xref: /netbsd-src/lib/libc/gen/vis.c (revision cf0cf9c7833901fda8ec7933a727043eadbe2bf2)
1 /*	$NetBSD: vis.c,v 1.20 2002/01/21 21:33:42 tv 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 #if HAVE_CONFIG_H
38 #include "config.h"
39 #else
40 #include <sys/cdefs.h>
41 #if !defined(lint)
42 __RCSID("$NetBSD: vis.c,v 1.20 2002/01/21 21:33:42 tv Exp $");
43 #endif /* not lint */
44 
45 #include "namespace.h"
46 #include <sys/types.h>
47 
48 #include <assert.h>
49 #include <vis.h>
50 
51 #ifdef __weak_alias
52 __weak_alias(strsvis,_strsvis)
53 __weak_alias(strsvisx,_strsvisx)
54 __weak_alias(strvis,_strvis)
55 __weak_alias(strvisx,_strvisx)
56 __weak_alias(svis,_svis)
57 __weak_alias(vis,_vis)
58 #endif
59 #endif
60 
61 #if !HAVE_VIS_H
62 #include <ctype.h>
63 #include <limits.h>
64 #include <stdio.h>
65 #include <string.h>
66 
67 #undef BELL
68 #if defined(__STDC__)
69 #define BELL '\a'
70 #else
71 #define BELL '\007'
72 #endif
73 
74 #define isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
75 #define iswhite(c)	(c == ' ' || c == '\t' || c == '\n')
76 #define issafe(c)	(c == '\b' || c == BELL || c == '\r')
77 
78 #define MAXEXTRAS       5
79 
80 
81 #define MAKEEXTRALIST(flag, extra)					      \
82 do {									      \
83 	char *pextra = extra;						      \
84 	if (flag & VIS_SP) *pextra++ = ' ';				      \
85 	if (flag & VIS_TAB) *pextra++ = '\t';				      \
86 	if (flag & VIS_NL) *pextra++ = '\n';				      \
87 	if ((flag & VIS_NOSLASH) == 0) *pextra++ = '\\';		      \
88 	*pextra = '\0';							      \
89 } while (/*CONSTCOND*/0)
90 
91 /*
92  * This is SVIS, the central macro of vis.
93  * dst:	      Pointer to the destination buffer
94  * c:	      Character to encode
95  * flag:      Flag word
96  * nextc:     The character following 'c'
97  * extra:     Pointer to the list of extra characters to be
98  *	      backslash-protected.
99  */
100 #define SVIS(dst, c, flag, nextc, extra)				      \
101 do {									      \
102 	int isextra, isc;						      \
103 	isextra = strchr(extra, c) != NULL;				      \
104 	if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||	      \
105 	    ((flag & VIS_SAFE) && issafe(c)))) {			      \
106 		*dst++ = c;						      \
107 		break;							      \
108 	}								      \
109 	isc = 0;							      \
110 	if (flag & VIS_CSTYLE) {					      \
111 		switch (c) {						      \
112 		case '\n':						      \
113 			isc = 1; *dst++ = '\\'; *dst++ = 'n';		      \
114 			break;						      \
115 		case '\r':						      \
116 			isc = 1; *dst++ = '\\'; *dst++ = 'r';		      \
117 			break;						      \
118 		case '\b':						      \
119 			isc = 1; *dst++ = '\\'; *dst++ = 'b';		      \
120 			break;						      \
121 		case BELL:						      \
122 			isc = 1; *dst++ = '\\'; *dst++ = 'a';		      \
123 			break;						      \
124 		case '\v':						      \
125 			isc = 1; *dst++ = '\\'; *dst++ = 'v';		      \
126 			break;						      \
127 		case '\t':						      \
128 			isc = 1; *dst++ = '\\'; *dst++ = 't';		      \
129 			break;						      \
130 		case '\f':						      \
131 			isc = 1; *dst++ = '\\'; *dst++ = 'f';		      \
132 			break;						      \
133 		case ' ':						      \
134 			isc = 1; *dst++ = '\\'; *dst++ = 's';		      \
135 			break;						      \
136 		case '\0':						      \
137 			isc = 1; *dst++ = '\\'; *dst++ = '0';		      \
138 			if (isoctal(nextc)) {				      \
139 				*dst++ = '0';				      \
140 				*dst++ = '0';				      \
141 			}						      \
142 		}							      \
143 	}								      \
144 	if (isc) break;							      \
145 	if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {	      \
146 		*dst++ = '\\';						      \
147 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';    \
