xref: /haiku/src/libs/bsd/vis.c (revision 1564b19c80637a2ba13949db0056215699b7b418)
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)
35 static 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 $");
39 
40 #include <sys/types.h>
41 #include <limits.h>
42 #include <ctype.h>
43 #include <stdio.h>
44 #include <vis.h>
45 
46 #define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
47 
48 /*
49  * vis - visually encode characters
50  */
51 char *
52 vis(dst, c, flag, nextc)
53 	char *dst;
54 	int c, nextc;
55 	int flag;
56 {
57 	c = (unsigned char)c;
58 
59 	if (flag & VIS_HTTPSTYLE) {
60 		/* Described in RFC 1808 */
61 		if (!(isalnum(c) /* alpha-numeric */
62 		    /* safe */
63 		    || c == '$' || 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 	}
156 done:
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  */
171 int
172 strvis(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 
186 int
187 strvisx(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