BSD 4_4 release

[unix-history] / usr / src / lib / libcurses / tscroll.c

/*-
* Copyright (c) 1992, 1993
*      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   8.1 (Berkeley) 6/4/93";
#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, n)
       const char *cap;
       int n;
{
       static char result[MAXRETURNSIZE];
       register char *dp;
       register int c;
       char *cp;

       if (cap == NULL) {
toohard:
               /*
                * ``We don't do that under BOZO's big top''
                */
               return ("OOPS");
       }

       cp = (char *) cap;
       dp = result;
       while (c = *cp++) {
               if (c != '%') {
                       *dp++ = c;
                       continue;
               }
               switch (c = *cp++) {
               case 'n':
                       n ^= 0140;
                       continue;
               case 'd':
                       if (n < 10)
                               goto one;
                       if (n < 100)
                               goto two;
                       /* fall into... */
               case '3':
                       *dp++ = (n / 100) | '0';
                       n %= 100;
                       /* fall into... */
               case '2':
two:    
                       *dp++ = n / 10 | '0';
one:
                       *dp++ = n % 10 | '0';
                       continue;
               case '>':
                       if (n > *cp++)
                               n += *cp++;
                       else
                               cp++;
                       continue;
               case '+':
                       n += *cp++;
                       /* fall into... */
               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;
               default:
                       goto toohard;
               }
       }
       *dp = '\0';
       return (result);
}