1 /*
2 * Copyright (c) 1983 Regents of the University of California.
3 * 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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #ifndef lint
35 static char sccsid[] = "@(#)printcap.c 5.7 (Berkeley) 3/4/91";
36 #endif /* not lint */
37
38 #include <ctype.h>
39 #include <stdio.h>
40 #include "pathnames.h"
41
42 #ifndef BUFSIZ
43 #define BUFSIZ 1024
44 #endif
45 #define MAXHOP 32 /* max number of tc= indirections */
46
47 /*
48 * termcap - routines for dealing with the terminal capability data base
49 *
50 * BUG: Should use a "last" pointer in tbuf, so that searching
51 * for capabilities alphabetically would not be a n**2/2
52 * process when large numbers of capabilities are given.
53 * Note: If we add a last pointer now we will screw up the
54 * tc capability. We really should compile termcap.
55 *
56 * Essentially all the work here is scanning and decoding escapes
57 * in string capabilities. We don't use stdio because the editor
58 * doesn't, and because living w/o it is not hard.
59 */
60
61 #define PRINTCAP
62
63 #ifdef PRINTCAP
64 #define tgetent pgetent
65 #define tskip pskip
66 #define tgetstr pgetstr
67 #define tdecode pdecode
68 #define tgetnum pgetnum
69 #define tgetflag pgetflag
70 #define tdecode pdecode
71 #define tnchktc pnchktc
72 #define tnamatch pnamatch
73 #define V6
74 #endif
75
76 static FILE *pfp = NULL; /* printcap data base file pointer */
77 static char *tbuf;
78 static int hopcount; /* detect infinite loops in termcap, init 0 */
79 char *tskip();
80 char *tgetstr();
81 char *tdecode();
82 char *getenv();
83
84 /*
85 * Similar to tgetent except it returns the next enrty instead of
86 * doing a lookup.
87 */
getprent(bp)88 getprent(bp)
89 register char *bp;
90 {
91 register int c, skip = 0;
92
93 if (pfp == NULL && (pfp = fopen(_PATH_PRINTCAP, "r")) == NULL)
94 return(-1);
95 tbuf = bp;
96 for (;;) {
97 switch (c = getc(pfp)) {
98 case EOF:
99 fclose(pfp);
100 pfp = NULL;
101 return(0);
102 case '\n':
103 if (bp == tbuf) {
104 skip = 0;
105 continue;
106 }
107 if (bp[-1] == '\\') {
108 bp--;
109 continue;
110 }
111 *bp = '\0';
112 return(1);
113 case '#':
114 if (bp == tbuf)
115 skip++;
116 default:
117 if (skip)
118 continue;
119 if (bp >= tbuf+BUFSIZ) {
120 write(2, "Termcap entry too long\n", 23);
121 *bp = '\0';
122 return(1);
123 }
124 *bp++ = c;
125 }
126 }
127 }
128
endprent()129 endprent()
130 {
131 if (pfp != NULL)
132 fclose(pfp);
133 }
134
135 /*
136 * Get an entry for terminal name in buffer bp,
137 * from the termcap file. Parse is very rudimentary;
138 * we just notice escaped newlines.
139 */
tgetent(bp,name)140 tgetent(bp, name)
141 char *bp, *name;
142 {
143 register char *cp;
144 register int c;
145 register int i = 0, cnt = 0;
146 char ibuf[BUFSIZ];
147 char *cp2;
148 int tf;
149
150 tbuf = bp;
151 tf = 0;
152 #ifndef V6
153 cp = getenv("TERMCAP");
154 /*
155 * TERMCAP can have one of two things in it. It can be the
156 * name of a file to use instead of /etc/termcap. In this
157 * case it better start with a "/". Or it can be an entry to
158 * use so we don't have to read the file. In this case it
159 * has to already have the newlines crunched out.
