str.c revision 12505
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 35static 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#include <ctype.h> 47 48#include "extern.h" 49 50static int backslash __P((STR *)); 51static int bracket __P((STR *)); 52static int c_class __P((const void *, const void *)); 53static void genclass __P((STR *)); 54static void genequiv __P((STR *)); 55static int genrange __P((STR *)); 56static void genseq __P((STR *)); 57 58int 59next(s) 60 register STR *s; 61{ 62 register int ch; 63 64 switch (s->state) { 65 case EOS: 66 return (0); 67 case INFINITE: 68 return (1); 69 case NORMAL: 70 switch (ch = *s->str) { 71 case '\0': 72 s->state = EOS; 73 return (0); 74 case '\\': 75 s->lastch = backslash(s); 76 break; 77 case '[': 78 if (bracket(s)) 79 return (next(s)); 80 /* FALLTHROUGH */ 81 default: 82 ++s->str; 83 s->lastch = ch; 84 break; 85 } 86 87 /* We can start a range at any time. */ 88 if (s->str[0] == '-' && genrange(s)) 89 return (next(s)); 90 return (1); 91 case RANGE: 92 if (s->cnt-- == 0) { 93 s->state = NORMAL; 94 return (next(s)); 95 } 96 ++s->lastch; 97 return (1); 98 case SEQUENCE: 99 if (s->cnt-- == 0) { 100 s->state = NORMAL; 101 return (next(s)); 102 } 103 return (1); 104 case SET: 105 if ((s->lastch = s->set[s->cnt++]) == OOBCH) { 106 s->state = NORMAL; 107 return (next(s)); 108 } 109 return (1); 110 } 111 /* NOTREACHED */ 112} 113 114static int 115bracket(s) 116 register STR *s; 117{ 118 register char *p; 119 120 switch (s->str[1]) { 121 case ':': /* "[:class:]" */ 122 if ((p = strstr(s->str + 2, ":]")) == NULL) 123 return (0); 124 *p = '\0'; 125 s->str += 2; 126 genclass(s); 127 s->str = p + 2; 128 return (1); 129 case '=': /* "[=equiv=]" */ 130 if ((p = strstr(s->str + 2, "=]")) == NULL) 131 return (0); 132 s->str += 2; 133 genequiv(s); 134 return (1); 135 default: /* "[\###*n]" or "[#*n]" */ 136 if ((p = strpbrk(s->str + 2, "*]")) == NULL) 137 return (0); 138 if (p[0] != '*' || index(p, ']') == NULL) 139 return (0); 140 s->str += 1; 141 genseq(s); 142 return (1); 143 } 144 /* NOTREACHED */ 145} 146 147typedef struct { 148 char *name; 149 int (*func) __P((int)); 150 int *set; 151} CLASS; 152 153static CLASS classes[] = { 154#undef isalnum 155 { "alnum", isalnum, }, 156#undef isalpha 157 { "alpha", isalpha, }, 158#undef isblank 159 { "blank", isblank, }, 160#undef iscntrl 161 { "cntrl", iscntrl, }, 162#undef isdigit 163 { "digit", isdigit, }, 164#undef isgraph 165 { "graph", isgraph, }, 166#undef islower 167 { "lower", islower, }, 168#undef isprint 169 { "print", isprint, }, 170#undef ispunct 171 { "punct", ispunct, }, 172#undef isspace 173 { "space", isspace, }, 174#undef isupper 175 { "upper", isupper, }, 176#undef isxdigit 177 { "xdigit", isxdigit, }, 178}; 179 180static void 181genclass(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 206static int 207c_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 */ 217static void 218genequiv(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 236static int 237genrange(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 255static void 256genseq(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/* 295 * Translate \??? into a character. Up to 3 octal digits, if no digits either 296 * an escape code or a literal character. 297 */ 298static int 299backslash(s) 300 register STR *s; 301{ 302 register int ch, cnt, val; 303 304 for (cnt = val = 0;;) { 305 ch = *++s->str; 306 if (!isascii(ch) || !isdigit(ch)) 307 break; 308 val = val * 8 + ch - '0'; 309 if (++cnt == 3) { 310 ++s->str; 311 break; 312 } 313 } 314 if (cnt) 315 return (val); 316 if (ch != '\0') 317 ++s->str; 318 switch (ch) { 319 case 'a': /* escape characters */ 320 return ('\7'); 321 case 'b': 322 return ('\b'); 323 case 'f': 324 return ('\f'); 325 case 'n': 326 return ('\n'); 327 case 'r': 328 return ('\r'); 329 case 't': 330 return ('\t'); 331 case 'v': 332 return ('\13'); 333 case '\0': /* \" -> \ */ 334 s->state = EOS; 335 return ('\\'); 336 default: /* \x" -> x */ 337 return (ch); 338 } 339} 340