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input.c revision 1.21
      1  1.21     elad /*	$NetBSD: input.c,v 1.21 2006/10/07 18:29:02 elad Exp $	*/
      2   1.3      cgd 
      3   1.1      cgd /*-
      4   1.3      cgd  * Copyright (c) 1990, 1993
      5   1.3      cgd  *	The Regents of the University of California.  All rights reserved.
      6   1.1      cgd  *
      7   1.1      cgd  * This code is derived from software contributed to Berkeley by
      8   1.1      cgd  * Ed James.
      9   1.1      cgd  *
     10   1.1      cgd  * Redistribution and use in source and binary forms, with or without
     11   1.1      cgd  * modification, are permitted provided that the following conditions
     12   1.1      cgd  * are met:
     13   1.1      cgd  * 1. Redistributions of source code must retain the above copyright
     14   1.1      cgd  *    notice, this list of conditions and the following disclaimer.
     15   1.1      cgd  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.1      cgd  *    notice, this list of conditions and the following disclaimer in the
     17   1.1      cgd  *    documentation and/or other materials provided with the distribution.
     18  1.15      agc  * 3. Neither the name of the University nor the names of its contributors
     19   1.1      cgd  *    may be used to endorse or promote products derived from this software
     20   1.1      cgd  *    without specific prior written permission.
     21   1.1      cgd  *
     22   1.1      cgd  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     23   1.1      cgd  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     24   1.1      cgd  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     25   1.1      cgd  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     26   1.1      cgd  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     27   1.1      cgd  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     28   1.1      cgd  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     29   1.1      cgd  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     30   1.1      cgd  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     31   1.1      cgd  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     32   1.1      cgd  * SUCH DAMAGE.
     33   1.1      cgd  */
     34   1.1      cgd 
     35   1.1      cgd /*
     36   1.1      cgd  * Copyright (c) 1987 by Ed James, UC Berkeley.  All rights reserved.
     37   1.1      cgd  *
     38   1.1      cgd  * Copy permission is hereby granted provided that this notice is
     39   1.1      cgd  * retained on all partial or complete copies.
     40   1.1      cgd  *
     41   1.1      cgd  * For more info on this and all of my stuff, mail edjames (at) berkeley.edu.
     42   1.1      cgd  */
     43   1.1      cgd 
     44   1.6    lukem #include <sys/cdefs.h>
     45   1.1      cgd #ifndef lint
     46   1.3      cgd #if 0
     47   1.3      cgd static char sccsid[] = "@(#)input.c	8.1 (Berkeley) 5/31/93";
     48   1.3      cgd #else
     49  1.21     elad __RCSID("$NetBSD: input.c,v 1.21 2006/10/07 18:29:02 elad Exp $");
     50   1.3      cgd #endif
     51  1.14      cgd #endif /* not lint */
     52   1.1      cgd 
     53   1.1      cgd #include "include.h"
     54   1.1      cgd #include "pathnames.h"
     55   1.1      cgd 
     56   1.1      cgd #define MAXRULES	6
     57   1.1      cgd #define MAXDEPTH	15
     58   1.1      cgd 
     59   1.1      cgd #define RETTOKEN	'\n'
     60   1.1      cgd #define REDRAWTOKEN	'\014'	/* CTRL(L) */
     61   1.1      cgd #define	SHELLTOKEN	'!'
     62   1.1      cgd #define HELPTOKEN	'?'
