xref: /freebsd/usr.bin/tr/str.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 
34 __FBSDID("$FreeBSD$");
35 
36 #ifndef lint
37 static const char sccsid[] = "@(#)str.c	8.2 (Berkeley) 4/28/95";
38 #endif
39 
40 #include <sys/types.h>
41 
42 #include <ctype.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <stddef.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <wchar.h>
50 #include <wctype.h>
51 
52 #include "extern.h"
53 
54 static int      backslash(STR *, int *);
55 static int	bracket(STR *);
56 static void	genclass(STR *);
57 static void	genequiv(STR *);
58 static int      genrange(STR *, int);
59 static void	genseq(STR *);
60 
61 wint_t
62 next(STR *s)
63 {
64 	int is_octal;
65 	wint_t ch;
66 	wchar_t wch;
67 	size_t clen;
68 
69 	switch (s->state) {
70 	case EOS:
71 		return (0);
72 	case INFINITE:
73 		return (1);
74 	case NORMAL:
75 		switch (*s->str) {
76 		case '\0':
77 			s->state = EOS;
78 			return (0);
79 		case '\\':
80 			s->lastch = backslash(s, &is_octal);
81 			break;
82 		case '[':
83 			if (bracket(s))
84 				return (next(s));
85 			/* FALLTHROUGH */
86 		default:
87 			clen = mbrtowc(&wch, s->str, MB_LEN_MAX, NULL);
88 			if (clen == (size_t)-1 || clen == (size_t)-2 ||
89 			    clen == 0)
90 				errc(1, EILSEQ, NULL);
91 			is_octal = 0;
92 			s->lastch = wch;
93 			s->str += clen;
94 			break;
95 		}
96 
97 		/* We can start a range at any time. */
98 		if (s->str[0] == '-' && genrange(s, is_octal))
99 			return (next(s));
100 		return (1);
101 	case RANGE:
102 		if (s->cnt-- == 0) {
103 			s->state = NORMAL;
104 			return (next(s));
105 		}
106 		++s->lastch;
107 		return (1);
108 	case SEQUENCE:
109 		if (s->cnt-- == 0) {
110 			s->state = NORMAL;
111 			return (next(s));
112 		}
113 		return (1);
114 	case CCLASS:
115 	case CCLASS_UPPER:
116 	case CCLASS_LOWER:
117 		s->cnt++;
118 		ch = nextwctype(s->lastch, s->cclass);
119 		if (ch == -1) {
120 			s->state = NORMAL;
121 			return (next(s));
122 		}
123 		s->lastch = ch;
124 		return (1);
125 	case SET:
126 		if ((ch = s->set[s->cnt++]) == OOBCH) {
127 			s->state = NORMAL;
128 			return (next(s));
129 		}
130 		s->lastch = ch;
131 		return (1);
132 	default:
133 		return (0);
134 	}
135 	/* NOTREACHED */
136 }
137 
138 static int
139 bracket(STR *s)
140 {
141 	char *p;
142 
143 	switch (s->str[1]) {
144 	case ':':				/* "[:class:]" */
145 		if ((p = strchr(s->str + 2, ']')) == NULL)
146 			return (0);
147 		if (*(p - 1) != ':' || p - s->str < 4)
148 			goto repeat;
149 		*(p - 1) = '\0';
150 		s->str += 2;
151 		genclass(s);
152 		s->str = p + 1;
153 		return (1);
154 	case '=':				/* "[=equiv=]" */
155 		if (s->str[2] == '\0' || (p = strchr(s->str + 3, ']')) == NULL)
156 			return (0);
157 		if (*(p - 1) != '=' || p - s->str < 4)
158 			goto repeat;
159 		s->str += 2;
160 		genequiv(s);
161 		return (1);
162 	default:				/* "[\###*n]" or "[#*n]" */
163 	repeat:
164 		if ((p = strpbrk(s->str + 2, "*]")) == NULL)
165 			return (0);
166 		if (p[0] != '*' || strchr(p, ']') == NULL)
167 			return (0);
168 		s->str += 1;
169 		genseq(s);
170 		return (1);
171 	}
172 	/* NOTREACHED */
173 }
174 
175 static void
176 genclass(STR *s)
177 {
178 
179 	if ((s->cclass = wctype(s->str)) == 0)
180 		errx(1, "unknown class %s", s->str);
181 	s->cnt = 0;
182 	s->lastch = -1;		/* incremented before check in next() */
183 	if (strcmp(s->str, "upper") == 0)
184 		s->state = CCLASS_UPPER;
185 	else if (strcmp(s->str, "lower") == 0)
186 		s->state = CCLASS_LOWER;
187 	else
188 		s->state = CCLASS;
189 }
190 
191 static void
192 genequiv(STR *s)
193 {
194 	int i, p, pri;
195 	char src[2], dst[3];
196 	size_t clen;
197 	wchar_t wc;
198 
199 	if (*s->str == '\\') {
200 		s->equiv[0] = backslash(s, NULL);
201 		if (*s->str != '=')
202 			errx(1, "misplaced equivalence equals sign");
203 		s->str += 2;
204 	} else {
205 		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
206 		if (clen == (size_t)-1 || clen == (size_t)-2 || clen == 0)
207 			errc(1, EILSEQ, NULL);
208 		s->equiv[0] = wc;
209 		if (s->str[clen] != '=')
210 			errx(1, "misplaced equivalence equals sign");
211 		s->str += clen + 2;
212 	}
213 
214 	/*
215 	 * Calculate the set of all characters in the same equivalence class
216 	 * as the specified character (they will have the same primary
217 	 * collation weights).
