1 /* OPENBSD ORIGINAL: lib/libc/gen/vis.c */ 2 3 /*- 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 #include "includes.h" 32 #if !defined(HAVE_STRNVIS) 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char rcsid[] = "$OpenBSD: vis.c,v 1.12 2003/06/02 20:18:35 millert Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <ctype.h> 39 #include <string.h> 40 41 #include "vis.h" 42 43 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 44 #define isvisible(c) (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 45 isgraph((u_char)(c))) || \ 46 ((flag & VIS_SP) == 0 && (c) == ' ') || \ 47 ((flag & VIS_TAB) == 0 && (c) == '\t') || \ 48 ((flag & VIS_NL) == 0 && (c) == '\n') || \ 49 ((flag & VIS_SAFE) && ((c) == '\b' || \ 50 (c) == '\007' || (c) == '\r' || \ 51 isgraph((u_char)(c))))) 52 53 /* 54 * vis - visually encode characters 55 */ 56 char * 57 vis(dst, c, flag, nextc) 58 register char *dst; 59 int c, nextc; 60 register int flag; 61 { 62 if (isvisible(c)) { 63 *dst++ = c; 64 if (c == '\\' && (flag & VIS_NOSLASH) == 0) 65 *dst++ = '\\'; 66 *dst = '\0'; 67 return (dst); 68 } 69 70 if (flag & VIS_CSTYLE) { 71 switch(c) { 72 case '\n': 73 *dst++ = '\\'; 74 *dst++ = 'n'; 75 goto done; 76 case '\r': 77 *dst++ = '\\'; 78 *dst++ = 'r'; 79 goto done; 80 case '\b': 81 *dst++ = '\\'; 82 *dst++ = 'b'; 83 goto done; 84 case '\a': 85 *dst++ = '\\'; 86 *dst++ = 'a'; 87 goto done; 88 case '\v': 89 *dst++ = '\\'; 90 *dst++ = 'v'; 91 goto done; 92 case '\t': 93 *dst++ = '\\'; 94 *dst++ = 't'; 95 goto done; 96 case '\f': 97 *dst++ = '\\'; 98 *dst++ = 'f'; 99 goto done; 100 case ' ': 101 *dst++ = '\\'; 102 *dst++ = 's'; 103 goto done; 104 case '\0': 105 *dst++ = '\\'; 106 *dst++ = '0'; 107 if (isoctal(nextc)) { 108 *dst++ = '0'; 109 *dst++ = '0'; 110 } 111 goto done; 112 } 113 } 114 if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) { 115 *dst++ = '\\'; 116 *dst++ = ((u_char)c >> 6 & 07) + '0'; 117 *dst++ = ((u_char)c >> 3 & 07) + '0'; 118 *dst++ = ((u_char)c & 07) + '0'; 119 goto done; 120 } 121 if ((flag & VIS_NOSLASH) == 0) 122 *dst++ = '\\'; 123 if (c & 0200) { 124 c &= 0177; 125 *dst++ = 'M'; 126 } 127 if (iscntrl(c)) { 128 *dst++ = '^'; 129 if (c == 0177) 130 *dst++ = '?'; 131 else 132 *dst++ = c + '@'; 133 } else { 134 *dst++ = '-'; 135 *dst++ = c; 136 } 137 done: 138 *dst = '\0'; 139 return (dst); 140 } 141 142 /* 143 * strvis, strnvis, strvisx - visually encode characters from src into dst 144 * 145 * Dst must be 4 times the size of src to account for possible 146 * expansion. The length of dst, not including the trailing NULL, 147 * is returned. 148 * 149 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 150 * The number of bytes needed to fully encode the string is returned. 151 * 152 * Strvisx encodes exactly len bytes from src into dst. 153 * This is useful for encoding a block of data. 154 */ 155 int 156 strvis(dst, src, flag) 157 register char *dst; 158 register const char *src; 159 int flag; 160 { 161 register char c; 162 char *start; 163 164 for (start = dst; (c = *src);) 165 dst = vis(dst, c, flag, *++src); 166 *dst = '\0'; 167 return (dst - start); 168 } 169 170 int 171 strnvis(dst, src, siz, flag) 172 char *dst; 173 const char *src; 174 size_t siz; 175 int flag; 176 { 177 char c; 178 char *start, *end; 179 char tbuf[5]; 180 int i; 181 182 i = 0; 183 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 184 if (isvisible(c)) { 185 i = 1; 186 *dst++ = c; 187 if (c == '\\' && (flag & VIS_NOSLASH) == 0) { 188 /* need space for the extra '\\' */ 189 if (dst < end) 190 *dst++ = '\\'; 191 else { 192 dst--; 193 i = 2; 194 break; 195 } 196 } 197 src++; 198 } else { 199 i = vis(tbuf, c, flag, *++src) - tbuf; 200 if (dst + i <= end) { 201 memcpy(dst, tbuf, i); 202 dst += i; 203 } else { 204 src--; 205 break; 206 } 207 } 208 } 209 if (siz > 0) 210 *dst = '\0'; 211 if (dst + i > end) { 212 /* adjust return value for truncation */ 213 while ((c = *src)) 214 dst += vis(tbuf, c, flag, *++src) - tbuf; 215 } 216 return (dst - start); 217 } 218 219 int 220 strvisx(dst, src, len, flag) 221 register char *dst; 222 register const char *src; 223 register size_t len; 224 int flag; 225 { 226 register char c; 227 char *start; 228 229 for (start = dst; len > 1; len--) { 230 c = *src; 231 dst = vis(dst, c, flag, *++src); 232 } 233 if (len) 234 dst = vis(dst, *src, flag, '\0'); 235 *dst = '\0'; 236 return (dst - start); 237 } 238 239 #endif 240