     63   1.1      cgd #define ALPHATOKEN	256
     64   1.1      cgd #define NUMTOKEN	257
     65   1.1      cgd 
     66   1.1      cgd typedef struct {
     67   1.1      cgd 	int	token;
     68   1.1      cgd 	int	to_state;
     69  1.11  hubertf 	const char	*str;
     70  1.18      jmc 	const char	*(*func)(int);
     71   1.1      cgd } RULE;
     72   1.1      cgd 
     73   1.1      cgd typedef struct {
     74   1.1      cgd 	int	num_rules;
     75   1.1      cgd 	RULE	*rule;
     76   1.1      cgd } STATE;
     77   1.1      cgd 
     78   1.1      cgd typedef struct {
     79   1.1      cgd 	char	str[20];
     80   1.1      cgd 	int	state;
     81   1.1      cgd 	int	rule;
     82   1.1      cgd 	int	ch;
     83   1.1      cgd 	int	pos;
     84   1.1      cgd } STACK;
     85   1.1      cgd 
     86   1.1      cgd #define T_RULE		stack[level].rule
     87   1.1      cgd #define T_STATE		stack[level].state
     88   1.1      cgd #define T_STR		stack[level].str
     89   1.1      cgd #define T_POS		stack[level].pos
     90   1.1      cgd #define	T_CH		stack[level].ch
     91   1.1      cgd 
     92   1.1      cgd #define NUMELS(a)	(sizeof (a) / sizeof (*(a)))
     93   1.1      cgd 
     94   1.1      cgd #define NUMSTATES	NUMELS(st)
     95   1.1      cgd 
     96   1.1      cgd 
     97   1.1      cgd RULE	state0[] = {	{ ALPHATOKEN,	1,	"%c:",		setplane},
     98   1.1      cgd 			{ RETTOKEN,	-1,	"",		NULL	},
     99   1.1      cgd 			{ HELPTOKEN,	12,	" [a-z]<ret>",	NULL	}},
    100   1.1      cgd 	state1[] = {	{ 't',		2,	" turn",	turn	},
    101   1.1      cgd 			{ 'a',		3,	" altitude:",	NULL	},
    102   1.1      cgd 			{ 'c',		4,	" circle",	circle	},
    103   1.1      cgd 			{ 'm',		7,	" mark",	mark	},
    104   1.1      cgd 			{ 'u',		7,	" unmark",	unmark	},
    105   1.1      cgd 			{ 'i',		7,	" ignore",	ignore	},
    106   1.1      cgd 			{ HELPTOKEN,	12,	" tacmui",	NULL	}},
    107   1.1      cgd 	state2[] = {	{ 'l',		6,	" left",	left	},
    108   1.1      cgd 			{ 'r',		6,	" right",	right	},
    109   1.1      cgd 			{ 'L',		4,	" left 90",	Left	},
    110   1.1      cgd 			{ 'R',		4,	" right 90",	Right	},
    111   1.1      cgd 			{ 't',		11,	" towards",	NULL	},
    112   1.1      cgd 			{ 'w',		4,	" to 0",	to_dir	},
    113   1.1      cgd 			{ 'e',		4,	" to 45",	to_dir	},
    114   1.1      cgd 			{ 'd',		4,	" to 90",	to_dir	},
    115   1.1      cgd 			{ 'c',		4,	" to 135",	to_dir	},
    116   1.1      cgd 			{ 'x',		4,	" to 180",	to_dir	},
    117   1.1      cgd 			{ 'z',		4,	" to 225",	to_dir	},
    118   1.1      cgd 			{ 'a',		4,	" to 270",	to_dir	},
    119   1.1      cgd 			{ 'q',		4,	" to 315",	to_dir	},
    120   1.1      cgd 			{ HELPTOKEN,	12,	" lrLRt<dir>",	NULL	}},
    121   1.1      cgd 	state3[] = {	{ '+',		10,	" climb",	climb	},
    122   1.1      cgd 			{ 'c',		10,	" climb",	climb	},
    123   1.1      cgd 			{ '-',		10,	" descend",	descend	},
    124   1.1      cgd 			{ 'd',		10,	" descend",	descend	},
    125   1.1      cgd 			{ NUMTOKEN,	7,	" %c000 feet",	setalt	},
    126   1.1      cgd 			{ HELPTOKEN,	12,	" +-cd[0-9]",	NULL	}},
    127   1.1      cgd 	state4[] = {	{ '@',		9,	" at",		NULL	},
    128   1.1      cgd 			{ 'a',		9,	" at",		NULL	},
    129   1.1      cgd 			{ RETTOKEN,	-1,	"",		NULL	},
    130   1.1      cgd 			{ HELPTOKEN,	12,	" @a<ret>",	NULL	}},
    131   1.1      cgd 	state5[] = {	{ NUMTOKEN,	7,	"%c",		delayb	},
    132   1.1      cgd 			{ HELPTOKEN,	12,	" [0-9]",	NULL	}},
    133   1.1      cgd 	state6[] = {	{ '@',		9,	" at",		NULL	},
    134   1.1      cgd 			{ 'a',		9,	" at",		NULL	},
    135   1.1      cgd 			{ 'w',		4,	" 0",		rel_dir	},
    136   1.1      cgd 			{ 'e',		4,	" 45",		rel_dir	},
    137   1.1      cgd 			{ 'd',		4,	" 90",		rel_dir	},
