Commit | Line | Data |
---|---|---|
d6a13ceb | 1 | /*- |
1af61e06 MT |
2 | * Copyright (c) 1989 The Regents of the University of California. |
3 | * All rights reserved. | |
4 | * | |
d6a13ceb | 5 | * %sccs.include.redist.c% |
1af61e06 MT |
6 | */ |
7 | ||
8 | #if defined(LIBC_SCCS) && !defined(lint) | |
c5980113 | 9 | static char sccsid[] = "@(#)unvis.c 1.4 (Berkeley) %G%"; |
1af61e06 MT |
10 | #endif /* LIBC_SCCS and not lint */ |
11 | ||
12 | #include <sys/types.h> | |
13 | #include <ctype.h> | |
14 | #include <vis.h> | |
15 | ||
16 | /* | |
17 | * decode driven by state machine | |
18 | */ | |
19 | #define S_GROUND 0 /* haven't seen escape char */ | |
20 | #define S_START 1 /* start decoding special sequence */ | |
21 | #define S_META 2 /* metachar started (M) */ | |
22 | #define S_META1 3 /* metachar more, regular char (-) */ | |
23 | #define S_CTRL 4 /* control char started (^) */ | |
24 | #define S_OCTAL2 5 /* octal digit 2 */ | |
25 | #define S_OCTAL3 6 /* octal digit 3 */ | |
26 | ||
d6a13ceb MT |
27 | #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') |
28 | ||
1af61e06 MT |
29 | /* |
30 | * unvis - decode characters previously encoded by vis | |
31 | */ | |
c5980113 DS |
32 | int |
33 | #if __STDC__ | |
34 | unvis(char *cp, char c, int *astate, int flag) | |
35 | #else | |
1af61e06 | 36 | unvis(cp, c, astate, flag) |
c5980113 | 37 | char *cp, c; |
1af61e06 | 38 | int *astate, flag; |
c5980113 | 39 | #endif |
1af61e06 MT |
40 | { |
41 | ||
42 | if (flag & UNVIS_END) { | |
43 | if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { | |
44 | *astate = S_GROUND; | |
45 | return (UNVIS_VALID); | |
46 | } | |
47 | return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); | |
48 | } | |
49 | ||
50 | switch (*astate) { | |
51 | ||
52 | case S_GROUND: | |
53 | *cp = 0; | |
54 | if (c == '\\') { | |
55 | *astate = S_START; | |
56 | return (0); | |
57 | } | |
58 | *cp = c; | |
59 | return (UNVIS_VALID); | |
60 | ||
61 | case S_START: | |
62 | switch(c) { | |
63 | case '\\': | |
64 | *cp = c; | |
65 | *astate = S_GROUND; | |
66 | return (UNVIS_VALID); | |
67 | case '0': case '1': case '2': case '3': | |
68 | case '4': case '5': case '6': case '7': | |
69 | *cp = (c - '0'); | |
70 | *astate = S_OCTAL2; | |
71 | return (0); | |
72 | case 'M': | |
73 | *cp = 0200; | |
74 | *astate = S_META; | |
75 | return (0); | |
76 | case '^': | |
77 | *astate = S_CTRL; | |
78 | return (0); | |
79 | case 'n': | |
80 | *cp = '\n'; | |
81 | *astate = S_GROUND; | |
82 | return (UNVIS_VALID); | |
83 | case 'r': | |
84 | *cp = '\r'; | |
85 | *astate = S_GROUND; | |
86 | return (UNVIS_VALID); | |
87 | case 'b': | |
88 | *cp = '\b'; | |
89 | *astate = S_GROUND; | |
90 | return (UNVIS_VALID); | |
91 | case 'a': | |
92 | *cp = '\007'; | |
93 | *astate = S_GROUND; | |
94 | return (UNVIS_VALID); | |
95 | case 'v': | |
96 | *cp = '\v'; | |
97 | *astate = S_GROUND; | |
98 | return (UNVIS_VALID); | |
99 | case 't': | |
100 | *cp = '\t'; | |
101 | *astate = S_GROUND; | |
102 | return (UNVIS_VALID); | |
103 | case 'f': | |
104 | *cp = '\f'; | |
105 | *astate = S_GROUND; | |
106 | return (UNVIS_VALID); | |
107 | case 's': | |
108 | *cp = ' '; | |
