unvis.c revision 1.9
1 /* $NetBSD: unvis.c,v 1.9 1997/10/20 22:05:32 thorpej 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 1.9 1997/10/20 22:05:32 thorpej Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #include "namespace.h" 46 #include <sys/types.h> 47 #include <ctype.h> 48 #include <vis.h> 49 50 #ifdef __weak_alias 51 __weak_alias(strunvis,_strunvis); 52 __weak_alias(unvis,_unvis); 53 #endif 54 55 /* 56 * decode driven by state machine 57 */ 58 #define S_GROUND 0 /* haven't seen escape char */ 59 #define S_START 1 /* start decoding special sequence */ 60 #define S_META 2 /* metachar started (M) */ 61 #define S_META1 3 /* metachar more, regular char (-) */ 62 #define S_CTRL 4 /* control char started (^) */ 63 #define S_OCTAL2 5 /* octal digit 2 */ 64 #define S_OCTAL3 6 /* octal digit 3 */ 65 66 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 67 68 #undef unvis 69 70 int 71 unvis(cp, c, astate, flag) 72 char *cp; 73 char c; 74 int *astate, flag; 75 { 76 return __unvis13(cp, (int)c, astate, flag); 77 } 78 79 /* 80 * unvis - decode characters previously encoded by vis 81 */ 82 int 83 __unvis13(cp, c, astate, flag) 84 char *cp; 85 int c; 86 int *astate, flag; 87 { 88 89 if (flag & UNVIS_END) { 90 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 91 *astate = S_GROUND; 92 return (UNVIS_VALID); 93 } 94 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 95 } 96 97 switch (*astate) { 98 99 case S_GROUND: 100 *cp = 0; 101 if (c == '\\') { 102 *astate = S_START; 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 = 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(c)) { 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(c)) { 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 default: 229 /* 230 * decoder in unknown state - (probably uninitialized) 231 */ 232 *astate = S_GROUND; 233 return (UNVIS_SYNBAD); 234 } 235 } 236 237 /* 238 * strunvis - decode src into dst 239 * 240 * Number of chars decoded into dst is returned, -1 on error. 241 * Dst is null terminated. 242 */ 243 244 int 245 strunvis(dst, src) 246 register char *dst; 247 register const char *src; 248 { 249 register char c; 250 char *start = dst; 251 int state = 0; 252 253 while ((c = *src++) != '\0') { 254 again: 255 switch (__unvis13(dst, c, &state, 0)) { 256 case UNVIS_VALID: 257 dst++; 258 break; 259 case UNVIS_VALIDPUSH: 260 dst++; 261 goto again; 262 case 0: 263 case UNVIS_NOCHAR: 264 break; 265 default: 266 return (-1); 267 } 268 } 269 if (__unvis13(dst, c, &state, UNVIS_END) == UNVIS_VALID) 270 dst++; 271 *dst = '\0'; 272 return (dst - start); 273 } 274
Indexes created Mon Sep 22 13:09:51 GMT 2025