1e5501b16Smarc /*-
2*bac379f5Sbostic * Copyright (c) 1989, 1993
3*bac379f5Sbostic * The Regents of the University of California. All rights reserved.
4361a39b6Smarc *
5e5501b16Smarc * %sccs.include.redist.c%
6361a39b6Smarc */
7361a39b6Smarc
8361a39b6Smarc #if defined(LIBC_SCCS) && !defined(lint)
9*bac379f5Sbostic static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 06/04/93";
10361a39b6Smarc #endif /* LIBC_SCCS and not lint */
11361a39b6Smarc
12361a39b6Smarc #include <sys/types.h>
13361a39b6Smarc #include <ctype.h>
14361a39b6Smarc #include <vis.h>
15361a39b6Smarc
16361a39b6Smarc /*
17361a39b6Smarc * decode driven by state machine
18361a39b6Smarc */
19361a39b6Smarc #define S_GROUND 0 /* haven't seen escape char */
20361a39b6Smarc #define S_START 1 /* start decoding special sequence */
21361a39b6Smarc #define S_META 2 /* metachar started (M) */
22361a39b6Smarc #define S_META1 3 /* metachar more, regular char (-) */
23361a39b6Smarc #define S_CTRL 4 /* control char started (^) */
24361a39b6Smarc #define S_OCTAL2 5 /* octal digit 2 */
25361a39b6Smarc #define S_OCTAL3 6 /* octal digit 3 */
26361a39b6Smarc
27e5501b16Smarc #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
28e5501b16Smarc
29361a39b6Smarc /*
30361a39b6Smarc * unvis - decode characters previously encoded by vis
31361a39b6Smarc */
32ae227ee3Sdonn int
unvis(cp,c,astate,flag)33361a39b6Smarc unvis(cp, c, astate, flag)
34318445bcSbostic char *cp;
35318445bcSbostic int c, *astate, flag;
36361a39b6Smarc {
37361a39b6Smarc
38361a39b6Smarc if (flag & UNVIS_END) {
39361a39b6Smarc if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
40361a39b6Smarc *astate = S_GROUND;
41361a39b6Smarc return (UNVIS_VALID);
42361a39b6Smarc }
43361a39b6Smarc return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
44361a39b6Smarc }
45361a39b6Smarc
46361a39b6Smarc switch (*astate) {
47361a39b6Smarc
48361a39b6Smarc case S_GROUND:
49361a39b6Smarc *cp = 0;
50361a39b6Smarc if (c == '\\') {
51361a39b6Smarc *astate = S_START;
52361a39b6Smarc return (0);
53361a39b6Smarc }
54361a39b6Smarc *cp = c;
55361a39b6Smarc return (UNVIS_VALID);
56361a39b6Smarc
57361a39b6Smarc case S_START:
58361a39b6Smarc switch(c) {
59361a39b6Smarc case '\\':
60361a39b6Smarc *cp = c;
61361a39b6Smarc *astate = S_GROUND;
62361a39b6Smarc return (UNVIS_VALID);
63361a39b6Smarc case '0': case '1': case '2': case '3':
64361a39b6Smarc case '4': case '5': case '6': case '7':
65361a39b6Smarc *cp = (c - '0');
66361a39b6Smarc *astate = S_OCTAL2;
67361a39b6Smarc return (0);
68361a39b6Smarc case 'M':
69361a39b6Smarc *cp = 0200;
70361a39b6Smarc *astate = S_META;
71361a39b6Smarc return (0);
72361a39b6Smarc case '^':
73361a39b6Smarc *astate = S_CTRL;
74361a39b6Smarc return (0);
75361a39b6Smarc case 'n':
76361a39b6Smarc *cp = '\n';
77361a39b6Smarc *astate = S_GROUND;
78361a39b6Smarc return (UNVIS_VALID);
79361a39b6Smarc case 'r':
80361a39b6Smarc *cp = '\r';
81361a39b6Smarc *astate = S_GROUND;
82361a39b6Smarc return (UNVIS_VALID);
83361a39b6Smarc case 'b':
84361a39b6Smarc *cp = '\b';
85361a39b6Smarc *astate = S_GROUND;
86361a39b6Smarc return (UNVIS_VALID);
87361a39b6Smarc case 'a':
88361a39b6Smarc *cp = '\007';
89361a39b6Smarc *astate = S_GROUND;
90361a39b6Smarc return (UNVIS_VALID);
91361a39b6Smarc case 'v':
92361a39b6Smarc *cp = '\v';
93361a39b6Smarc *astate = S_GROUND;
94361a39b6Smarc return (UNVIS_VALID);
95361a39b6Smarc case 't':
96361a39b6Smarc *cp = '\t';
97361a39b6Smarc *astate = S_GROUND;
98361a39b6Smarc return (UNVIS_VALID);
99361a39b6Smarc case 'f':
100361a39b6Smarc *cp = '\f';
101361a39b6Smarc *astate = S_GROUND;
102361a39b6Smarc return (UNVIS_VALID);
103361a39b6Smarc case 's':
104361a39b6Smarc *cp = ' ';
105361a39b6Smarc *astate = S_GROUND;
106361a39b6Smarc return (UNVIS_VALID);
