;
case '%':
*dp++ = c;
continue;
#ifdef CM_B
case 'B':
which = (which/10 << 4) + which%10;
continue;
#endif
#ifdef CM_D
case 'D':
which = which - 2 * (which%16);
continue;
#endif
default:
goto toohard;
}
}
strcpy(dp, added);
return (result);
}