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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/libc/gen/unvis.c,v 1.4 2005/11/13 00:07:42 swildner 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(char *cp, int c, int *astate, int flag)
66 if (flag & UNVIS_END) {
67 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
71 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
74 switch (*astate & ~S_HTTP) {
82 if (flag & VIS_HTTPSTYLE && c == '%') {
83 *astate = S_START | S_HTTP;
90 if (*astate & S_HTTP) {
91 if (ishex(tolower(c))) {
92 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
101 return (UNVIS_VALID);
102 case '0': case '1': case '2': case '3':
103 case '4': case '5': case '6': case '7':
117 return (UNVIS_VALID);
121 return (UNVIS_VALID);
125 return (UNVIS_VALID);
129 return (UNVIS_VALID);
133 return (UNVIS_VALID);
137 return (UNVIS_VALID);
141 return (UNVIS_VALID);
145 return (UNVIS_VALID);
149 return (UNVIS_VALID);
155 return (UNVIS_NOCHAR);
161 return (UNVIS_NOCHAR);
164 return (UNVIS_SYNBAD);
173 return (UNVIS_SYNBAD);
180 return (UNVIS_VALID);
188 return (UNVIS_VALID);
190 case S_OCTAL2: /* second possible octal digit */
193 * yes - and maybe a third
195 *cp = (*cp << 3) + (c - '0');
200 * no - done with current sequence, push back passed char
203 return (UNVIS_VALIDPUSH);
205 case S_OCTAL3: /* third possible octal digit */
208 *cp = (*cp << 3) + (c - '0');
209 return (UNVIS_VALID);
212 * we were done, push back passed char
214 return (UNVIS_VALIDPUSH);
216 case S_HEX2: /* second mandatory hex digit */
217 if (ishex(tolower(c))) {
218 *cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
221 return (UNVIS_VALID);
225 * decoder in unknown state - (probably uninitialized)
228 return (UNVIS_SYNBAD);
233 * strunvis - decode src into dst
235 * Number of chars decoded into dst is returned, -1 on error.
236 * Dst is null terminated.
240 strunvis(char *dst, const char *src)
246 while ( (c = *src++) ) {
248 switch (unvis(dst, c, &state, 0)) {
252 case UNVIS_VALIDPUSH:
262 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
265 return (dst - start);
269 strunvisx(char *dst, const char *src, int flag)
275 while ( (c = *src++) ) {
277 switch (unvis(dst, c, &state, flag)) {
281 case UNVIS_VALIDPUSH:
291 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
294 return (dst - start);