xref: /freebsd/contrib/ncurses/ncurses/tinfo/read_termcap.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1 /****************************************************************************
2  * Copyright (c) 1998-2005,2006 Free Software Foundation, Inc.              *
3  *                                                                          *
4  * Permission is hereby granted, free of charge, to any person obtaining a  *
5  * copy of this software and associated documentation files (the            *
6  * "Software"), to deal in the Software without restriction, including      *
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9  * copies of the Software, and to permit persons to whom the Software is    *
10  * furnished to do so, subject to the following conditions:                 *
11  *                                                                          *
12  * The above copyright notice and this permission notice shall be included  *
13  * in all copies or substantial portions of the Software.                   *
14  *                                                                          *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
16  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
18  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
19  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
20  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
21  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
22  *                                                                          *
23  * Except as contained in this notice, the name(s) of the above copyright   *
24  * holders shall not be used in advertising or otherwise to promote the     *
25  * sale, use or other dealings in this Software without prior written       *
26  * authorization.                                                           *
27  ****************************************************************************/
28 
29 /****************************************************************************
30  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
31  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
32  *     and: Thomas E. Dickey                        1996-on                 *
33  ****************************************************************************/
34 
35 /*
36  * Termcap compatibility support
37  *
38  * If your OS integrator didn't install a terminfo database, you can call
39  * _nc_read_termcap_entry() to support reading and translating capabilities
40  * from the system termcap file.  This is a kludge; it will bulk up and slow
41  * down every program that uses ncurses, and translated termcap entries cannot
42  * use full terminfo capabilities.  Don't use it unless you absolutely have to;
43  * instead, get your system people to run tic(1) from root on the terminfo
44  * master included with ncurses to translate it into a terminfo database.
45  *
46  * If USE_GETCAP is enabled, we use what is effectively a copy of the 4.4BSD
47  * getcap code to fetch entries.  There are disadvantages to this; mainly that
48  * getcap(3) does its own resolution, meaning that entries read in in this way
49  * can't reference the terminfo tree.  The only thing it buys is faster startup
50  * time, getcap(3) is much faster than our tic parser.
51  */
52 
53 #include <curses.priv.h>
54 
55 #include <ctype.h>
56 #include <sys/types.h>
57 #include <sys/stat.h>
58 #include <tic.h>
59 #include <term_entry.h>
60 
61 MODULE_ID("$Id: read_termcap.c,v 1.71 2006/07/29 12:06:51 tom Exp $")
62 
63 #if !PURE_TERMINFO
64 
65 #define TC_SUCCESS     0
66 #define TC_NOT_FOUND  -1
67 #define TC_SYS_ERR    -2
68 #define TC_REF_LOOP   -3
69 #define TC_UNRESOLVED -4	/* this is not returned by BSD cgetent */
70 
71 static NCURSES_CONST char *
72 get_termpath(void)
73 {
74     NCURSES_CONST char *result;
75 
76     if (!use_terminfo_vars() || (result = getenv("TERMPATH")) == 0)
77 	result = TERMPATH;
78     T(("TERMPATH is %s", result));
79     return result;
80 }
81 
82 #if USE_GETCAP
83 
84 #if HAVE_BSD_CGETENT
85 #define _nc_cgetcap   cgetcap
86 #define _nc_cgetent(buf, oline, db_array, name) cgetent(buf, db_array, name)
87 #define _nc_cgetmatch cgetmatch
88 #define _nc_cgetset   cgetset
89 #else
90 static int _nc_cgetmatch(char *, const char *);
91 static int _nc_getent(char **, unsigned *, int *, int, char **, int, const char
92 		      *, int, char *);
93 static int _nc_nfcmp(const char *, char *);
94 
95 /*-
96  * Copyright (c) 1992, 1993
97  *	The Regents of the University of California.  All rights reserved.
98  *
99  * This code is derived from software contributed to Berkeley by
100  * Casey Leedom of Lawrence Livermore National Laboratory.
101  *
102  * Redistribution and use in source and binary forms, with or without
103  * modification, are permitted provided that the following conditions
104  * are met:
105  * 1. Redistributions of source code must retain the above copyright
106  *    notice, this list of conditions and the following disclaimer.
107  * 2. Redistributions in binary form must reproduce the above copyright
108  *    notice, this list of conditions and the following disclaimer in the
109  *    documentation and/or other materials provided with the distribution.
110  * 3. All advertising materials mentioning features or use of this software
111  *    must display the following acknowledgment:
112  *	This product includes software developed by the University of
113  *	California, Berkeley and its contributors.
114  * 4. Neither the name of the University nor the names of its contributors
115  *    may be used to endorse or promote products derived from this software
116  *    without specific prior written permission.
117  *
118  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
119  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
120  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
121  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
122  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
123  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
124  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
125  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
126  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
127  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
128  * SUCH DAMAGE.
