xref: /csrg-svn/usr.bin/vgrind/vgrindefs.c (revision 17500)
1 #ifndef lint
2 static char sccsid[] = "@(#)vgrindefs.c	4.3 (Berkeley) 12/11/84";
3 #endif
4 
5 /* Copyright (c) 1979 Regents of the University of California */
6 
7 #define	BUFSIZ	1024
8 #define MAXHOP	32	/* max number of tc= indirections */
9 
10 #include <ctype.h>
11 /*
12  * grindcap - routines for dealing with the language definitions data base
13  *	(code stolen almost totally from termcap)
14  *
15  * BUG:		Should use a "last" pointer in tbuf, so that searching
16  *		for capabilities alphabetically would not be a n**2/2
17  *		process when large numbers of capabilities are given.
18  * Note:	If we add a last pointer now we will screw up the
19  *		tc capability. We really should compile termcap.
20  *
21  * Essentially all the work here is scanning and decoding escapes
22  * in string capabilities.  We don't use stdio because the editor
23  * doesn't, and because living w/o it is not hard.
24  */
25 
26 static	char *tbuf;
27 static	char *filename;
28 static	int hopcount;	/* detect infinite loops in termcap, init 0 */
29 char	*tskip();
30 char	*tgetstr();
31 char	*tdecode();
32 char	*getenv();
33 
34 /*
35  * Get an entry for terminal name in buffer bp,
36  * from the termcap file.  Parse is very rudimentary;
37  * we just notice escaped newlines.
38  */
39 tgetent(bp, name, file)
40 	char *bp, *name, *file;
41 {
42 	register char *cp;
43 	register int c;
44 	register int i = 0, cnt = 0;
45 	char ibuf[BUFSIZ];
46 	char *cp2;
47 	int tf;
48 
49 	tbuf = bp;
50 	tf = 0;
51 	filename = file;
52 	tf = open(filename, 0);
53 	if (tf < 0)
54 		return (-1);
55 	for (;;) {
56 		cp = bp;
57 		for (;;) {
58 			if (i == cnt) {
59 				cnt = read(tf, ibuf, BUFSIZ);
60 				if (cnt <= 0) {
61 					close(tf);
62 					return (0);
63 				}
64 				i = 0;
65 			}
66 			c = ibuf[i++];
67 			if (c == '\n') {
68 				if (cp > bp && cp[-1] == '\\'){
69 					cp--;
70 					continue;
71 				}
72 				break;
73 			}
74 			if (cp >= bp+BUFSIZ) {
75 				write(2,"Vgrind entry too long\n", 23);
76 				break;
77 			} else
78 				*cp++ = c;
79 		}
80 		*cp = 0;
81 
82 		/*
83 		 * The real work for the match.
84 		 */
85 		if (tnamatch(name)) {
86 			close(tf);
87 			return(tnchktc());
88 		}
89 	}
90 }
91 
92 /*
93  * tnchktc: check the last entry, see if it's tc=xxx. If so,
94  * recursively find xxx and append that entry (minus the names)
95  * to take the place of the tc=xxx entry. This allows termcap
96  * entries to say "like an HP2621 but doesn't turn on the labels".
97  * Note that this works because of the left to right scan.
98  */
99 tnchktc()
100 {
101 	register char *p, *q;
102 	char tcname[16];	/* name of similar terminal */
103 	char tcbuf[BUFSIZ];
104 	char *holdtbuf = tbuf;
105 	int l;
106 
107 	p = tbuf + strlen(tbuf) - 2;	/* before the last colon */
108 	while (*--p != ':')
109 		if (p<tbuf) {
110 			write(2, "Bad vgrind entry\n", 18);
111 			return (0);
112 		}
113 	p++;
114 	/* p now points to beginning of last field */
115 	if (p[0] != 't' || p[1] != 'c')
116 		return(1);
117 	strcpy(tcname,p+3);
118 	q = tcname;
119 	while (q && *q != ':')
120 		q++;
121 	*q = 0;
122 	if (++hopcount > MAXHOP) {
123 		write(2, "Infinite tc= loop\n", 18);
124 		return (0);
125 	}
126 	if (tgetent(tcbuf, tcname, filename) != 1)
127 		return(0);
128 	for (q=tcbuf; *q != ':'; q++)
129 		;
130 	l = p - holdtbuf + strlen(q);
131 	if (l > BUFSIZ) {
132 		write(2, "Vgrind entry too long\n", 23);
133 		q[BUFSIZ - (p-tbuf)] = 0;
134 	}
135 	strcpy(p, q+1);
136 	tbuf = holdtbuf;
137 	return(1);
138 }
139 
140 /*
141  * Tnamatch deals with name matching.  The first field of the termcap
142  * entry is a sequence of names separated by |'s, so we compare
143  * against each such name.  The normal : terminator after the last
144  * name (before the first field) stops us.
