unvis.c revision 1.10
1 /* $NetBSD: unvis.c,v 1.10 1997/10/22 00:55:33 fvdl 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 1.10 1997/10/22 00:55:33 fvdl 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 __weak_alias(__unvis13,___unvis13); 56 #endif 57 58 /* 59 * decode driven by state machine 60 */ 61 #define S_GROUND 0 /* haven't seen escape char */ 62 #define S_START 1 /* start decoding special sequence */ 63 #define S_META 2 /* metachar started (M) */ 64 #define S_META1 3 /* metachar more, regular char (-) */ 65 #define S_CTRL 4 /* control char started (^) */ 66 #define S_OCTAL2 5 /* octal digit 2 */ 67 #define S_OCTAL3 6 /* octal digit 3 */ 68 69 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 70 71 int 72 unvis(cp, c, astate, flag) 73 char *cp; 74 char c; 75 int *astate, flag; 76 { 77 return __unvis13(cp, (int)c, astate, flag); 78 } 79 80 /* 81 * unvis - decode characters previously encoded by vis 82 */ 83 int 84 __unvis13(cp, c, astate, flag) 85 char *cp; 86 int c; 87 int *astate, flag; 88 { 89 90 if (flag & UNVIS_END) { 91 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 92 *astate = S_GROUND; 93 return (UNVIS_VALID); 94 } 95 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 96 } 97 98 switch (*astate) { 99 100 case S_GROUND: 101 *cp = 0; 102 if (c == '\\') { 103 *astate = S_START; 104 return (0); 105 } 106 *cp = c; 107 return (UNVIS_VALID); 108 109 case S_START: 110 switch(c) { 111 case '\\': 112 *cp = c; 113 *astate = S_GROUND; 114 return (UNVIS_VALID); 115 case '0': case '1': case '2': case '3': 116 case '4': case '5': case '6': case '7': 117 *cp = (c - '0'); 118 *astate = S_OCTAL2; 119 return (0); 120 case 'M': 121 *cp = 0200; 122 *astate = S_META; 123 return (0); 124 case '^': 125 *astate = S_CTRL; 126 return (0); 127 case 'n': 128 *cp = '\n'; 129 *astate = S_GROUND; 130 return (UNVIS_VALID); 131 case 'r': 132 *cp = '\r'; 133 *astate = S_GROUND; 134 return (UNVIS_VALID); 135 case 'b': 136 *cp = '\b'; 137 *astate = S_GROUND; 138 return (UNVIS_VALID); 139 case 'a': 140 *cp = '\007'; 141 *astate = S_GROUND; 142 return (UNVIS_VALID); 143 case 'v': 144 *cp = '\v'; 145 *astate = S_GROUND; 146 return (UNVIS_VALID); 147 case 't': 148 *cp = '\t'; 149 *astate = S_GROUND; 150 return (UNVIS_VALID); 151 case 'f': 152 *cp = '\f'; 153 *astate = S_GROUND; 154 return (UNVIS_VALID); 155 case 's': 156 *cp = ' '; 157 *astate = S_GROUND; 158 return (UNVIS_VALID); 159 case 'E': 160 *cp = '\033'; 161 *astate = S_GROUND; 162 return (UNVIS_VALID); 163 case '\n': 164 /* 165 * hidden newline 166 */ 167 *astate = S_GROUND; 168 return (UNVIS_NOCHAR); 169 case '$': 170 /* 171 * hidden marker 172 */ 173 *astate = S_GROUND; 174 return (UNVIS_NOCHAR); 175 } 176 *astate = S_GROUND; 177 return (UNVIS_SYNBAD); 178 179 case S_META: 180 if (c == '-') 181 *astate = S_META1; 182 else if (c == '^') 183 *astate = S_CTRL; 184 else { 185 *astate = S_GROUND; 186 return (UNVIS_SYNBAD); 187 } 188 return (0); 189 190 case S_META1: 191 *astate = S_GROUND; 192 *cp |= c; 193 return (UNVIS_VALID); 194 195 case S_CTRL: 196 if (c == '?') 197 *cp |= 0177; 198 else 199 *cp |= c & 037; 200 *astate = S_GROUND; 201 return (UNVIS_VALID); 202 203 case S_OCTAL2: /* second possible octal digit */ 204 if (isoctal(c)) { 205 /* 206 * yes - and maybe a third 207 */ 208 *cp = (*cp << 3) + (c - '0'); 209 *astate = S_OCTAL3; 210 return (0); 211 } 212 /* 213 * no - done with current sequence, push back passed char 214 */ 215 *astate = S_GROUND; 216 return (UNVIS_VALIDPUSH); 217 218 case S_OCTAL3: /* third possible octal digit */ 219 *astate = S_GROUND; 220 if (isoctal(c)) { 221 *cp = (*cp << 3) + (c - '0'); 222 return (UNVIS_VALID); 223 } 224 /* 225 * we were done, push back passed char 226 */ 227 return (UNVIS_VALIDPUSH); 228 229 default: 230 /* 231 * decoder in unknown state - (probably uninitialized) 232 */ 233 *astate = S_GROUND; 234 return (UNVIS_SYNBAD); 235 } 236 } 237 238 /* 239 * strunvis - decode src into dst 240 * 241 * Number of chars decoded into dst is returned, -1 on error. 242 * Dst is null terminated. 243 */ 244 245 int 246 strunvis(dst, src) 247 register char *dst; 248 register const char *src; 249 { 250 register char c; 251 char *start = dst; 252 int state = 0; 253 254 while ((c = *src++) != '\0') { 255 again: 256 switch (__unvis13(dst, c, &state, 0)) { 257 case UNVIS_VALID: 258 dst++; 259 break; 260 case UNVIS_VALIDPUSH: 261 dst++; 262 goto again; 263 case 0: 264 case UNVIS_NOCHAR: 265 break; 266 default: 267 return (-1); 268 } 269 } 270 if (__unvis13(dst, c, &state, UNVIS_END) == UNVIS_VALID) 271 dst++; 272 *dst = '\0'; 273 return (dst - start); 274 } 275
Indexes created Tue Sep 23 02:09:52 GMT 2025