xref: /openbsd/lib/libcurses/tinfo/comp_scan.c (revision 73471bf0)
1 /* $OpenBSD: comp_scan.c,v 1.15 2010/01/12 23:22:06 nicm Exp $ */
2 
3 /****************************************************************************
4  * Copyright (c) 1998-2006,2008 Free Software Foundation, Inc.              *
5  *                                                                          *
6  * Permission is hereby granted, free of charge, to any person obtaining a  *
7  * copy of this software and associated documentation files (the            *
8  * "Software"), to deal in the Software without restriction, including      *
9  * without limitation the rights to use, copy, modify, merge, publish,      *
10  * distribute, distribute with modifications, sublicense, and/or sell       *
11  * copies of the Software, and to permit persons to whom the Software is    *
12  * furnished to do so, subject to the following conditions:                 *
13  *                                                                          *
14  * The above copyright notice and this permission notice shall be included  *
15  * in all copies or substantial portions of the Software.                   *
16  *                                                                          *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
20  * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
23  * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
24  *                                                                          *
25  * Except as contained in this notice, the name(s) of the above copyright   *
26  * holders shall not be used in advertising or otherwise to promote the     *
27  * sale, use or other dealings in this Software without prior written       *
28  * authorization.                                                           *
29  ****************************************************************************/
30 
31 /****************************************************************************
32  *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
33  *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
34  *     and: Thomas E. Dickey                        1996 on                 *
35  ****************************************************************************/
36 
37 /*
38  *	comp_scan.c --- Lexical scanner for terminfo compiler.
39  *
40  *	_nc_reset_input()
41  *	_nc_get_token()
42  *	_nc_panic_mode()
43  *	int _nc_syntax;
44  *	int _nc_curr_line;
45  *	long _nc_curr_file_pos;
46  *	long _nc_comment_start;
47  *	long _nc_comment_end;
48  */
49 
50 #include <curses.priv.h>
51 
52 #include <ctype.h>
53 #include <term_entry.h>
54 #include <tic.h>
55 
56 MODULE_ID("$Id: comp_scan.c,v 1.15 2010/01/12 23:22:06 nicm Exp $")
57 
58 /*
59  * Maximum length of string capability we'll accept before raising an error.
60  * Yes, there is a real capability in /etc/termcap this long, an "is".
61  */
62 #define MAXCAPLEN	600
63 
64 #define iswhite(ch)	(ch == ' '  ||  ch == '\t')
65 
66 NCURSES_EXPORT_VAR(int)
67 _nc_syntax = 0;			/* termcap or terminfo? */
68 NCURSES_EXPORT_VAR(long)
69 _nc_curr_file_pos = 0;		/* file offset of current line */
70 NCURSES_EXPORT_VAR(long)
71 _nc_comment_start = 0;		/* start of comment range before name */
72 NCURSES_EXPORT_VAR(long)
73 _nc_comment_end = 0;		/* end of comment range before name */
74 NCURSES_EXPORT_VAR(long)
75 _nc_start_line = 0;		/* start line of current entry */
76 
77 NCURSES_EXPORT_VAR(struct token)
78 _nc_curr_token =
79 {
80     0, 0, 0
81 };
82 
83 /*****************************************************************************
84  *
85  * Token-grabbing machinery
86  *
87  *****************************************************************************/
88 
89 static bool first_column;	/* See 'next_char()' below */
90 static bool had_newline;
91 static char separator;		/* capability separator */
92 static int pushtype;		/* type of pushback token */
93 static char *pushname;
94 
95 #if NCURSES_EXT_FUNCS
96 NCURSES_EXPORT_VAR(bool)
97 _nc_disable_period = FALSE;	/* used by tic -a option */
98 #endif
99 
100 /*****************************************************************************
101  *
102  * Character-stream handling
103  *
104  *****************************************************************************/
105 
106 #define LEXBUFSIZ	1024
107 
108 static char *bufptr;		/* otherwise, the input buffer pointer */
109 static char *bufstart;		/* start of buffer so we can compute offsets */
110 static FILE *yyin;		/* scanner's input file descriptor */
111 
112 /*
113  *	_nc_reset_input()
114  *
115  *	Resets the input-reading routines.  Used on initialization,
116  *	or after a seek has been done.  Exactly one argument must be
117  *	non-null.
