unvis.c revision 1.4
1 /* $NetBSD: unvis.c,v 1.4 1995/02/25 15:39:44 cgd 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 #if defined(LIBC_SCCS) && !defined(lint) 37 #if 0 38 static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 39 #else 40 static char rcsid[] = "$NetBSD: unvis.c,v 1.4 1995/02/25 15:39:44 cgd Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include <sys/types.h> 45 #include <ctype.h> 46 #include <vis.h> 47 48 /* 49 * decode driven by state machine 50 */ 51 #define S_GROUND 0 /* haven't seen escape char */ 52 #define S_START 1 /* start decoding special sequence */ 53 #define S_META 2 /* metachar started (M) */ 54 #define S_META1 3 /* metachar more, regular char (-) */ 55 #define S_CTRL 4 /* control char started (^) */ 56 #define S_OCTAL2 5 /* octal digit 2 */ 57 #define S_OCTAL3 6 /* octal digit 3 */ 58 59 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 60 61 /* 62 * unvis - decode characters previously encoded by vis 63 */ 64 int 65 unvis(cp, c, astate, flag) 66 char *cp; 67 int c, *astate, flag; 68 { 69 70 if (flag & UNVIS_END) { 71 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 72 *astate = S_GROUND; 73 return (UNVIS_VALID); 74 } 75 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 76 } 77 78 switch (*astate) { 79 80 case S_GROUND: 81 *cp = 0; 82 if (c == '\\') { 83 *astate = S_START; 84 return (0); 85 } 86 *cp = c; 87 return (UNVIS_VALID); 88 89 case S_START: 90 switch(c) { 91 case '\\': 92 *cp = c; 93 *astate = S_GROUND; 94 return (UNVIS_VALID); 95 case '0': case '1': case '2': case '3': 96 case '4': case '5': case '6': case '7': 97 *cp = (c - '0'); 98 *astate = S_OCTAL2; 99 return (0); 100 case 'M': 101 *cp = 0200; 102 *astate = S_META; 103 return (0); 104 case '^': 105 *astate = S_CTRL; 106 return (0); 107 case 'n': 108 *cp = '\n'; 109 *astate = S_GROUND; 110 return (UNVIS_VALID); 111 case 'r': 112 *cp = '\r'; 113 *astate = S_GROUND; 114 return (UNVIS_VALID); 115 case 'b': 116 *cp = '\b'; 117 *astate = S_GROUND; 118 return (UNVIS_VALID); 119 case 'a': 120 *cp = '\007'; 121 *astate = S_GROUND; 122 return (UNVIS_VALID); 123 case 'v': 124 *cp = '\v'; 125 *astate = S_GROUND; 126 return (UNVIS_VALID); 127 case 't': 128 *cp = '\t'; 129 *astate = S_GROUND; 130 return (UNVIS_VALID); 131 case 'f': 132 *cp = '\f'; 133 *astate = S_GROUND; 134 return (UNVIS_VALID); 135 case 's': 136 *cp = ' '; 137 *astate = S_GROUND; 138 return (UNVIS_VALID); 139 case 'E': 140 *cp = '\033'; 141 *astate = S_GROUND; 142 return (UNVIS_VALID); 143 case '\n': 144 /* 145 * hidden newline 146 */ 147 *astate = S_GROUND; 148 return (UNVIS_NOCHAR); 149 case '$': 150 /* 151 * hidden marker 152 */ 153 *astate = S_GROUND; 154 return (UNVIS_NOCHAR); 155 } 156 *astate = S_GROUND; 157 return (UNVIS_SYNBAD); 158 159 case S_META: 160 if (c == '-') 161 *astate = S_META1; 162 else if (c == '^') 163 *astate = S_CTRL; 164 else { 165 *astate = S_GROUND; 166 return (UNVIS_SYNBAD); 167 } 168 return (0); 169 170 case S_META1: 171 *astate = S_GROUND; 172 *cp |= c; 173 return (UNVIS_VALID); 174 175 case S_CTRL: 176 if (c == '?') 177 *cp |= 0177; 178 else 179 *cp |= c & 037; 180 *astate = S_GROUND; 181 return (UNVIS_VALID); 182 183 case S_OCTAL2: /* second possible octal digit */ 184 if (isoctal(c)) { 185 /* 186 * yes - and maybe a third 187 */ 188 *cp = (*cp << 3) + (c - '0'); 189 *astate = S_OCTAL3; 190 return (0); 191 } 192 /* 193 * no - done with current sequence, push back passed char 194 */ 195 *astate = S_GROUND; 196 return (UNVIS_VALIDPUSH); 197 198 case S_OCTAL3: /* third possible octal digit */ 199 *astate = S_GROUND; 200 if (isoctal(c)) { 201 *cp = (*cp << 3) + (c - '0'); 202 return (UNVIS_VALID); 203 } 204 /* 205 * we were done, push back passed char 206 */ 207 return (UNVIS_VALIDPUSH); 208 209 default: 210 /* 211 * decoder in unknown state - (probably uninitialized) 212 */ 213 *astate = S_GROUND; 214 return (UNVIS_SYNBAD); 215 } 216 } 217 218 /* 219 * strunvis - decode src into dst 220 * 221 * Number of chars decoded into dst is returned, -1 on error. 222 * Dst is null terminated. 223 */ 224 225 int 226 strunvis(dst, src) 227 register char *dst; 228 register const char *src; 229 { 230 register char c; 231 char *start = dst; 232 int state = 0; 233 234 while (c = *src++) { 235 again: 236 switch (unvis(dst, c, &state, 0)) { 237 case UNVIS_VALID: 238 dst++; 239 break; 240 case UNVIS_VALIDPUSH: 241 dst++; 242 goto again; 243 case 0: 244 case UNVIS_NOCHAR: 245 break; 246 default: 247 return (-1); 248 } 249 } 250 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 251 dst++; 252 *dst = '\0'; 253 return (dst - start); 254 } 255
Indexes created Mon Sep 22 13:09:51 GMT 2025