160 */
161 if (cp && *cp) {
162 if (*cp!='/') {
163 cp2 = getenv("TERM");
164 if (cp2==(char *) 0 || strcmp(name,cp2)==0) {
165 strcpy(bp,cp);
166 return(tnchktc());
167 } else {
168 tf = open(_PATH_PRINTCAP, 0);
169 }
170 } else
171 tf = open(cp, 0);
172 }
173 if (tf==0)
174 tf = open(_PATH_PRINTCAP, 0);
175 #else
176 tf = open(_PATH_PRINTCAP, 0);
177 #endif
178 if (tf < 0)
179 return (-1);
180 for (;;) {
181 cp = bp;
182 for (;;) {
183 if (i == cnt) {
184 cnt = read(tf, ibuf, BUFSIZ);
185 if (cnt <= 0) {
186 close(tf);
187 return (0);
188 }
189 i = 0;
190 }
191 c = ibuf[i++];
192 if (c == '\n') {
193 if (cp > bp && cp[-1] == '\\'){
194 cp--;
195 continue;
196 }
197 break;
198 }
199 if (cp >= bp+BUFSIZ) {
200 write(2,"Termcap entry too long\n", 23);
201 break;
202 } else
203 *cp++ = c;
204 }
205 *cp = 0;
206
207 /*
208 * The real work for the match.
209 */
210 if (tnamatch(name)) {
211 close(tf);
212 return(tnchktc());
213 }
214 }
215 }
216
217 /*
218 * tnchktc: check the last entry, see if it's tc=xxx. If so,
219 * recursively find xxx and append that entry (minus the names)
220 * to take the place of the tc=xxx entry. This allows termcap
221 * entries to say "like an HP2621 but doesn't turn on the labels".
222 * Note that this works because of the left to right scan.
223 */
tnchktc()224 tnchktc()
225 {
226 register char *p, *q;
227 char tcname[16]; /* name of similar terminal */
228 char tcbuf[BUFSIZ];
229 char *holdtbuf = tbuf;
230 int l;
231
232 p = tbuf + strlen(tbuf) - 2; /* before the last colon */
233 while (*--p != ':')
234 if (p<tbuf) {
235 write(2, "Bad termcap entry\n", 18);
236 return (0);
237 }
238 p++;
239 /* p now points to beginning of last field */
240 if (p[0] != 't' || p[1] != 'c')
241 return(1);
242 strcpy(tcname,p+3);
243 q = tcname;
244 while (q && *q != ':')
245 q++;
246 *q = 0;
247 if (++hopcount > MAXHOP) {
248 write(2, "Infinite tc= loop\n", 18);
249 return (0);
250 }
251 if (tgetent(tcbuf, tcname) != 1)
252 return(0);
253 for (q=tcbuf; *q != ':'; q++)
254 ;
255 l = p - holdtbuf + strlen(q);
256 if (l > BUFSIZ) {
257 write(2, "Termcap entry too long\n", 23);
258 q[BUFSIZ - (p-tbuf)] = 0;
259 }
260 strcpy(p, q+1);
261 tbuf = holdtbuf;
262 return(1);
263 }
264
265 /*
266 * Tnamatch deals with name matching. The first field of the termcap
267 * entry is a sequence of names separated by |'s, so we compare
268 * against each such name. The normal : terminator after the last
269 * name (before the first field) stops us.
270 */
tnamatch(np)271 tnamatch(np)
272 char *np;
273 {
274 register char *Np, *Bp;
275
276 Bp = tbuf;
277 if (*Bp == '#')
278 return(0);
279 for (;;) {
280 for (Np = np; *Np && *Bp == *Np; Bp++, Np++)
281 continue;
282 if (*Np == 0 && (*Bp == '|' || *Bp == ':' || *Bp == 0))
283 return (1);
284 while (*Bp && *Bp != ':' && *Bp != '|')
285 Bp++;
286 if (*Bp == 0 || *Bp == ':')
287 return (0);
288 Bp++;
289 }
290 }
291
292 /*
293 * Skip to the next field. Notice that this is very dumb, not
294 * knowing about \: escapes or any such. If necessary, :'s can be put
295 * into the termcap file in octal.
