1/*
2 * Copyright (c) 1980, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31
32__FBSDID("$FreeBSD$");
33
34#define	BUFSIZ	1024
35#define MAXHOP	32	/* max number of tc= indirections */
36
37#include <ctype.h>
38#include <unistd.h>
39
40/*
41 * grindcap - routines for dealing with the language definitions data base
42 *	(code stolen almost totally from termcap)
43 *
44 * BUG:		Should use a "last" pointer in tbuf, so that searching
45 *		for capabilities alphabetically would not be a n**2/2
46 *		process when large numbers of capabilities are given.
47 * Note:	If we add a last pointer now we will screw up the
48 *		tc capability. We really should compile termcap.
49 *
50 * Essentially all the work here is scanning and decoding escapes
51 * in string capabilities.  We don't use stdio because the editor
52 * doesn't, and because living w/o it is not hard.
53 */
54
55static	char *tbuf;
56static	char *filename;
57static	int hopcount;	/* detect infinite loops in termcap, init 0 */
58char	*tskip();
59char	*tgetstr();
60char	*tdecode();
61char	*getenv();
62
63/*
64 * Get an entry for terminal name in buffer bp,
65 * from the termcap file.  Parse is very rudimentary;
66 * we just notice escaped newlines.
67 */
68tgetent(bp, name, file)
69	char *bp, *name, *file;
70{
71	register char *cp;
72	register int c;
73	register int i = 0, cnt = 0;
74	char ibuf[BUFSIZ];
75	char *cp2;
76	int tf;
77
78	tbuf = bp;
79	tf = 0;
80	filename = file;
81	tf = open(filename, 0);
82	if (tf < 0)
83		return (-1);
84	for (;;) {
85		cp = bp;
86		for (;;) {
87			if (i == cnt) {
88				cnt = read(tf, ibuf, BUFSIZ);
89				if (cnt <= 0) {
90					close(tf);
91					return (0);
92				}
93				i = 0;
94			}
95			c = ibuf[i++];
96			if (c == '\n') {
97				if (cp > bp && cp[-1] == '\\'){
98					cp--;
99					continue;
100				}
101				break;
102			}
103			if (cp >= bp+BUFSIZ) {
104				write(STDERR_FILENO, "Vgrind entry too long\n", 23);
105				break;
106			} else
107				*cp++ = c;
108		}
109		*cp = 0;
110
111		/*
112		 * The real work for the match.
113		 */
114		if (tnamatch(name)) {
115			close(tf);
116			return(tnchktc());
117		}
118	}
119}
120
121/*
122 * tnchktc: check the last entry, see if it's tc=xxx. If so,
123 * recursively find xxx and append that entry (minus the names)
124 * to take the place of the tc=xxx entry. This allows termcap
125 * entries to say "like an HP2621 but doesn't turn on the labels".
126 * Note that this works because of the left to right scan.
127 */
128tnchktc()
129{
130	register char *p, *q;
131	char tcname[16];	/* name of similar terminal */
132	char tcbuf[BUFSIZ];
133	char *holdtbuf = tbuf;
134	int l;
135
136	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
137	while (*--p != ':')
138		if (p<tbuf) {
139			write(STDERR_FILENO, "Bad vgrind entry\n", 18);
140			return (0);
141		}
142	p++;
143	/* p now points to beginning of last field */
144	if (p[0] != 't' || p[1] != 'c')
145		return(1);
146	strcpy(tcname,p+3);
147	q = tcname;
148	while (q && *q != ':')
149		q++;
150	*q = 0;
151	if (++hopcount > MAXHOP) {
152		write(STDERR_FILENO, "Infinite tc= loop\n", 18);
153		return (0);
154	}
155	if (tgetent(tcbuf, tcname, filename) != 1)
156		return(0);
157	for (q=tcbuf; *q != ':'; q++)
158		;
159	l = p - holdtbuf + strlen(q);
160	if (l > BUFSIZ) {
161		write(STDERR_FILENO, "Vgrind entry too long\n", 23);
162		q[BUFSIZ - (p-tbuf)] = 0;
163	}
164	strcpy(p, q+1);
165	tbuf = holdtbuf;
166	return(1);
167}
168
169/*
170 * Tnamatch deals with name matching.  The first field of the termcap
171 * entry is a sequence of names separated by |'s, so we compare
172 * against each such name.  The normal : terminator after the last
173 * name (before the first field) stops us.
