unvis.c revision 1.28
1 /* $NetBSD: unvis.c,v 1.28 2005/09/13 01:44:09 christos Exp $ */ 2 3 /*- 4 * Copyright (c) 1989, 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 #if defined(LIBC_SCCS) && !defined(lint) 34 #if 0 35 static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 36 #else 37 __RCSID("$NetBSD: unvis.c,v 1.28 2005/09/13 01:44:09 christos Exp $"); 38 #endif 39 #endif /* LIBC_SCCS and not lint */ 40 41 #include "namespace.h" 42 #include <sys/types.h> 43 44 #include <assert.h> 45 #include <ctype.h> 46 #include <stdio.h> 47 #include <vis.h> 48 49 #ifdef __weak_alias 50 __weak_alias(strunvis,_strunvis) 51 #endif 52 53 #if !HAVE_VIS 54 /* 55 * decode driven by state machine 56 */ 57 #define S_GROUND 0 /* haven't seen escape char */ 58 #define S_START 1 /* start decoding special sequence */ 59 #define S_META 2 /* metachar started (M) */ 60 #define S_META1 3 /* metachar more, regular char (-) */ 61 #define S_CTRL 4 /* control char started (^) */ 62 #define S_OCTAL2 5 /* octal digit 2 */ 63 #define S_OCTAL3 6 /* octal digit 3 */ 64 #define S_HEX1 7 /* hex digit */ 65 #define S_HEX2 8 /* hex digit 2 */ 66 67 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 68 #define xtod(c) (isdigit(c) ? (c - '0') : ((tolower(c) - 'a') + 10)) 69 70 /* 71 * unvis - decode characters previously encoded by vis 72 */ 73 int 74 unvis(cp, c, astate, flag) 75 char *cp; 76 int c; 77 int *astate, flag; 78 { 79 unsigned char uc = (unsigned char)c; 80 81 _DIAGASSERT(cp != NULL); 82 _DIAGASSERT(astate != NULL); 83 84 if (flag & UNVIS_END) { 85 if (*astate == S_OCTAL2 || *astate == S_OCTAL3 86 || *astate == S_HEX2) { 87 *astate = S_GROUND; 88 return (UNVIS_VALID); 89 } 90 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 91 } 92 93 switch (*astate) { 94 95 case S_GROUND: 96 *cp = 0; 97 if (c == '\\') { 98 *astate = S_START; 99 return (0); 100 } 101 if ((flag & VIS_HTTPSTYLE) && c == '%') { 102 *astate = S_HEX1; 103 return (0); 104 } 105 *cp = c; 106 return (UNVIS_VALID); 107 108 case S_START: 109 switch(c) { 110 case '\\': 111 *cp = c; 112 *astate = S_GROUND; 113 return (UNVIS_VALID); 114 case '0': case '1': case '2': case '3': 115 case '4': case '5': case '6': case '7': 116 *cp = (c - '0'); 117 *astate = S_OCTAL2; 118 return (0); 119 case 'M': 120 *cp = (char)0200; 121 *astate = S_META; 122 return (0); 123 case '^': 124 *astate = S_CTRL; 125 return (0); 126 case 'n': 127 *cp = '\n'; 128 *astate = S_GROUND; 129 return (UNVIS_VALID); 130 case 'r': 131 *cp = '\r'; 132 *astate = S_GROUND; 133 return (UNVIS_VALID); 134 case 'b': 135 *cp = '\b'; 136 *astate = S_GROUND; 137 return (UNVIS_VALID); 138 case 'a': 139 *cp = '\007'; 140 *astate = S_GROUND; 141 return (UNVIS_VALID); 142 case 'v': 143 *cp = '\v'; 144 *astate = S_GROUND; 145 return (UNVIS_VALID); 146 case 't': 147 *cp = '\t'; 148 *astate = S_GROUND; 149 return (UNVIS_VALID); 150 case 'f': 151 *cp = '\f'; 152 *astate = S_GROUND; 153 return (UNVIS_VALID); 154 case 's': 155 *cp = ' '; 156 *astate = S_GROUND; 157 return (UNVIS_VALID); 158 case 'E': 159 *cp = '\033'; 160 *astate = S_GROUND; 161 return (UNVIS_VALID); 162 case '\n': 163 /* 164 * hidden newline 165 */ 166 *astate = S_GROUND; 167 return (UNVIS_NOCHAR); 168 case '$': 169 /* 170 * hidden marker 171 */ 172 *astate = S_GROUND; 173 return (UNVIS_NOCHAR); 174 } 175 *astate = S_GROUND; 176 return (UNVIS_SYNBAD); 177 178 case S_META: 179 if (c == '-') 180 *astate = S_META1; 181 else if (c == '^') 182 *astate = S_CTRL; 183 else { 184 *astate = S_GROUND; 185 return (UNVIS_SYNBAD); 186 } 187 return (0); 188 189 case S_META1: 190 *astate = S_GROUND; 191 *cp |= c; 192 return (UNVIS_VALID); 193 194 case S_CTRL: 195 if (c == '?') 196 *cp |= 0177; 197 else 198 *cp |= c & 037; 199 *astate = S_GROUND; 200 return (UNVIS_VALID); 201 202 case S_OCTAL2: /* second possible octal digit */ 203 if (isoctal(uc)) { 204 /* 205 * yes - and maybe a third 206 */ 207 *cp = (*cp << 3) + (c - '0'); 208 *astate = S_OCTAL3; 209 return (0); 210 } 211 /* 212 * no - done with current sequence, push back passed char 213 */ 214 *astate = S_GROUND; 215 return (UNVIS_VALIDPUSH); 216 217 case S_OCTAL3: /* third possible octal digit */ 218 *astate = S_GROUND; 219 if (isoctal(uc)) { 220 *cp = (*cp << 3) + (c - '0'); 221 return (UNVIS_VALID); 222 } 223 /* 224 * we were done, push back passed char 225 */ 226 return (UNVIS_VALIDPUSH); 227 228 case S_HEX1: 229 if (isxdigit(uc)) { 230 *cp = xtod(uc); 231 *astate = S_HEX2; 232 return (0); 233 } 234 /* 235 * no - done with current sequence, push back passed char 236 */ 237 *astate = S_GROUND; 238 return (UNVIS_VALIDPUSH); 239 240 case S_HEX2: 241 *astate = S_GROUND; 242 if (isxdigit(uc)) { 243 *cp = xtod(uc) | (*cp << 4); 244 return (UNVIS_VALID); 245 } 246 return (UNVIS_VALIDPUSH); 247 248 default: 249 /* 250 * decoder in unknown state - (probably uninitialized) 251 */ 252 *astate = S_GROUND; 253 return (UNVIS_SYNBAD); 254 } 255 } 256 257 /* 258 * strunvis - decode src into dst 259 * 260 * Number of chars decoded into dst is returned, -1 on error. 261 * Dst is null terminated. 262 */ 263 264 int 265 strunvisx(dst, src, flag) 266 char *dst; 267 const char *src; 268 int flag; 269 { 270 char c; 271 char *start = dst; 272 int state = 0; 273 274 _DIAGASSERT(src != NULL); 275 _DIAGASSERT(dst != NULL); 276 277 while ((c = *src++) != '\0') { 278 again: 279 switch (unvis(dst, c, &state, flag)) { 280 case UNVIS_VALID: 281 dst++; 282 break; 283 case UNVIS_VALIDPUSH: 284 dst++; 285 goto again; 286 case 0: 287 case UNVIS_NOCHAR: 288 break; 289 default: 290 return (-1); 291 } 292 } 293 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 294 dst++; 295 *dst = '\0'; 296 return (dst - start); 297 } 298 299 int 300 strunvis(dst, src) 301 char *dst; 302 const char *src; 303 { 304 return strunvisx(dst, src, 0); 305 } 306 #endif 307
Indexes created Tue Sep 30 07:10:03 GMT 2025