145  */
146 tnamatch(np)
147 	char *np;
148 {
149 	register char *Np, *Bp;
150 
151 	Bp = tbuf;
152 	if (*Bp == '#')
153 		return(0);
154 	for (;;) {
155 		for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
156 			continue;
157 		if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
158 			return (1);
159 		while (*Bp && *Bp != ':' && *Bp != '|')
160 			Bp++;
161 		if (*Bp == 0 || *Bp == ':')
162 			return (0);
163 		Bp++;
164 	}
165 }
166 
167 /*
168  * Skip to the next field.  Notice that this is very dumb, not
169  * knowing about \: escapes or any such.  If necessary, :'s can be put
170  * into the termcap file in octal.
171  */
172 static char *
173 tskip(bp)
174 	register char *bp;
175 {
176 
177 	while (*bp && *bp != ':')
178 		bp++;
179 	if (*bp == ':')
180 		bp++;
181 	return (bp);
182 }
183 
184 /*
185  * Return the (numeric) option id.
186  * Numeric options look like
187  *	li#80
188  * i.e. the option string is separated from the numeric value by
189  * a # character.  If the option is not found we return -1.
190  * Note that we handle octal numbers beginning with 0.
191  */
192 tgetnum(id)
193 	char *id;
194 {
195 	register int i, base;
196 	register char *bp = tbuf;
197 
198 	for (;;) {
199 		bp = tskip(bp);
200 		if (*bp == 0)
201 			return (-1);
202 		if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
203 			continue;
204 		if (*bp == '@')
205 			return(-1);
206 		if (*bp != '#')
207 			continue;
208 		bp++;
209 		base = 10;
210 		if (*bp == '0')
211 			base = 8;
212 		i = 0;
213 		while (isdigit(*bp))
214 			i *= base, i += *bp++ - '0';
215 		return (i);
216 	}
217 }
218 
219 /*
220  * Handle a flag option.
221  * Flag options are given "naked", i.e. followed by a : or the end
222  * of the buffer.  Return 1 if we find the option, or 0 if it is
223  * not given.
224  */
225 tgetflag(id)
226 	char *id;
227 {
228 	register char *bp = tbuf;
229 
230 	for (;;) {
231 		bp = tskip(bp);
232 		if (!*bp)
233 			return (0);
234 		if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
235 			if (!*bp || *bp == ':')
236 				return (1);
237 			else if (*bp == '@')
238 				return(0);
239 		}
240 	}
241 }
242 
243 /*
244  * Get a string valued option.
245  * These are given as
246  *	cl=^Z
247  * Much decoding is done on the strings, and the strings are
248  * placed in area, which is a ref parameter which is updated.
249  * No checking on area overflow.
250  */
251 char *
252 tgetstr(id, area)
253 	char *id, **area;
254 {
255 	register char *bp = tbuf;
256 
257 	for (;;) {
258 		bp = tskip(bp);
259 		if (!*bp)
260 			return (0);
261 		if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
262 			continue;
263 		if (*bp == '@')
264 			return(0);
265 		if (*bp != '=')
266 			continue;
267 		bp++;
268 		return (tdecode(bp, area));
269 	}
270 }
271 
272 /*
273  * Tdecode does the grung work to decode the
274  * string capability escapes.
275  */
276 static char *
277 tdecode(str, area)
278 	register char *str;
279 	char **area;
280 {
281 	register char *cp;
282 	register int c;
283 	int i;
284 
285 	cp = *area;
286 	while (c = *str++) {
287 	    if (c == ':' && *(cp-1) != '\\')
288 		break;
289 	    *cp++ = c;
290 	}
291 	*cp++ = 0;
292 	str = *area;
293 	*area = cp;
294 	return (str);
295 }
296