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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 1.5 2005/11/19 22:32:53 swildner Exp $
36 * @(#)unvis.c 8.1 (Berkeley) 6/4/93
39 #include <sys/types.h>
44 * decode driven by state machine
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 */
55 #define S_HTTP 0x080 /* %HEXHEX escape */
57 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
58 #define ishex(c) ((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') || (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f'))
61 * unvis - decode characters previously encoded by vis
64 unvis(char *cp, int c, int *astate, int flag)
67 if (flag & UNVIS_END) {
68 if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
72 return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
75 switch (*astate & ~S_HTTP) {
83 if (flag & VIS_HTTPSTYLE && c == '%') {
84 *astate = S_START | S_HTTP;
91 if (*astate & S_HTTP) {
92 if (ishex(tolower(c))) {
93 *cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
102 return (UNVIS_VALID);
103 case '0': case '1': case '2': case '3':
104 case '4': case '5': case '6': case '7':
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);
150 return (UNVIS_VALID);
156 return (UNVIS_NOCHAR);
162 return (UNVIS_NOCHAR);
165 return (UNVIS_SYNBAD);
174 return (UNVIS_SYNBAD);
181 return (UNVIS_VALID);
189 return (UNVIS_VALID);
191 case S_OCTAL2: /* second possible octal digit */
194 * yes - and maybe a third
196 *cp = (*cp << 3) + (c - '0');
201 * no - done with current sequence, push back passed char
204 return (UNVIS_VALIDPUSH);
206 case S_OCTAL3: /* third possible octal digit */
209 *cp = (*cp << 3) + (c - '0');
210 return (UNVIS_VALID);
213 * we were done, push back passed char
215 return (UNVIS_VALIDPUSH);
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));
222 return (UNVIS_VALID);
226 * decoder in unknown state - (probably uninitialized)
229 return (UNVIS_SYNBAD);
234 * strunvis - decode src into dst
236 * Number of chars decoded into dst is returned, -1 on error.
237 * Dst is null terminated.
241 strunvis(char *dst, const char *src)
247 while ( (c = *src++) ) {
249 switch (unvis(dst, c, &state, 0)) {
253 case UNVIS_VALIDPUSH:
263 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
266 return (dst - start);
270 strunvisx(char *dst, const char *src, int flag)
276 while ( (c = *src++) ) {
278 switch (unvis(dst, c, &state, flag)) {
282 case UNVIS_VALIDPUSH:
292 if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
295 return (dst - start);