2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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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
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33 * $FreeBSD: src/lib/libc/gen/vis.c,v 1.5.8.2 2001/03/05 09:44:34 obrien Exp $
36 #if defined(LIBC_SCCS) && !defined(lint)
37 static char sccsid[] = "@(#)vis.c 8.1 (Berkeley) 7/19/93";
38 #endif /* LIBC_SCCS and not lint */
40 #include <sys/types.h>
46 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
49 * vis - visually encode characters
52 vis(dst, c, flag, nextc)
59 if (flag & VIS_HTTPSTYLE) {
60 /* Described in RFC 1808 */
61 if (!(isalnum(c) /* alpha-numeric */
63 || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
65 || c == '!' || c == '*' || c == '\'' || c == '('
66 || c == ')' || c == ',')) {
68 snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
75 ((flag & VIS_SP) == 0 && c == ' ') ||
76 ((flag & VIS_TAB) == 0 && c == '\t') ||
77 ((flag & VIS_NL) == 0 && c == '\n') ||
78 ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
80 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
86 if (flag & VIS_CSTYLE) {
127 if (isoctal(nextc)) {
134 if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
136 *dst++ = ((u_char)c >> 6 & 07) + '0';
137 *dst++ = ((u_char)c >> 3 & 07) + '0';
138 *dst++ = ((u_char)c & 07) + '0';
141 if ((flag & VIS_NOSLASH) == 0)
163 * strvis, strvisx - visually encode characters from src into dst
165 * Dst must be 4 times the size of src to account for possible
166 * expansion. The length of dst, not including the trailing NULL,
169 * Strvisx encodes exactly len bytes from src into dst.
170 * This is useful for encoding a block of data.
173 strvis(dst, src, flag)
175 register const char *src;
181 for (start = dst; (c = *src); )
182 dst = vis(dst, c, flag, *++src);
184 return (dst - start);
188 strvisx(dst, src, len, flag)
190 register const char *src;
197 for (start = dst; len > 1; len--) {
199 dst = vis(dst, c, flag, *++src);
202 dst = vis(dst, *src, flag, '\0');
205 return (dst - start);