129  */
130 
131 /* static char sccsid[] = "@(#)getcap.c	8.3 (Berkeley) 3/25/94"; */
132 
133 #define	BFRAG		1024
134 #define	BSIZE		1024
135 #define	MAX_RECURSION	32	/* maximum getent recursion */
136 
137 static size_t topreclen;	/* toprec length */
138 static char *toprec;		/* Additional record specified by cgetset() */
139 static int gottoprec;		/* Flag indicating retrieval of toprecord */
140 
141 /*
142  * Cgetset() allows the addition of a user specified buffer to be added to the
143  * database array, in effect "pushing" the buffer on top of the virtual
144  * database.  0 is returned on success, -1 on failure.
145  */
146 static int
147 _nc_cgetset(const char *ent)
148 {
149     if (ent == 0) {
150 	FreeIfNeeded(toprec);
151 	toprec = 0;
152 	topreclen = 0;
153 	return (0);
154     }
155     topreclen = strlen(ent);
156     if ((toprec = typeMalloc(char, topreclen + 1)) == 0) {
157 	errno = ENOMEM;
158 	return (-1);
159     }
160     gottoprec = 0;
161     (void) strcpy(toprec, ent);
162     return (0);
163 }
164 
165 /*
166  * Cgetcap searches the capability record buf for the capability cap with type
167  * `type'.  A pointer to the value of cap is returned on success, 0 if the
168  * requested capability couldn't be found.
169  *
170  * Specifying a type of ':' means that nothing should follow cap (:cap:).  In
171  * this case a pointer to the terminating ':' or NUL will be returned if cap is
172  * found.
173  *
174  * If (cap, '@') or (cap, terminator, '@') is found before (cap, terminator)
175  * return 0.
176  */
177 static char *
178 _nc_cgetcap(char *buf, const char *cap, int type)
179 {
180     register const char *cp;
181     register char *bp;
182 
183     bp = buf;
184     for (;;) {
185 	/*
186 	 * Skip past the current capability field - it's either the
187 	 * name field if this is the first time through the loop, or
188 	 * the remainder of a field whose name failed to match cap.
189 	 */
190 	for (;;) {
191 	    if (*bp == '\0')
192 		return (0);
193 	    else if (*bp++ == ':')
194 		break;
195 	}
196 
197 	/*
198 	 * Try to match (cap, type) in buf.
199 	 */
200 	for (cp = cap; *cp == *bp && *bp != '\0'; cp++, bp++)
201 	    continue;
202 	if (*cp != '\0')
203 	    continue;
204 	if (*bp == '@')
205 	    return (0);
206 	if (type == ':') {
207 	    if (*bp != '\0' && *bp != ':')
208 		continue;
209 	    return (bp);
210 	}
211 	if (*bp != type)
212 	    continue;
213 	bp++;
214 	return (*bp == '@' ? 0 : bp);
215     }
216     /* NOTREACHED */
217 }
218 
219 /*
220  * Cgetent extracts the capability record name from the NULL terminated file
221  * array db_array and returns a pointer to a malloc'd copy of it in buf.  Buf
222  * must be retained through all subsequent calls to cgetcap, cgetnum, cgetflag,
223  * and cgetstr, but may then be freed.
224  *
225  * Returns:
226  *
227  * positive #    on success (i.e., the index in db_array)
228  * TC_NOT_FOUND  if the requested record couldn't be found
229  * TC_SYS_ERR    if a system error was encountered (e.g.,couldn't open a file)
230  * TC_REF_LOOP   if a potential reference loop is detected
231  * TC_UNRESOLVED if we had too many recurrences to resolve
232  */
233 static int
234 _nc_cgetent(char **buf, int *oline, char **db_array, const char *name)
235 {
236     unsigned dummy;
237 
238     return (_nc_getent(buf, &dummy, oline, 0, db_array, -1, name, 0, 0));
239 }
240 
241 /*
242  * Getent implements the functions of cgetent.  If fd is non-negative,
243  * *db_array has already been opened and fd is the open file descriptor.  We
244  * do this to save time and avoid using up file descriptors for tc=
245  * recursions.
246  *
247  * Getent returns the same success/failure codes as cgetent.  On success, a
248  * pointer to a malloc'd capability record with all tc= capabilities fully
249  * expanded and its length (not including trailing ASCII NUL) are left in
250  * *cap and *len.
251  *
252  * Basic algorithm:
253  *	+ Allocate memory incrementally as needed in chunks of size BFRAG
254  *	  for capability buffer.
255  *	+ Recurse for each tc=name and interpolate result.  Stop when all
256  *	  names interpolated, a name can't be found, or depth exceeds
257  *	  MAX_RECURSION.
258  */
259 #define DOALLOC(size) typeRealloc(char, size, record)
260 static int
261 _nc_getent(
262 	      char **cap,	/* termcap-content */
263 	      unsigned *len,	/* length, needed for recursion */
264 	      int *beginning,	/* line-number at match */
265 	      int in_array,	/* index in 'db_array[] */
266 	      char **db_array,	/* list of files to search */
267 	      int fd,
268 	      const char *name,
269 	      int depth,
270 	      char *nfield)
271 {
272     register char *r_end, *rp;
273     int myfd = FALSE;
274     char *record = 0;
275     int tc_not_resolved;
276     int current;
277     int lineno;
278 
279     /*
280      * Return with ``loop detected'' error if we've recurred more than
281      * MAX_RECURSION times.
