1 /* $OpenBSD: str.c,v 1.11 2009/10/27 23:59:46 deraadt Exp $ */ 2 /* $NetBSD: str.c,v 1.7 1995/08/31 22:13:47 jtc Exp $ */ 3 4 /*- 5 * Copyright (c) 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #include <sys/cdefs.h> 34 #include <sys/types.h> 35 36 #include <errno.h> 37 #include <stddef.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <ctype.h> 42 #include <err.h> 43 44 #include "extern.h" 45 46 static int backslash(STR *); 47 static int bracket(STR *); 48 static int c_class(const void *, const void *); 49 static void genclass(STR *); 50 static void genequiv(STR *); 51 static int genrange(STR *); 52 static void genseq(STR *); 53 54 int 55 next(s) 56 STR *s; 57 { 58 int ch; 59 60 switch (s->state) { 61 case EOS: 62 return (0); 63 case INFINITE: 64 return (1); 65 case NORMAL: 66 switch (ch = *s->str) { 67 case '\0': 68 s->state = EOS; 69 return (0); 70 case '\\': 71 s->lastch = backslash(s); 72 break; 73 case '[': 74 if (bracket(s)) 75 return (next(s)); 76 /* FALLTHROUGH */ 77 default: 78 ++s->str; 79 s->lastch = ch; 80 break; 81 } 82 83 /* We can start a range at any time. */ 84 if (s->str[0] == '-' && genrange(s)) 85 return (next(s)); 86 return (1); 87 case RANGE: 88 if (s->cnt-- == 0) { 89 s->state = NORMAL; 90 return (next(s)); 91 } 92 ++s->lastch; 93 return (1); 94 case SEQUENCE: 95 if (s->cnt-- == 0) { 96 s->state = NORMAL; 97 return (next(s)); 98 } 99 return (1); 100 case SET: 101 if ((s->lastch = s->set[s->cnt++]) == OOBCH) { 102 s->state = NORMAL; 103 return (next(s)); 104 } 105 return (1); 106 default: 107 return 0; 108 } 109 /* NOTREACHED */ 110 } 111 112 static int 113 bracket(s) 114 STR *s; 115 { 116 char *p; 117 118 switch (s->str[1]) { 119 case ':': /* "[:class:]" */ 120 if ((p = strstr((char *)s->str + 2, ":]")) == NULL) 121 return (0); 122 *p = '\0'; 123 s->str += 2; 124 genclass(s); 125 s->str = (unsigned char *)p + 2; 126 return (1); 127 case '=': /* "[=equiv=]" */ 128 if ((p = strstr((char *)s->str + 2, "=]")) == NULL) 129 return (0); 130 s->str += 2; 131 genequiv(s); 132 return (1); 133 default: /* "[\###*n]" or "[#*n]" */ 134 if ((p = strpbrk((char *)s->str + 2, "*]")) == NULL) 135 return (0); 136 if (p[0] != '*' || strchr(p, ']') == NULL) 137 return (0); 138 s->str += 1; 139 genseq(s); 140 return (1); 141 } 142 /* NOTREACHED */ 143 } 144 145 typedef struct { 146 char *name; 147 int (*func)(int); 148 int *set; 149 } CLASS; 150 151 static CLASS classes[] = { 152 { "alnum", isalnum, }, 153 { "alpha", isalpha, }, 154 { "blank", isblank, }, 155 { "cntrl", iscntrl, }, 156 { "digit", isdigit, }, 157 { "graph", isgraph, }, 158 { "lower", islower, }, 159 { "print", isprint, }, 160 { "punct", ispunct, }, 161 { "space", isspace, }, 162 { "upper", isupper, }, 163 { "xdigit", isxdigit, }, 164 }; 165 166 static void 167 genclass(s) 168 STR *s; 169 { 170 int cnt, (*func)(int); 171 CLASS *cp, tmp; 172 int *p; 173 174 tmp.name = (char *)s->str; 175 if ((cp = (CLASS *)bsearch(&tmp, classes, sizeof(classes) / 176 