unvis.c revision 1.5.4.1
1 /* $NetBSD: unvis.c,v 1.5.4.1 1996/09/19 20:04:20 jtc 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 1.5.4.1 1996/09/19 20:04:20 jtc Exp $"; 41 #endif 42 #endif /* LIBC_SCCS and not lint */ 43 44 #include "namespace.h" 45 #include <sys/types.h> 46 #include <ctype.h> 47 #include <vis.h> 48 49 #ifdef __weak_alias 50 __weak_alias(unvis,_unvis); 51 __weak_alias(strunvis,_strunvis); 52 #endif 53 54 /* 55 * decode driven by state machine 56 */ 57 #define S_GROUND 0 /* haven't seen escape char */ 58 #define S_START 1 /* start decoding special sequence */ 59 #define S_META 2 /* metachar started (M) */ 60 #define S_META1 3 /* metachar more, regular char (-) */ 61 #define S_CTRL 4 /* control char started (^) */ 62 #define S_OCTAL2 5 /* octal digit 2 */ 63 #define S_OCTAL3 6 /* octal digit 3 */ 64 65 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 66 67 /* 68 * unvis - decode characters previously encoded by vis 69 */ 70 int 71 unvis(cp, c, astate, flag) 72 char *cp; 73 char c; 74 int *astate, flag; 75 { 76 77 if (flag & UNVIS_END) { 78 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 79 *astate = S_GROUND; 80 return (UNVIS_VALID); 81 } 82 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 83 } 84 85 switch (*astate) { 86 87 case S_GROUND: 88 *cp = 0; 89 if (c == '\\') { 90 *astate = S_START; 91 return (0); 92 } 93 *cp = c; 94 return (UNVIS_VALID); 95 96 case S_START: 97 switch(c) { 98 case '\\': 99 *cp = c; 100 *astate = S_GROUND; 101 return (UNVIS_VALID); 102 case '0': case '1': case '2': case '3': 103 case '4': case '5': case '6': case '7': 104 *cp = (c - '0'); 105 *astate = S_OCTAL2; 106 return (0); 107 case 'M': 108 *cp = 0200; 109 *astate = S_META; 110 return (0); 111 case '^': 112 *astate = S_CTRL; 113 return (0); 114 case 'n': 115 *cp = '\n'; 116 *astate = S_GROUND; 117 return (UNVIS_VALID); 118 case 'r': 119 *cp = '\r'; 120 *astate = S_GROUND; 121 return (UNVIS_VALID); 122 case 'b': 123 *cp = '\b'; 124 *astate = S_GROUND; 125 return (UNVIS_VALID); 126 case 'a': 127 *cp = '\007'; 128 *astate = S_GROUND; 129 return (UNVIS_VALID); 130 case 'v': 131 *cp = '\v'; 132 *astate = S_GROUND; 133 return (UNVIS_VALID); 134 case 't': 135 *cp = '\t'; 136 *astate = S_GROUND; 137 return (UNVIS_VALID); 138 case 'f': 139 *cp = '\f'; 140 *astate = S_GROUND; 141 return (UNVIS_VALID); 142 case 's': 143 *cp = ' '; 144 *astate = S_GROUND; 145 return (UNVIS_VALID); 146 case 'E': 147 *cp = '\033'; 148 *astate = S_GROUND; 149 return (UNVIS_VALID); 150 case '\n': 151 /* 152 * hidden newline 153 */ 154 *astate = S_GROUND; 155 return (UNVIS_NOCHAR); 156 case '$': 157 /* 158 * hidden marker 159 */ 160 *astate = S_GROUND; 161 return (UNVIS_NOCHAR); 162 } 163 *astate = S_GROUND; 164 return (UNVIS_SYNBAD); 165 166 case S_META: 167 if (c == '-') 168 *astate = S_META1; 169 else if (c == '^') 170 *astate = S_CTRL; 171 else { 172 *astate = S_GROUND; 173 return (UNVIS_SYNBAD); 174 } 175 return (0); 176 177 case S_META1: 178 *astate = S_GROUND; 179 *cp |= c; 180 return (UNVIS_VALID); 181 182 case S_CTRL: 183 if (c == '?') 184 *cp |= 0177; 185 else 186 *cp |= c & 037; 187 *astate = S_GROUND; 188 return (UNVIS_VALID); 189 190 case S_OCTAL2: /* second possible octal digit */ 191 if (isoctal(c)) { 192 /* 193 * yes - and maybe a third 194 */ 195 *cp = (*cp << 3) + (c - '0'); 196 *astate = S_OCTAL3; 197 return (0); 198 } 199 /* 200 * no - done with current sequence, push back passed char 201 */ 202 *astate = S_GROUND; 203 return (UNVIS_VALIDPUSH); 204 205 case S_OCTAL3: /* third possible octal digit */ 206 *astate = S_GROUND; 207 if (isoctal(c)) { 208 *cp = (*cp << 3) + (c - '0'); 209 return (UNVIS_VALID); 210 } 211 /* 212 * we were done, push back passed char 213 */ 214 return (UNVIS_VALIDPUSH); 215 216 default: 217 /* 218 * decoder in unknown state - (probably uninitialized) 219 */ 220 *astate = S_GROUND; 221 return (UNVIS_SYNBAD); 222 } 223 } 224 225 /* 226 * strunvis - decode src into dst 227 * 228 * Number of chars decoded into dst is returned, -1 on error. 229 * Dst is null terminated. 230 */ 231 232 int 233 strunvis(dst, src) 234 register char *dst; 235 register const char *src; 236 { 237 register char c; 238 char *start = dst; 239 int state = 0; 240 241 while (c = *src++) { 242 again: 243 switch (unvis(dst, c, &state, 0)) { 244 case UNVIS_VALID: 245 dst++; 246 break; 247 case UNVIS_VALIDPUSH: 248 dst++; 249 goto again; 250 case 0: 251 case UNVIS_NOCHAR: 252 break; 253 default: 254 return (-1); 255 } 256 } 257 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 258 dst++; 259 *dst = '\0'; 260 return (dst - start); 261 } 262
Indexes created Tue Sep 30 07:10:03 GMT 2025