282      */
283     if (depth > MAX_RECURSION)
284 	return (TC_REF_LOOP);
285 
286     /*
287      * Check if we have a top record from cgetset().
288      */
289     if (depth == 0 && toprec != 0 && _nc_cgetmatch(toprec, name) == 0) {
290 	if ((record = DOALLOC(topreclen + BFRAG)) == 0) {
291 	    errno = ENOMEM;
292 	    return (TC_SYS_ERR);
293 	}
294 	(void) strcpy(record, toprec);
295 	rp = record + topreclen + 1;
296 	r_end = rp + BFRAG;
297 	current = in_array;
298     } else {
299 	int foundit;
300 
301 	/*
302 	 * Allocate first chunk of memory.
303 	 */
304 	if ((record = DOALLOC(BFRAG)) == 0) {
305 	    errno = ENOMEM;
306 	    return (TC_SYS_ERR);
307 	}
308 	rp = r_end = record + BFRAG;
309 	foundit = FALSE;
310 
311 	/*
312 	 * Loop through database array until finding the record.
313 	 */
314 	for (current = in_array; db_array[current] != 0; current++) {
315 	    int eof = FALSE;
316 
317 	    /*
318 	     * Open database if not already open.
319 	     */
320 	    if (fd >= 0) {
321 		(void) lseek(fd, (off_t) 0, SEEK_SET);
322 	    } else if ((_nc_access(db_array[current], R_OK) < 0)
323 		       || (fd = open(db_array[current], O_RDONLY, 0)) < 0) {
324 		/* No error on unfound file. */
325 		if (errno == ENOENT)
326 		    continue;
327 		free(record);
328 		return (TC_SYS_ERR);
329 	    } else {
330 		myfd = TRUE;
331 	    }
332 	    lineno = 0;
333 
334 	    /*
335 	     * Find the requested capability record ...
336 	     */
337 	    {
338 		char buf[2048];
339 		register char *b_end = buf;
340 		register char *bp = buf;
341 		register int c;
342 
343 		/*
344 		 * Loop invariants:
345 		 *      There is always room for one more character in record.
346 		 *      R_end always points just past end of record.
347 		 *      Rp always points just past last character in record.
348 		 *      B_end always points just past last character in buf.
349 		 *      Bp always points at next character in buf.
350 		 */
351 
352 		for (;;) {
353 		    int first = lineno + 1;
354 
355 		    /*
356 		     * Read in a line implementing (\, newline)
357 		     * line continuation.
358 		     */
359 		    rp = record;
360 		    for (;;) {
361 			if (bp >= b_end) {
362 			    int n;
363 
364 			    n = read(fd, buf, sizeof(buf));
365 			    if (n <= 0) {
366 				if (myfd)
367 				    (void) close(fd);
368 				if (n < 0) {
369 				    free(record);
370 				    return (TC_SYS_ERR);
371 				}
372 				fd = -1;
373 				eof = TRUE;
374 				break;
375 			    }
376 			    b_end = buf + n;
377 			    bp = buf;
378 			}
379 
380 			c = *bp++;
381 			if (c == '\n') {
382 			    lineno++;
383 			    if (rp == record || *(rp - 1) != '\\')
384 				break;
385 			}
386 			*rp++ = c;
387 
388 			/*
389 			 * Enforce loop invariant: if no room
390 			 * left in record buffer, try to get
391 			 * some more.
392 			 */
393 			if (rp >= r_end) {
394 			    unsigned pos;
395 			    size_t newsize;
396 
397 			    pos = rp - record;
398 			    newsize = r_end - record + BFRAG;
399 			    record = DOALLOC(newsize);
400 			    if (record == 0) {
401 				if (myfd)
402 				    (void) close(fd);
403 				errno = ENOMEM;
404 				return (TC_SYS_ERR);
405 			    }
406 			    r_end = record + newsize;
407 			    rp = record + pos;
408 			}
409 		    }
410 		    /* loop invariant lets us do this */
411 		    *rp++ = '\0';
412 
413 		    /*
414 		     * If encountered eof check next file.
415 		     */
416 		    if (eof)
417 			break;
418 
419 		    /*
420 		     * Toss blank lines and comments.
421 		     */
422 		    if (*record == '\0' || *record == '#')
423 			continue;
424 
425 		    /*
426 		     * See if this is the record we want ...
427 		     */
428 		    if (_nc_cgetmatch(record, name) == 0
429 			&& (nfield == 0
430 			    || !_nc_nfcmp(nfield, record))) {
431 			foundit = TRUE;
432 			*beginning = first;
433 			break;	/* found it! */
434 		    }
435 		}
436 	    }
437 	    if (foundit)
438 		break;
439 	}
440 
441 	if (!foundit)
442 	    return (TC_NOT_FOUND);
443     }
444 
445     /*
446      * Got the capability record, but now we have to expand all tc=name
447      * references in it ...
448      */
449     {
450 	register char *newicap, *s;
451 	register int newilen;
452 	unsigned ilen;
453 	int diff, iret, tclen, oline;
454 	char *icap, *scan, *tc, *tcstart, *tcend;
455 
456 	/*
457 	 * Loop invariants:
458 	 *      There is room for one more character in record.
