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302d677f | 1 | /* $Id$ |
2 | * vis functions - visually encode characters | |
3 | * Originally from OpenBSD | |
4 | */ | |
5 | ||
6 | /*- | |
7 | * Copyright (c) 1989, 1993 | |
8 | * The Regents of the University of California. All rights reserved. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * 3. All advertising materials mentioning features or use of this software | |
19 | * must display the following acknowledgement: | |
20 | * This product includes software developed by the University of | |
21 | * California, Berkeley and its contributors. | |
22 | * 4. Neither the name of the University nor the names of its contributors | |
23 | * may be used to endorse or promote products derived from this software | |
24 | * without specific prior written permission. | |
25 | * | |
26 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
27 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
28 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
29 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
30 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
31 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
32 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
33 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
34 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
35 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
36 | * SUCH DAMAGE. | |
37 | */ | |
38 | ||
39 | #ifndef HAVE_STRVIS | |
40 | #include "vis.h" | |
41 | /* | |
42 | * vis - visually encode characters | |
43 | */ | |
44 | char * | |
45 | vis(dst, c, flag, nextc) | |
46 | register char *dst; | |
47 | int c, nextc; | |
48 | register int flag; | |
49 | { | |
50 | if (isvisible(c)) { | |
51 | *dst++ = c; | |
52 | if (c == '\\' && (flag & VIS_NOSLASH) == 0) | |
53 | *dst++ = '\\'; | |
54 | *dst = '\0'; | |
55 | return (dst); | |
56 | } | |
57 | ||
58 | if (flag & VIS_CSTYLE) { | |
59 | switch(c) { | |
60 | case '\n': | |
61 | *dst++ = '\\'; | |
62 | *dst++ = 'n'; | |
63 | goto done; | |
64 | case '\r': | |
65 | *dst++ = '\\'; | |
66 | *dst++ = 'r'; | |
67 | goto done; | |
68 | case '\b': | |
69 | *dst++ = '\\'; | |
70 | *dst++ = 'b'; | |
71 | goto done; | |
72 | #ifdef __STDC__ | |
73 | case '\a': | |
74 | #else | |
75 | case '\007': | |
76 | #endif | |
77 | *dst++ = '\\'; | |
78 | *dst++ = 'a'; | |
79 | goto done; | |
80 | case '\v': | |
81 | *dst++ = '\\'; | |
82 | *dst++ = 'v'; | |
83 | goto done; | |
84 | case '\t': | |
85 | *dst++ = '\\'; | |
86 | *dst++ = 't'; | |
87 | goto done; | |
88 | case '\f': | |
89 | *dst++ = '\\'; | |
90 | *dst++ = 'f'; | |
91 | goto done; | |
92 | case ' ': | |
93 | *dst++ = '\\'; | |
94 | *dst++ = 's'; | |
95 | goto done; | |
96 | case '\0': | |
97 | *dst++ = '\\'; | |
98 | *dst++ = '0'; | |
99 | if (isoctal(nextc)) { | |
100 | *dst++ = '0'; | |
101 | *dst++ = '0'; | |
102 | } | |
103 | goto done; | |
104 | } | |
105 | } | |
106 | if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) { | |
107 | *dst++ = '\\'; | |
108 | *dst++ = ((u_char)c >> 6 & 07) + '0'; | |
109 | *dst++ = ((u_char)c >> 3 & 07) + '0'; | |
110 | *dst++ = ((u_char)c & 07) + '0'; | |
111 | goto done; | |
112 | } | |
113 | if ((flag & VIS_NOSLASH) == 0) | |
114 | *dst++ = '\\'; | |
115 | if (c & 0200) { | |
116 | c &= 0177; | |
117 | *dst++ = 'M'; | |
118 | } | |
119 | if (iscntrl(c)) { | |
120 | *dst++ = '^'; | |
121 | if (c == 0177) | |
122 | *dst++ = '?'; | |
123 | else | |
124 | *dst++ = c + '@'; | |
125 | } else { | |
126 | *dst++ = '-'; | |
127 | *dst++ = c; | |
128 | } | |
129 | done: | |
130 | *dst = '\0'; | |
131 | return (dst); | |
132 | } | |
133 | ||
134 | /* | |
135 | * strvis, strnvis, strvisx - visually encode characters from src into dst | |
