xref: /netbsd-src/lib/libc/gen/vis.c (revision 1f2744e6e4915c9da2a3f980279398c4cf7d5e6d)
1 /*	$NetBSD: vis.c,v 1.6 1995/02/25 15:40:09 cgd 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 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)vis.c	8.1 (Berkeley) 7/19/93";
39 #else
40 static char rcsid[] = "$NetBSD: vis.c,v 1.6 1995/02/25 15:40:09 cgd Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include <sys/types.h>
45 #include <limits.h>
46 #include <ctype.h>
47 #include <vis.h>
48 
49 #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
50 
51 /*
52  * vis - visually encode characters
53  */
54 char *
55 vis(dst, c, flag, nextc)
56 	register char *dst;
57 	int c, nextc;
58 	register int flag;
59 {
60 	if ((u_int)c <= UCHAR_MAX && isascii(c) && isgraph(c) ||
61 	   ((flag & VIS_SP) == 0 && c == ' ') ||
62 	   ((flag & VIS_TAB) == 0 && c == '\t') ||
63 	   ((flag & VIS_NL) == 0 && c == '\n') ||
64 	   ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
65 		*dst++ = c;
66 		if (c == '\\' && (flag & VIS_NOSLASH) == 0)
67 			*dst++ = '\\';
68 		*dst = '\0';
69 		return (dst);
70 	}
71 
72 	if (flag & VIS_CSTYLE) {
73 		switch(c) {
74 		case '\n':
75 			*dst++ = '\\';
76 			*dst++ = 'n';
77 			goto done;
78 		case '\r':
79 			*dst++ = '\\';
80 			*dst++ = 'r';
81 			goto done;
82 		case '\b':
83 			*dst++ = '\\';
84 			*dst++ = 'b';
85 			goto done;
86 #if __STDC__
87 		case '\a':
88 #else
89 		case '\007':
90 #endif
91 			*dst++ = '\\';
92 			*dst++ = 'a';
93 			goto done;
94 		case '\v':
95 			*dst++ = '\\';
96 			*dst++ = 'v';
97 			goto done;
98 		case '\t':
99 			*dst++ = '\\';
100 			*dst++ = 't';
101 			goto done;
102 		case '\f':
103 			*dst++ = '\\';
104 			*dst++ = 'f';
105 			goto done;
106 		case ' ':
107 			*dst++ = '\\';
108 			*dst++ = 's';
109 			goto done;
110 		case '\0':
111 			*dst++ = '\\';
112 			*dst++ = '0';
113 			if (isoctal(nextc)) {
114 				*dst++ = '0';
115 				*dst++ = '0';
116 			}
117 			goto done;
118 		}
119 	}
120 	if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
121 		*dst++ = '\\';
122 		*dst++ = ((u_char)c >> 6 & 07) + '0';
123 		*dst++ = ((u_char)c >> 3 & 07) + '0';
124 		*dst++ = ((u_char)c & 07) + '0';
125 		goto done;
126 	}
127 	if ((flag & VIS_NOSLASH) == 0)
128 		*dst++ = '\\';
129 	if (c & 0200) {
130 		c &= 0177;
131 		*dst++ = 'M';
132 	}
133 	if (iscntrl(c)) {
134 		*dst++ = '^';
135 		if (c == 0177)
136 			*dst++ = '?';
137 		else
138 			*dst++ = c + '@';
139 	} else {
140 		*dst++ = '-';
141 		*dst++ = c;
142 	}
143 done:
144 	*dst = '\0';
145 	return (dst);
146 }
147 
148 /*
149  * strvis, strvisx - visually encode characters from src into dst
150  *
151  *	Dst must be 4 times the size of src to account for possible
152  *	expansion.  The length of dst, not including the trailing NULL,
153  *	is returned.
154  *
155  *	Strvisx encodes exactly len bytes from src into dst.
156  *	This is useful for encoding a block of data.
157  */
158 int
159 strvis(dst, src, flag)
160 	register char *dst;
161 	register const char *src;
162 	int flag;
163 {
164 	register char c;
165 	char *start;
166 
167 	for (start = dst; c = *src;)
168 		dst = vis(dst, c, flag, *++src);
169 	*dst = '\0';
170 	return (dst - start);
171 }
172 
173 int
174 strvisx(dst, src, len, flag)
175 	register char *dst;
176 	register const char *src;
177 	register size_t len;
178 	int flag;
179 {
180 	register char c;
181 	char *start;
182 
183 	for (start = dst; len > 1; len--) {
184 		c = *src;
185 		dst = vis(dst, c, flag, *++src);
186 	}
187 	if (len)
188 		dst = vis(dst, *src, flag, '\0');
189 	*dst = '\0';
190 
191 	return (dst - start);
192 }
193