459 	 *      R_end points just past end of record.
460 	 *      Rp points just past last character in record.
461 	 *      Scan points at remainder of record that needs to be
462 	 *      scanned for tc=name constructs.
463 	 */
464 	scan = record;
465 	tc_not_resolved = FALSE;
466 	for (;;) {
467 	    if ((tc = _nc_cgetcap(scan, "tc", '=')) == 0)
468 		break;
469 
470 	    /*
471 	     * Find end of tc=name and stomp on the trailing `:'
472 	     * (if present) so we can use it to call ourselves.
473 	     */
474 	    s = tc;
475 	    while (*s != '\0') {
476 		if (*s++ == ':') {
477 		    *(s - 1) = '\0';
478 		    break;
479 		}
480 	    }
481 	    tcstart = tc - 3;
482 	    tclen = s - tcstart;
483 	    tcend = s;
484 
485 	    iret = _nc_getent(&icap, &ilen, &oline, current, db_array, fd,
486 			      tc, depth + 1, 0);
487 	    newicap = icap;	/* Put into a register. */
488 	    newilen = ilen;
489 	    if (iret != TC_SUCCESS) {
490 		/* an error */
491 		if (iret < TC_NOT_FOUND) {
492 		    if (myfd)
493 			(void) close(fd);
494 		    free(record);
495 		    return (iret);
496 		}
497 		if (iret == TC_UNRESOLVED)
498 		    tc_not_resolved = TRUE;
499 		/* couldn't resolve tc */
500 		if (iret == TC_NOT_FOUND) {
501 		    *(s - 1) = ':';
502 		    scan = s - 1;
503 		    tc_not_resolved = TRUE;
504 		    continue;
505 		}
506 	    }
507 
508 	    /* not interested in name field of tc'ed record */
509 	    s = newicap;
510 	    while (*s != '\0' && *s++ != ':') ;
511 	    newilen -= s - newicap;
512 	    newicap = s;
513 
514 	    /* make sure interpolated record is `:'-terminated */
515 	    s += newilen;
516 	    if (*(s - 1) != ':') {
517 		*s = ':';	/* overwrite NUL with : */
518 		newilen++;
519 	    }
520 
521 	    /*
522 	     * Make sure there's enough room to insert the
523 	     * new record.
524 	     */
525 	    diff = newilen - tclen;
526 	    if (diff >= r_end - rp) {
527 		unsigned pos, tcpos, tcposend;
528 		size_t newsize;
529 
530 		pos = rp - record;
531 		newsize = r_end - record + diff + BFRAG;
532 		tcpos = tcstart - record;
533 		tcposend = tcend - record;
534 		record = DOALLOC(newsize);
535 		if (record == 0) {
536 		    if (myfd)
537 			(void) close(fd);
538 		    free(icap);
539 		    errno = ENOMEM;
540 		    return (TC_SYS_ERR);
541 		}
542 		r_end = record + newsize;
543 		rp = record + pos;
544 		tcstart = record + tcpos;
545 		tcend = record + tcposend;
546 	    }
547 
548 	    /*
549 	     * Insert tc'ed record into our record.
550 	     */
551 	    s = tcstart + newilen;
552 	    memmove(s, tcend, (size_t) (rp - tcend));
553 	    memmove(tcstart, newicap, (size_t) newilen);
554 	    rp += diff;
555 	    free(icap);
556 
557 	    /*
558 	     * Start scan on `:' so next cgetcap works properly
559 	     * (cgetcap always skips first field).
560 	     */
561 	    scan = s - 1;
562 	}
563     }
564 
565     /*
566      * Close file (if we opened it), give back any extra memory, and
567      * return capability, length and success.
568      */
569     if (myfd)
570 	(void) close(fd);
571     *len = rp - record - 1;	/* don't count NUL */
572     if (r_end > rp) {
573 	if ((record = DOALLOC((size_t) (rp - record))) == 0) {
574 	    errno = ENOMEM;
575 	    return (TC_SYS_ERR);
576 	}
577     }
578 
579     *cap = record;
580     if (tc_not_resolved)
581 	return (TC_UNRESOLVED);
582     return (current);
583 }
584 
585 /*
586  * Cgetmatch will return 0 if name is one of the names of the capability
587  * record buf, -1 if not.
588  */
589 static int
590 _nc_cgetmatch(char *buf, const char *name)
591 {
592     register const char *np;
593     register char *bp;
594 
595     /*
596      * Start search at beginning of record.
597      */
598     bp = buf;
599     for (;;) {
600 	/*
601 	 * Try to match a record name.
602 	 */
603 	np = name;
604 	for (;;) {
605 	    if (*np == '\0') {
606 		if (*bp == '|' || *bp == ':' || *bp == '\0')
607 		    return (0);
608 		else
609 		    break;
610 	    } else if (*bp++ != *np++) {
611 		break;
612 	    }
613 	}
614 
615 	/*
616 	 * Match failed, skip to next name in record.