218 	 * XXX Knows too much about how strxfrm() is implemented. Assumes
219 	 * it fills the string with primary collation weight bytes. Only one-
220 	 * to-one mappings are supported.
221 	 * XXX Equivalence classes not supported in multibyte locales.
222 	 */
223 	src[0] = (char)s->equiv[0];
224 	src[1] = '\0';
225 	if (MB_CUR_MAX == 1 && strxfrm(dst, src, sizeof(dst)) == 1) {
226 		pri = (unsigned char)*dst;
227 		for (p = 1, i = 1; i < NCHARS_SB; i++) {
228 			*src = i;
229 			if (strxfrm(dst, src, sizeof(dst)) == 1 && pri &&
230 			    pri == (unsigned char)*dst)
231 				s->equiv[p++] = i;
232 		}
233 		s->equiv[p] = OOBCH;
234 	}
235 
236 	s->cnt = 0;
237 	s->state = SET;
238 	s->set = s->equiv;
239 }
240 
241 static int
242 genrange(STR *s, int was_octal)
243 {
244 	int stopval, octal;
245 	char *savestart;
246 	int n, cnt, *p;
247 	size_t clen;
248 	wchar_t wc;
249 
250 	octal = 0;
251 	savestart = s->str;
252 	if (*++s->str == '\\')
253 		stopval = backslash(s, &octal);
254 	else {
255 		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
256 		if (clen == (size_t)-1 || clen == (size_t)-2)
257 			errc(1, EILSEQ, NULL);
258 		stopval = wc;
259 		s->str += clen;
260 	}
261 	/*
262 	 * XXX Characters are not ordered according to collating sequence in
263 	 * multibyte locales.
264 	 */
265 	if (octal || was_octal || MB_CUR_MAX > 1) {
266 		if (stopval < s->lastch) {
267 			s->str = savestart;
268 			return (0);
269 		}
270 		s->cnt = stopval - s->lastch + 1;
271 		s->state = RANGE;
272 		--s->lastch;
273 		return (1);
274 	}
275 	if (charcoll((const void *)&stopval, (const void *)&(s->lastch)) < 0) {
276 		s->str = savestart;
277 		return (0);
278 	}
279 	if ((s->set = p = malloc((NCHARS_SB + 1) * sizeof(int))) == NULL)
280 		err(1, "genrange() malloc");
281 	for (cnt = 0; cnt < NCHARS_SB; cnt++)
282 		if (charcoll((const void *)&cnt, (const void *)&(s->lastch)) >= 0 &&
283 		    charcoll((const void *)&cnt, (const void *)&stopval) <= 0)
284 			*p++ = cnt;
285 	*p = OOBCH;
286 	n = p - s->set;
287 
288 	s->cnt = 0;
289 	s->state = SET;
290 	if (n > 1)
291 		mergesort(s->set, n, sizeof(*(s->set)), charcoll);
292 	return (1);
293 }
294 
295 static void
296 genseq(STR *s)
297 {
298 	char *ep;
299 	wchar_t wc;
300 	size_t clen;
301 
302 	if (s->which == STRING1)
303 		errx(1, "sequences only valid in string2");
304 
305 	if (*s->str == '\\')
306 		s->lastch = backslash(s, NULL);
307 	else {
308 		clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
309 		if (clen == (size_t)-1 || clen == (size_t)-2)
310 			errc(1, EILSEQ, NULL);
311 		s->lastch = wc;
312 		s->str += clen;
313 	}
314 	if (*s->str != '*')
315 		errx(1, "misplaced sequence asterisk");
316 
317 	switch (*++s->str) {
318 	case '\\':
319 		s->cnt = backslash(s, NULL);
320 		break;
321 	case ']':
322 		s->cnt = 0;
323 		++s->str;
324 		break;
325 	default:
326 		if (isdigit((u_char)*s->str)) {
327 			s->cnt = strtol(s->str, &ep, 0);
328 			if (*ep == ']') {
329 				s->str = ep + 1;
330 				break;
331 			}
332 		}
333 		errx(1, "illegal sequence count");
334 		/* NOTREACHED */
335 	}
336 
337 	s->state = s->cnt ? SEQUENCE : INFINITE;
338 }
339 
340 /*
341  * Translate \??? into a character.  Up to 3 octal digits, if no digits either
342  * an escape code or a literal character.
343  */
344 static int
345 backslash(STR *s, int *is_octal)
346 {
347 	int ch, cnt, val;
348 
349 	if (is_octal != NULL)
350 		*is_octal = 0;
351 	for (cnt = val = 0;;) {
352 		ch = (u_char)*++s->str;
353 		if (!isdigit(ch) || ch > '7')
354 			break;
355 		val = val * 8 + ch - '0';
356 		if (++cnt == 3) {
357 			++s->str;
358 			break;
359 		}
360 	}
361 	if (cnt) {
362 		if (is_octal != NULL)
363 			*is_octal = 1;
364 		return (val);
365 	}
366 	if (ch != '\0')
367 		++s->str;
368 	switch (ch) {
369 		case 'a':			/* escape characters */
370 			return ('\7');
371 		case 'b':
372 			return ('\b');
373 		case 'f':
374 			return ('\f');
375 		case 'n':
376 			return ('\n');
377 		case 'r':
378 			return ('\r');
379 		case 't':
380 			return ('\t');
381 		case 'v':
382 			return ('\13');
383 		case '\0':			/*  \" -> \ */
384 			s->state = EOS;
385 			return ('\\');
386 		default:			/* \x" -> x */
387 			return (ch);
388 	}
389 }
390