    138   1.1      cgd 			{ 'c',		4,	" 135",		rel_dir	},
    139   1.1      cgd 			{ 'x',		4,	" 180",		rel_dir	},
    140   1.1      cgd 			{ 'z',		4,	" 225",		rel_dir	},
    141   1.1      cgd 			{ 'a',		4,	" 270",		rel_dir	},
    142   1.1      cgd 			{ 'q',		4,	" 315",		rel_dir	},
    143   1.1      cgd 			{ RETTOKEN,	-1,	"",		NULL	},
    144   1.1      cgd 			{ HELPTOKEN,	12,	" @a<dir><ret>",NULL	}},
    145   1.1      cgd 	state7[] = {	{ RETTOKEN,	-1,	"",		NULL	},
    146   1.1      cgd 			{ HELPTOKEN,	12,	" <ret>",	NULL	}},
    147   1.1      cgd 	state8[] = {	{ NUMTOKEN,	4,	"%c",		benum	},
    148   1.1      cgd 			{ HELPTOKEN,	12,	" [0-9]",	NULL	}},
    149   1.1      cgd 	state9[] = {	{ 'b',		5,	" beacon #",	NULL	},
    150   1.1      cgd 			{ '*',		5,	" beacon #",	NULL	},
    151   1.1      cgd 			{ HELPTOKEN,	12,	" b*",		NULL	}},
    152   1.1      cgd 	state10[] = {	{ NUMTOKEN,	7,	" %c000 ft",	setrelalt},
    153   1.1      cgd 			{ HELPTOKEN,	12,	" [0-9]",	NULL	}},
    154   1.1      cgd 	state11[] = {	{ 'b',		8,	" beacon #",	beacon	},
    155   1.1      cgd 			{ '*',		8,	" beacon #",	beacon	},
    156   1.1      cgd 			{ 'e',		8,	" exit #",	ex_it	},
    157   1.1      cgd 			{ 'a',		8,	" airport #",	airport	},
    158   1.1      cgd 			{ HELPTOKEN,	12,	" b*ea",	NULL	}},
    159   1.1      cgd 	state12[] = {	{ -1,		-1,	"",		NULL	}};
    160   1.1      cgd 
    161   1.1      cgd #define DEF_STATE(s)	{ NUMELS(s),	(s)	}
    162   1.1      cgd 
    163   1.1      cgd STATE	st[] = {
    164   1.1      cgd 	DEF_STATE(state0), DEF_STATE(state1), DEF_STATE(state2),
    165   1.1      cgd 	DEF_STATE(state3), DEF_STATE(state4), DEF_STATE(state5),
    166   1.1      cgd 	DEF_STATE(state6), DEF_STATE(state7), DEF_STATE(state8),
    167   1.1      cgd 	DEF_STATE(state9), DEF_STATE(state10), DEF_STATE(state11),
    168   1.1      cgd 	DEF_STATE(state12)
    169   1.1      cgd };
    170   1.1      cgd 
    171   1.1      cgd PLANE	p;
    172   1.1      cgd STACK	stack[MAXDEPTH];
    173   1.1      cgd int	level;
    174   1.1      cgd int	tval;
    175   1.1      cgd int	dest_type, dest_no, dir;
    176   1.1      cgd 
    177   1.6    lukem int
    178  1.18      jmc pop(void)
    179   1.1      cgd {
    180   1.1      cgd 	if (level == 0)
    181   1.1      cgd 		return (-1);
    182   1.1      cgd 	level--;
    183   1.1      cgd 
    184   1.1      cgd 	ioclrtoeol(T_POS);
    185   1.1      cgd 
    186  1.19   rpaulo 	(void)strcpy(T_STR, "");
    187   1.1      cgd 	T_RULE = -1;
    188   1.1      cgd 	T_CH = -1;
    189   1.1      cgd 	return (0);
    190   1.1      cgd }
    191   1.1      cgd 
    192   1.6    lukem void
    193  1.18      jmc rezero(void)
    194   1.1      cgd {
    195   1.1      cgd 	iomove(0);
    196   1.1      cgd 
    197   1.1      cgd 	level = 0;
    198   1.1      cgd 	T_STATE = 0;
    199   1.1      cgd 	T_RULE = -1;
    200   1.1      cgd 	T_CH = -1;
    201   1.1      cgd 	T_POS = 0;
    202  1.19   rpaulo 	(void)strcpy(T_STR, "");
    203   1.1      cgd }
    204   1.1      cgd 
    205   1.6    lukem void
    206  1.18      jmc push(int ruleno, int ch)
    207   1.1      cgd {
    208   1.1      cgd 	int	newstate, newpos;
    209   1.1      cgd 
    210  1.20  jnemeth 	assert(level < (MAXDEPTH - 1));
    211   1.1      cgd 	(void)sprintf(T_STR, st[T_STATE].rule[ruleno].str, tval);
    212   1.1      cgd 	T_RULE = ruleno;
    213   1.1      cgd 	T_CH = ch;
    214   1.1      cgd 	newstate = st[T_STATE].rule[ruleno].to_state;
    215   1.1      cgd 	newpos = T_POS + strlen(T_STR);
    216   1.1      cgd 
    217   1.1      cgd 	ioaddstr(T_POS, T_STR);
    218   1.1      cgd 
    219   1.1      cgd 	if (level == 0)
    220   1.1      cgd 		ioclrtobot();
    221   1.1      cgd 	level++;
