unvis.c revision 1.5
1 /* $NetBSD: unvis.c,v 1.5 1995/02/25 17:18:31 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 1.5 1995/02/25 17:18:31 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 char c; 68 int *astate, flag; 69 { 70 71 if (flag & UNVIS_END) { 72 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 73 *astate = S_GROUND; 74 return (UNVIS_VALID); 75 } 76 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 77 } 78 79 switch (*astate) { 80 81 case S_GROUND: 82 *cp = 0; 83 if (c == '\\') { 84 *astate = S_START; 85 return (0); 86 } 87 *cp = c; 88 return (UNVIS_VALID); 89 90 case S_START: 91 switch(c) { 92 case '\\': 93 *cp = c; 94 *astate = S_GROUND; 95 return (UNVIS_VALID); 96 case '0': case '1': case '2': case '3': 97 case '4': case '5': case '6': case '7': 98 *cp = (c - '0'); 99 *astate = S_OCTAL2; 100 return (0); 101 case 'M': 102 *cp = 0200; 103 *astate = S_META; 104 return (0); 105 case '^': 106 *astate = S_CTRL; 107 return (0); 108 case 'n': 109 *cp = '\n'; 110 *astate = S_GROUND; 111 return (UNVIS_VALID); 112 case 'r': 113 *cp = '\r'; 114 *astate = S_GROUND; 115 return (UNVIS_VALID); 116 case 'b': 117 *cp = '\b'; 118 *astate = S_GROUND; 119 return (UNVIS_VALID); 120 case 'a': 121 *cp = '\007'; 122 *astate = S_GROUND; 123 return (UNVIS_VALID); 124 case 'v': 125 *cp = '\v'; 126 *astate = S_GROUND; 127 return (UNVIS_VALID); 128 case 't': 129 *cp = '\t'; 130 *astate = S_GROUND; 131 return (UNVIS_VALID); 132 case 'f': 133 *cp = '\f'; 134 *astate = S_GROUND; 135 return (UNVIS_VALID); 136 case 's': 137 *cp = ' '; 138 *astate = S_GROUND; 139 return (UNVIS_VALID); 140 case 'E': 141 *cp = '\033'; 142 *astate = S_GROUND; 143 return (UNVIS_VALID); 144 case '\n': 145 /* 146 * hidden newline 147 */ 148 *astate = S_GROUND; 149 return (UNVIS_NOCHAR); 150 case '$': 151 /* 152 * hidden marker 153 */ 154 *astate = S_GROUND; 155 return (UNVIS_NOCHAR); 156 } 157 *astate = S_GROUND; 158 return (UNVIS_SYNBAD); 159 160 case S_META: 161 if (c == '-') 162 *astate = S_META1; 163 else if (c == '^') 164 *astate = S_CTRL; 165 else { 166 *astate = S_GROUND; 167 return (UNVIS_SYNBAD); 168 } 169 return (0); 170 171 case S_META1: 172 *astate = S_GROUND; 173 *cp |= c; 174 return (UNVIS_VALID); 175 176 case S_CTRL: 177 if (c == '?') 178 *cp |= 0177; 179 else 180 *cp |= c & 037; 181 *astate = S_GROUND; 182 return (UNVIS_VALID); 183 184 case S_OCTAL2: /* second possible octal digit */ 185 if (isoctal(c)) { 186 /* 187 * yes - and maybe a third 188 */ 189 *cp = (*cp << 3) + (c - '0'); 190 *astate = S_OCTAL3; 191 return (0); 192 } 193 /* 194 * no - done with current sequence, push back passed char 195 */ 196 *astate = S_GROUND; 197 return (UNVIS_VALIDPUSH); 198 199 case S_OCTAL3: /* third possible octal digit */ 200 *astate = S_GROUND; 201 if (isoctal(c)) { 202 *cp = (*cp << 3) + (c - '0'); 203 return (UNVIS_VALID); 204 } 205 /* 206 * we were done, push back passed char 207 */ 208 return (UNVIS_VALIDPUSH); 209 210 default: 211 /* 212 * decoder in unknown state - (probably uninitialized) 213 */ 214 *astate = S_GROUND; 215 return (UNVIS_SYNBAD); 216 } 217 } 218 219 /* 220 * strunvis - decode src into dst 221 * 222 * Number of chars decoded into dst is returned, -1 on error. 223 * Dst is null terminated. 224 */ 225 226 int 227 strunvis(dst, src) 228 register char *dst; 229 register const char *src; 230 { 231 register char c; 232 char *start = dst; 233 int state = 0; 234 235 while (c = *src++) { 236 again: 237 switch (unvis(dst, c, &state, 0)) { 238 case UNVIS_VALID: 239 dst++; 240 break; 241 case UNVIS_VALIDPUSH: 242 dst++; 243 goto again; 244 case 0: 245 case UNVIS_NOCHAR: 246 break; 247 default: 248 return (-1); 249 } 250 } 251 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 252 dst++; 253 *dst = '\0'; 254 return (dst - start); 255 } 256
Indexes created Mon Sep 22 05:09:51 GMT 2025