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) | |
2e93102d | 9 | static char sccsid[] = "@(#)unvis.c 1.3 (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 | */ | |
32 | unvis(cp, c, astate, flag) | |
33 | u_char *cp, c; | |
34 | int *astate, flag; | |
35 | { | |
36 | ||
37 | if (flag & UNVIS_END) { | |
38 | if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { | |
39 | *astate = S_GROUND; | |
40 | return (UNVIS_VALID); | |
41 | } | |
42 | return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); | |
43 | } | |
44 | ||
45 | switch (*astate) { | |
46 | ||
47 | case S_GROUND: | |
48 | *cp = 0; | |
49 | if (c == '\\') { | |
50 | *astate = S_START; | |
51 | return (0); | |
52 | } | |
53 | *cp = c; | |
54 | return (UNVIS_VALID); | |
55 | ||
56 | case S_START: | |
57 | switch(c) { | |
58 | case '\\': | |
59 | *cp = c; | |
60 | *astate = S_GROUND; | |
61 | return (UNVIS_VALID); | |
62 | case '0': case '1': case '2': case '3': | |
63 | case '4': case '5': case '6': case '7': | |
64 | *cp = (c - '0'); | |
65 | *astate = S_OCTAL2; | |
66 | return (0); | |
67 | case 'M': | |
68 | *cp = 0200; | |
69 | *astate = S_META; | |
70 | return (0); | |
71 | case '^': | |
72 | *astate = S_CTRL; | |
73 | return (0); | |
74 | case 'n': | |
75 | *cp = '\n'; | |
76 | *astate = S_GROUND; | |
77 | return (UNVIS_VALID); | |
78 | case 'r': | |
79 | *cp = '\r'; | |
80 | *astate = S_GROUND; | |
81 | return (UNVIS_VALID); | |
82 | case 'b': | |
83 | *cp = '\b'; | |
84 | *astate = S_GROUND; | |
85 | return (UNVIS_VALID); | |
86 | case 'a': | |
87 | *cp = '\007'; | |
88 | *astate = S_GROUND; | |
89 | return (UNVIS_VALID); | |
90 | case 'v': | |
91 | *cp = '\v'; | |
92 | *astate = S_GROUND; | |
93 | return (UNVIS_VALID); | |
94 | case 't': | |
95 | *cp = '\t'; | |
96 | *astate = S_GROUND; | |
97 | return (UNVIS_VALID); | |
98 | case 'f': | |
99 | *cp = '\f'; | |
100 | *astate = S_GROUND; | |
101 | return (UNVIS_VALID); | |
102 | case 's': | |
103 | *cp = ' '; | |
104 | *astate = S_GROUND; | |
105 | return (UNVIS_VALID); | |
106 | case 'E': | |
107 | *cp = '\033'; | |
108 | *astate = S_GROUND; | |
109 | return (UNVIS_VALID); | |
110 | case '\n': | |
111 | /* | |
112 | * hidden newline | |
113 | */ | |
114 | *astate = S_GROUND; | |
115 | return (UNVIS_NOCHAR); | |
d6a13ceb MT |
116 | case '$': |
117 | /* | |
118 | * hidden marker | |
119 | */ | |
120 | *astate = S_GROUND; | |
121 | return (UNVIS_NOCHAR); | |
1af61e06 MT |
122 | } |
123 | *astate = S_GROUND; | |
124 | return (UNVIS_SYNBAD); | |
125 | ||
126 | case S_META: | |
127 | if (c == '-') | |
128 | *astate = S_META1; | |
129 | else if (c == '^') | |
130 | *astate = S_CTRL; | |
131 | else { | |
132 | *astate = S_GROUND; | |
133 | return (UNVIS_SYNBAD); | |
134 | } | |
135 | return (0); | |
136 | ||
137 | case S_META1: | |
138 | *astate = S_GROUND; | |
139 | *cp |= c; | |
140 | return (UNVIS_VALID); | |
141 | ||
142 | case S_CTRL: | |
143 | if (c == '?') | |
144 | *cp |= 0177; | |
145 | else | |
146 | *cp |= c & 037; | |
147 | *astate = S_GROUND; | |
148 | return (UNVIS_VALID); | |
149 | ||
150 | case S_OCTAL2: /* second possible octal digit */ | |
151 | if (isoctal(c)) { | |
152 | /* | |
153 | * yes - and maybe a third | |
154 | */ | |
155 | *cp = (*cp << 3) + (c - '0'); | |
156 | *astate = S_OCTAL3; | |
157 | return (0); | |
158 | } | |
159 | /* | |
160 | * no - done with current sequence, push back passed char | |
161 | */ | |
162 | *astate = S_GROUND; | |
163 | return (UNVIS_VALIDPUSH); | |
164 | ||
165 | case S_OCTAL3: /* third possible octal digit */ | |
166 | *astate = S_GROUND; | |
167 | if (isoctal(c)) { | |
168 | *cp = (*cp << 3) + (c - '0'); | |
169 | return (UNVIS_VALID); | |
170 | } | |
171 | /* | |
172 | * we were done, push back passed char | |
173 | */ | |
174 | return (UNVIS_VALIDPUSH); | |
175 | ||
176 | default: | |
177 | /* | |
178 | * decoder in unknown state - (probably uninitialized) | |
179 | */ | |
2e93102d MT |
180 | *astate = S_GROUND; |
181 | return (UNVIS_SYNBAD); | |
1af61e06 MT |
182 | } |
183 | } | |
184 | ||
185 | /* | |
d6a13ceb | 186 | * strunvis - decode src into dst |
1af61e06 | 187 | * |
d6a13ceb MT |
188 | * Number of chars decoded into dst is returned, -1 on error. |
189 | * Dst is null terminated. | |
1af61e06 | 190 | */ |
d6a13ceb MT |
191 | |
192 | strunvis(dst, src) | |
1af61e06 | 193 | register char *dst, *src; |
1af61e06 | 194 | { |
d6a13ceb | 195 | register char c; |
1af61e06 | 196 | char *start = dst; |
2e93102d | 197 | int state = 0; |
1af61e06 | 198 | |
d6a13ceb MT |
199 | while (c = *src++) { |
200 | again: | |
201 | switch (unvis(dst, c, &state, 0)) { | |
202 | case UNVIS_VALID: | |
203 | dst++; | |
1af61e06 | 204 | break; |
d6a13ceb MT |
205 | case UNVIS_VALIDPUSH: |
206 | dst++; | |
207 | goto again; | |
208 | case 0: | |
209 | case UNVIS_NOCHAR: | |
210 | break; | |
211 | default: | |
212 | return (-1); | |
213 | } | |
1af61e06 | 214 | } |
2e93102d MT |
215 | if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) |
216 | dst++; | |
d6a13ceb | 217 | *dst = '\0'; |
1af61e06 MT |
218 | return (dst - start); |
219 | } |