    222   1.1      cgd 	T_STATE = newstate;
    223   1.1      cgd 	T_POS = newpos;
    224   1.1      cgd 	T_RULE = -1;
    225  1.19   rpaulo 	(void)strcpy(T_STR, "");
    226   1.1      cgd }
    227   1.1      cgd 
    228   1.6    lukem int
    229  1.18      jmc getcommand(void)
    230   1.1      cgd {
    231   1.1      cgd 	int	c, i, done;
    232  1.18      jmc 	const char	*s, *(*func)(int);
    233   1.1      cgd 	PLANE	*pp;
    234   1.1      cgd 
    235   1.1      cgd 	rezero();
    236   1.1      cgd 
    237   1.1      cgd 	do {
    238   1.1      cgd 		c = gettoken();
    239   1.4  mycroft 		if (c == tty_new.c_cc[VERASE]) {
    240   1.1      cgd 			if (pop() < 0)
    241   1.1      cgd 				noise();
    242   1.4  mycroft 		} else if (c == tty_new.c_cc[VKILL]) {
    243   1.1      cgd 			while (pop() >= 0)
    244   1.1      cgd 				;
    245   1.1      cgd 		} else {
    246   1.1      cgd 			done = 0;
    247   1.1      cgd 			for (i = 0; i < st[T_STATE].num_rules; i++) {
    248   1.1      cgd 				if (st[T_STATE].rule[i].token == c ||
    249   1.1      cgd 				    st[T_STATE].rule[i].token == tval) {
    250   1.1      cgd 					push(i, (c >= ALPHATOKEN) ? tval : c);
    251   1.1      cgd 					done = 1;
    252   1.1      cgd 					break;
    253   1.1      cgd 				}
    254   1.1      cgd 			}
    255   1.1      cgd 			if (!done)
    256   1.1      cgd 				noise();
    257   1.1      cgd 		}
    258   1.1      cgd 	} while (T_STATE != -1);
    259   1.1      cgd 
    260   1.1      cgd 	if (level == 1)
    261   1.1      cgd 		return (1);	/* forced update */
    262   1.1      cgd 
    263   1.1      cgd 	dest_type = T_NODEST;
    264   1.1      cgd 
    265   1.1      cgd 	for (i = 0; i < level; i++) {
    266   1.1      cgd 		func = st[stack[i].state].rule[stack[i].rule].func;
    267   1.1      cgd 		if (func != NULL)
    268   1.1      cgd 			if ((s = (*func)(stack[i].ch)) != NULL) {
    269  1.19   rpaulo 				ioerror(stack[i].pos,
    270  1.19   rpaulo 				    (int)strlen(stack[i].str), s);
    271   1.1      cgd 				return (-1);
    272   1.1      cgd 			}
    273   1.1      cgd 	}
    274   1.1      cgd 
    275   1.1      cgd 	pp = findplane(p.plane_no);
    276   1.1      cgd 	if (pp->new_altitude != p.new_altitude)
    277   1.1      cgd 		pp->new_altitude = p.new_altitude;
    278   1.1      cgd 	else if (pp->status != p.status)
    279   1.1      cgd 		pp->status = p.status;
    280   1.1      cgd 	else {
    281   1.1      cgd 		pp->new_dir = p.new_dir;
    282   1.1      cgd 		pp->delayd = p.delayd;
    283   1.1      cgd 		pp->delayd_no = p.delayd_no;
    284   1.1      cgd 	}
    285   1.1      cgd 	return (0);
    286   1.1      cgd }
    287   1.1      cgd 
    288   1.6    lukem void
    289  1.18      jmc noise(void)
    290   1.1      cgd {
    291  1.19   rpaulo 	(void)putchar('\07');
    292  1.19   rpaulo 	(void)fflush(stdout);
    293   1.1      cgd }
    294   1.1      cgd 
    295   1.6    lukem int
    296  1.18      jmc gettoken(void)
    297   1.1      cgd {
    298   1.1      cgd 	while ((tval = getAChar()) == REDRAWTOKEN || tval == SHELLTOKEN)
    299   1.1      cgd 	{
    300   1.1      cgd 		if (tval == SHELLTOKEN)
    301   1.1      cgd 		{
    302   1.1      cgd #ifdef BSD
    303   1.1      cgd 			struct itimerval	itv;
    304   1.1      cgd 			itv.it_value.tv_sec = 0;
    305   1.1      cgd 			itv.it_value.tv_usec = 0;
    306  1.19   rpaulo 			(void)setitimer(ITIMER_REAL, &itv, NULL);
    307   1.1      cgd #endif
    308   1.1      cgd #ifdef SYSV
    309   1.1      cgd 			int aval;
    310   1.1      cgd 			aval = alarm(0);
    311   1.1      cgd #endif
    312   1.1      cgd 			if (fork() == 0)	/* child */
    313   1.1      cgd 			{
