xref: /freebsd/usr.bin/tr/str.c (revision 0da30e9aa76c5df66cd092f30b904824b0594ccc)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  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[] = "@(#)str.c	8.2 (Berkeley) 4/28/95";
36 #endif /* not lint */
37 
38 #include <sys/cdefs.h>
39 #include <sys/types.h>
40 
41 #include <errno.h>
42 #include <stddef.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 
47 #include "extern.h"
48 
49 static int	backslash __P((STR *));
50 static int	bracket __P((STR *));
51 static int	c_class __P((const void *, const void *));
52 static void	genclass __P((STR *));
53 static void	genequiv __P((STR *));
54 static int	genrange __P((STR *));
55 static void	genseq __P((STR *));
56 
57 int
58 next(s)
59 	register STR *s;
60 {
61 	register int ch;
62 
63 	switch (s->state) {
64 	case EOS:
65 		return (0);
66 	case INFINITE:
67 		return (1);
68 	case NORMAL:
69 		switch (ch = *s->str) {
70 		case '\0':
71 			s->state = EOS;
72 			return (0);
73 		case '\\':
74 			s->lastch = backslash(s);
75 			break;
76 		case '[':
77 			if (bracket(s))
78 				return (next(s));
79 			/* FALLTHROUGH */
80 		default:
81 			++s->str;
82 			s->lastch = ch;
83 			break;
84 		}
85 
86 		/* We can start a range at any time. */
87 		if (s->str[0] == '-' && genrange(s))
88 			return (next(s));
89 		return (1);
90 	case RANGE:
91 		if (s->cnt-- == 0) {
92 			s->state = NORMAL;
93 			return (next(s));
94 		}
95 		++s->lastch;
96 		return (1);
97 	case SEQUENCE:
98 		if (s->cnt-- == 0) {
99 			s->state = NORMAL;
100 			return (next(s));
101 		}
102 		return (1);
103 	case SET:
104 		if ((s->lastch = s->set[s->cnt++]) == OOBCH) {
105 			s->state = NORMAL;
106 			return (next(s));
107 		}
108 		return (1);
109 	}
110 	/* NOTREACHED */
111 }
112 
113 static int
114 bracket(s)
115 	register STR *s;
116 {
117 	register char *p;
118 
119 	switch (s->str[1]) {
120 	case ':':				/* "[:class:]" */
121 		if ((p = strstr(s->str + 2, ":]")) == NULL)
122 			return (0);
123 		*p = '\0';
124 		s->str += 2;
125 		genclass(s);
126 		s->str = p + 2;
127 		return (1);
128 	case '=':				/* "[=equiv=]" */
129 		if ((p = strstr(s->str + 2, "=]")) == NULL)
130 			return (0);
131 		s->str += 2;
132 		genequiv(s);
133 		return (1);
134 	default:				/* "[\###*n]" or "[#*n]" */
135 		if ((p = strpbrk(s->str + 2, "*]")) == NULL)
136 			return (0);
137 		if (p[0] != '*' || index(p, ']') == NULL)
138 			return (0);
139 		s->str += 1;
140 		genseq(s);
141 		return (1);
142 	}
143 	/* NOTREACHED */
144 }
145 
146 int isalnum __P((int)),
147     isalpha __P((int)),
148     isblank __P((int)),
149     isspace __P((int)),
150     iscntrl __P((int)),
151     isdigit __P((int)),
152     isgraph __P((int)),
153     islower __P((int)),
154     isprint __P((int)),
155     ispunct __P((int)),
156     isupper __P((int)),
157     isxdigit __P((int));
158 
159 typedef struct {
160 	char *name;
161 	int (*func) __P((int));
162 	int *set;
163 } CLASS;
164 
165 static CLASS classes[] = {
166 	{ "alnum",  isalnum,  },
167 	{ "alpha",  isalpha,  },
168 	{ "blank",  isblank,  },
169 	{ "cntrl",  iscntrl,  },
170 	{ "digit",  isdigit,  },
171 	{ "graph",  isgraph,  },
172 	{ "lower",  islower,  },
173 	{ "print",  isupper,  },
174 	{ "punct",  ispunct,  },
175 	{ "space",  isspace,  },
176 	{ "upper",  isupper,  },
177 	{ "xdigit", isxdigit, },
178 };
179 
180 static void
181 genclass(s)
182 	STR *s;
183 {
184 	register int cnt, (*func) __P((int));
185 	CLASS *cp, tmp;
186 	int *p;
187 
188 	tmp.name = s->str;
189 	if ((cp = (CLASS *)bsearch(&tmp, classes, sizeof(classes) /
190 	    sizeof(CLASS), sizeof(CLASS), c_class)) == NULL)
191 		err("unknown class %s", s->str);
192 
193 	if ((cp->set = p = malloc((NCHARS + 1) * sizeof(int))) == NULL)
194 		err("%s", strerror(errno));
195 	bzero(p, (NCHARS + 1) * sizeof(int));
196 	for (cnt = 0, func = cp->func; cnt < NCHARS; ++cnt)
197 		if ((func)(cnt))
198 			*p++ = cnt;
199 	*p = OOBCH;
200 
201 	s->cnt = 0;
202 	s->state = SET;
203 	s->set = cp->set;
204 }
205 
206 static int
207 c_class(a, b)
208 	const void *a, *b;
209 {
210 	return (strcmp(((CLASS *)a)->name, ((CLASS *)b)->name));
211 }
212 
213 /*
214  * English doesn't have any equivalence classes, so for now
215  * we just syntax check and grab the character.
