text: /*-
   * Copyright (c) 1992, 1993, 1994
   *	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.
   */
  
  #ifndef lint
  static char sccsid[] = "@(#)tscroll.c	8.4 (Berkeley) 7/27/94";
  #endif /* not lint */
  
  #include "curses.h"
  
  #define	MAXRETURNSIZE	64
  
  /*
   * Routine to perform scrolling.  Derived from tgoto.c in tercamp(3)
   * library.  Cap is a string containing printf type escapes to allow
   * scrolling.  The following escapes are defined for substituting n:
   *
   *	%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
   *	%i	increments n
   *	%%	gives %
   *	%B	BCD (2 decimal digits encoded in one byte)
   *	%D	Delta Data (backwards bcd)
   *
   * all other characters are ``self-inserting''.
   */
  char *
  __tscroll(cap, n1, n2)
  	const char *cap;
  	int n1, n2;
  {
  	static char result[MAXRETURNSIZE];
  	int c, n;
  	char *dp;
  
  	if (cap == NULL)
  		goto err;
  	for (n = n1, dp = result; (c = *cap++) != '\0';) {
  		if (c != '%') {
  			*dp++ = c;
  			continue;
  		}
  		switch (c = *cap++) {
  		case 'n':
  			n ^= 0140;
  			continue;
  		case 'd':
  			if (n < 10)
  				goto one;
  			if (n < 100)
  				goto two;
  			/* FALLTHROUGH */
  		case '3':
  			*dp++ = (n / 100) | '0';
  			n %= 100;
  			/* FALLTHROUGH */
  		case '2':
  two:			*dp++ = n / 10 | '0';
  one:			*dp++ = n % 10 | '0';
  			n = n2;
  			continue;
  		case '>':
  			if (n > *cap++)
  				n += *cap++;
  			else
  				cap++;
  			continue;
  		case '+':
  			n += *cap++;
  			/* FALLTHROUGH */
  		case '.':
  			*dp++ = n;
  			continue;
  		case 'i':
  			n++;
  			continue;
  		case '%':
  			*dp++ = c;
  			continue;
  		case 'B':
  			n = (n / 10 << 4) + n % 10;
  			continue;
  		case 'D':
  			n = n - 2 * (n % 16);
  			continue;
  		/*
  		 * XXX
  		 * System V terminfo files have lots of extra gunk.
  		 * The only one we've seen in scrolling strings is
  		 * %pN, and it seems to work okay if we ignore it.
  		 */
  		case 'p':
  			++cap;
  			continue;
  		default:
  			goto err;
  		}
  	}
  	*dp = '\0';
  	return (result);
  
  err:	return("curses: __tscroll failed");
  }
  