source: branches/libc-0.6/src/emx/bsd/libterm/tgoto.c

/*
 * 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.
 */

#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);
}