- Document ttyname_r().
[dragonfly.git] / lib / libc / gen / unvis.c
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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 * $FreeBSD: src/lib/libc/gen/unvis.c,v 1.4.8.1 2000/08/17 08:25:54 jhb Exp $
b0e25abd 34 * $DragonFly: src/lib/libc/gen/unvis.c,v 1.5 2005/11/19 22:32:53 swildner Exp $
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35 *
36 * @(#)unvis.c 8.1 (Berkeley) 6/4/93
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37 */
38
984263bc 39#include <sys/types.h>
b0e25abd 40#include <ctype.h>
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41#include <vis.h>
42
43/*
44 * decode driven by state machine
45 */
46#define S_GROUND 0 /* haven't seen escape char */
47#define S_START 1 /* start decoding special sequence */
48#define S_META 2 /* metachar started (M) */
49#define S_META1 3 /* metachar more, regular char (-) */
50#define S_CTRL 4 /* control char started (^) */
51#define S_OCTAL2 5 /* octal digit 2 */
52#define S_OCTAL3 6 /* octal digit 3 */
53#define S_HEX2 7 /* hex digit 2 */
54
55#define S_HTTP 0x080 /* %HEXHEX escape */
56
57#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
b0e25abd 58#define ishex(c) ((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') || (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f'))
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59
60/*
61 * unvis - decode characters previously encoded by vis
62 */
63int
0f52d283 64unvis(char *cp, int c, int *astate, int flag)
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65{
66
67 if (flag & UNVIS_END) {
68 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
69 *astate = S_GROUND;
70 return (UNVIS_VALID);
71 }
72 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
73 }
74
75 switch (*astate & ~S_HTTP) {
76
77 case S_GROUND:
78 *cp = 0;
79 if (c == '\\') {
80 *astate = S_START;
81 return (0);
82 }
83 if (flag & VIS_HTTPSTYLE && c == '%') {
84 *astate = S_START | S_HTTP;
85 return (0);
86 }
87 *cp = c;
88 return (UNVIS_VALID);
89
90 case S_START:
91 if (*astate & S_HTTP) {
92 if (ishex(tolower(c))) {
93 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
94 *astate = S_HEX2;
95 return (0);
96 }
97 }
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':
b0e25abd 109 *cp = (char)0200;
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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 case S_HEX2: /* second mandatory hex digit */
218 if (ishex(tolower(c))) {
219 *cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
220 }
221 *astate = S_GROUND;
222 return (UNVIS_VALID);
223
224 default:
225 /*
226 * decoder in unknown state - (probably uninitialized)
227 */
228 *astate = S_GROUND;
229 return (UNVIS_SYNBAD);
230 }
231}
232
233/*
234 * strunvis - decode src into dst
235 *
236 * Number of chars decoded into dst is returned, -1 on error.
237 * Dst is null terminated.
238 */
239
240int
0f52d283 241strunvis(char *dst, const char *src)
984263bc 242{
e27dad4e 243 char c;
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244 char *start = dst;
245 int state = 0;
246
247 while ( (c = *src++) ) {
248 again:
249 switch (unvis(dst, c, &state, 0)) {
250 case UNVIS_VALID:
251 dst++;
252 break;
253 case UNVIS_VALIDPUSH:
254 dst++;
255 goto again;
256 case 0:
257 case UNVIS_NOCHAR:
258 break;
259 default:
260 return (-1);
261 }
262 }
263 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
264 dst++;
265 *dst = '\0';
266 return (dst - start);
267}
268
269int
0f52d283 270strunvisx(char *dst, const char *src, int flag)
984263bc 271{
e27dad4e 272 char c;
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273 char *start = dst;
274 int state = 0;
275
276 while ( (c = *src++) ) {
277 again:
278 switch (unvis(dst, c, &state, flag)) {
279 case UNVIS_VALID:
280 dst++;
281 break;
282 case UNVIS_VALIDPUSH:
283 dst++;
284 goto again;
285 case 0:
286 case UNVIS_NOCHAR:
287 break;
288 default:
289 return (-1);
290 }
291 }
292 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
293 dst++;
294 *dst = '\0';
295 return (dst - start);
296}