296 */
297 static char *
tskip(bp)298 tskip(bp)
299 register char *bp;
300 {
301
302 while (*bp && *bp != ':')
303 bp++;
304 if (*bp == ':')
305 bp++;
306 return (bp);
307 }
308
309 /*
310 * Return the (numeric) option id.
311 * Numeric options look like
312 * li#80
313 * i.e. the option string is separated from the numeric value by
314 * a # character. If the option is not found we return -1.
315 * Note that we handle octal numbers beginning with 0.
316 */
tgetnum(id)317 tgetnum(id)
318 char *id;
319 {
320 register int i, base;
321 register char *bp = tbuf;
322
323 for (;;) {
324 bp = tskip(bp);
325 if (*bp == 0)
326 return (-1);
327 if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
328 continue;
329 if (*bp == '@')
330 return(-1);
331 if (*bp != '#')
332 continue;
333 bp++;
334 base = 10;
335 if (*bp == '0')
336 base = 8;
337 i = 0;
338 while (isdigit(*bp))
339 i *= base, i += *bp++ - '0';
340 return (i);
341 }
342 }
343
344 /*
345 * Handle a flag option.
346 * Flag options are given "naked", i.e. followed by a : or the end
347 * of the buffer. Return 1 if we find the option, or 0 if it is
348 * not given.
349 */
tgetflag(id)350 tgetflag(id)
351 char *id;
352 {
353 register char *bp = tbuf;
354
355 for (;;) {
356 bp = tskip(bp);
357 if (!*bp)
358 return (0);
359 if (*bp++ == id[0] && *bp != 0 && *bp++ == id[1]) {
360 if (!*bp || *bp == ':')
361 return (1);
362 else if (*bp == '@')
363 return(0);
364 }
365 }
366 }
367
368 /*
369 * Get a string valued option.
370 * These are given as
371 * cl=^Z
372 * Much decoding is done on the strings, and the strings are
373 * placed in area, which is a ref parameter which is updated.
374 * No checking on area overflow.
375 */
376 char *
tgetstr(id,area)377 tgetstr(id, area)
378 char *id, **area;
379 {
380 register char *bp = tbuf;
381
382 for (;;) {
383 bp = tskip(bp);
384 if (!*bp)
385 return (0);
386 if (*bp++ != id[0] || *bp == 0 || *bp++ != id[1])
387 continue;
388 if (*bp == '@')
389 return(0);
390 if (*bp != '=')
391 continue;
392 bp++;
393 return (tdecode(bp, area));
394 }
395 }
396
397 /*
398 * Tdecode does the grung work to decode the
399 * string capability escapes.
400 */
401 static char *
tdecode(str,area)402 tdecode(str, area)
403 register char *str;
404 char **area;
405 {
406 register char *cp;
407 register int c;
408 register char *dp;
409 int i;
410
411 cp = *area;
412 while ((c = *str++) && c != ':') {
413 switch (c) {
414
415 case '^':
416 c = *str++ & 037;
417 break;
418
419 case '\\':
420 dp = "E\033^^\\\\::n\nr\rt\tb\bf\f";
421 c = *str++;
422 nextc:
423 if (*dp++ == c) {
424 c = *dp++;
425 break;
426 }
427 dp++;
428 if (*dp)
429 goto nextc;
430 if (isdigit(c)) {
431 c -= '0', i = 2;
432 do
433 c <<= 3, c |= *str++ - '0';
434 while (--i && isdigit(*str));
435 }
436 break;
437 }
438 *cp++ = c;
439 }
440 *cp++ = 0;
441 str = *area;
442 *area = cp;
443 return (str);
444 }
445