unvis.c revision 1.13
1 /* $NetBSD: unvis.c,v 1.13 1998/11/13 12:31:53 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. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by the University of 18 * California, Berkeley and its contributors. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: unvis.c,v 1.13 1998/11/13 12:31:53 christos Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #define __LIBC12_SOURCE__ 46 47 #include "namespace.h" 48 #include <sys/types.h> 49 #include <ctype.h> 50 #include <vis.h> 51 52 #ifdef __weak_alias 53 __weak_alias(strunvis,_strunvis); 54 __weak_alias(unvis,_unvis); 55 #error "XXX THIS IS NOT CORRECT!" 56 __weak_alias(__unvis13,___unvis13); 57 #endif 58 59 /* 60 * decode driven by state machine 61 */ 62 #define S_GROUND 0 /* haven't seen escape char */ 63 #define S_START 1 /* start decoding special sequence */ 64 #define S_META 2 /* metachar started (M) */ 65 #define S_META1 3 /* metachar more, regular char (-) */ 66 #define S_CTRL 4 /* control char started (^) */ 67 #define S_OCTAL2 5 /* octal digit 2 */ 68 #define S_OCTAL3 6 /* octal digit 3 */ 69 70 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 71 72 int 73 unvis(cp, c, astate, flag) 74 char *cp; 75 int c; 76 int *astate, flag; 77 { 78 return __unvis13(cp, (int)c, astate, flag); 79 } 80 81 /* 82 * unvis - decode characters previously encoded by vis 83 */ 84 int 85 __unvis13(cp, c, astate, flag) 86 char *cp; 87 int c; 88 int *astate, flag; 89 { 90 91 if (flag & UNVIS_END) { 92 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 93 *astate = S_GROUND; 94 return (UNVIS_VALID); 95 } 96 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 97 } 98 99 switch (*astate) { 100 101 case S_GROUND: 102 *cp = 0; 103 if (c == '\\') { 104 *astate = S_START; 105 return (0); 106 } 107 *cp = c; 108 return (UNVIS_VALID); 109 110 case S_START: 111 switch(c) { 112 case '\\': 113 *cp = c; 114 *astate = S_GROUND; 115 return (UNVIS_VALID); 116 case '0': case '1': case '2': case '3': 117 case '4': case '5': case '6': case '7': 118 *cp = (c - '0'); 119 *astate = S_OCTAL2; 120 return (0); 121 case 'M': 122 *cp = (char)0200; 123 *astate = S_META; 124 return (0); 125 case '^': 126 *astate = S_CTRL; 127 return (0); 128 case 'n': 129 *cp = '\n'; 130 *astate = S_GROUND; 131 return (UNVIS_VALID); 132 case 'r': 133 *cp = '\r'; 134 *astate = S_GROUND; 135 return (UNVIS_VALID); 136 case 'b': 137 *cp = '\b'; 138 *astate = S_GROUND; 139 return (UNVIS_VALID); 140 case 'a': 141 *cp = '\007'; 142 *astate = S_GROUND; 143 return (UNVIS_VALID); 144 case 'v': 145 *cp = '\v'; 146 *astate = S_GROUND; 147 return (UNVIS_VALID); 148 case 't': 149 *cp = '\t'; 150 *astate = S_GROUND; 151 return (UNVIS_VALID); 152 case 'f': 153 *cp = '\f'; 154 *astate = S_GROUND; 155 return (UNVIS_VALID); 156 case 's': 157 *cp = ' '; 158 *astate = S_GROUND; 159 return (UNVIS_VALID); 160 case 'E': 161 *cp = '\033'; 162 *astate = S_GROUND; 163 return (UNVIS_VALID); 164 case '\n': 165 /* 166 * hidden newline 167 */ 168 *astate = S_GROUND; 169 return (UNVIS_NOCHAR); 170 case '$': 171 /* 172 * hidden marker 173 */ 174 *astate = S_GROUND; 175 return (UNVIS_NOCHAR); 176 } 177 *astate = S_GROUND; 178 return (UNVIS_SYNBAD); 179 180 case S_META: 181 if (c == '-') 182 *astate = S_META1; 183 else if (c == '^') 184 *astate = S_CTRL; 185 else { 186 *astate = S_GROUND; 187 return (UNVIS_SYNBAD); 188 } 189 return (0); 190 191 case S_META1: 192 *astate = S_GROUND; 193 *cp |= c; 194 return (UNVIS_VALID); 195 196 case S_CTRL: 197 if (c == '?') 198 *cp |= 0177; 199 else 200 *cp |= c & 037; 201 *astate = S_GROUND; 202 return (UNVIS_VALID); 203 204 case S_OCTAL2: /* second possible octal digit */ 205 if (isoctal(c)) { 206 /* 207 * yes - and maybe a third 208 */ 209 *cp = (*cp << 3) + (c - '0'); 210 *astate = S_OCTAL3; 211 return (0); 212 } 213 /* 214 * no - done with current sequence, push back passed char 215 */ 216 *astate = S_GROUND; 217 return (UNVIS_VALIDPUSH); 218 219 case S_OCTAL3: /* third possible octal digit */ 220 *astate = S_GROUND; 221 if (isoctal(c)) { 222 *cp = (*cp << 3) + (c - '0'); 223 return (UNVIS_VALID); 224 } 225 /* 226 * we were done, push back passed char 227 */ 228 return (UNVIS_VALIDPUSH); 229 230 default: 231 /* 232 * decoder in unknown state - (probably uninitialized) 233 */ 234 *astate = S_GROUND; 235 return (UNVIS_SYNBAD); 236 } 237 } 238 239 /* 240 * strunvis - decode src into dst 241 * 242 * Number of chars decoded into dst is returned, -1 on error. 243 * Dst is null terminated. 244 */ 245 246 int 247 strunvis(dst, src) 248 char *dst; 249 const char *src; 250 { 251 char c; 252 char *start = dst; 253 int state = 0; 254 255 while ((c = *src++) != '\0') { 256 again: 257 switch (__unvis13(dst, c, &state, 0)) { 258 case UNVIS_VALID: 259 dst++; 260 break; 261 case UNVIS_VALIDPUSH: 262 dst++; 263 goto again; 264 case 0: 265 case UNVIS_NOCHAR: 266 break; 267 default: 268 return (-1); 269 } 270 } 271 if (__unvis13(dst, c, &state, UNVIS_END) == UNVIS_VALID) 272 dst++; 273 *dst = '\0'; 274 return (dst - start); 275 } 276
Indexes created Sun Sep 21 20:09:37 GMT 2025