sizeof(CLASS), sizeof(CLASS), c_class)) == NULL) 177 errx(1, "unknown class %s", s->str); 178 179 if ((cp->set = p = calloc(NCHARS + 1, sizeof(int))) == NULL) 180 errx(1, "no memory for a class"); 181 for (cnt = 0, func = cp->func; cnt < NCHARS; ++cnt) 182 if ((func)(cnt)) 183 *p++ = cnt; 184 *p = OOBCH; 185 186 s->cnt = 0; 187 s->state = SET; 188 s->set = cp->set; 189 } 190 191 static int 192 c_class(a, b) 193 const void *a, *b; 194 { 195 return (strcmp(((CLASS *)a)->name, ((CLASS *)b)->name)); 196 } 197 198 /* 199 * English doesn't have any equivalence classes, so for now 200 * we just syntax check and grab the character. 201 */ 202 static void 203 genequiv(s) 204 STR *s; 205 { 206 if (*s->str == '\\') { 207 s->equiv[0] = backslash(s); 208 if (*s->str != '=') 209 errx(1, "misplaced equivalence equals sign"); 210 } else { 211 s->equiv[0] = s->str[0]; 212 if (s->str[1] != '=') 213 errx(1, "misplaced equivalence equals sign"); 214 } 215 s->str += 2; 216 s->cnt = 0; 217 s->state = SET; 218 s->set = s->equiv; 219 } 220 221 static int 222 genrange(s) 223 STR *s; 224 { 225 int stopval; 226 unsigned char *savestart; 227 228 savestart = s->str; 229 stopval = *++s->str == '\\' ? backslash(s) : *s->str++; 230 if (stopval < (u_char)s->lastch) { 231 s->str = savestart; 232 return (0); 233 } 234 s->cnt = stopval - s->lastch + 1; 235 s->state = RANGE; 236 --s->lastch; 237 return (1); 238 } 239 240 static void 241 genseq(s) 242 STR *s; 243 { 244 char *ep; 245 246 if (s->which == STRING1) 247 errx(1, "sequences only valid in string2"); 248 249 if (*s->str == '\\') 250 s->lastch = backslash(s); 251 else 252 s->lastch = *s->str++; 253 if (*s->str != '*') 254 errx(1, "misplaced sequence asterisk"); 255 256 switch (*++s->str) { 257 case '\\': 258 s->cnt = backslash(s); 259 break; 260 case ']': 261 s->cnt = 0; 262 ++s->str; 263 break; 264 default: 265 if (isdigit(*s->str)) { 266 s->cnt = strtol((char *)s->str, &ep, 0); 267 if (*ep == ']') { 268 s->str = (unsigned char *)ep + 1; 269 break; 270 } 271 } 272 errx(1, "illegal sequence count"); 273 /* NOTREACHED */ 274 } 275 276 s->state = s->cnt ? SEQUENCE : INFINITE; 277 } 278 279 /* 280 * Translate \??? into a character. Up to 3 octal digits, if no digits either 281 * an escape code or a literal character. 282 */ 283 static int 284 backslash(s) 285 STR *s; 286 { 287 int ch, cnt, val; 288 289 for (cnt = val = 0;;) { 290 ch = *++s->str; 291 if (!isascii(ch) || !isdigit(ch)) 292 break; 293 val = val * 8 + ch - '0'; 294 if (++cnt == 3) { 295 ++s->str; 296 break; 297 } 298 } 299 if (cnt) 300 return (val); 301 if (ch != '\0') 302 ++s->str; 303 switch (ch) { 304 case 'a': /* escape characters */ 305 return ('\7'); 306 case 'b': 307 return ('\b'); 308 case 'f': 309 return ('\f'); 310 case 'n': 311 return ('\n'); 312 case 'r': 313 return ('\r'); 314 case 't': 315 return ('\t'); 316 case 'v': 317 return ('\13'); 318 case '\0': /* \" -> \ */ 319 s->state = EOS; 320 return ('\\'); 321 default: /* \x" -> x */ 322 return (ch); 323 } 324 } 325