1/*-
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  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)
35static char sccsid[] = "@(#)vis.c	8.1 (Berkeley) 7/19/93";
36#endif /* LIBC_SCCS and not lint */
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: src/lib/libc/gen/vis.c,v 1.13 2003/10/30 12:41:50 phk Exp $");
39
40#include <sys/types.h>
41#include <limits.h>
42#include <ctype.h>
43#include <stdio.h>
44#include <vis.h>
45
46#define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
47
48/*
49 * vis - visually encode characters
50 */
51char *
52vis(dst, c, flag, nextc)
53	char *dst;
54	int c, nextc;
55	int flag;
56{
57	c = (unsigned char)c;
58
59	if (flag & VIS_HTTPSTYLE) {
60		/* Described in RFC 1808 */
61		if (!(isalnum(c) /* alpha-numeric */
62		    /* safe */
63		    || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
64		    /* extra */
65		    || c == '!' || c == '*' || c == '\'' || c == '('
66		    || c == ')' || c == ',')) {
67			*dst++ = '%';
68			snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
69			dst += 2;
70			goto done;
71		}
72	}
73
74	if ((flag & VIS_GLOB) &&
75	    (c == '*' || c == '?' || c == '[' || c == '#'))
76		;
77	else if (isgraph(c) ||
78	   ((flag & VIS_SP) == 0 && c == ' ') ||
79	   ((flag & VIS_TAB) == 0 && c == '\t') ||
80	   ((flag & VIS_NL) == 0 && c == '\n') ||
81	   ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
82		*dst++ = c;
83		if (c == '\\' && (flag & VIS_NOSLASH) == 0)
84			*dst++ = '\\';
85		*dst = '\0';
86		return (dst);
87	}
88
89	if (flag & VIS_CSTYLE) {
90		switch(c) {
91		case '\n':
92			*dst++ = '\\';
93			*dst++ = 'n';
94			goto done;
95		case '\r':
96			*dst++ = '\\';
97			*dst++ = 'r';
98			goto done;
99		case '\b':
100			*dst++ = '\\';
101			*dst++ = 'b';
102			goto done;
103		case '\a':
104			*dst++ = '\\';
105			*dst++ = 'a';
106			goto done;
107		case '\v':
108			*dst++ = '\\';
109			*dst++ = 'v';
110			goto done;
111		case '\t':
112			*dst++ = '\\';
113			*dst++ = 't';
114			goto done;
115		case '\f':
116			*dst++ = '\\';
117			*dst++ = 'f';
118			goto done;
119		case ' ':
120			*dst++ = '\\';
121			*dst++ = 's';
122			goto done;
123		case '\0':
124			*dst++ = '\\';
125			*dst++ = '0';
126			if (isoctal(nextc)) {
127				*dst++ = '0';
128				*dst++ = '0';
129			}
130			goto done;
131		}
132	}
133	if (((c & 0177) == ' ') || isgraph(c) || (flag & VIS_OCTAL)) {
134		*dst++ = '\\';
135		*dst++ = ((u_char)c >> 6 & 07) + '0';
136		*dst++ = ((u_char)c >> 3 & 07) + '0';
137		*dst++ = ((u_char)c & 07) + '0';
138		goto done;
139	}
140	if ((flag & VIS_NOSLASH) == 0)
141		*dst++ = '\\';
142	if (c & 0200) {
143		c &= 0177;
144		*dst++ = 'M';
145	}
146	if (iscntrl(c)) {
147		*dst++ = '^';
148		if (c == 0177)
149			*dst++ = '?';
150		else
151			*dst++ = c + '@';
152	} else {
153		*dst++ = '-';
154		*dst++ = c;
155	}
156done:
157	*dst = '\0';
158	return (dst);
159}
160
161/*
162 * strvis, strvisx - visually encode characters from src into dst
163 *
164 *	Dst must be 4 times the size of src to account for possible
165 *	expansion.  The length of dst, not including the trailing NUL,
166 *	is returned.
167 *
168 *	Strvisx encodes exactly len bytes from src into dst.
169 *	This is useful for encoding a block of data.
170 */
171int
172strvis(dst, src, flag)
173	char *dst;
174	const char *src;
175	int flag;
176{
177	char c;
178	char *start;
179
180	for (start = dst; (c = *src); )
181		dst = vis(dst, c, flag, *++src);
182	*dst = '\0';
183	return (dst - start);
184}
185
186int
187strvisx(dst, src, len, flag)
188	char *dst;
189	const char *src;
190	size_t len;
191	int flag;
192{
193	int c;
194	char *start;
195
196	for (start = dst; len > 1; len--) {
197		c = *src;
198		dst = vis(dst, c, flag, *++src);
199	}
200	if (len)
201		dst = vis(dst, *src, flag, '\0');
202	*dst = '\0';
203
204	return (dst - start);
205}
206