xref: /netbsd-src/lib/libc/gen/vis.c (revision 0dd5877adce57db949b16ae963e5a6831cccdfb6)
1 /*	$NetBSD: vis.c,v 1.21 2002/01/31 22:43:39 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 #include <sys/cdefs.h>
38 #if defined(LIBC_SCCS) && !defined(lint)
39 __RCSID("$NetBSD: vis.c,v 1.21 2002/01/31 22:43:39 tv 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 
48 #ifdef __weak_alias
49 __weak_alias(strsvis,_strsvis)
50 __weak_alias(strsvisx,_strsvisx)
51 __weak_alias(strvis,_strvis)
52 __weak_alias(strvisx,_strvisx)
53 __weak_alias(svis,_svis)
54 __weak_alias(vis,_vis)
55 #endif
56 
57 #if !HAVE_VIS_H
58 #include <ctype.h>
59 #include <limits.h>
60 #include <stdio.h>
61 #include <string.h>
62 
63 #undef BELL
64 #if defined(__STDC__)
65 #define BELL '\a'
66 #else
67 #define BELL '\007'
68 #endif
69 
70 #define isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
71 #define iswhite(c)	(c == ' ' || c == '\t' || c == '\n')
72 #define issafe(c)	(c == '\b' || c == BELL || c == '\r')
73 
74 #define MAXEXTRAS       5
75 
76 
77 #define MAKEEXTRALIST(flag, extra)					      \
78 do {									      \
79 	char *pextra = extra;						      \
80 	if (flag & VIS_SP) *pextra++ = ' ';				      \
81 	if (flag & VIS_TAB) *pextra++ = '\t';				      \
82 	if (flag & VIS_NL) *pextra++ = '\n';				      \
83 	if ((flag & VIS_NOSLASH) == 0) *pextra++ = '\\';		      \
84 	*pextra = '\0';							      \
85 } while (/*CONSTCOND*/0)
86 
87 /*
88  * This is SVIS, the central macro of vis.
89  * dst:	      Pointer to the destination buffer
90  * c:	      Character to encode
91  * flag:      Flag word
92  * nextc:     The character following 'c'
93  * extra:     Pointer to the list of extra characters to be
94  *	      backslash-protected.
95  */
96 #define SVIS(dst, c, flag, nextc, extra)				      \
97 do {									      \
98 	int isextra, isc;						      \
99 	isextra = strchr(extra, c) != NULL;				      \
100 	if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||	      \
101 	    ((flag & VIS_SAFE) && issafe(c)))) {			      \
102 		*dst++ = c;						      \
103 		break;							      \
104 	}								      \
105 	isc = 0;							      \
106 	if (flag & VIS_CSTYLE) {					      \
107 		switch (c) {						      \
108 		case '\n':						      \
109 			isc = 1; *dst++ = '\\'; *dst++ = 'n';		      \
110 			break;						      \
111 		case '\r':						      \
112 			isc = 1; *dst++ = '\\'; *dst++ = 'r';		      \
113 			break;						      \
114 		case '\b':						      \
115 			isc = 1; *dst++ = '\\'; *dst++ = 'b';		      \
116 			break;						      \
117 		case BELL:						      \
118 			isc = 1; *dst++ = '\\'; *dst++ = 'a';		      \
119 			break;						      \
120 		case '\v':						      \
121 			isc = 1; *dst++ = '\\'; *dst++ = 'v';		      \
122 			break;						      \
123 		case '\t':						      \
124 			isc = 1; *dst++ = '\\'; *dst++ = 't';		      \
125 			break;						      \
126 		case '\f':						      \
127 			isc = 1; *dst++ = '\\'; *dst++ = 'f';		      \
128 			break;						      \
129 		case ' ':						      \
130 			isc = 1; *dst++ = '\\'; *dst++ = 's';		      \
131 			break;						      \
132 		case '\0':						      \
133 			isc = 1; *dst++ = '\\'; *dst++ = '0';		      \
134 			if (isoctal(nextc)) {				      \
135 				*dst++ = '0';				      \
136 				*dst++ = '0';				      \
137 			}						      \
138 		}							      \
139 	}								      \
140 	if (isc) break;							      \
141 	if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {	      \
142 		*dst++ = '\\';						      \
143 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';    \
144 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';    \