118  */
119 
120 NCURSES_EXPORT(void)
121 _nc_reset_input(FILE *fp, char *buf)
122 {
123     pushtype = NO_PUSHBACK;
124     if (pushname != 0)
125 	pushname[0] = '\0';
126     yyin = fp;
127     bufstart = bufptr = buf;
128     _nc_curr_file_pos = 0L;
129     if (fp != 0)
130 	_nc_curr_line = 0;
131     _nc_curr_col = 0;
132 }
133 
134 /*
135  *	int last_char()
136  *
137  *	Returns the final nonblank character on the current input buffer
138  */
139 static int
140 last_char(void)
141 {
142     size_t len = strlen(bufptr);
143     while (len--) {
144 	if (!isspace(UChar(bufptr[len])))
145 	    return bufptr[len];
146     }
147     return 0;
148 }
149 
150 /*
151  *	int next_char()
152  *
153  *	Returns the next character in the input stream.  Comments and leading
154  *	white space are stripped.
155  *
156  *	The global state variable 'firstcolumn' is set TRUE if the character
157  *	returned is from the first column of the input line.
158  *
159  *	The global variable _nc_curr_line is incremented for each new line.
160  *	The global variable _nc_curr_file_pos is set to the file offset of the
161  *	beginning of each line.
162  */
163 
164 static int
165 next_char(void)
166 {
167     static char *result;
168     static size_t allocated;
169     int the_char;
170 
171     if (!yyin) {
172 	if (result != 0) {
173 	    FreeAndNull(result);
174 	    FreeAndNull(pushname);
175 	    allocated = 0;
176 	}
177 	/*
178 	 * An string with an embedded null will truncate the input.  This is
179 	 * intentional (we don't read binary files here).
180 	 */
181 	if (bufptr == 0 || *bufptr == '\0')
182 	    return (EOF);
183 	if (*bufptr == '\n') {
184 	    _nc_curr_line++;
185 	    _nc_curr_col = 0;
186 	} else if (*bufptr == '\t') {
187 	    _nc_curr_col = (_nc_curr_col | 7);
188 	}
189     } else if (!bufptr || !*bufptr) {
190 	/*
191 	 * In theory this could be recoded to do its I/O one character at a
192 	 * time, saving the buffer space.  In practice, this turns out to be
193 	 * quite hard to get completely right.  Try it and see.  If you
194 	 * succeed, don't forget to hack push_back() correspondingly.
195 	 */
196 	size_t used;
197 	size_t len;
198 
199 	do {
200 	    bufstart = 0;
201 	    used = 0;
202 	    do {
203 		if (used + (LEXBUFSIZ / 4) >= allocated) {
204 		    allocated += (allocated + LEXBUFSIZ);
205 		    result = typeRealloc(char, allocated, result);
206 		    if (result == 0)
207 			return (EOF);
208 		    bufstart = result;
209 		}
210 		if (used == 0)
211 		    _nc_curr_file_pos = ftell(yyin);
212 
213 		if (fgets(result + used, (int) (allocated - used), yyin) != 0) {
214 		    bufstart = result;
215 		    if (used == 0) {
216 			_nc_curr_line++;
217 			_nc_curr_col = 0;
218 		    }
219 		} else {
220 		    if (used != 0)
221 			strlcat(result, "\n", allocated);
222 		}
223 		if ((bufptr = bufstart) != 0) {
224 		    used = strlen(bufptr);
225 		    while (iswhite(*bufptr)) {
226 			if (*bufptr == '\t') {
227 			    _nc_curr_col = (_nc_curr_col | 7) + 1;
228 			} else {
229 			    _nc_curr_col++;
230 			}
231 			bufptr++;
232 		    }
233 
234 		    /*
235 		     * Treat a trailing <cr><lf> the same as a <newline> so we
236 		     * can read files on OS/2, etc.