136 | * | |
137 | * Dst must be 4 times the size of src to account for possible | |
138 | * expansion. The length of dst, not including the trailing NULL, | |
139 | * is returned. | |
140 | * | |
141 | * Strnvis will write no more than siz-1 bytes (and will NULL terminate). | |
142 | * The number of bytes needed to fully encode the string is returned. | |
143 | * | |
144 | * Strvisx encodes exactly len bytes from src into dst. | |
145 | * This is useful for encoding a block of data. | |
146 | */ | |
147 | int | |
148 | strvis(dst, src, flag) | |
149 | register char *dst; | |
150 | register const char *src; | |
151 | int flag; | |
152 | { | |
153 | register char c; | |
154 | char *start; | |
155 | ||
156 | for (start = dst; (c = *src);) | |
157 | dst = vis(dst, c, flag, *++src); | |
158 | *dst = '\0'; | |
159 | return (dst - start); | |
160 | } | |
161 | ||
162 | int | |
163 | strnvis(dst, src, siz, flag) | |
164 | register char *dst; | |
165 | register const char *src; | |
166 | size_t siz; | |
167 | int flag; | |
168 | { | |
169 | register char c; | |
170 | char *start, *end; | |
171 | ||
172 | for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { | |
173 | if (isvisible(c)) { | |
174 | *dst++ = c; | |
175 | if (c == '\\' && (flag & VIS_NOSLASH) == 0) { | |
176 | /* need space for the extra '\\' */ | |
177 | if (dst < end) | |
178 | *dst++ = '\\'; | |
179 | else { | |
180 | dst--; | |
181 | break; | |
182 | } | |
183 | } | |
184 | src++; | |
185 | } else { | |
186 | /* vis(3) requires up to 4 chars */ | |
187 | if (dst + 3 < end) | |
188 | dst = vis(dst, c, flag, *++src); | |
189 | else | |
190 | break; | |
191 | } | |
192 | } | |
193 | *dst = '\0'; | |
194 | if (dst >= end) { | |
195 | char tbuf[5]; | |
196 | ||
197 | /* adjust return value for truncation */ | |
198 | while ((c = *src)) | |
199 | dst += vis(tbuf, c, flag, *++src) - tbuf; | |
200 | } | |
201 | return (dst - start); | |
202 | } | |
203 | ||
204 | int | |
205 | strvisx(dst, src, len, flag) | |
206 | register char *dst; | |
207 | register const char *src; | |
208 | register size_t len; | |
209 | int flag; | |
210 | { | |
211 | register char c; | |
212 | char *start; | |
213 | ||
214 | for (start = dst; len > 1; len--) { | |
215 | c = *src; | |
216 | dst = vis(dst, c, flag, *++src); | |
217 | } | |
218 | if (len) | |
219 | dst = vis(dst, *src, flag, '\0'); | |
220 | *dst = '\0'; | |
221 | return (dst - start); | |
222 | } | |
223 | ||
224 | /* | |
225 | * unvis - decode characters previously encoded by vis | |
226 | */ | |
227 | int | |
228 | #ifdef __STDC__ | |
229 | unvis(char *cp, char c, int *astate, int flag) | |
230 | #else | |
231 | unvis(cp, c, astate, flag) | |
232 | char *cp; | |
233 | char c; | |
234 | int *astate, flag; | |
235 | #endif | |
236 | { | |
237 | ||
238 | if (flag & UNVIS_END) { | |
239 | if (*astate == S_OCTAL2 || *astate == S_OCTAL3) { | |
240 | *astate = S_GROUND; | |
241 | return (UNVIS_VALID); | |
242 | } | |
243 | return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD); | |
244 | } | |
245 | ||
246 | switch (*astate) { | |
247 | ||
248 | case S_GROUND: | |
249 | *cp = 0; | |
250 | if (c == '\\') { | |
251 | *astate = S_START; | |
252 | return (0); | |
253 | } | |
254 | *cp = c; | |
255 | return (UNVIS_VALID); | |
256 | ||
257 | case S_START: | |
258 | switch(c) { | |
259 | case '\\': | |
260 | *cp = c; | |
261 | *astate = S_GROUND; | |
262 | return (UNVIS_VALID); | |
263 | case '0': case '1': case '2': case '3': | |
264 | case '4': case '5': case '6': case '7': | |
265 | *cp = (c - '0'); | |
266 | *astate = S_OCTAL2; | |
267 | return (0); | |
268 | case 'M': | |
269 | *cp = (char) 0200; | |
270 | *astate = S_META; | |
271 | return (0); | |
272 | case '^': | |
273 | *astate = S_CTRL; | |