145 		*dst++ =			     (c	      & 07) + '0';    \
146 	} else {							      \
147 		if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';		      \
148 		if (c & 0200) {						      \
149 			c &= 0177; *dst++ = 'M';			      \
150 		}							      \
151 		if (iscntrl(c)) {					      \
152 			*dst++ = '^';					      \
153 			if (c == 0177)					      \
154 				*dst++ = '?';				      \
155 			else						      \
156 				*dst++ = c + '@';			      \
157 		} else {						      \
158 			*dst++ = '-'; *dst++ = c;			      \
159 		}							      \
160 	}								      \
161 } while (/*CONSTCOND*/0)
162 
163 
164 /*
165  * svis - visually encode characters, also encoding the characters
166  * 	  pointed to by `extra'
167  */
168 char *
169 svis(dst, c, flag, nextc, extra)
170 	char *dst;
171 	int c, flag, nextc;
172 	const char *extra;
173 {
174 	_DIAGASSERT(dst != NULL);
175 	_DIAGASSERT(extra != NULL);
176 
177 	SVIS(dst, c, flag, nextc, extra);
178 	*dst = '\0';
179 	return(dst);
180 }
181 
182 
183 /*
184  * strsvis, strsvisx - visually encode characters from src into dst
185  *
186  *	Extra is a pointer to a \0-terminated list of characters to
187  *	be encoded, too. These functions are useful e. g. to
188  *	encode strings in such a way so that they are not interpreted
189  *	by a shell.
190  *
191  *	Dst must be 4 times the size of src to account for possible
192  *	expansion.  The length of dst, not including the trailing NULL,
193  *	is returned.
194  *
195  *	Strsvisx encodes exactly len bytes from src into dst.
196  *	This is useful for encoding a block of data.
197  */
198 int
199 strsvis(dst, src, flag, extra)
200 	char *dst;
201 	const char *src;
202 	int flag;
203 	const char *extra;
204 {
205 	char c;
206 	char *start;
207 
208 	_DIAGASSERT(dst != NULL);
209 	_DIAGASSERT(src != NULL);
210 	_DIAGASSERT(extra != NULL);
211 
212 	for (start = dst; (c = *src++) != '\0'; /* empty */)
213 	    SVIS(dst, c, flag, *src, extra);
214 	*dst = '\0';
215 	return (dst - start);
216 }
217 
218 
219 int
220 strsvisx(dst, src, len, flag, extra)
221 	char *dst;
222 	const char *src;
223 	size_t len;
224 	int flag;
225 	const char *extra;
226 {
227 	char c;
228 	char *start;
229 
230 	_DIAGASSERT(dst != NULL);
231 	_DIAGASSERT(src != NULL);
232 	_DIAGASSERT(extra != NULL);
233 
234 	for (start = dst; len > 0; len--) {
235 		c = *src++;
236 		SVIS(dst, c, flag, len ? *src : '\0', extra);
237 	}
238 	*dst = '\0';
239 	return (dst - start);
240 }
241 
242 
243 /*
244  * vis - visually encode characters
245  */
246 char *
247 vis(dst, c, flag, nextc)
248 	char *dst;
249 	int c, flag, nextc;
250 
251 {
252 	char extra[MAXEXTRAS];
253 
254 	_DIAGASSERT(dst != NULL);
255 
256 	MAKEEXTRALIST(flag, extra);
257 	SVIS(dst, c, flag, nextc, extra);
258 	*dst = '\0';
259 	return (dst);
260 }
261 
262 
263 /*
264  * strvis, strvisx - visually encode characters from src into dst
265  *
266  *	Dst must be 4 times the size of src to account for possible
267  *	expansion.  The length of dst, not including the trailing NULL,
268  *	is returned.
269  *
270  *	Strvisx encodes exactly len bytes from src into dst.
271  *	This is useful for encoding a block of data.
272  */
273 int
274 strvis(dst, src, flag)
275 	char *dst;
276 	const char *src;
277 	int flag;
278 {
279 	char extra[MAXEXTRAS];
280 
281 	MAKEEXTRALIST(flag, extra);
282 	return (strsvis(dst, src, flag, extra));
283 }
284 
285 
286 int
287 strvisx(dst, src, len, flag)
288 	char *dst;
289 	const char *src;
290 	size_t len;
291 	int flag;
292 {
293 	char extra[MAXEXTRAS];
294 
295 	MAKEEXTRALIST(flag, extra);
296 	return (strsvisx(dst, src, len, flag, extra));
297 }
298 #endif
299