text: /*
   * Copyright (c) 1980 The Regents of the University of California.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the University of
   *	California, Berkeley and its contributors.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  #include <string.h>
  
  #ifndef lint
  static char sccsid[] = "@(#)tgoto.c	5.4 (Berkeley) 6/1/90";
  #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);
  }
  