107361a39b6Smarc case 'E':
108361a39b6Smarc *cp = '\033';
109361a39b6Smarc *astate = S_GROUND;
110361a39b6Smarc return (UNVIS_VALID);
111361a39b6Smarc case '\n':
112361a39b6Smarc /*
113361a39b6Smarc * hidden newline
114361a39b6Smarc */
115361a39b6Smarc *astate = S_GROUND;
116361a39b6Smarc return (UNVIS_NOCHAR);
117e5501b16Smarc case '$':
118e5501b16Smarc /*
119e5501b16Smarc * hidden marker
120e5501b16Smarc */
121e5501b16Smarc *astate = S_GROUND;
122e5501b16Smarc return (UNVIS_NOCHAR);
123361a39b6Smarc }
124361a39b6Smarc *astate = S_GROUND;
125361a39b6Smarc return (UNVIS_SYNBAD);
126361a39b6Smarc
127361a39b6Smarc case S_META:
128361a39b6Smarc if (c == '-')
129361a39b6Smarc *astate = S_META1;
130361a39b6Smarc else if (c == '^')
131361a39b6Smarc *astate = S_CTRL;
132361a39b6Smarc else {
133361a39b6Smarc *astate = S_GROUND;
134361a39b6Smarc return (UNVIS_SYNBAD);
135361a39b6Smarc }
136361a39b6Smarc return (0);
137361a39b6Smarc
138361a39b6Smarc case S_META1:
139361a39b6Smarc *astate = S_GROUND;
140361a39b6Smarc *cp |= c;
141361a39b6Smarc return (UNVIS_VALID);
142361a39b6Smarc
143361a39b6Smarc case S_CTRL:
144361a39b6Smarc if (c == '?')
145361a39b6Smarc *cp |= 0177;
146361a39b6Smarc else
147361a39b6Smarc *cp |= c & 037;
148361a39b6Smarc *astate = S_GROUND;
149361a39b6Smarc return (UNVIS_VALID);
150361a39b6Smarc
151361a39b6Smarc case S_OCTAL2: /* second possible octal digit */
152361a39b6Smarc if (isoctal(c)) {
153361a39b6Smarc /*
154361a39b6Smarc * yes - and maybe a third
155361a39b6Smarc */
156361a39b6Smarc *cp = (*cp << 3) + (c - '0');
157361a39b6Smarc *astate = S_OCTAL3;
158361a39b6Smarc return (0);
159361a39b6Smarc }
160361a39b6Smarc /*
161361a39b6Smarc * no - done with current sequence, push back passed char
162361a39b6Smarc */
163361a39b6Smarc *astate = S_GROUND;
164361a39b6Smarc return (UNVIS_VALIDPUSH);
165361a39b6Smarc
166361a39b6Smarc case S_OCTAL3: /* third possible octal digit */
167361a39b6Smarc *astate = S_GROUND;
168361a39b6Smarc if (isoctal(c)) {
169361a39b6Smarc *cp = (*cp << 3) + (c - '0');
170361a39b6Smarc return (UNVIS_VALID);
171361a39b6Smarc }
172361a39b6Smarc /*
173361a39b6Smarc * we were done, push back passed char
174361a39b6Smarc */
175361a39b6Smarc return (UNVIS_VALIDPUSH);
176361a39b6Smarc
177361a39b6Smarc default:
178361a39b6Smarc /*
179361a39b6Smarc * decoder in unknown state - (probably uninitialized)
180361a39b6Smarc */
18105c3be26Smarc *astate = S_GROUND;
18205c3be26Smarc return (UNVIS_SYNBAD);
183361a39b6Smarc }
184361a39b6Smarc }
185361a39b6Smarc
186361a39b6Smarc /*
187e5501b16Smarc * strunvis - decode src into dst
188361a39b6Smarc *
189e5501b16Smarc * Number of chars decoded into dst is returned, -1 on error.
190e5501b16Smarc * Dst is null terminated.
191361a39b6Smarc */
192e5501b16Smarc
193ae227ee3Sdonn int
strunvis(dst,src)194e5501b16Smarc strunvis(dst, src)
195ae227ee3Sdonn register char *dst;
196ae227ee3Sdonn register const char *src;
197361a39b6Smarc {
198e5501b16Smarc register char c;
199361a39b6Smarc char *start = dst;
20005c3be26Smarc int state = 0;
201361a39b6Smarc
202e5501b16Smarc while (c = *src++) {
203e5501b16Smarc again:
204e5501b16Smarc switch (unvis(dst, c, &state, 0)) {
205e5501b16Smarc case UNVIS_VALID:
206e5501b16Smarc dst++;
207361a39b6Smarc break;
208e5501b16Smarc case UNVIS_VALIDPUSH:
209e5501b16Smarc dst++;
210e5501b16Smarc goto again;
211e5501b16Smarc case 0:
212e5501b16Smarc case UNVIS_NOCHAR:
213361a39b6Smarc break;
214e5501b16Smarc default:
215e5501b16Smarc return (-1);
216361a39b6Smarc }
217e5501b16Smarc }
21805c3be26Smarc if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
21905c3be26Smarc dst++;
220e5501b16Smarc *dst = '\0';
221361a39b6Smarc return (dst - start);
222361a39b6Smarc }
223