617 	 */
618 	bp--;			/* a '|' or ':' may have stopped the match */
619 	for (;;) {
620 	    if (*bp == '\0' || *bp == ':')
621 		return (-1);	/* match failed totally */
622 	    else if (*bp++ == '|')
623 		break;		/* found next name */
624 	}
625     }
626 }
627 
628 /*
629  * Compare name field of record.
630  */
631 static int
632 _nc_nfcmp(const char *nf, char *rec)
633 {
634     char *cp, tmp;
635     int ret;
636 
637     for (cp = rec; *cp != ':'; cp++) ;
638 
639     tmp = *(cp + 1);
640     *(cp + 1) = '\0';
641     ret = strcmp(nf, rec);
642     *(cp + 1) = tmp;
643 
644     return (ret);
645 }
646 #endif /* HAVE_BSD_CGETENT */
647 
648 /*
649  * Since ncurses provides its own 'tgetent()', we cannot use the native one.
650  * So we reproduce the logic to get down to cgetent() -- or our cut-down
651  * version of that -- to circumvent the problem of configuring against the
652  * termcap library.
653  */
654 #define USE_BSD_TGETENT 1
655 
656 #if USE_BSD_TGETENT
657 /*
658  * Copyright (c) 1980, 1993
659  *	The Regents of the University of California.  All rights reserved.
660  *
661  * Redistribution and use in source and binary forms, with or without
662  * modification, are permitted provided that the following conditions
663  * are met:
664  * 1. Redistributions of source code must retain the above copyright
665  *    notice, this list of conditions and the following disclaimer.
666  * 2. Redistributions in binary form must reproduce the above copyright
667  *    notice, this list of conditions and the following disclaimer in the
668  *    documentation and/or other materials provided with the distribution.
669  * 3. All advertising materials mentioning features or use of this software
670  *    must display the following acknowledgment:
671  *	This product includes software developed by the University of
672  *	California, Berkeley and its contributors.
673  * 4. Neither the name of the University nor the names of its contributors
674  *    may be used to endorse or promote products derived from this software
675  *    without specific prior written permission.
676  *
677  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
678  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
679  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
680  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
681  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
682  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
683  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
684  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
685  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
686  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
687  * SUCH DAMAGE.
688  */
689 
690 /* static char sccsid[] = "@(#)termcap.c	8.1 (Berkeley) 6/4/93" */
691 
692 #define	PBUFSIZ		512	/* max length of filename path */
693 #define	PVECSIZ		32	/* max number of names in path */
694 #define TBUFSIZ (2048*2)
695 
696 static char *tbuf;
697 
698 /*
699  * On entry, srcp points to a non ':' character which is the beginning of the
700  * token, if any.  We'll try to return a string that doesn't end with a ':'.
701  */
702 static char *
703 get_tc_token(char **srcp, int *endp)
704 {
705     int ch;
706     bool found = FALSE;
707     char *s, *base;
708     char *tok = 0;
709 
710     *endp = TRUE;
711     for (s = base = *srcp; *s != '\0';) {
712 	ch = *s++;
713 	if (ch == '\\') {
714 	    if (*s == '\0') {
715 		break;
716 	    } else if (*s++ == '\n') {
717 		while (isspace(UChar(*s)))
718 		    s++;
719 	    } else {
720 		found = TRUE;
721 	    }
722 	} else if (ch == ':') {
723 	    if (found) {
724 		tok = base;
725 		s[-1] = '\0';
726 		*srcp = s;
727 		*endp = FALSE;
728 		break;
729 	    }
730 	    base = s;
731 	} else if (isgraph(UChar(ch))) {
732 	    found = TRUE;
733 	}
734     }
735 
736     /* malformed entry may end without a ':' */
737     if (tok == 0 && found) {
738 	tok = base;
739     }
740 
741     return tok;
742 }
743 
744 static char *
745 copy_tc_token(char *dst, const char *src, size_t len)
746 {
747     int ch;
748 
749     while ((ch = *src++) != '\0') {
750 	if (ch == '\\' && *src == '\n') {
751 	    while (isspace(UChar(*src)))
752 		src++;
753 	    continue;
754 	}
755 	if (--len == 0) {
756 	    dst = 0;
757 	    break;
758 	}
759 	*dst++ = ch;
760     }
761     return dst;
762 }
763 
764 /*
765  * Get an entry for terminal name in buffer bp from the termcap file.
766  */
767 static int
768 _nc_tgetent(char *bp, char **sourcename, int *lineno, const char *name)
769 {
770     static char *the_source;
771 
772     register char *p;
773     register char *cp;
774     char *dummy = NULL;
775     char **fname;
776     char *home;
777     int i;
778     char pathbuf[PBUFSIZ];	/* holds raw path of filenames */
779     char *pathvec[PVECSIZ];	/* to point to names in pathbuf */
780     char **pvec;		/* holds usable tail of path vector */
781     NCURSES_CONST char *termpath;
782     string_desc desc;
783 
784     fname = pathvec;
785     pvec = pathvec;
786     tbuf = bp;
787     p = pathbuf;
788     cp = use_terminfo_vars()? getenv("TERMCAP") : NULL;
789 
790     /*
791      * TERMCAP can have one of two things in it.  It can be the name of a file
792      * to use instead of /etc/termcap.  In this case it better start with a
793      * "/".  Or it can be an entry to use so we don't have to read the file.
