xref: /netbsd-src/lib/libc/gen/vis.c (revision c3de1627bea3f8145539ecad5cb08e7d93cd83ac)
1 /*	$NetBSD: vis.c,v 1.22 2002/03/23 17:38:27 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
5  * Copyright (c) 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #if defined(LIBC_SCCS) && !defined(lint)
39 __RCSID("$NetBSD: vis.c,v 1.22 2002/03/23 17:38:27 christos Exp $");
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include "namespace.h"
43 #include <sys/types.h>
44 
45 #include <assert.h>
46 #include <vis.h>
47 #include <stdlib.h>
48 
49 #ifdef __weak_alias
50 __weak_alias(strsvis,_strsvis)
51 __weak_alias(strsvisx,_strsvisx)
52 __weak_alias(strvis,_strvis)
53 __weak_alias(strvisx,_strvisx)
54 __weak_alias(svis,_svis)
55 __weak_alias(vis,_vis)
56 #endif
57 
58 #if !HAVE_VIS_H
59 #include <ctype.h>
60 #include <limits.h>
61 #include <stdio.h>
62 #include <string.h>
63 
64 #undef BELL
65 #if defined(__STDC__)
66 #define BELL '\a'
67 #else
68 #define BELL '\007'
69 #endif
70 
71 #define isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
72 #define iswhite(c)	(c == ' ' || c == '\t' || c == '\n')
73 #define issafe(c)	(c == '\b' || c == BELL || c == '\r')
74 #define xtoa(c)		"0123456789abcdef"[c]
75 
76 #define MAXEXTRAS       5
77 
78 
79 #define MAKEEXTRALIST(flag, extra, orig)				      \
80 do {									      \
81 	const char *o = orig;						      \
82 	char *e;						      	      \
83 	while (*o++)							      \
84 		continue;						      \
85 	extra = alloca((size_t)((o - orig) + MAXEXTRAS));	      	      \
86 	for (o = orig, e = extra; (*e++ = *o++) != '\0';)		      \
87 		continue;						      \
88 	e--;								      \
89 	if (flag & VIS_SP) *e++ = ' ';				      	      \
90 	if (flag & VIS_TAB) *e++ = '\t';				      \
91 	if (flag & VIS_NL) *e++ = '\n';				      	      \
92 	if ((flag & VIS_NOSLASH) == 0) *e++ = '\\';		      	      \
93 	*e = '\0';							      \
94 } while (/*CONSTCOND*/0)
95 
96 
97 /*
98  * This is HVIS, the macro of vis used to HTTP style (RFC 1808)
99  */
100 #define HVIS(dst, c, flag, nextc, extra)				      \
101 do 									      \
102 	if (!isascii(c) || !isalnum(c) || strchr("$-_.+!*'(),", c) != NULL) { \
103 		*dst++ = '%';						      \
104 		*dst++ = xtoa(((unsigned int)c >> 4) & 0xf);		      \
105 		*dst++ = xtoa((unsigned int)c & 0xf);			      \
106 	} else {							      \
107 		SVIS(dst, c, flag, nextc, extra);			      \
108 	}								      \
109 while (/*CONSTCOND*/0)
110 
111 /*
112  * This is SVIS, the central macro of vis.
113  * dst:	      Pointer to the destination buffer
114  * c:	      Character to encode
115  * flag:      Flag word
116  * nextc:     The character following 'c'
117  * extra:     Pointer to the list of extra characters to be
118  *	      backslash-protected.
119  */
120 #define SVIS(dst, c, flag, nextc, extra)				      \
121 do {									      \
122 	int isextra, isc;						      \
123 	isextra = strchr(extra, c) != NULL;				      \
124 	if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||	      \
125 	    ((flag & VIS_SAFE) && issafe(c)))) {			      \
126 		*dst++ = c;						      \
127 		break;							      \
128 	}								      \
129 	isc = 0;							      \
130 	if (flag & VIS_CSTYLE) {					      \
131 		switch (c) {						      \
132 		case '\n':						      \
133 			isc = 1; *dst++ = '\\'; *dst++ = 'n';		      \
134 			break;						      \
135 		case '\r':						      \
136 			isc = 1; *dst++ = '\\'; *dst++ = 'r';		      \
137 			break;						      \
138 		case '\b':						      \
139 			isc = 1; *dst++ = '\\'; *dst++ = 'b';		      \
140 			break;						      \
141 		case BELL:						      \
142 			isc = 1; *dst++ = '\\'; *dst++ = 'a';		      \
143 			break;						      \
144 		case '\v':						      \
145 			isc = 1; *dst++ = '\\'; *dst++ = 'v';		      \
146 			break;						      \
147 		case '\t':						      \
148 			isc = 1; *dst++ = '\\'; *dst++ = 't';		      \
149 			break;						      \
150 		case '\f':						      \
151 			isc = 1; *dst++ = '\\'; *dst++ = 'f';		      \
152 			break;						      \
153 		case ' ':						      \
154 			isc = 1; *dst++ = '\\'; *dst++ = 's';		      \
155 			break;						      \
156 		case '\0':						      \
157 			isc = 1; *dst++ = '\\'; *dst++ = '0';		      \
158 			if (isoctal(nextc)) {				      \
159 				*dst++ = '0';				      \
160 				*dst++ = '0';				      \
161 			}						      \
162 		}							      \
163 	}								      \
164 	if (isc) break;							      \
165 	if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {	      \
