vis.c
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 "portable.h"
32
33#ifndef HAVE_STRAVIS
34
35#include <sys/types.h>
36#include <errno.h>
37#include <ctype.h>
38#include <limits.h>
39#include <string.h>
40#include <stdlib.h>
41
42#include "vis.h"
43
44#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
45#define isvisible(c,flag) \
46 (((c) == '\\' || (flag & VIS_ALL) == 0) && \
47 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \
48 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \
49 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \
50 ((flag & VIS_SP) == 0 && (c) == ' ') || \
51 ((flag & VIS_TAB) == 0 && (c) == '\t') || \
52 ((flag & VIS_NL) == 0 && (c) == '\n') || \
53 ((flag & VIS_SAFE) && ((c) == '\b' || \
54 (c) == '\007' || (c) == '\r' || \
55 isgraph((u_char)(c))))))
56
57/*
58 * vis - visually encode characters
59 */
60static char *
61evis(char *dst, int c, int flag, int nextc)
62{
63 if (isvisible(c, flag)) {
64 if ((c == '"' && (flag & VIS_DQ) != 0) ||
65 (c == '\\' && (flag & VIS_NOSLASH) == 0))
66 *dst++ = '\\';
67 *dst++ = c;
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 case '\a':
87 *dst++ = '\\';
88 *dst++ = 'a';
89 goto done;
90 case '\v':
91 *dst++ = '\\';
92 *dst++ = 'v';
93 goto done;
94 case '\t':
95 *dst++ = '\\';
96 *dst++ = 't';
97 goto done;
98 case '\f':
99 *dst++ = '\\';
100 *dst++ = 'f';
101 goto done;
102 case ' ':
103 *dst++ = '\\';
104 *dst++ = 's';
105 goto done;
106 case '\0':
107 *dst++ = '\\';
108 *dst++ = '0';
109 if (isoctal(nextc)) {
110 *dst++ = '0';
111 *dst++ = '0';
112 }
113 goto done;
114 }
115 }
116 if (((c & 0177) == ' ') || (flag & VIS_OCTAL) ||
117 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) {
118 *dst++ = '\\';
119 *dst++ = ((u_char)c >> 6 & 07) + '0';
120 *dst++ = ((u_char)c >> 3 & 07) + '0';
121 *dst++ = ((u_char)c & 07) + '0';
122 goto done;
123 }
124 if ((flag & VIS_NOSLASH) == 0)
125 *dst++ = '\\';
126 if (c & 0200) {
127 c &= 0177;
128 *dst++ = 'M';
129 }
130 if (iscntrl((u_char)c)) {
131 *dst++ = '^';
132 if (c == 0177)
133 *dst++ = '?';
134 else
135 *dst++ = c + '@';
136 } else {
137 *dst++ = '-';
138 *dst++ = c;
139 }
140done:
141 *dst = '\0';
142 return (dst);
143}
144
145/*
146 * strvis, strnvis, strvisx - visually encode characters from src into dst
147 *
148 * Dst must be 4 times the size of src to account for possible
149 * expansion. The length of dst, not including the trailing NULL,
150 * is returned.
151 *
152 * Strnvis will write no more than siz-1 bytes (and will NULL terminate).
153 * The number of bytes needed to fully encode the string is returned.
154 *
155 * Strvisx encodes exactly len bytes from src into dst.
156 * This is useful for encoding a block of data.
157 */
158static int
159estrvis(char *dst, const char *src, int flag)
160{
161 char c;
162 char *start;
163
164 for (start = dst; (c = *src);)
165 dst = evis(dst, c, flag, *++src);
166 *dst = '\0';
167 return (dst - start);
168}
169
170int
171stravis(char **outp, const char *src, int flag)
172{
173 char *buf;
174 int len, serrno;
175
176 buf = reallocarray(NULL, 4, strlen(src) + 1);
177 if (buf == NULL)
178 return -1;
179 len = estrvis(buf, src, flag);
180 serrno = errno;
181 *outp = realloc(buf, len + 1);
182 if (*outp == NULL) {
183 *outp = buf;
184 errno = serrno;
185 }
186 return (len);
187}
188
189#endif /* !HAVE_STRAVIS */