237 		     */
238 		    if ((len = strlen(bufptr)) > 1) {
239 			if (bufptr[len - 1] == '\n'
240 			    && bufptr[len - 2] == '\r') {
241 			    len--;
242 			    bufptr[len - 1] = '\n';
243 			    bufptr[len] = '\0';
244 			}
245 		    }
246 		} else {
247 		    return (EOF);
248 		}
249 	    } while (bufptr[len - 1] != '\n');	/* complete a line */
250 	} while (result[0] == '#');	/* ignore comments */
251     } else if (*bufptr == '\t') {
252 	_nc_curr_col = (_nc_curr_col | 7);
253     }
254 
255     first_column = (bufptr == bufstart);
256     if (first_column)
257 	had_newline = FALSE;
258 
259     _nc_curr_col++;
260     the_char = *bufptr++;
261     return UChar(the_char);
262 }
263 
264 static void
265 push_back(char c)
266 /* push a character back onto the input stream */
267 {
268     if (bufptr == bufstart)
269 	_nc_syserr_abort("Can't backspace off beginning of line");
270     *--bufptr = c;
271     _nc_curr_col--;
272 }
273 
274 static long
275 stream_pos(void)
276 /* return our current character position in the input stream */
277 {
278     return (yyin ? ftell(yyin) : (bufptr ? bufptr - bufstart : 0));
279 }
280 
281 static bool
282 end_of_stream(void)
283 /* are we at end of input? */
284 {
285     return ((yyin ? feof(yyin) : (bufptr && *bufptr == '\0'))
286 	    ? TRUE : FALSE);
287 }
288 
289 /* Assume we may be looking at a termcap-style continuation */
290 static NCURSES_INLINE int
291 eat_escaped_newline(int ch)
292 {
293     if (ch == '\\')
294 	while ((ch = next_char()) == '\n' || iswhite(ch))
295 	    continue;
296     return ch;
297 }
298 
299 #define TOK_BUF_SIZE MAX_ENTRY_SIZE
300 
301 #define OkToAdd() \
302 	((tok_ptr - tok_buf) < (TOK_BUF_SIZE - 2))
303 
304 #define AddCh(ch) \
305 	*tok_ptr++ = (char) ch; \
306 	*tok_ptr = '\0'
307 
308 /*
309  *	int
310  *	get_token()
311  *
312  *	Scans the input for the next token, storing the specifics in the
313  *	global structure 'curr_token' and returning one of the following:
314  *
315  *		NAMES		A line beginning in column 1.  'name'
316  *				will be set to point to everything up to but
317  *				not including the first separator on the line.
318  *		BOOLEAN		An entry consisting of a name followed by
319  *				a separator.  'name' will be set to point to
320  *				the name of the capability.
321  *		NUMBER		An entry of the form
322  *					name#digits,
323  *				'name' will be set to point to the capability
324  *				name and 'valnumber' to the number given.
325  *		STRING		An entry of the form
326  *					name=characters,
327  *				'name' is set to the capability name and
328  *				'valstring' to the string of characters, with
329  *				input translations done.
330  *		CANCEL		An entry of the form
331  *					name@,
332  *				'name' is set to the capability name and
333  *				'valnumber' to -1.
334  *		EOF		The end of the file has been reached.
335  *
336  *	A `separator' is either a comma or a semicolon, depending on whether
337  *	we are in termcap or terminfo mode.
