xref: /netbsd-src/lib/libc/gen/vis.c (revision 1ca5c1b28139779176bd5c13ad7c5f25c0bcd5f8)
1 /*	$NetBSD: vis.c,v 1.19 2000/01/22 22:42:45 mycroft 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 
38 #include <sys/cdefs.h>
39 #if !defined(lint)
40 __RCSID("$NetBSD: vis.c,v 1.19 2000/01/22 22:42:45 mycroft Exp $");
41 #endif /* not lint */
42 
43 #include "namespace.h"
44 #include <sys/types.h>
45 
46 #include <assert.h>
47 #include <ctype.h>
48 #include <limits.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <vis.h>
52 
53 #ifdef __weak_alias
54 __weak_alias(strsvis,_strsvis)
55 __weak_alias(strsvisx,_strsvisx)
56 __weak_alias(strvis,_strvis)
57 __weak_alias(strvisx,_strvisx)
58 __weak_alias(svis,_svis)
59 __weak_alias(vis,_vis)
60 #endif
61 
62 #undef BELL
63 #if defined(__STDC__)
64 #define BELL '\a'
65 #else
66 #define BELL '\007'
67 #endif
68 
69 #define isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
70 #define iswhite(c)	(c == ' ' || c == '\t' || c == '\n')
71 #define issafe(c)	(c == '\b' || c == BELL || c == '\r')
72 
73 #define MAXEXTRAS       5
74 
75 
76 #define MAKEEXTRALIST(flag, extra)					      \
77 do {									      \
78 	char *pextra = extra;						      \
79 	if (flag & VIS_SP) *pextra++ = ' ';				      \
80 	if (flag & VIS_TAB) *pextra++ = '\t';				      \
81 	if (flag & VIS_NL) *pextra++ = '\n';				      \
82 	if ((flag & VIS_NOSLASH) == 0) *pextra++ = '\\';		      \
83 	*pextra = '\0';							      \
84 } while (/*CONSTCOND*/0)
85 
86 /*
87  * This is SVIS, the central macro of vis.
88  * dst:	      Pointer to the destination buffer
89  * c:	      Character to encode
90  * flag:      Flag word
91  * nextc:     The character following 'c'
92  * extra:     Pointer to the list of extra characters to be
93  *	      backslash-protected.
94  */
95 #define SVIS(dst, c, flag, nextc, extra)				      \
96 do {									      \
97 	int isextra, isc;						      \
98 	isextra = strchr(extra, c) != NULL;				      \
99 	if (!isextra && isascii(c) && (isgraph(c) || iswhite(c) ||	      \
100 	    ((flag & VIS_SAFE) && issafe(c)))) {			      \
101 		*dst++ = c;						      \
102 		break;							      \
103 	}								      \
104 	isc = 0;							      \
105 	if (flag & VIS_CSTYLE) {					      \
106 		switch (c) {						      \
107 		case '\n':						      \
108 			isc = 1; *dst++ = '\\'; *dst++ = 'n';		      \
109 			break;						      \
110 		case '\r':						      \
111 			isc = 1; *dst++ = '\\'; *dst++ = 'r';		      \
112 			break;						      \
113 		case '\b':						      \
114 			isc = 1; *dst++ = '\\'; *dst++ = 'b';		      \
115 			break;						      \
116 		case BELL:						      \
117 			isc = 1; *dst++ = '\\'; *dst++ = 'a';		      \
118 			break;						      \
119 		case '\v':						      \
120 			isc = 1; *dst++ = '\\'; *dst++ = 'v';		      \
121 			break;						      \
122 		case '\t':						      \
123 			isc = 1; *dst++ = '\\'; *dst++ = 't';		      \
124 			break;						      \
125 		case '\f':						      \
126 			isc = 1; *dst++ = '\\'; *dst++ = 'f';		      \
127 			break;						      \
128 		case ' ':						      \
129 			isc = 1; *dst++ = '\\'; *dst++ = 's';		      \
130 			break;						      \
131 		case '\0':						      \
132 			isc = 1; *dst++ = '\\'; *dst++ = '0';		      \
133 			if (isoctal(nextc)) {				      \
134 				*dst++ = '0';				      \
135 				*dst++ = '0';				      \
136 			}						      \
137 		}							      \
138 	}								      \
139 	if (isc) break;							      \
140 	if (isextra || ((c & 0177) == ' ') || (flag & VIS_OCTAL)) {	      \
141 		*dst++ = '\\';						      \
142 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 6) & 03) + '0';    \
143 		*dst++ = (u_char)(((u_int32_t)(u_char)c >> 3) & 07) + '0';    \
