1 /* $OpenBSD: vis.c,v 1.19 2005/09/01 17:15:49 millert Exp $ */
2 /*-
3 * Copyright (c) 1989, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /* OPENBSD ORIGINAL: lib/libc/gen/vis.c */
32
33 #include "includes.h"
34 #if !defined(HAVE_STRNVIS)
35
36 #include <ctype.h>
37 #include <string.h>
38
39 #include "vis.h"
40
41 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
42 #define isvisible(c) \
43 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \
44 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \
45 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \
46 ((flag & VIS_SP) == 0 && (c) == ' ') || \
47 ((flag & VIS_TAB) == 0 && (c) == '\t') || \
48 ((flag & VIS_NL) == 0 && (c) == '\n') || \
49 ((flag & VIS_SAFE) && ((c) == '\b' || \
50 (c) == '\007' || (c) == '\r' || \
51 isgraph((u_char)(c)))))
52
53 /*
54 * vis - visually encode characters
55 */
56 char *
vis(char * dst,int c,int flag,int nextc)57 vis(char *dst, int c, int flag, int nextc)
58 {
59 if (isvisible(c)) {
60 *dst++ = c;
61 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
62 *dst++ = '\\';
63 *dst = '\0';
64 return (dst);
65 }
66
67 if (flag & VIS_CSTYLE) {
68 switch(c) {
69 case '\n':
70 *dst++ = '\\';
71 *dst++ = 'n';
72 goto done;
73 case '\r':
74 *dst++ = '\\';
75 *dst++ = 'r';
76 goto done;
77 case '\b':
78 *dst++ = '\\';
79 *dst++ = 'b';
80 goto done;
81 case '\a':
82 *dst++ = '\\';
83 *dst++ = 'a';
84 goto done;
85 case '\v':
86 *dst++ = '\\';
87 *dst++ = 'v';
88 goto done;
89 case '\t':
90 *dst++ = '\\';
91 *dst++ = 't';
92 goto done;
93 case '\f':
94 *dst++ = '\\';
95 *dst++ = 'f';
96 goto done;
97 case ' ':
98 *dst++ = '\\';
99 *dst++ = 's';
100 goto done;
101 case '\0':
102 *dst++ = '\\';
103 *dst++ = '0';
104 if (isoctal(nextc)) {
105 *dst++ = '0';
106 *dst++ = '0';
107 }
108 goto done;
109 }
110 }
111 if (((c & 0177) == ' ') || (flag & VIS_OCTAL) ||
112 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) {
113 *dst++ = '\\';
114 *dst++ = ((u_char)c >> 6 & 07) + '0';
115 *dst++ = ((u_char)c >> 3 & 07) + '0';
116 *dst++ = ((u_char)c & 07) + '0';
117 goto done;
118 }
119 if ((flag & VIS_NOSLASH) == 0)
120 *dst++ = '\\';
121 if (c & 0200) {
122 c &= 0177;
123 *dst++ = 'M';
124 }
125 if (iscntrl((u_char)c)) {
126 *dst++ = '^';
127 if (c == 0177)
128 *dst++ = '?';
129 else
130 *dst++ = c + '@';
131 } else {
132 *dst++ = '-';
133 *dst++ = c;
134 }
135 done:
136 *dst = '\0';
137 return (dst);
138 }
139
140 /*
141 * strvis, strnvis, strvisx - visually encode characters from src into dst
142 *
143 * Dst must be 4 times the size of src to account for possible
144 * expansion. The length of dst, not including the trailing NULL,
145 * is returned.
146 *
147 * Strnvis will write no more than siz-1 bytes (and will NULL terminate).
148 * The number of bytes needed to fully encode the string is returned.
149 *
150 * Strvisx encodes exactly len bytes from src into dst.
151 * This is useful for encoding a block of data.
152 */
153 int
strvis(char * dst,const char * src,int flag)154 strvis(char *dst, const char *src, int flag)
155 {
156 char c;
157 char *start;
158
159 for (start = dst; (c = *src);)
160 dst = vis(dst, c, flag, *++src);
161 *dst = '\0';
162 return (dst - start);
163 }
164
165 int
strnvis(char * dst,const char * src,size_t siz,int flag)166 strnvis(char *dst, const char *src, size_t siz, int flag)
167 {
168 char *start, *end;
169 char tbuf[5];
170 int c, i;
171
172 i = 0;
173 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
174 if (isvisible(c)) {
175 i = 1;
176 *dst++ = c;
177 if (c == '\\' && (flag & VIS_NOSLASH) == 0) {
178 /* need space for the extra '\\' */
179 if (dst < end)
180 *dst++ = '\\';
181 else {
182 dst--;
183 i = 2;
184 break;
185 }
186 }
187 src++;
188 } else {
189 i = vis(tbuf, c, flag, *++src) - tbuf;
190 if (dst + i <= end) {
191 memcpy(dst, tbuf, i);
192 dst += i;
193 } else {
194 src--;
195 break;
196 }
197 }
198 }
199 if (siz > 0)
200 *dst = '\0';
201 if (dst + i > end) {
202 /* adjust return value for truncation */
203 while ((c = *src))
204 dst += vis(tbuf, c, flag, *++src) - tbuf;
205 }
206 return (dst - start);
207 }
208
209 int
strvisx(char * dst,const char * src,size_t len,int flag)210 strvisx(char *dst, const char *src, size_t len, int flag)
211 {
212 char c;
213 char *start;
214
215 for (start = dst; len > 1; len--) {
216 c = *src;
217 dst = vis(dst, c, flag, *++src);
218 }
219 if (len)
220 dst = vis(dst, *src, flag, '\0');
221 *dst = '\0';
222 return (dst - start);
223 }
224
225 #endif
226