794      * In this case it has to already have the newlines crunched out.  If
795      * TERMCAP does not hold a file name then a path of names is searched
796      * instead.  The path is found in the TERMPATH variable, or becomes
797      * "$HOME/.termcap /etc/termcap" if no TERMPATH exists.
798      */
799     _nc_str_init(&desc, pathbuf, sizeof(pathbuf));
800     if (cp == NULL) {
801 	_nc_safe_strcpy(&desc, get_termpath());
802     } else if (!_nc_is_abs_path(cp)) {	/* TERMCAP holds an entry */
803 	if ((termpath = get_termpath()) != 0) {
804 	    _nc_safe_strcat(&desc, termpath);
805 	} else {
806 	    char temp[PBUFSIZ];
807 	    temp[0] = 0;
808 	    if ((home = getenv("HOME")) != 0 && *home != '\0'
809 		&& strchr(home, ' ') == 0
810 		&& strlen(home) < sizeof(temp) - 10) {	/* setup path */
811 		sprintf(temp, "%s/", home);	/* $HOME first */
812 	    }
813 	    /* if no $HOME look in current directory */
814 	    strcat(temp, ".termcap");
815 	    _nc_safe_strcat(&desc, temp);
816 	    _nc_safe_strcat(&desc, " ");
817 	    _nc_safe_strcat(&desc, get_termpath());
818 	}
819     } else {			/* user-defined name in TERMCAP */
820 	_nc_safe_strcat(&desc, cp);	/* still can be tokenized */
821     }
822 
823     *fname++ = pathbuf;		/* tokenize path into vector of names */
824     while (*++p) {
825 	if (*p == ' ' || *p == NCURSES_PATHSEP) {
826 	    *p = '\0';
827 	    while (*++p)
828 		if (*p != ' ' && *p != NCURSES_PATHSEP)
829 		    break;
830 	    if (*p == '\0')
831 		break;
832 	    *fname++ = p;
833 	    if (fname >= pathvec + PVECSIZ) {
834 		fname--;
835 		break;
836 	    }
837 	}
838     }
839     *fname = 0;			/* mark end of vector */
840     if (_nc_is_abs_path(cp)) {
841 	if (_nc_cgetset(cp) < 0) {
842 	    return (TC_SYS_ERR);
843 	}
844     }
845 
846     i = _nc_cgetent(&dummy, lineno, pathvec, name);
847 
848     /* ncurses' termcap-parsing routines cannot handle multiple adjacent
849      * empty fields, and mistakenly use the last valid cap entry instead of
850      * the first (breaks tc= includes)
851      */
852     if (i >= 0) {
853 	char *pd, *ps, *tok;
854 	int endflag = FALSE;
855 	char *list[1023];
856 	size_t n, count = 0;
857 
858 	pd = bp;
859 	ps = dummy;
860 	while (!endflag && (tok = get_tc_token(&ps, &endflag)) != 0) {
861 	    bool ignore = FALSE;
862 
863 	    for (n = 1; n < count; n++) {
864 		char *s = list[n];
865 		if (s[0] == tok[0]
866 		    && s[1] == tok[1]) {
867 		    ignore = TRUE;
868 		    break;
869 		}
870 	    }
871 	    if (ignore != TRUE) {
872 		list[count++] = tok;
873 		pd = copy_tc_token(pd, tok, TBUFSIZ - (2 + pd - bp));
874 		if (pd == 0) {
875 		    i = -1;
876 		    break;
877 		}
878 		*pd++ = ':';
879 		*pd = '\0';
880 	    }
881 	}
882     }
883 
884     FreeIfNeeded(dummy);
885     FreeIfNeeded(the_source);
886     the_source = 0;
887 
888     /* This is not related to the BSD cgetent(), but to fake up a suitable
889      * filename for ncurses' error reporting.  (If we are not using BSD
890      * cgetent, then it is the actual filename).
891      */
892     if (i >= 0) {
893 #if HAVE_BSD_CGETENT
894 	char temp[PATH_MAX];
895 
896 	_nc_str_init(&desc, temp, sizeof(temp));
897 	_nc_safe_strcpy(&desc, pathvec[i]);
898 	_nc_safe_strcat(&desc, ".db");
899 	if (_nc_access(temp, R_OK) == 0) {
900 	    _nc_safe_strcpy(&desc, pathvec[i]);
901 	}
902 	if ((the_source = strdup(temp)) != 0)
903 	    *sourcename = the_source;
904 #else
905 	if ((the_source = strdup(pathvec[i])) != 0)
906 	    *sourcename = the_source;
907 #endif
908     }
909 
910     return (i);
911 }
912 #endif /* USE_BSD_TGETENT */
913 #endif /* USE_GETCAP */
914 
915 #define MAXPATHS	32
916 
917 /*
918  * Add a filename to the list in 'termpaths[]', checking that we really have
919  * a right to open the file.
