1 /*-
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)vis.c 5.6 (Berkeley) 2/5/92";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <sys/types.h>
39 #include <limits.h>
40 #include <ctype.h>
41 #include <vis.h>
42
43 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
44
45 /*
46 * vis - visually encode characters
47 */
48 char *
vis(dst,c,flag,nextc)49 vis(dst, c, flag, nextc)
50 register char *dst;
51 int c, nextc;
52 register int flag;
53 {
54 if ((u_int)c <= UCHAR_MAX && isgraph(c) ||
55 ((flag & VIS_SP) == 0 && c == ' ') ||
56 ((flag & VIS_TAB) == 0 && c == '\t') ||
57 ((flag & VIS_NL) == 0 && c == '\n') ||
58 ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
59 *dst++ = c;
60 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
61 *dst++ = '\\';
62 *dst = '\0';
63 return (dst);
64 }
65
66 if (flag & VIS_CSTYLE) {
67 switch(c) {
68 case '\n':
69 *dst++ = '\\';
70 *dst++ = 'n';
71 goto done;
72 case '\r':
73 *dst++ = '\\';
74 *dst++ = 'r';
75 goto done;
76 case '\b':
77 *dst++ = '\\';
78 *dst++ = 'b';
79 goto done;
80 #if __STDC__
81 case '\a':
82 #else
83 case '\007':
84 #endif
85 *dst++ = '\\';
86 *dst++ = 'a';
87 goto done;
88 case '\v':
89 *dst++ = '\\';
90 *dst++ = 'v';
91 goto done;
92 case '\t':
93 *dst++ = '\\';
94 *dst++ = 't';
95 goto done;
96 case '\f':
97 *dst++ = '\\';
98 *dst++ = 'f';
99 goto done;
100 case ' ':
101 *dst++ = '\\';
102 *dst++ = 's';
103 goto done;
104 case '\0':
105 *dst++ = '\\';
106 *dst++ = '0';
107 if (isoctal(nextc)) {
108 *dst++ = '0';
109 *dst++ = '0';
110 }
111 goto done;
112 }
113 }
114 if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
115 *dst++ = '\\';
116 *dst++ = ((u_char)c >> 6 & 07) + '0';
117 *dst++ = ((u_char)c >> 3 & 07) + '0';
118 *dst++ = ((u_char)c & 07) + '0';
119 goto done;
120 }
121 if ((flag & VIS_NOSLASH) == 0)
122 *dst++ = '\\';
123 if (c & 0200) {
124 c &= 0177;
125 *dst++ = 'M';
126 }
127 if (iscntrl(c)) {
128 *dst++ = '^';
129 if (c == 0177)
130 *dst++ = '?';
131 else
132 *dst++ = c + '@';
133 } else {
134 *dst++ = '-';
135 *dst++ = c;
136 }
137 done:
138 *dst = '\0';
139 return (dst);
140 }
141
142 /*
143 * strvis, strvisx - visually encode characters from src into dst
144 *
145 * Dst must be 4 times the size of src to account for possible
146 * expansion. The length of dst, not including the trailing NULL,
147 * is returned.
148 *
149 * Strvisx encodes exactly len bytes from src into dst.
150 * This is useful for encoding a block of data.
151 */
152 int
strvis(dst,src,flag)153 strvis(dst, src, flag)
154 register char *dst;
155 register const char *src;
156 int flag;
157 {
158 register char c;
159 char *start;
160
161 for (start = dst; c = *src;)
162 dst = vis(dst, c, flag, *++src);
163 *dst = '\0';
164 return (dst - start);
165 }
166
167 int
strvisx(dst,src,len,flag)168 strvisx(dst, src, len, flag)
169 register char *dst;
170 register const char *src;
171 register size_t len;
172 int flag;
173 {
174 char *start = dst;
175
176 while (len > 1) {
177 dst = vis(dst, *src, flag, *(src+1));
178 len--;
179 }
180 if (len)
181 dst = vis(dst, *src, flag, '\0');
182
183 return (dst - start);
184 }
185