174 */
175tnamatch(np)
176	char *np;
177{
178	register char *Np, *Bp;
179
180	Bp = tbuf;
181	if (*Bp == '#')
182		return(0);
183	for (;;) {
184		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
185			continue;
186		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
187			return (1);
188		while (*Bp && *Bp != ':' && *Bp != '|')
189			Bp++;
190		if (*Bp == 0 || *Bp == ':')
191			return (0);
192		Bp++;
193	}
194}
195
196/*
197 * Skip to the next field.  Notice that this is very dumb, not
198 * knowing about \: escapes or any such.  If necessary, :'s can be put
199 * into the termcap file in octal.
200 */
201static char *
202tskip(bp)
203	register char *bp;
204{
205
206	while (*bp && *bp != ':')
207		bp++;
208	if (*bp == ':')
209		bp++;
210	return (bp);
211}
212
213/*
214 * Return the (numeric) option id.
215 * Numeric options look like
216 *	li#80
217 * i.e. the option string is separated from the numeric value by
218 * a # character.  If the option is not found we return -1.
219 * Note that we handle octal numbers beginning with 0.
220 */
221tgetnum(id)
222	char *id;
223{
224	register int i, base;
225	register char *bp = tbuf;
226
227	for (;;) {
228		bp = tskip(bp);
229		if (*bp == 0)
230			return (-1);
231		if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
232			continue;
233		if (*bp == '@')
234			return(-1);
235		if (*bp != '#')
236			continue;
237		bp++;
238		base = 10;
239		if (*bp == '0')
240			base = 8;
241		i = 0;
242		while (isdigit(*bp))
243			i *= base, i += *bp++ - '0';
244		return (i);
245	}
246}
247
248/*
249 * Handle a flag option.
250 * Flag options are given "naked", i.e. followed by a : or the end
251 * of the buffer.  Return 1 if we find the option, or 0 if it is
252 * not given.
253 */
254tgetflag(id)
255	char *id;
256{
257	register char *bp = tbuf;
258
259	for (;;) {
260		bp = tskip(bp);
261		if (!*bp)
262			return (0);
263		if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
264			if (!*bp || *bp == ':')
265				return (1);
266			else if (*bp == '@')
267				return(0);
268		}
269	}
270}
271
272/*
273 * Get a string valued option.
274 * These are given as
275 *	cl=^Z
276 * Much decoding is done on the strings, and the strings are
277 * placed in area, which is a ref parameter which is updated.
278 * No checking on area overflow.
279 */
280char *
281tgetstr(id, area)
282	char *id, **area;
283{
284	register char *bp = tbuf;
285
286	for (;;) {
287		bp = tskip(bp);
288		if (!*bp)
289			return (0);
290		if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
291			continue;
292		if (*bp == '@')
293			return(0);
294		if (*bp != '=')
295			continue;
296		bp++;
297		return (tdecode(bp, area));
298	}
299}
300
301/*
302 * Tdecode does the grung work to decode the
303 * string capability escapes.
304 */
305static char *
306tdecode(str, area)
307	register char *str;
308	char **area;
309{
310	register char *cp;
311	register int c;
312	int i;
313
314	cp = *area;
315	while (c = *str++) {
316	    if (c == ':' && *(cp-1) != '\\')
317		break;
318	    *cp++ = c;
319	}
320	*cp++ = 0;
321	str = *area;
322	*area = cp;
323	return (str);
324}
325