216  */
217 static void
218 genequiv(s)
219 	STR *s;
220 {
221 	if (*s->str == '\\') {
222 		s->equiv[0] = backslash(s);
223 		if (*s->str != '=')
224 			err("misplaced equivalence equals sign");
225 	} else {
226 		s->equiv[0] = s->str[0];
227 		if (s->str[1] != '=')
228 			err("misplaced equivalence equals sign");
229 	}
230 	s->str += 2;
231 	s->cnt = 0;
232 	s->state = SET;
233 	s->set = s->equiv;
234 }
235 
236 static int
237 genrange(s)
238 	STR *s;
239 {
240 	int stopval;
241 	char *savestart;
242 
243 	savestart = s->str;
244 	stopval = *++s->str == '\\' ? backslash(s) : *s->str++;
245 	if (stopval < (u_char)s->lastch) {
246 		s->str = savestart;
247 		return (0);
248 	}
249 	s->cnt = stopval - s->lastch + 1;
250 	s->state = RANGE;
251 	--s->lastch;
252 	return (1);
253 }
254 
255 static void
256 genseq(s)
257 	STR *s;
258 {
259 	char *ep;
260 
261 	if (s->which == STRING1)
262 		err("sequences only valid in string2");
263 
264 	if (*s->str == '\\')
265 		s->lastch = backslash(s);
266 	else
267 		s->lastch = *s->str++;
268 	if (*s->str != '*')
269 		err("misplaced sequence asterisk");
270 
271 	switch (*++s->str) {
272 	case '\\':
273 		s->cnt = backslash(s);
274 		break;
275 	case ']':
276 		s->cnt = 0;
277 		++s->str;
278 		break;
279 	default:
280 		if (isdigit(*s->str)) {
281 			s->cnt = strtol(s->str, &ep, 0);
282 			if (*ep == ']') {
283 				s->str = ep + 1;
284 				break;
285 			}
286 		}
287 		err("illegal sequence count");
288 		/* NOTREACHED */
289 	}
290 
291 	s->state = s->cnt ? SEQUENCE : INFINITE;
292 }
293 
294 /* Use the #defines isXXX() here, DON'T use them above. */
295 #include <ctype.h>
296 
297 /*
298  * Translate \??? into a character.  Up to 3 octal digits, if no digits either
299  * an escape code or a literal character.
300  */
301 static int
302 backslash(s)
303 	register STR *s;
304 {
305 	register int ch, cnt, val;
306 
307 	for (cnt = val = 0;;) {
308 		ch = *++s->str;
309 		if (!isascii(ch) || !isdigit(ch))
310 			break;
311 		val = val * 8 + ch - '0';
312 		if (++cnt == 3) {
313 			++s->str;
314 			break;
315 		}
316 	}
317 	if (cnt)
318 		return (val);
319 	if (ch != '\0')
320 		++s->str;
321 	switch (ch) {
322 		case 'a':			/* escape characters */
323 			return ('\7');
324 		case 'b':
325 			return ('\b');
326 		case 'f':
327 			return ('\f');
328 		case 'n':
329 			return ('\n');
330 		case 'r':
331 			return ('\r');
332 		case 't':
333 			return ('\t');
334 		case 'v':
335 			return ('\13');
336 		case '\0':			/*  \" -> \ */
337 			s->state = EOS;
338 			return ('\\');
339 		default:			/* \x" -> x */
340 			return (ch);
341 	}
342 }
343