148 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';    \
149 		*dst++ =			     (c	      & 07) + '0';    \
150 	} else {							      \
151 		if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';		      \
152 		if (c & 0200) {						      \
153 			c &= 0177; *dst++ = 'M';			      \
154 		}							      \
155 		if (iscntrl(c)) {					      \
156 			*dst++ = '^';					      \
157 			if (c == 0177)					      \
158 				*dst++ = '?';				      \
159 			else						      \
160 				*dst++ = c + '@';			      \
161 		} else {						      \
162 			*dst++ = '-'; *dst++ = c;			      \
163 		}							      \
164 	}								      \
165 } while (/*CONSTCOND*/0)
166 
167 
168 /*
169  * svis - visually encode characters, also encoding the characters
170  * 	  pointed to by `extra'
171  */
172 char *
173 svis(dst, c, flag, nextc, extra)
174 	char *dst;
175 	int c, flag, nextc;
176 	const char *extra;
177 {
178 	_DIAGASSERT(dst != NULL);
179 	_DIAGASSERT(extra != NULL);
180 
181 	SVIS(dst, c, flag, nextc, extra);
182 	*dst = '\0';
183 	return(dst);
184 }
185 
186 
187 /*
188  * strsvis, strsvisx - visually encode characters from src into dst
189  *
190  *	Extra is a pointer to a \0-terminated list of characters to
191  *	be encoded, too. These functions are useful e. g. to
192  *	encode strings in such a way so that they are not interpreted
193  *	by a shell.
194  *
195  *	Dst must be 4 times the size of src to account for possible
196  *	expansion.  The length of dst, not including the trailing NULL,
197  *	is returned.
198  *
199  *	Strsvisx encodes exactly len bytes from src into dst.
200  *	This is useful for encoding a block of data.
201  */
202 int
203 strsvis(dst, src, flag, extra)
204 	char *dst;
205 	const char *src;
206 	int flag;
207 	const char *extra;
208 {
209 	char c;
210 	char *start;
211 
212 	_DIAGASSERT(dst != NULL);
213 	_DIAGASSERT(src != NULL);
214 	_DIAGASSERT(extra != NULL);
215 
216 	for (start = dst; (c = *src++) != '\0'; /* empty */)
217 	    SVIS(dst, c, flag, *src, extra);
218 	*dst = '\0';
219 	return (dst - start);
220 }
221 
222 
223 int
224 strsvisx(dst, src, len, flag, extra)
225 	char *dst;
226 	const char *src;
227 	size_t len;
228 	int flag;
229 	const char *extra;
230 {
231 	char c;
232 	char *start;
233 
234 	_DIAGASSERT(dst != NULL);
235 	_DIAGASSERT(src != NULL);
236 	_DIAGASSERT(extra != NULL);
237 
238 	for (start = dst; len > 0; len--) {
239 		c = *src++;
240 		SVIS(dst, c, flag, len ? *src : '\0', extra);
241 	}
242 	*dst = '\0';
243 	return (dst - start);
244 }
245 
246 
247 /*
248  * vis - visually encode characters
249  */
250 char *
251 vis(dst, c, flag, nextc)
252 	char *dst;
253 	int c, flag, nextc;
254 
255 {
256 	char extra[MAXEXTRAS];
257 
258 	_DIAGASSERT(dst != NULL);
259 
260 	MAKEEXTRALIST(flag, extra);
261 	SVIS(dst, c, flag, nextc, extra);
262 	*dst = '\0';
263 	return (dst);
264 }
265 
266 
267 /*
268  * strvis, strvisx - visually encode characters from src into dst
269  *
270  *	Dst must be 4 times the size of src to account for possible
271  *	expansion.  The length of dst, not including the trailing NULL,
272  *	is returned.
273  *
274  *	Strvisx encodes exactly len bytes from src into dst.
275  *	This is useful for encoding a block of data.
276  */
277 int
278 strvis(dst, src, flag)
279 	char *dst;
280 	const char *src;
281 	int flag;
282 {
283 	char extra[MAXEXTRAS];
284 
285 	MAKEEXTRALIST(flag, extra);
286 	return (strsvis(dst, src, flag, extra));
287 }
288 
289 
290 int
291 strvisx(dst, src, len, flag)
292 	char *dst;
293 	const char *src;
294 	size_t len;
295 	int flag;
296 {
297 	char extra[MAXEXTRAS];
298 
299 	MAKEEXTRALIST(flag, extra);
300 	return (strsvisx(dst, src, len, flag, extra));
301 }
302 #endif
303