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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #if defined(LIBC_SCCS) && !defined(lint) 31 static char rcsid[] = "$OpenBSD: vis.c,v 1.12 2003/06/02 20:18:35 millert Exp $"; 32 #endif /* LIBC_SCCS and not lint */ 33 34 #include <sys/types.h> 35 #include <limits.h> 36 #include <ctype.h> 37 #include <string.h> 38 #include <vis.h> 39 40 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 41 #define isvisible(c) (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 42 isgraph((u_char)(c))) || \ 43 ((flag & VIS_SP) == 0 && (c) == ' ') || \ 44 ((flag & VIS_TAB) == 0 && (c) == '\t') || \ 45 ((flag & VIS_NL) == 0 && (c) == '\n') || \ 46 ((flag & VIS_SAFE) && ((c) == '\b' || \ 47 (c) == '\007' || (c) == '\r' || \ 48 isgraph((u_char)(c))))) 49 50 /* 51 * vis - visually encode characters 52 */ 53 char * 54 vis(dst, c, flag, nextc) 55 register char *dst; 56 int c, nextc; 57 register int flag; 58 { 59 if (isvisible(c)) { 60 *dst++ = c; 61 if (c == '\\' && (flag & VIS_NOSLASH) == 0) 62 *dst++ = '\\'; 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 *dst++ = '\\'; 113 *dst++ = ((u_char)c >> 6 & 07) + '0'; 114 *dst++ = ((u_char)c >> 3 & 07) + '0'; 115 *dst++ = ((u_char)c & 07) + '0'; 116 goto done; 117 } 118 if ((flag & VIS_NOSLASH) == 0) 119 *dst++ = '\\'; 120 if (c & 0200) { 121 c &= 0177; 122 *dst++ = 'M'; 123 } 124 if (iscntrl(c)) { 125 *dst++ = '^'; 126 if (c == 0177) 127 *dst++ = '?'; 128 else 129 *dst++ = c + '@'; 130 } else { 131 *dst++ = '-'; 132 *dst++ = c; 133 } 134 done: 135 *dst = '\0'; 136 return (dst); 137 } 138 139 /* 140 * strvis, strnvis, strvisx - visually encode characters from src into dst 141 * 142 * Dst must be 4 times the size of src to account for possible 143 * expansion. The length of dst, not including the trailing NULL, 144 * is returned. 145 * 146 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 147 * The number of bytes needed to fully encode the string is returned. 148 * 149 * Strvisx encodes exactly len bytes from src into dst. 150 * This is useful for encoding a block of data. 151 */ 152 int 153 strvis(dst, src, flag) 154 register char *dst; 155 register const char *src; 156 int flag; 157 { 158 register char c; 159 char *start; 160 161 for (start = dst; (c = *src);) 162 dst = vis(dst, c, flag, *++src); 163 *dst = '\0'; 164 return (dst - start); 165 } 166 167 int 168 strnvis(dst, src, siz, flag) 169 char *dst; 170 const char *src; 171 size_t siz; 172 int flag; 173 { 174 char c; 175 char *start, *end; 176 char tbuf[5]; 177 int i; 178 179 i = 0; 180 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 181 if (isvisible(c)) { 182 i = 1; 183 *dst++ = c; 184 if (c == '\\' && (flag & VIS_NOSLASH) == 0) { 185 /* need space for the extra '\\' */ 186 if (dst < end) 187 *dst++ = '\\'; 188 else { 189 dst--; 190 i = 2; 191 break; 192 } 193 } 194 src++; 195 } else { 196 i = vis(tbuf, c, flag, *++src) - tbuf; 197 if (dst + i <= end) { 198 memcpy(dst, tbuf, i); 199 dst += i; 200 } else { 201 src--; 202 break; 203 } 204 } 205 } 206 if (siz > 0) 207 *dst = '\0'; 208 if (dst + i > end) { 209 /* adjust return value for truncation */ 210 while ((c = *src)) 211 dst += vis(tbuf, c, flag, *++src) - tbuf; 212 } 213 return (dst - start); 214 } 215 216 int 217 strvisx(dst, src, len, flag) 218 register char *dst; 219 register const char *src; 220 register size_t len; 221 int flag; 222 { 223 register char c; 224 char *start; 225 226 for (start = dst; len > 1; len--) { 227 c = *src; 228 dst = vis(dst, c, flag, *++src); 229 } 230 if (len) 231 dst = vis(dst, *src, flag, '\0'); 232 *dst = '\0'; 233 return (dst - start); 234 } 235