    314   1.6    lukem 				char *shell, *base;
    315   1.1      cgd 
    316   1.1      cgd 				done_screen();
    317   1.1      cgd 
    318   1.1      cgd 						 /* run user's favorite shell */
    319   1.1      cgd 				if ((shell = getenv("SHELL")) != NULL)
    320   1.1      cgd 				{
    321   1.1      cgd 					base = strrchr(shell, '/');
    322   1.1      cgd 					if (base == NULL)
    323   1.1      cgd 						base = shell;
    324   1.1      cgd 					else
    325   1.1      cgd 						base++;
    326  1.19   rpaulo 					(void)execl(shell, base, (char *) 0);
    327   1.1      cgd 				}
    328   1.1      cgd 				else
    329  1.19   rpaulo 					(void)execl(_PATH_BSHELL, "sh",
    330  1.19   rpaulo 					    (char *) 0);
    331   1.1      cgd 
    332   1.1      cgd 				exit(0);	/* oops */
    333   1.1      cgd 			}
    334   1.1      cgd 
    335  1.19   rpaulo 			(void)wait(0);
    336  1.19   rpaulo 			(void)tcsetattr(fileno(stdin), TCSADRAIN, &tty_new);
    337   1.1      cgd #ifdef BSD
    338   1.1      cgd 			itv.it_value.tv_sec = 0;
    339   1.1      cgd 			itv.it_value.tv_usec = 1;
    340   1.1      cgd 			itv.it_interval.tv_sec = sp->update_secs;
    341   1.1      cgd 			itv.it_interval.tv_usec = 0;
    342  1.19   rpaulo 			(void)setitimer(ITIMER_REAL, &itv, NULL);
    343   1.1      cgd #endif
    344   1.1      cgd #ifdef SYSV
    345   1.1      cgd 			alarm(aval);
    346   1.1      cgd #endif
    347   1.1      cgd 		}
    348  1.19   rpaulo 		(void)redraw();
    349   1.1      cgd 	}
    350   1.1      cgd 
    351   1.1      cgd 	if (isdigit(tval))
    352   1.1      cgd 		return (NUMTOKEN);
    353   1.1      cgd 	else if (isalpha(tval))
    354   1.1      cgd 		return (ALPHATOKEN);
    355   1.1      cgd 	else
    356   1.1      cgd 		return (tval);
    357   1.1      cgd }
    358   1.1      cgd 
    359  1.18      jmc const char *
    360  1.18      jmc setplane(int c)
    361   1.1      cgd {
    362   1.1      cgd 	PLANE	*pp;
    363   1.1      cgd 
    364   1.1      cgd 	pp = findplane(number(c));
    365   1.1      cgd 	if (pp == NULL)
    366   1.1      cgd 		return ("Unknown Plane");
    367  1.19   rpaulo 	(void)memcpy(&p, pp, sizeof (p));
    368   1.1      cgd 	p.delayd = 0;
    369   1.1      cgd 	return (NULL);
    370   1.1      cgd }
    371   1.1      cgd 
    372  1.19   rpaulo /* ARGSUSED */
    373  1.18      jmc const char *
    374  1.18      jmc turn(int c __attribute__((__unused__)))
    375   1.1      cgd {
    376   1.1      cgd 	if (p.altitude == 0)
    377   1.1      cgd 		return ("Planes at airports may not change direction");
    378   1.1      cgd 	return (NULL);
    379   1.1      cgd }
    380   1.1      cgd 
    381  1.19   rpaulo /* ARGSUSED */
    382  1.18      jmc const char *
    383  1.18      jmc circle(int c __attribute__((__unused__)))
    384   1.1      cgd {
    385   1.1      cgd 	if (p.altitude == 0)
    386   1.1      cgd 		return ("Planes cannot circle on the ground");
    387   1.1      cgd 	p.new_dir = MAXDIR;
    388   1.1      cgd 	return (NULL);
    389   1.1      cgd }
    390   1.1      cgd 
    391  1.19   rpaulo /* ARGSUSED */
    392  1.18      jmc const char *
    393  1.18      jmc left(int c __attribute__((__unused__)))
    394   1.1      cgd {
    395   1.1      cgd 	dir = D_LEFT;
    396   1.1      cgd 	p.new_dir = p.dir - 1;
    397   1.1      cgd 	if (p.new_dir < 0)
    398   1.1      cgd 		p.new_dir += MAXDIR;
    399   1.1      cgd 	return (NULL);
    400   1.1      cgd }
    401   1.1      cgd 
    402  1.19   rpaulo /* ARGSUSED */
    403  1.18      jmc const char *
    404  1.18      jmc right(int c __attribute__((__unused__)))
    405   1.1      cgd {
    406   1.1      cgd 	dir = D_RIGHT;
    407   1.1      cgd 	p.new_dir = p.dir + 1;