109 | *astate = S_GROUND; | |
110 | return (UNVIS_VALID); | |
111 | case 'E': | |
112 | *cp = '\033'; | |
113 | *astate = S_GROUND; | |
114 | return (UNVIS_VALID); | |
115 | case '\n': | |
116 | /* | |
117 | * hidden newline | |
118 | */ | |
119 | *astate = S_GROUND; | |
120 | return (UNVIS_NOCHAR); | |
d6a13ceb MT |
121 | case '$': |
122 | /* | |
123 | * hidden marker | |
124 | */ | |
125 | *astate = S_GROUND; | |
126 | return (UNVIS_NOCHAR); | |
1af61e06 MT |
127 | } |
128 | *astate = S_GROUND; | |
129 | return (UNVIS_SYNBAD); | |
130 | ||
131 | case S_META: | |
132 | if (c == '-') | |
133 | *astate = S_META1; | |
134 | else if (c == '^') | |
135 | *astate = S_CTRL; | |
136 | else { | |
137 | *astate = S_GROUND; | |
138 | return (UNVIS_SYNBAD); | |
139 | } | |
140 | return (0); | |
141 | ||
142 | case S_META1: | |
143 | *astate = S_GROUND; | |
144 | *cp |= c; | |
145 | return (UNVIS_VALID); | |
146 | ||
147 | case S_CTRL: | |
148 | if (c == '?') | |
149 | *cp |= 0177; | |
150 | else | |
151 | *cp |= c & 037; | |
152 | *astate = S_GROUND; | |
153 | return (UNVIS_VALID); | |
154 | ||
155 | case S_OCTAL2: /* second possible octal digit */ | |
156 | if (isoctal(c)) { | |
157 | /* | |
158 | * yes - and maybe a third | |
159 | */ | |
160 | *cp = (*cp << 3) + (c - '0'); | |
161 | *astate = S_OCTAL3; | |
162 | return (0); | |
163 | } | |
164 | /* | |
165 | * no - done with current sequence, push back passed char | |
166 | */ | |
167 | *astate = S_GROUND; | |
168 | return (UNVIS_VALIDPUSH); | |
169 | ||
170 | case S_OCTAL3: /* third possible octal digit */ | |
171 | *astate = S_GROUND; | |
172 | if (isoctal(c)) { | |
173 | *cp = (*cp << 3) + (c - '0'); | |
174 | return (UNVIS_VALID); | |
175 | } | |
176 | /* | |
177 | * we were done, push back passed char | |
178 | */ | |
179 | return (UNVIS_VALIDPUSH); | |
180 | ||
181 | default: | |
182 | /* | |
183 | * decoder in unknown state - (probably uninitialized) | |
184 | */ | |
2e93102d MT |
185 | *astate = S_GROUND; |
186 | return (UNVIS_SYNBAD); | |
1af61e06 MT |
187 | } |
188 | } | |
189 | ||
190 | /* | |
d6a13ceb | 191 | * strunvis - decode src into dst |
1af61e06 | 192 | * |
d6a13ceb MT |
193 | * Number of chars decoded into dst is returned, -1 on error. |
194 | * Dst is null terminated. | |
1af61e06 | 195 | */ |
d6a13ceb | 196 | |
c5980113 | 197 | int |
d6a13ceb | 198 | strunvis(dst, src) |
c5980113 DS |
199 | register char *dst; |
200 | register const char *src; | |
1af61e06 | 201 | { |
d6a13ceb | 202 | register char c; |
1af61e06 | 203 | char *start = dst; |
2e93102d | 204 | int state = 0; |
1af61e06 | 205 | |
d6a13ceb MT |
206 | while (c = *src++) { |
207 | again: | |
208 | switch (unvis(dst, c, &state, 0)) { | |
209 | case UNVIS_VALID: | |
210 | dst++; | |
1af61e06 | 211 | break; |
d6a13ceb MT |
212 | case UNVIS_VALIDPUSH: |
213 | dst++; | |
214 | goto again; | |
215 | case 0: | |
216 | case UNVIS_NOCHAR: | |
217 | break; | |
218 | default: | |
219 | return (-1); | |
220 | } | |
1af61e06 | 221 | } |
2e93102d MT |
222 | if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) |
223 | dst++; | |
d6a13ceb | 224 | *dst = '\0'; |
1af61e06 MT |
225 | return (dst - start); |
226 | } |