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29 * $FreeBSD: src/lib/libc/gen/unvis.c,v 1.4.8.1 2000/08/17 08:25:54 jhb Exp $
30 * $DragonFly: src/lib/libc/gen/unvis.c,v 1.5 2005/11/19 22:32:53 swildner Exp $
32 * @(#)unvis.c 8.1 (Berkeley) 6/4/93
35 #include <sys/types.h>
40 * decode driven by state machine
42 #define S_GROUND 0 /* haven't seen escape char */
43 #define S_START 1 /* start decoding special sequence */
44 #define S_META 2 /* metachar started (M) */
45 #define S_META1 3 /* metachar more, regular char (-) */
46 #define S_CTRL 4 /* control char started (^) */
47 #define S_OCTAL2 5 /* octal digit 2 */
48 #define S_OCTAL3 6 /* octal digit 3 */
49 #define S_HEX2 7 /* hex digit 2 */
51 #define S_HTTP 0x080 /* %HEXHEX escape */
53 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
54 #define ishex(c) ((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') || (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f'))
57 * unvis - decode characters previously encoded by vis
60 unvis(char *cp, int c, int *astate, int flag)
63 if (flag & UNVIS_END) {
64 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
68 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
71 switch (*astate & ~S_HTTP) {
79 if (flag & VIS_HTTPSTYLE && c == '%') {
80 *astate = S_START | S_HTTP;
87 if (*astate & S_HTTP) {
88 if (ishex(tolower(c))) {
89 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
99 case '0': case '1': case '2': case '3':
100 case '4': case '5': case '6': case '7':
114 return (UNVIS_VALID);
118 return (UNVIS_VALID);
122 return (UNVIS_VALID);
126 return (UNVIS_VALID);
130 return (UNVIS_VALID);
134 return (UNVIS_VALID);
138 return (UNVIS_VALID);
142 return (UNVIS_VALID);
146 return (UNVIS_VALID);
152 return (UNVIS_NOCHAR);
158 return (UNVIS_NOCHAR);
161 return (UNVIS_SYNBAD);
170 return (UNVIS_SYNBAD);
177 return (UNVIS_VALID);
185 return (UNVIS_VALID);
187 case S_OCTAL2: /* second possible octal digit */
190 * yes - and maybe a third
192 *cp = (*cp << 3) + (c - '0');
197 * no - done with current sequence, push back passed char
200 return (UNVIS_VALIDPUSH);
202 case S_OCTAL3: /* third possible octal digit */
205 *cp = (*cp << 3) + (c - '0');
206 return (UNVIS_VALID);
209 * we were done, push back passed char
211 return (UNVIS_VALIDPUSH);
213 case S_HEX2: /* second mandatory hex digit */
214 if (ishex(tolower(c))) {
215 *cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
218 return (UNVIS_VALID);
222 * decoder in unknown state - (probably uninitialized)
225 return (UNVIS_SYNBAD);
230 * strunvis - decode src into dst
232 * Number of chars decoded into dst is returned, -1 on error.
233 * Dst is null terminated.
237 strunvis(char *dst, const char *src)
243 while ( (c = *src++) ) {
245 switch (unvis(dst, c, &state, 0)) {
249 case UNVIS_VALIDPUSH:
259 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
262 return (dst - start);
266 strunvisx(char *dst, const char *src, int flag)
272 while ( (c = *src++) ) {
274 switch (unvis(dst, c, &state, flag)) {
278 case UNVIS_VALIDPUSH:
288 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
291 return (dst - start);