338  *
339  */
340 
341 NCURSES_EXPORT(int)
342 _nc_get_token(bool silent)
343 {
344     static const char terminfo_punct[] = "@%&*!#";
345     static char *tok_buf;
346 
347     char *after_list;
348     char *after_name;
349     char *numchk;
350     char *tok_ptr;
351     char *s;
352     char numbuf[80];
353     int ch;
354     int dot_flag = FALSE;
355     int type;
356     long number;
357     long token_start;
358     unsigned found;
359 #ifdef TRACE
360     int old_line;
361     int old_col;
362 #endif
363 
364     if (pushtype != NO_PUSHBACK) {
365 	int retval = pushtype;
366 
367 	_nc_set_type(pushname != 0 ? pushname : "");
368 	DEBUG(3, ("pushed-back token: `%s', class %d",
369 		  _nc_curr_token.tk_name, pushtype));
370 
371 	pushtype = NO_PUSHBACK;
372 	if (pushname != 0)
373 	    pushname[0] = '\0';
374 
375 	/* currtok wasn't altered by _nc_push_token() */
376 	return (retval);
377     }
378 
379     if (end_of_stream()) {
380 	yyin = 0;
381 	next_char();		/* frees its allocated memory */
382 	if (tok_buf != 0) {
383 	    if (_nc_curr_token.tk_name == tok_buf)
384 		_nc_curr_token.tk_name = 0;
385 	    FreeAndNull(tok_buf);
386 	}
387 	return (EOF);
388     }
389 
390   start_token:
391     token_start = stream_pos();
392     while ((ch = next_char()) == '\n' || iswhite(ch)) {
393 	if (ch == '\n')
394 	    had_newline = TRUE;
395 	continue;
396     }
397 
398     ch = eat_escaped_newline(ch);
399 
400 #ifdef TRACE
401     old_line = _nc_curr_line;
402     old_col = _nc_curr_col;
403 #endif
404     if (ch == EOF)
405 	type = EOF;
406     else {
407 	/* if this is a termcap entry, skip a leading separator */
408 	if (separator == ':' && ch == ':')
409 	    ch = next_char();
410 
411 	if (ch == '.'
412 #if NCURSES_EXT_FUNCS
413 	    && !_nc_disable_period
414 #endif
415 	    ) {
416 	    dot_flag = TRUE;
417 	    DEBUG(8, ("dot-flag set"));
418 
419 	    while ((ch = next_char()) == '.' || iswhite(ch))
420 		continue;
421 	}
422 
423 	if (ch == EOF) {
424 	    type = EOF;
425 	    goto end_of_token;
426 	}
427 
428 	/* have to make some punctuation chars legal for terminfo */
429 	if (!isalnum(UChar(ch))
430 #if NCURSES_EXT_FUNCS
431 	    && !(ch == '.' && _nc_disable_period)
432 #endif
433 	    && !strchr(terminfo_punct, (char) ch)) {
434 	    if (!silent)
435 		_nc_warning("Illegal character (expected alphanumeric or %s) - '%s'",
436 			    terminfo_punct, unctrl((chtype) ch));
437 	    _nc_panic_mode(separator);
438 	    goto start_token;
439 	}
440 
441 	if (tok_buf == 0)
442 	    tok_buf = typeMalloc(char, TOK_BUF_SIZE);
443 
444 #ifdef TRACE
445 	old_line = _nc_curr_line;
446 	old_col = _nc_curr_col;
447 #endif
448 	tok_ptr = tok_buf;
449 	AddCh(ch);
450 
451 	if (first_column) {
452 	    _nc_comment_start = token_start;
453 	    _nc_comment_end = _nc_curr_file_pos;
454 	    _nc_start_line = _nc_curr_line;
455 
456 	    _nc_syntax = ERR;
457 	    after_name = 0;
458 	    after_list = 0;
459 	    while ((ch = next_char()) != '\n') {
460 		if (ch == EOF) {
461 		    _nc_err_abort(MSG_NO_INPUTS);
462 		} else if (ch == '|') {
463 		    after_list = tok_ptr;
464 		    if (after_name == 0)
465 			after_name = tok_ptr;
466 		} else if (ch == ':' && last_char() != ',') {
467 		    _nc_syntax = SYN_TERMCAP;
468 		    separator = ':';
469 		    break;
470 		} else if (ch == ',') {
471 		    _nc_syntax = SYN_TERMINFO;
472 		    separator = ',';
473 		    /*
474 		     * If we did not see a '|', then we found a name with no
475 		     * aliases or description.