166 		*dst++ = '\\';						      \
167 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';    \
168 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';    \
169 		*dst++ =			     (c	      & 07) + '0';    \
170 	} else {							      \
171 		if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';		      \
172 		if (c & 0200) {						      \
173 			c &= 0177; *dst++ = 'M';			      \
174 		}							      \
175 		if (iscntrl(c)) {					      \
176 			*dst++ = '^';					      \
177 			if (c == 0177)					      \
178 				*dst++ = '?';				      \
179 			else						      \
180 				*dst++ = c + '@';			      \
181 		} else {						      \
182 			*dst++ = '-'; *dst++ = c;			      \
183 		}							      \
184 	}								      \
185 } while (/*CONSTCOND*/0)
186 
187 
188 /*
189  * svis - visually encode characters, also encoding the characters
190  * 	  pointed to by `extra'
191  */
192 char *
193 svis(dst, c, flag, nextc, extra)
194 	char *dst;
195 	int c, flag, nextc;
196 	const char *extra;
197 {
198 	char *nextra;
199 	_DIAGASSERT(dst != NULL);
200 	_DIAGASSERT(extra != NULL);
201 	MAKEEXTRALIST(flag, nextra, extra);
202 	if (flag & VIS_HTTPSTYLE)
203 		HVIS(dst, c, flag, nextc, nextra);
204 	else
205 		SVIS(dst, c, flag, nextc, nextra);
206 	*dst = '\0';
207 	return(dst);
208 }
209 
210 
211 /*
212  * strsvis, strsvisx - visually encode characters from src into dst
213  *
214  *	Extra is a pointer to a \0-terminated list of characters to
215  *	be encoded, too. These functions are useful e. g. to
216  *	encode strings in such a way so that they are not interpreted
217  *	by a shell.
218  *
219  *	Dst must be 4 times the size of src to account for possible
220  *	expansion.  The length of dst, not including the trailing NULL,
221  *	is returned.
222  *
223  *	Strsvisx encodes exactly len bytes from src into dst.
224  *	This is useful for encoding a block of data.
225  */
226 int
227 strsvis(dst, src, flag, extra)
228 	char *dst;
229 	const char *src;
230 	int flag;
231 	const char *extra;
232 {
233 	char c;
234 	char *start;
235 	char *nextra;
236 
237 	_DIAGASSERT(dst != NULL);
238 	_DIAGASSERT(src != NULL);
239 	_DIAGASSERT(extra != NULL);
240 	MAKEEXTRALIST(flag, nextra, extra);
241 	if (flag & VIS_HTTPSTYLE) {
242 		for (start = dst; (c = *src++) != '\0'; /* empty */)
243 			HVIS(dst, c, flag, *src, nextra);
244 	} else {
245 		for (start = dst; (c = *src++) != '\0'; /* empty */)
246 			SVIS(dst, c, flag, *src, nextra);
247 	}
248 	*dst = '\0';
249 	return (dst - start);
250 }
251 
252 
253 int
254 strsvisx(dst, src, len, flag, extra)
255 	char *dst;
256 	const char *src;
257 	size_t len;
258 	int flag;
259 	const char *extra;
260 {
261 	char c;
262 	char *start;
263 	char *nextra;
264 
265 	_DIAGASSERT(dst != NULL);
266 	_DIAGASSERT(src != NULL);
267 	_DIAGASSERT(extra != NULL);
268 	MAKEEXTRALIST(flag, nextra, extra);
269 
270 	if (flag & VIS_HTTPSTYLE) {
271 		for (start = dst; len > 0; len--) {
272 			c = *src++;
273 			HVIS(dst, c, flag, len ? *src : '\0', nextra);
274 		}
275 	} else {
276 		for (start = dst; len > 0; len--) {
277 			c = *src++;
278 			SVIS(dst, c, flag, len ? *src : '\0', nextra);
279 		}
280 	}
281 	*dst = '\0';
282 	return (dst - start);
283 }
284 
285 
286 /*
287  * vis - visually encode characters
288  */
289 char *
290 vis(dst, c, flag, nextc)
291 	char *dst;
292 	int c, flag, nextc;
293 
294 {
295 	char *extra;
296 
297 	_DIAGASSERT(dst != NULL);
298 
299 	MAKEEXTRALIST(flag, extra, "");
300 	if (flag & VIS_HTTPSTYLE)
301 	    HVIS(dst, c, flag, nextc, extra);
302 	else
303 	    SVIS(dst, c, flag, nextc, extra);
304 	*dst = '\0';
305 	return (dst);
306 }
307 
308 
309 /*
310  * strvis, strvisx - visually encode characters from src into dst
311  *
312  *	Dst must be 4 times the size of src to account for possible
313  *	expansion.  The length of dst, not including the trailing NULL,
314  *	is returned.
315  *
316  *	Strvisx encodes exactly len bytes from src into dst.
317  *	This is useful for encoding a block of data.
318  */
319 int
320 strvis(dst, src, flag)
321 	char *dst;
322 	const char *src;
323 	int flag;
324 {
325 	char *extra;
326 
327 	MAKEEXTRALIST(flag, extra, "");
328 	return (strsvis(dst, src, flag, extra));
329 }
330 
331 
332 int
333 strvisx(dst, src, len, flag)
334 	char *dst;
335 	const char *src;
336 	size_t len;
337 	int flag;
338 {
339 	char *extra;
340 
341 	MAKEEXTRALIST(flag, extra, "");
342 	return (strsvisx(dst, src, len, flag, extra));
343 }
344 #endif
345