unvis.c revision 1.1.1.2
1 /*- 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 #include <ctype.h> 40 #include <vis.h> 41 42 /* 43 * decode driven by state machine 44 */ 45 #define S_GROUND 0 /* haven't seen escape char */ 46 #define S_START 1 /* start decoding special sequence */ 47 #define S_META 2 /* metachar started (M) */ 48 #define S_META1 3 /* metachar more, regular char (-) */ 49 #define S_CTRL 4 /* control char started (^) */ 50 #define S_OCTAL2 5 /* octal digit 2 */ 51 #define S_OCTAL3 6 /* octal digit 3 */ 52 53 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 54 55 /* 56 * unvis - decode characters previously encoded by vis 57 */ 58 int 59 unvis(cp, c, astate, flag) 60 char *cp; 61 int c, *astate, flag; 62 { 63 64 if (flag & UNVIS_END) { 65 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { 66 *astate = S_GROUND; 67 return (UNVIS_VALID); 68 } 69 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); 70 } 71 72 switch (*astate) { 73 74 case S_GROUND: 75 *cp = 0; 76 if (c == '\\') { 77 *astate = S_START; 78 return (0); 79 } 80 *cp = c; 81 return (UNVIS_VALID); 82 83 case S_START: 84 switch(c) { 85 case '\\': 86 *cp = c; 87 *astate = S_GROUND; 88 return (UNVIS_VALID); 89 case '0': case '1': case '2': case '3': 90 case '4': case '5': case '6': case '7': 91 *cp = (c - '0'); 92 *astate = S_OCTAL2; 93 return (0); 94 case 'M': 95 *cp = 0200; 96 *astate = S_META; 97 return (0); 98 case '^': 99 *astate = S_CTRL; 100 return (0); 101 case 'n': 102 *cp = '\n'; 103 *astate = S_GROUND; 104 return (UNVIS_VALID); 105 case 'r': 106 *cp = '\r'; 107 *astate = S_GROUND; 108 return (UNVIS_VALID); 109 case 'b': 110 *cp = '\b'; 111 *astate = S_GROUND; 112 return (UNVIS_VALID); 113 case 'a': 114 *cp = '\007'; 115 *astate = S_GROUND; 116 return (UNVIS_VALID); 117 case 'v': 118 *cp = '\v'; 119 *astate = S_GROUND; 120 return (UNVIS_VALID); 121 case 't': 122 *cp = '\t'; 123 *astate = S_GROUND; 124 return (UNVIS_VALID); 125 case 'f': 126 *cp = '\f'; 127 *astate = S_GROUND; 128 return (UNVIS_VALID); 129 case 's': 130 *cp = ' '; 131 *astate = S_GROUND; 132 return (UNVIS_VALID); 133 case 'E': 134 *cp = '\033'; 135 *astate = S_GROUND; 136 return (UNVIS_VALID); 137 case '\n': 138 /* 139 * hidden newline 140 */ 141 *astate = S_GROUND; 142 return (UNVIS_NOCHAR); 143 case '$': 144 /* 145 * hidden marker 146 */ 147 *astate = S_GROUND; 148 return (UNVIS_NOCHAR); 149 } 150 *astate = S_GROUND; 151 return (UNVIS_SYNBAD); 152 153 case S_META: 154 if (c == '-') 155 *astate = S_META1; 156 else if (c == '^') 157 *astate = S_CTRL; 158 else { 159 *astate = S_GROUND; 160 return (UNVIS_SYNBAD); 161 } 162 return (0); 163 164 case S_META1: 165 *astate = S_GROUND; 166 *cp |= c; 167 return (UNVIS_VALID); 168 169 case S_CTRL: 170 if (c == '?') 171 *cp |= 0177; 172 else 173 *cp |= c & 037; 174 *astate = S_GROUND; 175 return (UNVIS_VALID); 176 177 case S_OCTAL2: /* second possible octal digit */ 178 if (isoctal(c)) { 179 /* 180 * yes - and maybe a third 181 */ 182 *cp = (*cp << 3) + (c - '0'); 183 *astate = S_OCTAL3; 184 return (0); 185 } 186 /* 187 * no - done with current sequence, push back passed char 188 */ 189 *astate = S_GROUND; 190 return (UNVIS_VALIDPUSH); 191 192 case S_OCTAL3: /* third possible octal digit */ 193 *astate = S_GROUND; 194 if (isoctal(c)) { 195 *cp = (*cp << 3) + (c - '0'); 196 return (UNVIS_VALID); 197 } 198 /* 199 * we were done, push back passed char 200 */ 201 return (UNVIS_VALIDPUSH); 202 203 default: 204 /* 205 * decoder in unknown state - (probably uninitialized) 206 */ 207 *astate = S_GROUND; 208 return (UNVIS_SYNBAD); 209 } 210 } 211 212 /* 213 * strunvis - decode src into dst 214 * 215 * Number of chars decoded into dst is returned, -1 on error. 216 * Dst is null terminated. 217 */ 218 219 int 220 strunvis(dst, src) 221 register char *dst; 222 register const char *src; 223 { 224 register char c; 225 char *start = dst; 226 int state = 0; 227 228 while (c = *src++) { 229 again: 230 switch (unvis(dst, c, &state, 0)) { 231 case UNVIS_VALID: 232 dst++; 233 break; 234 case UNVIS_VALIDPUSH: 235 dst++; 236 goto again; 237 case 0: 238 case UNVIS_NOCHAR: 239 break; 240 default: 241 return (-1); 242 } 243 } 244 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) 245 dst++; 246 *dst = '\0'; 247 return (dst - start); 248 } 249
Indexes created Tue Sep 30 10:09:55 GMT 2025