476 		     */
477 		    if (after_name == 0)
478 			break;
479 		    /*
480 		     * If we see a comma, we assume this is terminfo unless we
481 		     * subsequently run into a colon.  But we don't stop
482 		     * looking for a colon until hitting a newline.  This
483 		     * allows commas to be embedded in description fields of
484 		     * either syntax.
485 		     */
486 		} else
487 		    ch = eat_escaped_newline(ch);
488 
489 		if (OkToAdd()) {
490 		    AddCh(ch);
491 		} else {
492 		    ch = EOF;
493 		    break;
494 		}
495 	    }
496 	    *tok_ptr = '\0';
497 	    if (_nc_syntax == ERR) {
498 		/*
499 		 * Grrr...what we ought to do here is barf, complaining that
500 		 * the entry is malformed.  But because a couple of name fields
501 		 * in the 8.2 termcap file end with |\, we just have to assume
502 		 * it's termcap syntax.
503 		 */
504 		_nc_syntax = SYN_TERMCAP;
505 		separator = ':';
506 	    } else if (_nc_syntax == SYN_TERMINFO) {
507 		/* throw away trailing /, *$/ */
508 		for (--tok_ptr;
509 		     iswhite(*tok_ptr) || *tok_ptr == ',';
510 		     tok_ptr--)
511 		    continue;
512 		tok_ptr[1] = '\0';
513 	    }
514 
515 	    /*
516 	     * This is the soonest we have the terminal name fetched.  Set up
517 	     * for following warning messages.  If there's no '|', then there
518 	     * is no description.
519 	     */
520 	    if (after_name != 0) {
521 		ch = *after_name;
522 		*after_name = '\0';
523 		_nc_set_type(tok_buf);
524 		*after_name = (char) ch;
525 	    }
526 
527 	    /*
528 	     * Compute the boundary between the aliases and the description
529 	     * field for syntax-checking purposes.
530 	     */
531 	    if (after_list != 0) {
532 		if (!silent) {
533 		    if (*after_list == '\0')
534 			_nc_warning("empty longname field");
535 		    else if (strchr(after_list, ' ') == 0)
536 			_nc_warning("older tic versions may treat the description field as an alias");
537 		}
538 	    } else {
539 		after_list = tok_buf + strlen(tok_buf);
540 		DEBUG(1, ("missing description"));
541 	    }
542 
543 	    /*
544 	     * Whitespace in a name field other than the long name can confuse
545 	     * rdist and some termcap tools.  Slashes are a no-no.  Other
546 	     * special characters can be dangerous due to shell expansion.