920  */
921 #if !USE_GETCAP
922 static int
923 add_tc(char *termpaths[], char *path, int count)
924 {
925     char *save = strchr(path, NCURSES_PATHSEP);
926     if (save != 0)
927 	*save = '\0';
928     if (count < MAXPATHS
929 	&& _nc_access(path, R_OK) == 0) {
930 	termpaths[count++] = path;
931 	T(("Adding termpath %s", path));
932     }
933     termpaths[count] = 0;
934     if (save != 0)
935 	*save = NCURSES_PATHSEP;
936     return count;
937 }
938 #define ADD_TC(path, count) filecount = add_tc(termpaths, path, count)
939 #endif /* !USE_GETCAP */
940 
941 NCURSES_EXPORT(int)
942 _nc_read_termcap_entry(const char *const tn, TERMTYPE *const tp)
943 {
944     int found = TGETENT_NO;
945     ENTRY *ep;
946 #if USE_GETCAP_CACHE
947     char cwd_buf[PATH_MAX];
948 #endif
949 #if USE_GETCAP
950     char *p, tc[TBUFSIZ];
951     int status;
952     static char *source;
953     static int lineno;
954 
955     T(("read termcap entry for %s", tn));
956 
957     if (strlen(tn) == 0
958 	|| strcmp(tn, ".") == 0
959 	|| strcmp(tn, "..") == 0
960 	|| _nc_pathlast(tn) != 0) {
961 	T(("illegal or missing entry name '%s'", tn));
962 	return TGETENT_NO;
963     }
964 
965     if (use_terminfo_vars() && (p = getenv("TERMCAP")) != 0
966 	&& !_nc_is_abs_path(p) && _nc_name_match(p, tn, "|:")) {
967 	/* TERMCAP holds a termcap entry */
968 	strncpy(tc, p, sizeof(tc) - 1);
969 	tc[sizeof(tc) - 1] = '\0';
970 	_nc_set_source("TERMCAP");
971     } else {
972 	/* we're using getcap(3) */
973 	if ((status = _nc_tgetent(tc, &source, &lineno, tn)) < 0)
974 	    return (status == TC_NOT_FOUND ? TGETENT_NO : TGETENT_ERR);
975 
976 	_nc_curr_line = lineno;
977 	_nc_set_source(source);
978     }
979     _nc_read_entry_source((FILE *) 0, tc, FALSE, FALSE, NULLHOOK);
980 #else
981     /*
982      * Here is what the 4.4BSD termcap(3) page prescribes:
983      *
984      * It will look in the environment for a TERMCAP variable.  If found, and
985      * the value does not begin with a slash, and the terminal type name is the
986      * same as the environment string TERM, the TERMCAP string is used instead
987      * of reading a termcap file.  If it does begin with a slash, the string is
988      * used as a path name of the termcap file to search.  If TERMCAP does not
989      * begin with a slash and name is different from TERM, tgetent() searches
990      * the files $HOME/.termcap and /usr/share/misc/termcap, in that order,
991      * unless the environment variable TERMPATH exists, in which case it
992      * specifies a list of file pathnames (separated by spaces or colons) to be
993      * searched instead.
994      *
995      * It goes on to state:
996      *
997      * Whenever multiple files are searched and a tc field occurs in the
998      * requested entry, the entry it names must be found in the same file or
999      * one of the succeeding files.
1000      *
1001      * However, this restriction is relaxed in ncurses; tc references to
1002      * previous files are permitted.
1003      *
1004      * This routine returns 1 if an entry is found, 0 if not found, and -1 if
1005      * the database is not accessible.
1006      */
1007     FILE *fp;
1008     char *tc, *termpaths[MAXPATHS];
1009     int filecount = 0;
1010     int j, k;
1011     bool use_buffer = FALSE;
1012     bool normal = TRUE;
1013     char tc_buf[1024];
1014     char pathbuf[PATH_MAX];
1015     char *copied = 0;
1016     char *cp;
1017     struct stat test_stat[MAXPATHS];
1018 
1019     termpaths[filecount] = 0;
1020     if (use_terminfo_vars() && (tc = getenv("TERMCAP")) != 0) {
1021 	if (_nc_is_abs_path(tc)) {	/* interpret as a filename */
1022 	    ADD_TC(tc, 0);
1023 	    normal = FALSE;
1024 	} else if (_nc_name_match(tc, tn, "|:")) {	/* treat as a capability file */
1025 	    use_buffer = TRUE;
1026 	    (void) sprintf(tc_buf, "%.*s\n", (int) sizeof(tc_buf) - 2, tc);
1027 	    normal = FALSE;
1028 	}
1029     }
1030 
1031     if (normal) {		/* normal case */
1032 	char envhome[PATH_MAX], *h;
1033 
1034 	copied = strdup(get_termpath());
1035 	for (cp = copied; *cp; cp++) {
1036 	    if (*cp == NCURSES_PATHSEP)
1037 		*cp = '\0';
1038 	    else if (cp == copied || cp[-1] == '\0') {
1039 		ADD_TC(cp, filecount);
1040 	    }
1041 	}
1042 
1043 #define PRIVATE_CAP "%s/.termcap"
1044 
1045 	if (use_terminfo_vars() && (h = getenv("HOME")) != NULL && *h != '\0'
1046 	    && (strlen(h) + sizeof(PRIVATE_CAP)) < PATH_MAX) {
1047 	    /* user's .termcap, if any, should override it */
1048 	    (void) strcpy(envhome, h);
1049 	    (void) sprintf(pathbuf, PRIVATE_CAP, envhome);
1050 	    ADD_TC(pathbuf, filecount);
1051 	}
1052     }
1053 
1054     /*
1055      * Probably /etc/termcap is a symlink to /usr/share/misc/termcap.
