xref: /netbsd-src/lib/libc/gen/vis.c (revision 3b435a73967be44dfb4a27315acd72bfacde430c)
1 /*	$NetBSD: vis.c,v 1.13 1999/09/20 04:39:07 lukem Exp $	*/
2 
3 /*-
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #if defined(LIBC_SCCS) && !defined(lint)
38 #if 0
39 static char sccsid[] = "@(#)vis.c	8.1 (Berkeley) 7/19/93";
40 #else
41 __RCSID("$NetBSD: vis.c,v 1.13 1999/09/20 04:39:07 lukem Exp $");
42 #endif
43 #endif /* LIBC_SCCS and not lint */
44 
45 #include "namespace.h"
46 #include <sys/types.h>
47 
48 #include <assert.h>
49 #include <ctype.h>
50 #include <limits.h>
51 #include <stdio.h>
52 #include <vis.h>
53 
54 #ifdef __weak_alias
55 __weak_alias(strvis,_strvis);
56 __weak_alias(strvisx,_strvisx);
57 __weak_alias(vis,_vis);
58 #endif
59 
60 #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
61 
62 /*
63  * vis - visually encode characters
64  */
65 char *
66 vis(dst, c, flag, nextc)
67 	char *dst;
68 	int c, nextc;
69 	int flag;
70 {
71 
72 	_DIAGASSERT(dst != NULL);
73 
74 	if (((u_int)c <= UCHAR_MAX && isascii(c) && isgraph(c)) ||
75 	   ((flag & VIS_SP) == 0 && c == ' ') ||
76 	   ((flag & VIS_TAB) == 0 && c == '\t') ||
77 	   ((flag & VIS_NL) == 0 && c == '\n') ||
78 	   ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
79 		*dst++ = c;
80 		if (c == '\\' && (flag & VIS_NOSLASH) == 0)
81 			*dst++ = '\\';
82 		*dst = '\0';
83 		return (dst);
84 	}
85 
86 	if (flag & VIS_CSTYLE) {
87 		switch(c) {
88 		case '\n':
89 			*dst++ = '\\';
90 			*dst++ = 'n';
91 			goto done;
92 		case '\r':
93 			*dst++ = '\\';
94 			*dst++ = 'r';
95 			goto done;
96 		case '\b':
97 			*dst++ = '\\';
98 			*dst++ = 'b';
99 			goto done;
100 #if __STDC__
101 		case '\a':
102 #else
103 		case '\007':
104 #endif
105 			*dst++ = '\\';
106 			*dst++ = 'a';
107 			goto done;
108 		case '\v':
109 			*dst++ = '\\';
110 			*dst++ = 'v';
111 			goto done;
112 		case '\t':
113 			*dst++ = '\\';
114 			*dst++ = 't';
115 			goto done;
116 		case '\f':
117 			*dst++ = '\\';
118 			*dst++ = 'f';
119 			goto done;
120 		case ' ':
121 			*dst++ = '\\';
122 			*dst++ = 's';
123 			goto done;
124 		case '\0':
125 			*dst++ = '\\';
126 			*dst++ = '0';
127 			if (isoctal(nextc)) {
128 				*dst++ = '0';
129 				*dst++ = '0';
130 			}
131 			goto done;
132 		}
133 	}
134 	if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
135 		*dst++ = '\\';
136 		*dst++ = ((((u_int32_t)c) >> 6) & 07) + '0';
137 		*dst++ = ((((u_int32_t)c) >> 3) & 07) + '0';
138 		*dst++ = (((u_char)c) & 07) + '0';
139 		goto done;
140 	}
141 	if ((flag & VIS_NOSLASH) == 0)
142 		*dst++ = '\\';
143 	if (c & 0200) {
144 		c &= 0177;
145 		*dst++ = 'M';
146 	}
147 	if (iscntrl(c)) {
148 		*dst++ = '^';
149 		if (c == 0177)
150 			*dst++ = '?';
151 		else
152 			*dst++ = c + '@';
153 	} else {
154 		*dst++ = '-';
155 		*dst++ = c;
156 	}
157 done:
158 	*dst = '\0';
159 	return (dst);
160 }
161 
162 /*
163  * strvis, strvisx - visually encode characters from src into dst
164  *
165  *	Dst must be 4 times the size of src to account for possible
166  *	expansion.  The length of dst, not including the trailing NULL,
167  *	is returned.
168  *
169  *	Strvisx encodes exactly len bytes from src into dst.
170  *	This is useful for encoding a block of data.
171  */
172 int
173 strvis(dst, src, flag)
174 	char *dst;
175 	const char *src;
176 	int flag;
177 {
178 	char c;
179 	char *start;
180 
181 	_DIAGASSERT(dst != NULL);
182 	_DIAGASSERT(src != NULL);
183 
184 	for (start = dst; (c = *src) != '\0';)
185 		dst = vis(dst, c, flag, *++src);
186 	*dst = '\0';
187 	return (dst - start);
188 }
189 
190 int
191 strvisx(dst, src, len, flag)
192 	char *dst;
193 	const char *src;
194 	size_t len;
195 	int flag;
196 {
197 	char c;
198 	char *start;
199 
200 	_DIAGASSERT(dst != NULL);
201 	_DIAGASSERT(src != NULL);
202 
203 	for (start = dst; len > 1; len--) {
204 		c = *src;
205 		dst = vis(dst, c, flag, *++src);
206 	}
207 	if (len)
208 		dst = vis(dst, *src, flag, '\0');
209 	*dst = '\0';
210 
211 	return (dst - start);
212 }
213