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33 * $FreeBSD: src/lib/libc/gen/unvis.c,v 1.4.8.1 2000/08/17 08:25:54 jhb Exp $
34 * $DragonFly: src/lib/libcr/gen/Attic/unvis.c,v 1.3 2004/07/05 17:30:59 eirikn Exp $
36 * @(#)unvis.c 8.1 (Berkeley) 6/4/93
39 #include <sys/types.h>
43 * decode driven by state machine
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 #define S_HEX2 7 /* hex digit 2 */
54 #define S_HTTP 0x080 /* %HEXHEX escape */
56 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
57 #define ishex(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '9' || ((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f')
60 * unvis - decode characters previously encoded by vis
63 unvis(cp, c, astate, flag)
68 if (flag & UNVIS_END) {
69 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
73 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
76 switch (*astate & ~S_HTTP) {
84 if (flag & VIS_HTTPSTYLE && c == '%') {
85 *astate = S_START | S_HTTP;
92 if (*astate & S_HTTP) {
93 if (ishex(tolower(c))) {
94 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
103 return (UNVIS_VALID);
104 case '0': case '1': case '2': case '3':
105 case '4': case '5': case '6': case '7':
119 return (UNVIS_VALID);
123 return (UNVIS_VALID);
127 return (UNVIS_VALID);
131 return (UNVIS_VALID);
135 return (UNVIS_VALID);
139 return (UNVIS_VALID);
143 return (UNVIS_VALID);
147 return (UNVIS_VALID);
151 return (UNVIS_VALID);
157 return (UNVIS_NOCHAR);
163 return (UNVIS_NOCHAR);
166 return (UNVIS_SYNBAD);
175 return (UNVIS_SYNBAD);
182 return (UNVIS_VALID);
190 return (UNVIS_VALID);
192 case S_OCTAL2: /* second possible octal digit */
195 * yes - and maybe a third
197 *cp = (*cp << 3) + (c - '0');
202 * no - done with current sequence, push back passed char
205 return (UNVIS_VALIDPUSH);
207 case S_OCTAL3: /* third possible octal digit */
210 *cp = (*cp << 3) + (c - '0');
211 return (UNVIS_VALID);
214 * we were done, push back passed char
216 return (UNVIS_VALIDPUSH);
218 case S_HEX2: /* second mandatory hex digit */
219 if (ishex(tolower(c))) {
220 *cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
223 return (UNVIS_VALID);
227 * decoder in unknown state - (probably uninitialized)
230 return (UNVIS_SYNBAD);
235 * strunvis - decode src into dst
237 * Number of chars decoded into dst is returned, -1 on error.
238 * Dst is null terminated.
250 while ( (c = *src++) ) {
252 switch (unvis(dst, c, &state, 0)) {
256 case UNVIS_VALIDPUSH:
266 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
269 return (dst - start);
273 strunvisx(dst, src, flag)
281 while ( (c = *src++) ) {
283 switch (unvis(dst, c, &state, flag)) {
287 case UNVIS_VALIDPUSH:
297 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
300 return (dst - start);