1056      * Avoid reading the same file twice.
1057      */
1058 #if HAVE_LINK
1059     for (j = 0; j < filecount; j++) {
1060 	bool omit = FALSE;
1061 	if (stat(termpaths[j], &test_stat[j]) != 0
1062 	    || (test_stat[j].st_mode & S_IFMT) != S_IFREG) {
1063 	    omit = TRUE;
1064 	} else {
1065 	    for (k = 0; k < j; k++) {
1066 		if (test_stat[k].st_dev == test_stat[j].st_dev
1067 		    && test_stat[k].st_ino == test_stat[j].st_ino) {
1068 		    omit = TRUE;
1069 		    break;
1070 		}
1071 	    }
1072 	}
1073 	if (omit) {
1074 	    T(("Path %s is a duplicate", termpaths[j]));
1075 	    for (k = j + 1; k < filecount; k++) {
1076 		termpaths[k - 1] = termpaths[k];
1077 		test_stat[k - 1] = test_stat[k];
1078 	    }
1079 	    --filecount;
1080 	    --j;
1081 	}
1082     }
1083 #endif
1084 
1085     /* parse the sources */
1086     if (use_buffer) {
1087 	_nc_set_source("TERMCAP");
1088 
1089 	/*
1090 	 * We don't suppress warning messages here.  The presumption is
1091 	 * that since it's just a single entry, they won't be a pain.
1092 	 */
1093 	_nc_read_entry_source((FILE *) 0, tc_buf, FALSE, FALSE, NULLHOOK);
1094     } else {
1095 	int i;
1096 
1097 	for (i = 0; i < filecount; i++) {
1098 
1099 	    T(("Looking for %s in %s", tn, termpaths[i]));
1100 	    if (_nc_access(termpaths[i], R_OK) == 0
1101 		&& (fp = fopen(termpaths[i], "r")) != (FILE *) 0) {
1102 		_nc_set_source(termpaths[i]);
1103 
1104 		/*
1105 		 * Suppress warning messages.  Otherwise you get 400 lines of
1106 		 * crap from archaic termcap files as ncurses complains about
1107 		 * all the obsolete capabilities.
1108 		 */
1109 		_nc_read_entry_source(fp, (char *) 0, FALSE, TRUE, NULLHOOK);
1110 
1111 		(void) fclose(fp);
1112 	    }
1113 	}
1114     }
1115     if (copied != 0)
1116 	free(copied);
1117 #endif /* USE_GETCAP */
1118 
1119     if (_nc_head == 0)
1120 	return (TGETENT_ERR);
1121 
1122     /* resolve all use references */
1123     _nc_resolve_uses2(TRUE, FALSE);
1124 
1125     /* find a terminal matching tn, if we can */
1126 #if USE_GETCAP_CACHE
1127     if (getcwd(cwd_buf, sizeof(cwd_buf)) != 0) {
1128 	_nc_set_writedir((char *) 0);	/* note: this does a chdir */
1129 #endif
1130 	for_entry_list(ep) {
1131 	    if (_nc_name_match(ep->tterm.term_names, tn, "|:")) {
1132 		/*
1133 		 * Make a local copy of the terminal capabilities, delinked
1134 		 * from the list.
1135 		 */
1136 		*tp = ep->tterm;
1137 		_nc_delink_entry(_nc_head, &(ep->tterm));
1138 		free(ep);
1139 
1140 		/*
1141 		 * OK, now try to write the type to user's terminfo directory.
1142 		 * Next time he loads this, it will come through terminfo.
1143 		 *
1144 		 * Advantage:  Second and subsequent fetches of this entry will
1145 		 * be very fast.
1146 		 *
1147 		 * Disadvantage:  After the first time a termcap type is loaded
1148 		 * by its user, editing it in the /etc/termcap file, or in
1149 		 * TERMCAP, or in a local ~/.termcap, will be ineffective
1150 		 * unless the terminfo entry is explicitly removed.
1151 		 */
1152 #if USE_GETCAP_CACHE
1153 		(void) _nc_write_entry(tp);
1154 #endif
1155 		found = TGETENT_YES;
1156 		break;
1157 	    }
1158 	}
1159 #if USE_GETCAP_CACHE
1160 	chdir(cwd_buf);
1161     }
1162 #endif
1163 
1164     return (found);
1165 }
1166 #else
1167 extern
1168 NCURSES_EXPORT(void)
1169 _nc_read_termcap(void);
1170 NCURSES_EXPORT(void)
1171 _nc_read_termcap(void)
1172 {
1173 }
1174 #endif /* PURE_TERMINFO */
1175