144 		*dst++ =			     (c	      & 07) + '0';    \
145 	} else {							      \
146 		if ((flag & VIS_NOSLASH) == 0) *dst++ = '\\';		      \
147 		if (c & 0200) {						      \
148 			c &= 0177; *dst++ = 'M';			      \
149 		}							      \
150 		if (iscntrl(c)) {					      \
151 			*dst++ = '^';					      \
152 			if (c == 0177)					      \
153 				*dst++ = '?';				      \
154 			else						      \
155 				*dst++ = c + '@';			      \
156 		} else {						      \
157 			*dst++ = '-'; *dst++ = c;			      \
158 		}							      \
159 	}								      \
160 } while (/*CONSTCOND*/0)
161 
162 
163 /*
164  * svis - visually encode characters, also encoding the characters
165  * 	  pointed to by `extra'
166  */
167 char *
168 svis(dst, c, flag, nextc, extra)
169 	char *dst;
170 	int c, flag, nextc;
171 	const char *extra;
172 {
173 	_DIAGASSERT(dst != NULL);
174 	_DIAGASSERT(extra != NULL);
175 
176 	SVIS(dst, c, flag, nextc, extra);
177 	*dst = '\0';
178 	return(dst);
179 }
180 
181 
182 /*
183  * strsvis, strsvisx - visually encode characters from src into dst
184  *
185  *	Extra is a pointer to a \0-terminated list of characters to
186  *	be encoded, too. These functions are useful e. g. to
187  *	encode strings in such a way so that they are not interpreted
188  *	by a shell.
189  *
190  *	Dst must be 4 times the size of src to account for possible
191  *	expansion.  The length of dst, not including the trailing NULL,
192  *	is returned.
193  *
194  *	Strsvisx encodes exactly len bytes from src into dst.
195  *	This is useful for encoding a block of data.
196  */
197 int
198 strsvis(dst, src, flag, extra)
199 	char *dst;
200 	const char *src;
201 	int flag;
202 	const char *extra;
203 {
204 	char c;
205 	char *start;
206 
207 	_DIAGASSERT(dst != NULL);
208 	_DIAGASSERT(src != NULL);
209 	_DIAGASSERT(extra != NULL);
210 
211 	for (start = dst; (c = *src++) != '\0'; /* empty */)
212 	    SVIS(dst, c, flag, *src, extra);
213 	*dst = '\0';
214 	return (dst - start);
215 }
216 
217 
218 int
219 strsvisx(dst, src, len, flag, extra)
220 	char *dst;
221 	const char *src;
222 	size_t len;
223 	int flag;
224 	const char *extra;
225 {
226 	char c;
227 	char *start;
228 
229 	_DIAGASSERT(dst != NULL);
230 	_DIAGASSERT(src != NULL);
231 	_DIAGASSERT(extra != NULL);
232 
233 	for (start = dst; len > 0; len--) {
234 		c = *src++;
235 		SVIS(dst, c, flag, len ? *src : '\0', extra);
236 	}
237 	*dst = '\0';
238 	return (dst - start);
239 }
240 
241 
242 /*
243  * vis - visually encode characters
244  */
245 char *
246 vis(dst, c, flag, nextc)
247 	char *dst;
248 	int c, flag, nextc;
249 
250 {
251 	char extra[MAXEXTRAS];
252 
253 	_DIAGASSERT(dst != NULL);
254 
255 	MAKEEXTRALIST(flag, extra);
256 	SVIS(dst, c, flag, nextc, extra);
257 	*dst = '\0';
258 	return (dst);
259 }
260 
261 
262 /*
263  * strvis, strvisx - visually encode characters from src into dst
264  *
265  *	Dst must be 4 times the size of src to account for possible
266  *	expansion.  The length of dst, not including the trailing NULL,
267  *	is returned.
268  *
269  *	Strvisx encodes exactly len bytes from src into dst.
270  *	This is useful for encoding a block of data.
271  */
272 int
273 strvis(dst, src, flag)
274 	char *dst;
275 	const char *src;
276 	int flag;
277 {
278 	char extra[MAXEXTRAS];
279 
280 	MAKEEXTRALIST(flag, extra);
281 	return (strsvis(dst, src, flag, extra));
282 }
283 
284 
285 int
286 strvisx(dst, src, len, flag)
287 	char *dst;
288 	const char *src;
289 	size_t len;
290 	int flag;
291 {
292 	char extra[MAXEXTRAS];
293 
294 	MAKEEXTRALIST(flag, extra);
295 	return (strsvisx(dst, src, len, flag, extra));
296 }
297