    408   1.9   briggs 	if (p.new_dir >= MAXDIR)
    409   1.1      cgd 		p.new_dir -= MAXDIR;
    410   1.1      cgd 	return (NULL);
    411   1.1      cgd }
    412   1.1      cgd 
    413  1.19   rpaulo /* ARGSUSED */
    414  1.18      jmc const char *
    415  1.18      jmc Left(int c __attribute__((__unused__)))
    416   1.1      cgd {
    417   1.1      cgd 	p.new_dir = p.dir - 2;
    418   1.1      cgd 	if (p.new_dir < 0)
    419   1.1      cgd 		p.new_dir += MAXDIR;
    420   1.1      cgd 	return (NULL);
    421   1.1      cgd }
    422   1.1      cgd 
    423  1.19   rpaulo /* ARGSUSED */
    424  1.18      jmc const char *
    425  1.18      jmc Right(int c __attribute__((__unused__)))
    426   1.1      cgd {
    427   1.1      cgd 	p.new_dir = p.dir + 2;
    428   1.8   briggs 	if (p.new_dir >= MAXDIR)
    429   1.1      cgd 		p.new_dir -= MAXDIR;
    430   1.1      cgd 	return (NULL);
    431   1.1      cgd }
    432   1.1      cgd 
    433  1.18      jmc const char *
    434  1.18      jmc delayb(int c)
    435   1.1      cgd {
    436   1.1      cgd 	int	xdiff, ydiff;
    437   1.1      cgd 
    438   1.1      cgd 	c -= '0';
    439   1.1      cgd 
    440   1.1      cgd 	if (c >= sp->num_beacons)
    441   1.1      cgd 		return ("Unknown beacon");
    442   1.7      mrg 	xdiff = sp->beacon[(int)c].x - p.xpos;
    443   1.1      cgd 	xdiff = SGN(xdiff);
    444   1.7      mrg 	ydiff = sp->beacon[(int)c].y - p.ypos;
    445   1.1      cgd 	ydiff = SGN(ydiff);
    446   1.1      cgd 	if (xdiff != displacement[p.dir].dx || ydiff != displacement[p.dir].dy)
    447   1.1      cgd 		return ("Beacon is not in flight path");
    448   1.1      cgd 	p.delayd = 1;
    449   1.1      cgd 	p.delayd_no = c;
    450   1.1      cgd 
    451   1.1      cgd 	if (dest_type != T_NODEST) {
    452   1.1      cgd 		switch (dest_type) {
    453   1.1      cgd 		case T_BEACON:
    454   1.7      mrg 			xdiff = sp->beacon[dest_no].x - sp->beacon[(int)c].x;
    455   1.7      mrg 			ydiff = sp->beacon[dest_no].y - sp->beacon[(int)c].y;
    456   1.1      cgd 			break;
    457   1.1      cgd 		case T_EXIT:
    458   1.7      mrg 			xdiff = sp->exit[dest_no].x - sp->beacon[(int)c].x;
    459   1.7      mrg 			ydiff = sp->exit[dest_no].y - sp->beacon[(int)c].y;
    460   1.1      cgd 			break;
    461   1.1      cgd 		case T_AIRPORT:
    462   1.7      mrg 			xdiff = sp->airport[dest_no].x - sp->beacon[(int)c].x;
    463   1.7      mrg 			ydiff = sp->airport[dest_no].y - sp->beacon[(int)c].y;
    464   1.1      cgd 			break;
    465   1.1      cgd 		default:
    466   1.1      cgd 			return ("Bad case in delayb!  Get help!");
    467   1.1      cgd 		}
    468   1.1      cgd 		if (xdiff == 0 && ydiff == 0)
    469   1.1      cgd 			return ("Would already be there");
    470   1.1      cgd 		p.new_dir = DIR_FROM_DXDY(xdiff, ydiff);
    471   1.1      cgd 		if (p.new_dir == p.dir)
    472   1.1      cgd 			return ("Already going in that direction");
    473   1.1      cgd 	}
    474   1.1      cgd 	return (NULL);
    475   1.1      cgd }
    476   1.1      cgd 
    477  1.19   rpaulo /* ARGSUSED */
    478  1.18      jmc const char *
    479  1.18      jmc beacon(int c __attribute__((__unused__)))
    480   1.1      cgd {
    481   1.1      cgd 	dest_type = T_BEACON;
    482   1.1      cgd 	return (NULL);
    483   1.1      cgd }
    484   1.1      cgd 
    485  1.19   rpaulo /* ARGSUSED */
    486  1.18      jmc const char *
    487  1.18      jmc ex_it(int c __attribute__((__unused__)))
    488   1.1      cgd {
    489   1.1      cgd 	dest_type = T_EXIT;
    490   1.1      cgd 	return (NULL);
    491   1.1      cgd }
    492   1.1      cgd 
    493  1.19   rpaulo /* ARGSUSED */
    494  1.18      jmc const char *
