xref: /openbsd/distrib/special/more/tgoto.c (revision 73471bf0)
1 /*	$OpenBSD: tgoto.c,v 1.2 2015/11/15 07:12:50 deraadt Exp $	*/
2 /*	$NetBSD: tgoto.c,v 1.5 1995/06/05 19:45:54 pk Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <string.h>
34 #include <curses.h>
35 
36 #define	CTRL(c)	((c) & 037)
37 
38 #define MAXRETURNSIZE 64
39 
40 char	*UP;
41 char	*BC;
42 
43 /*
44  * Routine to perform cursor addressing.
45  * CM is a string containing printf type escapes to allow
46  * cursor addressing.  We start out ready to print the destination
47  * line, and switch each time we print row or column.
48  * The following escapes are defined for substituting row/column:
49  *
50  *	%d	as in printf
51  *	%2	like %2d
52  *	%3	like %3d
53  *	%.	gives %c hacking special case characters
54  *	%+x	like %c but adding x first
55  *
56  *	The codes below affect the state but don't use up a value.
57  *
58  *	%>xy	if value > x add y
59  *	%r	reverses row/column
60  *	%i	increments row/column (for one origin indexing)
61  *	%%	gives %
62  *	%B	BCD (2 decimal digits encoded in one byte)
63  *	%D	Delta Data (backwards bcd)
64  *
65  * all other characters are ``self-inserting''.
66  */
67 char *
68 tgoto(char *CM, int destcol, int destline)
69 {
70 	static char result[MAXRETURNSIZE];
71 	static char added[10];
72 	char *cp = CM;
73 	char *dp = result;
74 	int c;
75 	int oncol = 0;
76 	int which = destline;
77 
78 	if (cp == 0) {
79 toohard:
80 		/*
81 		 * ``We don't do that under BOZO's big top''
82 		 */
83 		return ("OOPS");
84 	}
85 	added[0] = 0;
86 	while ((c = *cp++) != '\0') {
87 		if (c != '%') {
88 			if (dp >= &result[MAXRETURNSIZE])
89 				goto toohard;
90 			*dp++ = c;
91 			continue;
92 		}
93 		switch (c = *cp++) {
94 
95 #ifdef CM_N
96 		case 'n':
97 			destcol ^= 0140;
98 			destline ^= 0140;
99 			goto setwhich;
100 #endif
101 
102 		case 'd':
103 			if (which < 10)
104 				goto one;
105 			if (which < 100)
106 				goto two;
107 			/* fall into... */
108 
109 		case '3':
110 			if (dp >= &result[MAXRETURNSIZE])
111 				goto toohard;
112 			*dp++ = (which / 100) | '0';
113 			which %= 100;
114 			/* fall into... */
115 
116 		case '2':
117 two:
118 			if (dp >= &result[MAXRETURNSIZE])
119 				goto toohard;
120 			*dp++ = which / 10 | '0';
121 one:
122 			if (dp >= &result[MAXRETURNSIZE])
123 				goto toohard;
124 			*dp++ = which % 10 | '0';
125 swap:
126 			oncol = 1 - oncol;
127 setwhich:
128 			which = oncol ? destcol : destline;
129 			continue;
130 
131 #ifdef CM_GT
132 		case '>':
133 			if (which > *cp++)
134 				which += *cp++;
135 			else
136 				cp++;
137 			continue;
138 #endif
139 
140 		case '+':
141 			which += *cp++;
142 			/* fall into... */
143 
144 		case '.':
145 			/*
146 			 * This code is worth scratching your head at for a
147 			 * while.  The idea is that various weird things can
148 			 * happen to nulls, EOT's, tabs, and newlines by the
149 			 * tty driver, arpanet, and so on, so we don't send
150 			 * them if we can help it.
151 			 *
152 			 * Tab is taken out to get Ann Arbors to work, otherwise
153 			 * when they go to column 9 we increment which is wrong
154 			 * because bcd isn't continuous.  We should take out
155 			 * the rest too, or run the thing through more than
156 			 * once until it doesn't make any of these, but that
157 			 * would make termlib (and hence pdp-11 ex) bigger,
158 			 * and also somewhat slower.  This requires all
159 			 * programs which use termlib to stty tabs so they
160 			 * don't get expanded.  They should do this anyway
161 			 * because some terminals use ^I for other things,
162 			 * like nondestructive space.
163 			 */
164 			if ((which == 0 || which == CTRL('d') || which == '\n')
165 			    && (oncol || UP)) /* Assumption: backspace works */
166 				/*
167 				 * Loop needed because newline happens
168 				 * to be the successor of tab.
169 				 */
170 				do {
171 					if (strlcat(added, oncol ?
172 					    (BC ? BC : "\b") : UP,
173 					    sizeof(added)) >= sizeof(added))
174 						goto toohard;
175 					which++;
176 				} while (which == '\n');
177 			if (dp >= &result[MAXRETURNSIZE])
178 				goto toohard;
179 			*dp++ = which;
180 			goto swap;
181 
182 		case 'r':
183 			oncol = 1;
184 			goto setwhich;
185 
186 		case 'i':
187 			destcol++;
188 			destline++;
189 			which++;
190 			continue;
191 
192 		case '%':
193 			if (dp >= &result[MAXRETURNSIZE])
194 				goto toohard;
195 			*dp++ = c;
196 			continue;
197 
198 #ifdef CM_B
199 		case 'B':
200 			which = (which/10 << 4) + which%10;
201 			continue;
202 #endif
203 
204 #ifdef CM_D
205 		case 'D':
206 			which = which - 2 * (which%16);
207 			continue;
208 #endif
209 
210 		default:
211 			goto toohard;
212 		}
213 	}
214 	if (strlcpy(dp, added, sizeof(result) - (dp - result))
215 	    >= sizeof(result) - (dp - result))
216 		goto toohard;
217 	return (result);
218 }
219