547 	     */
548 	    for (s = tok_buf; s < after_list; ++s) {
549 		if (isspace(UChar(*s))) {
550 		    if (!silent)
551 			_nc_warning("whitespace in name or alias field");
552 		    break;
553 		} else if (*s == '/') {
554 		    if (!silent)
555 			_nc_warning("slashes aren't allowed in names or aliases");
556 		    break;
557 		} else if (strchr("$[]!*?", *s)) {
558 		    if (!silent)
559 			_nc_warning("dubious character `%c' in name or alias field", *s);
560 		    break;
561 		}
562 	    }
563 
564 	    _nc_curr_token.tk_name = tok_buf;
565 	    type = NAMES;
566 	} else {
567 	    if (had_newline && _nc_syntax == SYN_TERMCAP) {
568 		_nc_warning("Missing backslash before newline");
569 		had_newline = FALSE;
570 	    }
571 	    while ((ch = next_char()) != EOF) {
572 		if (!isalnum(UChar(ch))) {
573 		    if (_nc_syntax == SYN_TERMINFO) {
574 			if (ch != '_')
575 			    break;
576 		    } else {	/* allow ';' for "k;" */
577 			if (ch != ';')
578 			    break;
579 		    }
580 		}
581 		if (OkToAdd()) {
582 		    AddCh(ch);
583 		} else {
584 		    ch = EOF;
585 		    break;
586 		}
587 	    }
588 
589 	    *tok_ptr++ = '\0';	/* separate name/value in buffer */
590 	    switch (ch) {
591 	    case ',':
592 	    case ':':
593 		if (ch != separator)
594 		    _nc_err_abort("Separator inconsistent with syntax");
595 		_nc_curr_token.tk_name = tok_buf;
596 		type = BOOLEAN;
597 		break;
598 	    case '@':
599 		if ((ch = next_char()) != separator && !silent)
600 		    _nc_warning("Missing separator after `%s', have %s",
601 				tok_buf, unctrl((chtype) ch));
602 		_nc_curr_token.tk_name = tok_buf;
603 		type = CANCEL;
604 		break;
605 
606 	    case '#':
607 		found = 0;
608 		while (isalnum(ch = next_char())) {
609 		    numbuf[found++] = (char) ch;
610 		    if (found >= sizeof(numbuf) - 1)
611 			break;
612 		}
613 		numbuf[found] = '\0';
614 		number = strtol(numbuf, &numchk, 0);
615 		if (!silent) {
616 		    if (numchk == numbuf)
617 			_nc_warning("no value given for `%s'", tok_buf);
618 		    if ((*numchk != '\0') || (ch != separator))
619 			_nc_warning("Missing separator");
620 		}
621 		_nc_curr_token.tk_name = tok_buf;
622 		_nc_curr_token.tk_valnumber = number;
623 		type = NUMBER;
624 		break;
625 
626 	    case '=':
627 		ch = _nc_trans_string(tok_ptr, tok_buf + TOK_BUF_SIZE);
628 		if (!silent && ch != separator)
629 		    _nc_warning("Missing separator");
630 		_nc_curr_token.tk_name = tok_buf;
631 		_nc_curr_token.tk_valstring = tok_ptr;
632 		type = STRING;
633 		break;
634 
635 	    case EOF:
636 		type = EOF;
637 		break;
638 	    default:
639 		/* just to get rid of the compiler warning */
640 		type = UNDEF;
641 		if (!silent)
642 		    _nc_warning("Illegal character - '%s'", unctrl((chtype) ch));
643 	    }
644 	}			/* end else (first_column == FALSE) */
645     }				/* end else (ch != EOF) */
646 
647   end_of_token:
648 
649 #ifdef TRACE
650     if (dot_flag == TRUE)
651 	DEBUG(8, ("Commented out "));
652 
653     if (_nc_tracing >= DEBUG_LEVEL(8)) {
654 	_tracef("parsed %d.%d to %d.%d",
655 		old_line, old_col,
656 		_nc_curr_line, _nc_curr_col);
657     }
658     if (_nc_tracing >= DEBUG_LEVEL(7)) {
659 	switch (type) {
660 	case BOOLEAN:
661 	    _tracef("Token: Boolean; name='%s'",
662 		    _nc_curr_token.tk_name);
663 	    break;
664 
665 	case NUMBER:
666 	    _tracef("Token: Number;  name='%s', value=%d",
667 		    _nc_curr_token.tk_name,
668 		    _nc_curr_token.tk_valnumber);
669 	    break;
670 
671 	case STRING:
672 	    _tracef("Token: String;  name='%s', value=%s",
673 		    _nc_curr_token.tk_name,
674 		    _nc_visbuf(_nc_curr_token.tk_valstring));
675 	    break;
676 
677 	case CANCEL:
678 	    _tracef("Token: Cancel; name='%s'",
679 		    _nc_curr_token.tk_name);
680 	    break;
681 
682 	case NAMES:
683 
684 	    _tracef("Token: Names; value='%s'",
685 		    _nc_curr_token.tk_name);
686 	    break;
687 
688 	case EOF:
689 	    _tracef("Token: End of file");
690 	    break;
691 
692 	default:
693 	    _nc_warning("Bad token type");
694 	}
695     }
696 #endif
697 
698     if (dot_flag == TRUE)	/* if commented out, use the next one */
699 	type = _nc_get_token(silent);
700 
701     DEBUG(3, ("token: `%s', class %d",
702 	      ((_nc_curr_token.tk_name != 0)
703 	       ? _nc_curr_token.tk_name
704 	       : "<null>"),
705 	      type));
706 
707     return (type);
708 }
709 
710 /*
711  *	char
712  *	trans_string(ptr)
713  *
714  *	Reads characters using next_char() until encountering a separator, nl,
715  *	or end-of-file.  The returned value is the character which caused
716  *	reading to stop.  The following translations are done on the input:
717  *
718  *		^X  goes to  ctrl-X (i.e. X & 037)
719  *		{\E,\n,\r,\b,\t,\f}  go to
720  *			{ESCAPE,newline,carriage-return,backspace,tab,formfeed}
721  *		{\^,\\}  go to  {carat,backslash}
722  *		\ddd (for ddd = up to three octal digits)  goes to the character ddd
723  *
724  *		\e == \E
725  *		\0 == \200
726  *
727  */
728 
729 NCURSES_EXPORT(int)
730 _nc_trans_string(char *ptr, char *last)
731 {
732     int count = 0;
733     int number = 0;
734     int i, c;
735     chtype ch, last_ch = '\0';
736     bool ignored = FALSE;
737     bool long_warning = FALSE;
738 
739     while ((ch = c = next_char()) != (chtype) separator && c != EOF) {
740 	if (ptr >= (last - 1)) {
741 	    if (c != EOF) {
742 		while ((c = next_char()) != separator && c != EOF) {
743 		    ;
744 		}
745 		ch = c;
746 	    }
747 	    break;
748 	}
749 	if ((_nc_syntax == SYN_TERMCAP) && c == '\n')
750 	    break;
751 	if (ch == '^' && last_ch != '%') {
752 	    ch = c = next_char();
753 	    if (c == EOF)
754 		_nc_err_abort(MSG_NO_INPUTS);
755 
756 	    if (!(is7bits(ch) && isprint(ch))) {
757 		_nc_warning("Illegal ^ character - '%s'", unctrl(ch));
758 	    }
759 	    if (ch == '?') {
760 		*(ptr++) = '\177';
761 		if (_nc_tracing)
762 		    _nc_warning("Allow ^? as synonym for \\177");
763 	    } else {
764 		if ((ch &= 037) == 0)
765 		    ch = 128;
766 		*(ptr++) = (char) (ch);
767 	    }
768 	} else if (ch == '\\') {
769 	    ch = c = next_char();
770 	    if (c == EOF)
771 		_nc_err_abort(MSG_NO_INPUTS);
772 
773 	    if (ch >= '0' && ch <= '7') {
774 		number = ch - '0';
775 		for (i = 0; i < 2; i++) {
776 		    ch = c = next_char();
777 		    if (c == EOF)
778 			_nc_err_abort(MSG_NO_INPUTS);
779 
780 		    if (c < '0' || c > '7') {
781 			if (isdigit(c)) {
782 			    _nc_warning("Non-octal digit `%c' in \\ sequence", c);
783 			    /* allow the digit; it'll do less harm */
784 			} else {
785 			    push_back((char) c);
786 			    break;
787 			}
788 		    }
789 
790 		    number = number * 8 + c - '0';