    495  1.18      jmc airport(int c __attribute__((__unused__)))
    496   1.1      cgd {
    497   1.1      cgd 	dest_type = T_AIRPORT;
    498   1.1      cgd 	return (NULL);
    499   1.1      cgd }
    500   1.1      cgd 
    501  1.19   rpaulo /* ARGSUSED */
    502  1.18      jmc const char *
    503  1.18      jmc climb(int c __attribute__((__unused__)))
    504   1.1      cgd {
    505   1.1      cgd 	dir = D_UP;
    506   1.1      cgd 	return (NULL);
    507   1.1      cgd }
    508   1.1      cgd 
    509  1.19   rpaulo /* ARGSUSED */
    510  1.18      jmc const char *
    511  1.18      jmc descend(int c __attribute__((__unused__)))
    512   1.1      cgd {
    513   1.1      cgd 	dir = D_DOWN;
    514   1.1      cgd 	return (NULL);
    515   1.1      cgd }
    516   1.1      cgd 
    517  1.18      jmc const char *
    518  1.18      jmc setalt(int c)
    519   1.1      cgd {
    520  1.21     elad 	int newalt = c - '0';
    521  1.21     elad 	if ((p.altitude == newalt) && (p.new_altitude == p.altitude))
    522   1.1      cgd 		return ("Already at that altitude");
    523  1.21     elad 	if (p.new_altitude == newalt) {
    524  1.21     elad 		return ("Already going to that altitude");
    525  1.21     elad 	}
    526  1.21     elad 	p.new_altitude = newalt;
    527   1.1      cgd 	return (NULL);
    528   1.1      cgd }
    529   1.1      cgd 
    530  1.18      jmc const char *
    531  1.18      jmc setrelalt(int c)
    532   1.1      cgd {
    533  1.21     elad 	int newalt;
    534  1.21     elad 
    535   1.1      cgd 	if (c == 0)
    536   1.1      cgd 		return ("altitude not changed");
    537   1.1      cgd 
    538   1.1      cgd 	switch (dir) {
    539   1.1      cgd 	case D_UP:
    540  1.21     elad 		newalt = p.altitude + c - '0';
    541   1.1      cgd 		break;
    542   1.1      cgd 	case D_DOWN:
    543  1.21     elad 		newalt = p.altitude - (c - '0');
    544   1.1      cgd 		break;
    545   1.1      cgd 	default:
    546   1.1      cgd 		return ("Unknown case in setrelalt!  Get help!");
    547   1.1      cgd 	}
    548  1.21     elad 
    549  1.21     elad 	if (p.new_altitude == newalt)
    550  1.21     elad 		return ("Already going to that altitude");
    551  1.21     elad 
    552  1.21     elad 	p.new_altitude = newalt;
    553  1.21     elad 
    554   1.1      cgd 	if (p.new_altitude < 0)
    555   1.1      cgd 		return ("Altitude would be too low");
    556   1.1      cgd 	else if (p.new_altitude > 9)
    557   1.1      cgd 		return ("Altitude would be too high");
    558   1.1      cgd 	return (NULL);
    559   1.1      cgd }
    560   1.1      cgd 
    561  1.18      jmc const char *
    562  1.18      jmc benum(int c)
    563   1.1      cgd {
    564   1.1      cgd 	dest_no = c -= '0';
    565   1.1      cgd 
    566   1.1      cgd 	switch (dest_type) {
    567   1.1      cgd 	case T_BEACON:
    568   1.1      cgd 		if (c >= sp->num_beacons)
    569   1.1      cgd 			return ("Unknown beacon");
    570   1.7      mrg 		p.new_dir = DIR_FROM_DXDY(sp->beacon[(int)c].x - p.xpos,
    571   1.7      mrg 			sp->beacon[(int)c].y - p.ypos);
    572   1.1      cgd 		break;
    573   1.1      cgd 	case T_EXIT:
    574   1.1      cgd 		if (c >= sp->num_exits)
    575   1.1      cgd 			return ("Unknown exit");
    576   1.7      mrg 		p.new_dir = DIR_FROM_DXDY(sp->exit[(int)c].x - p.xpos,
    577   1.7      mrg 			sp->exit[(int)c].y - p.ypos);
    578   1.1      cgd 		break;
    579   1.1      cgd 	case T_AIRPORT:
    580   1.1      cgd 		if (c >= sp->num_airports)
    581   1.1      cgd 			return ("Unknown airport");
    582   1.7      mrg 		p.new_dir = DIR_FROM_DXDY(sp->airport[(int)c].x - p.xpos,
    583   1.7      mrg 			sp->airport[(int)c].y - p.ypos);
    584   1.1      cgd 		break;
