1 /* $OpenBSD: vis.c,v 1.25 2015/09/13 11:32:51 guenther 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 #include <sys/types.h>
32 #include <errno.h>
33 #include <ctype.h>
34 #include <limits.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <vis.h>
38
39 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
40 #define isvisible(c,flag) \
41 (((c) == '\\' || (flag & VIS_ALL) == 0) && \
42 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \
43 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \
44 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \
45 ((flag & VIS_SP) == 0 && (c) == ' ') || \
46 ((flag & VIS_TAB) == 0 && (c) == '\t') || \
47 ((flag & VIS_NL) == 0 && (c) == '\n') || \
48 ((flag & VIS_SAFE) && ((c) == '\b' || \
49 (c) == '\007' || (c) == '\r' || \
50 isgraph((u_char)(c))))))
51
52 /*
53 * vis - visually encode characters
54 */
55 char *
vis(char * dst,int c,int flag,int nextc)56 vis(char *dst, int c, int flag, int nextc)
57 {
58 if (isvisible(c, flag)) {
59 if ((c == '"' && (flag & VIS_DQ) != 0) ||
60 (c == '\\' && (flag & VIS_NOSLASH) == 0))
61 *dst++ = '\\';
62 *dst++ = c;
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 DEF_WEAK(vis);
140
141 /*
142 * strvis, strnvis, strvisx - visually encode characters from src into dst
143 *
144 * Dst must be 4 times the size of src to account for possible
145 * expansion. The length of dst, not including the trailing NULL,
146 * is returned.
147 *
148 * Strnvis will write no more than siz-1 bytes (and will NULL terminate).
149 * The number of bytes needed to fully encode the string is returned.
150 *
151 * Strvisx encodes exactly len bytes from src into dst.
152 * This is useful for encoding a block of data.
153 */
154 int
strvis(char * dst,const char * src,int flag)155 strvis(char *dst, const char *src, int flag)
156 {
157 char c;
158 char *start;
159
160 for (start = dst; (c = *src);)
161 dst = vis(dst, c, flag, *++src);
162 *dst = '\0';
163 return (dst - start);
164 }
165 DEF_WEAK(strvis);
166
167 int
strnvis(char * dst,const char * src,size_t siz,int flag)168 strnvis(char *dst, const char *src, size_t siz, int flag)
169 {
170 char *start, *end;
171 char tbuf[5];
172 int c, i;
173
174 i = 0;
175 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
176 if (isvisible(c, flag)) {
177 if ((c == '"' && (flag & VIS_DQ) != 0) ||
178 (c == '\\' && (flag & VIS_NOSLASH) == 0)) {
179 /* need space for the extra '\\' */
180 if (dst + 1 >= end) {
181 i = 2;
182 break;
183 }
184 *dst++ = '\\';
185 }
186 i = 1;
187 *dst++ = c;
188 src++;
189 } else {
190 i = vis(tbuf, c, flag, *++src) - tbuf;
191 if (dst + i <= end) {
192 memcpy(dst, tbuf, i);
193 dst += i;
194 } else {
195 src--;
196 break;
197 }
198 }
199 }
200 if (siz > 0)
201 *dst = '\0';
202 if (dst + i > end) {
203 /* adjust return value for truncation */
204 while ((c = *src))
205 dst += vis(tbuf, c, flag, *++src) - tbuf;
206 }
207 return (dst - start);
208 }
209
210 int
stravis(char ** outp,const char * src,int flag)211 stravis(char **outp, const char *src, int flag)
212 {
213 char *buf;
214 int len, serrno;
215
216 buf = reallocarray(NULL, 4, strlen(src) + 1);
217 if (buf == NULL)
218 return -1;
219 len = strvis(buf, src, flag);
220 serrno = errno;
221 *outp = realloc(buf, len + 1);
222 if (*outp == NULL) {
223 *outp = buf;
224 errno = serrno;
225 }
226 return (len);
227 }
228
229 int
strvisx(char * dst,const char * src,size_t len,int flag)230 strvisx(char *dst, const char *src, size_t len, int flag)
231 {
232 char c;
233 char *start;
234
235 for (start = dst; len > 1; len--) {
236 c = *src;
237 dst = vis(dst, c, flag, *++src);
238 }
239 if (len)
240 dst = vis(dst, *src, flag, '\0');
241 *dst = '\0';
242 return (dst - start);
243 }
244