274 | return (0); | |
275 | case 'n': | |
276 | *cp = '\n'; | |
277 | *astate = S_GROUND; | |
278 | return (UNVIS_VALID); | |
279 | case 'r': | |
280 | *cp = '\r'; | |
281 | *astate = S_GROUND; | |
282 | return (UNVIS_VALID); | |
283 | case 'b': | |
284 | *cp = '\b'; | |
285 | *astate = S_GROUND; | |
286 | return (UNVIS_VALID); | |
287 | case 'a': | |
288 | *cp = '\007'; | |
289 | *astate = S_GROUND; | |
290 | return (UNVIS_VALID); | |
291 | case 'v': | |
292 | *cp = '\v'; | |
293 | *astate = S_GROUND; | |
294 | return (UNVIS_VALID); | |
295 | case 't': | |
296 | *cp = '\t'; | |
297 | *astate = S_GROUND; | |
298 | return (UNVIS_VALID); | |
299 | case 'f': | |
300 | *cp = '\f'; | |
301 | *astate = S_GROUND; | |
302 | return (UNVIS_VALID); | |
303 | case 's': | |
304 | *cp = ' '; | |
305 | *astate = S_GROUND; | |
306 | return (UNVIS_VALID); | |
307 | case 'E': | |
308 | *cp = '\033'; | |
309 | *astate = S_GROUND; | |
310 | return (UNVIS_VALID); | |
311 | case '\n': | |
312 | /* | |
313 | * hidden newline | |
314 | */ | |
315 | *astate = S_GROUND; | |
316 | return (UNVIS_NOCHAR); | |
317 | case '$': | |
318 | /* | |
319 | * hidden marker | |
320 | */ | |
321 | *astate = S_GROUND; | |
322 | return (UNVIS_NOCHAR); | |
323 | } | |
324 | *astate = S_GROUND; | |
325 | return (UNVIS_SYNBAD); | |
326 | ||
327 | case S_META: | |
328 | if (c == '-') | |
329 | *astate = S_META1; | |
330 | else if (c == '^') | |
331 | *astate = S_CTRL; | |
332 | else { | |
333 | *astate = S_GROUND; | |
334 | return (UNVIS_SYNBAD); | |
335 | } | |
336 | return (0); | |
337 | ||
338 | case S_META1: | |
339 | *astate = S_GROUND; | |
340 | *cp |= c; | |
341 | return (UNVIS_VALID); | |
342 | ||
343 | case S_CTRL: | |
344 | if (c == '?') | |
345 | *cp |= 0177; | |
346 | else | |
347 | *cp |= c & 037; | |
348 | *astate = S_GROUND; | |
349 | return (UNVIS_VALID); | |
350 | ||
351 | case S_OCTAL2: /* second possible octal digit */ | |
352 | if (isoctal(c)) { | |
353 | /* | |
354 | * yes - and maybe a third | |
355 | */ | |
356 | *cp = (*cp << 3) + (c - '0'); | |
357 | *astate = S_OCTAL3; | |
358 | return (0); | |
359 | } | |
360 | /* | |
361 | * no - done with current sequence, push back passed char | |
362 | */ | |
363 | *astate = S_GROUND; | |
364 | return (UNVIS_VALIDPUSH); | |
365 | ||
366 | case S_OCTAL3: /* third possible octal digit */ | |
367 | *astate = S_GROUND; | |
368 | if (isoctal(c)) { | |
369 | *cp = (*cp << 3) + (c - '0'); | |
370 | return (UNVIS_VALID); | |
371 | } | |
372 | /* | |
373 | * we were done, push back passed char | |
374 | */ | |
375 | return (UNVIS_VALIDPUSH); | |
376 | ||
377 | default: | |
378 | /* | |
379 | * decoder in unknown state - (probably uninitialized) | |
380 | */ | |
381 | *astate = S_GROUND; | |
382 | return (UNVIS_SYNBAD); | |
383 | } | |
384 | } | |
385 | ||
386 | /* | |
387 | * strunvis - decode src into dst | |
388 | * | |
389 | * Number of chars decoded into dst is returned, -1 on error. | |
390 | * Dst is null terminated. | |
391 | */ | |
392 | ||
393 | int | |
394 | strunvis(dst, src) | |
395 | register char *dst; | |
396 | register const char *src; | |
397 | { | |
398 | register char c; | |
399 | char *start = dst; | |
400 | int state = 0; | |
401 | ||
402 | while ((c = *src++)) { | |
403 | again: | |
404 | switch (unvis(dst, c, &state, 0)) { | |
405 | case UNVIS_VALID: | |
406 | dst++; | |
407 | break; | |
408 | case UNVIS_VALIDPUSH: | |
409 | dst++; | |
410 | goto again; | |
411 | case 0: | |
412 | case UNVIS_NOCHAR: | |
413 | break; | |
414 | default: | |
415 | return (-1); | |
416 | } | |
417 | } | |
418 | if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID) | |
419 | dst++; | |
420 | *dst = '\0'; | |
421 | return (dst - start); | |
422 | } | |
423 | ||
424 | #endif /* HAVE_STRVIS */ |