    585   1.1      cgd 	default:
    586   1.1      cgd 		return ("Unknown case in benum!  Get help!");
    587   1.1      cgd 	}
    588   1.1      cgd 	return (NULL);
    589   1.1      cgd }
    590   1.1      cgd 
    591  1.18      jmc const char *
    592  1.18      jmc to_dir(int c)
    593   1.1      cgd {
    594   1.1      cgd 	p.new_dir = dir_no(c);
    595   1.1      cgd 	return (NULL);
    596   1.1      cgd }
    597   1.1      cgd 
    598  1.18      jmc const char *
    599  1.18      jmc rel_dir(int c)
    600   1.1      cgd {
    601   1.1      cgd 	int	angle;
    602   1.1      cgd 
    603   1.1      cgd 	angle = dir_no(c);
    604   1.1      cgd 	switch (dir) {
    605   1.1      cgd 	case D_LEFT:
    606   1.1      cgd 		p.new_dir = p.dir - angle;
    607   1.1      cgd 		if (p.new_dir < 0)
    608   1.1      cgd 			p.new_dir += MAXDIR;
    609   1.1      cgd 		break;
    610   1.1      cgd 	case D_RIGHT:
    611   1.1      cgd 		p.new_dir = p.dir + angle;
    612   1.1      cgd 		if (p.new_dir >= MAXDIR)
    613   1.1      cgd 			p.new_dir -= MAXDIR;
    614   1.1      cgd 		break;
    615   1.1      cgd 	default:
    616   1.1      cgd 		return ("Bizarre direction in rel_dir!  Get help!");
    617   1.1      cgd 	}
    618   1.1      cgd 	return (NULL);
    619   1.1      cgd }
    620   1.1      cgd 
    621  1.19   rpaulo /* ARGSUSED */
    622  1.18      jmc const char *
    623  1.18      jmc mark(int c __attribute__((__unused__)))
    624   1.1      cgd {
    625   1.1      cgd 	if (p.altitude == 0)
    626   1.1      cgd 		return ("Cannot mark planes on the ground");
    627   1.1      cgd 	if (p.status == S_MARKED)
    628   1.1      cgd 		return ("Already marked");
    629   1.1      cgd 	p.status = S_MARKED;
    630   1.1      cgd 	return (NULL);
    631   1.1      cgd }
    632   1.1      cgd 
    633  1.19   rpaulo /* ARGSUSED */
    634  1.18      jmc const char *
    635  1.18      jmc unmark(int c __attribute__((__unused__)))
    636   1.1      cgd {
    637   1.1      cgd 	if (p.altitude == 0)
    638   1.1      cgd 		return ("Cannot unmark planes on the ground");
    639   1.1      cgd 	if (p.status == S_UNMARKED)
    640   1.1      cgd 		return ("Already unmarked");
    641   1.1      cgd 	p.status = S_UNMARKED;
    642   1.1      cgd 	return (NULL);
    643   1.1      cgd }
    644   1.1      cgd 
    645  1.19   rpaulo /* ARGSUSED */
    646  1.18      jmc const char *
    647  1.18      jmc ignore(int c __attribute__((__unused__)))
    648   1.1      cgd {
    649   1.1      cgd 	if (p.altitude == 0)
    650   1.1      cgd 		return ("Cannot ignore planes on the ground");
    651   1.1      cgd 	if (p.status == S_IGNORED)
    652   1.1      cgd 		return ("Already ignored");
    653   1.1      cgd 	p.status = S_IGNORED;
    654   1.1      cgd 	return (NULL);
    655   1.1      cgd }
    656   1.1      cgd 
    657   1.6    lukem int
    658  1.18      jmc dir_no(int ch)
    659   1.1      cgd {
    660  1.18      jmc 	int	dirno;
    661   1.1      cgd 
    662  1.18      jmc 	dirno = -1;
    663   1.1      cgd 	switch (ch) {
    664  1.18      jmc 	case 'w':	dirno = 0;	break;
    665  1.18      jmc 	case 'e':	dirno = 1;	break;
    666  1.18      jmc 	case 'd':	dirno = 2;	break;
    667  1.18      jmc 	case 'c':	dirno = 3;	break;
    668  1.18      jmc 	case 'x':	dirno = 4;	break;
    669  1.18      jmc 	case 'z':	dirno = 5;	break;
    670  1.18      jmc 	case 'a':	dirno = 6;	break;
    671  1.18      jmc 	case 'q':	dirno = 7;	break;
    672   1.1      cgd 	default:
    673  1.19   rpaulo 		(void)fprintf(stderr, "bad character in dir_no\n");
    674   1.1      cgd 		break;
    675   1.1      cgd 	}
    676  1.18      jmc 	return (dirno);
    677   1.1      cgd }
    678