791 		}
792 
793 		if (number == 0)
794 		    number = 0200;
795 		*(ptr++) = (char) number;
796 	    } else {
797 		switch (c) {
798 		case 'E':
799 		case 'e':
800 		    *(ptr++) = '\033';
801 		    break;
802 
803 		case 'a':
804 		    *(ptr++) = '\007';
805 		    break;
806 
807 		case 'l':
808 		case 'n':
809 		    *(ptr++) = '\n';
810 		    break;
811 
812 		case 'r':
813 		    *(ptr++) = '\r';
814 		    break;
815 
816 		case 'b':
817 		    *(ptr++) = '\010';
818 		    break;
819 
820 		case 's':
821 		    *(ptr++) = ' ';
822 		    break;
823 
824 		case 'f':
825 		    *(ptr++) = '\014';
826 		    break;
827 
828 		case 't':
829 		    *(ptr++) = '\t';
830 		    break;
831 
832 		case '\\':
833 		    *(ptr++) = '\\';
834 		    break;
835 
836 		case '^':
837 		    *(ptr++) = '^';
838 		    break;
839 
840 		case ',':
841 		    *(ptr++) = ',';
842 		    break;
843 
844 		case ':':
845 		    *(ptr++) = ':';
846 		    break;
847 
848 		case '\n':
849 		    continue;
850 
851 		default:
852 		    _nc_warning("Illegal character '%s' in \\ sequence",
853 				unctrl(ch));
854 		    /* FALLTHRU */
855 		case '|':
856 		    *(ptr++) = (char) ch;
857 		}		/* endswitch (ch) */
858 	    }			/* endelse (ch < '0' ||  ch > '7') */
859 	}
860 	/* end else if (ch == '\\') */
861 	else if (ch == '\n' && (_nc_syntax == SYN_TERMINFO)) {
862 	    /*
863 	     * Newlines embedded in a terminfo string are ignored, provided
864 	     * that the next line begins with whitespace.
865 	     */
866 	    ignored = TRUE;
867 	} else {
868 	    *(ptr++) = (char) ch;
869 	}
870 
871 	if (!ignored) {
872 	    if (_nc_curr_col <= 1) {
873 		push_back((char) ch);
874 		ch = '\n';
875 		break;
876 	    }
877 	    last_ch = ch;
878 	    count++;
879 	}
880 	ignored = FALSE;
881 
882 	if (count > MAXCAPLEN && !long_warning) {
883 	    _nc_warning("Very long string found.  Missing separator?");
884 	    long_warning = TRUE;
885 	}
886     }				/* end while */
887 
888     *ptr = '\0';
889 
890     return (ch);
891 }
892 
893 /*
894  *	_nc_push_token()
895  *
896  *	Push a token of given type so that it will be reread by the next
897  *	get_token() call.
898  */
899 
900 NCURSES_EXPORT(void)
901 _nc_push_token(int tokclass)
902 {
903     /*
904      * This implementation is kind of bogus, it will fail if we ever do more
905      * than one pushback at a time between get_token() calls.  It relies on the
906      * fact that _nc_curr_token is static storage that nothing but
907      * _nc_get_token() touches.
908      */
909     pushtype = tokclass;
910     if (pushname == 0)
911 	pushname = typeMalloc(char, MAX_NAME_SIZE + 1);
912     _nc_get_type(pushname);
913 
914     DEBUG(3, ("pushing token: `%s', class %d",
915 	      ((_nc_curr_token.tk_name != 0)
916 	       ? _nc_curr_token.tk_name
917 	       : "<null>"),
918 	      pushtype));
919 }
920 
921 /*
922  * Panic mode error recovery - skip everything until a "ch" is found.
923  */
924 NCURSES_EXPORT(void)
925 _nc_panic_mode(char ch)
926 {
927     int c;
928 
929     for (;;) {
930 	c = next_char();
931 	if (c == ch)
932 	    return;
933 	if (c == EOF)
934 	    return;
935     }
936 }
937 
938 #if NO_LEAKS
939 NCURSES_EXPORT(void)
940 _nc_comp_scan_leaks(void)
941 {
942     if (pushname != 0) {
943 	FreeAndNull(pushname);
944     }
945 }
946 #endif
947