unvis.c revision 1.8
1 /* $NetBSD: unvis.c,v 1.8 1997/10/16 23:06:13 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 1.8 1997/10/16 23:06:13 christos 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 /* 69 * unvis - decode characters previously encoded by vis 70 */ 71 int 72 unvis(cp, c, astate, flag) 73 char *cp; 74 int c; 75 int *astate, flag; 76 { 77 78 if (flag & UNVIS_END) { 79 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 80 *astate = S_GROUND; 81 return (UNVIS_VALID); 82 } 83 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 84 } 85 86 switch (*astate) { 87 88 case S_GROUND: 89 *cp = 0; 90 if (c == '\\') { 91 *astate = S_START; 92 return (0); 93 } 94 *cp = c; 95 return (UNVIS_VALID); 96 97 case S_START: 98 switch(c) { 99 case '\\': 100 *cp = c; 101 *astate = S_GROUND; 102 return (UNVIS_VALID); 103 case '0': case '1': case '2': case '3': 104 case '4': case '5': case '6': case '7': 105 *cp = (c - '0'); 106 *astate = S_OCTAL2; 107 return (0); 108 case 'M': 109 *cp = 0200; 110 *astate = S_META; 111 return (0); 112 case '^': 113 *astate = S_CTRL; 114 return (0); 115 case 'n': 116 *cp = '\n'; 117 *astate = S_GROUND; 118 return (UNVIS_VALID); 119 case 'r': 120 *cp = '\r'; 121 *astate = S_GROUND; 122 return (UNVIS_VALID); 123 case 'b': 124 *cp = '\b'; 125 *astate = S_GROUND; 126 return (UNVIS_VALID); 127 case 'a': 128 *cp = '\007'; 129 *astate = S_GROUND; 130 return (UNVIS_VALID); 131 case 'v': 132 *cp = '\v'; 133 *astate = S_GROUND; 134 return (UNVIS_VALID); 135 case 't': 136 *cp = '\t'; 137 *astate = S_GROUND; 138 return (UNVIS_VALID); 139 case 'f': 140 *cp = '\f'; 141 *astate = S_GROUND; 142 return (UNVIS_VALID); 143 case 's': 144 *cp = ' '; 145 *astate = S_GROUND; 146 return (UNVIS_VALID); 147 case 'E': 148 *cp = '\033'; 149 *astate = S_GROUND; 150 return (UNVIS_VALID); 151 case '\n': 152 /* 153 * hidden newline 154 */ 155 *astate = S_GROUND; 156 return (UNVIS_NOCHAR); 157 case '$': 158 /* 159 * hidden marker 160 */ 161 *astate = S_GROUND; 162 return (UNVIS_NOCHAR); 163 } 164 *astate = S_GROUND; 165 return (UNVIS_SYNBAD); 166 167 case S_META: 168 if (c == '-') 169 *astate = S_META1; 170 else if (c == '^') 171 *astate = S_CTRL; 172 else { 173 *astate = S_GROUND; 174 return (UNVIS_SYNBAD); 175 } 176 return (0); 177 178 case S_META1: 179 *astate = S_GROUND; 180 *cp |= c; 181 return (UNVIS_VALID); 182 183 case S_CTRL: 184 if (c == '?') 185 *cp |= 0177; 186 else 187 *cp |= c & 037; 188 *astate = S_GROUND; 189 return (UNVIS_VALID); 190 191 case S_OCTAL2: /* second possible octal digit */ 192 if (isoctal(c)) { 193 /* 194 * yes - and maybe a third 195 */ 196 *cp = (*cp << 3) + (c - '0'); 197 *astate = S_OCTAL3; 198 return (0); 199 } 200 /* 201 * no - done with current sequence, push back passed char 202 */ 203 *astate = S_GROUND; 204 return (UNVIS_VALIDPUSH); 205 206 case S_OCTAL3: /* third possible octal digit */ 207 *astate = S_GROUND; 208 if (isoctal(c)) { 209 *cp = (*cp << 3) + (c - '0'); 210 return (UNVIS_VALID); 211 } 212 /* 213 * we were done, push back passed char 214 */ 215 return (UNVIS_VALIDPUSH); 216 217 default: 218 /* 219 * decoder in unknown state - (probably uninitialized) 220 */ 221 *astate = S_GROUND; 222 return (UNVIS_SYNBAD); 223 } 224 } 225 226 /* 227 * strunvis - decode src into dst 228 * 229 * Number of chars decoded into dst is returned, -1 on error. 230 * Dst is null terminated. 231 */ 232 233 int 234 strunvis(dst, src) 235 register char *dst; 236 register const char *src; 237 { 238 register char c; 239 char *start = dst; 240 int state = 0; 241 242 while ((c = *src++) != '\0') { 243 again: 244 switch (unvis(dst, c, &state, 0)) { 245 case UNVIS_VALID: 246 dst++; 247 break; 248 case UNVIS_VALIDPUSH: 249 dst++; 250 goto again; 251 case 0: 252 case UNVIS_NOCHAR: 253 break; 254 default: 255 return (-1); 256 } 257 } 258 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 259 dst++; 260 *dst = '\0'; 261 return (dst - start); 262 } 263
Indexes created Mon Sep 22 13:09:51 GMT 2025