1 /* $OpenBSD: vis.c,v 1.19 2005/09/01 17:15:49 millert Exp $ */ 2 /*- 3 * Copyright (c) 1989, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* OPENBSD ORIGINAL: lib/libc/gen/vis.c */ 32 33 #include "includes.h" 34 #if !defined(HAVE_STRNVIS) || defined(BROKEN_STRNVIS) 35 36 #include <ctype.h> 37 #include <string.h> 38 39 #include "vis.h" 40 41 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 42 #define isvisible(c) \ 43 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 44 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \ 45 (flag & VIS_GLOB) == 0) && 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(char *dst, int c, int flag, int nextc) 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 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) { 113 *dst++ = '\\'; 114 *dst++ = ((u_char)c >> 6 & 07) + '0'; 115 *dst++ = ((u_char)c >> 3 & 07) + '0'; 116 *dst++ = ((u_char)c & 07) + '0'; 117 goto done; 118 } 119 if ((flag & VIS_NOSLASH) == 0) 120 *dst++ = '\\'; 121 if (c & 0200) { 122 c &= 0177; 123 *dst++ = 'M'; 124 } 125 if (iscntrl((u_char)c)) { 126 *dst++ = '^'; 127 if (c == 0177) 128 *dst++ = '?'; 129 else 130 *dst++ = c + '@'; 131 } else { 132 *dst++ = '-'; 133 *dst++ = c; 134 } 135 done: 136 *dst = '\0'; 137 return (dst); 138 } 139 140 /* 141 * strvis, strnvis, strvisx - visually encode characters from src into dst 142 * 143 * Dst must be 4 times the size of src to account for possible 144 * expansion. The length of dst, not including the trailing NULL, 145 * is returned. 146 * 147 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 148 * The number of bytes needed to fully encode the string is returned. 149 * 150 * Strvisx encodes exactly len bytes from src into dst. 151 * This is useful for encoding a block of data. 152 */ 153 int 154 strvis(char *dst, const char *src, int flag) 155 { 156 char c; 157 char *start; 158 159 for (start = dst; (c = *src);) 160 dst = vis(dst, c, flag, *++src); 161 *dst = '\0'; 162 return (dst - start); 163 } 164 165 int 166 strnvis(char *dst, const char *src, size_t siz, int flag) 167 { 168 char *start, *end; 169 char tbuf[5]; 170 int c, i; 171 172 i = 0; 173 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 174 if (isvisible(c)) { 175 i = 1; 176 *dst++ = c; 177 if (c == '\\' && (flag & VIS_NOSLASH) == 0) { 178 /* need space for the extra '\\' */ 179 if (dst < end) 180 *dst++ = '\\'; 181 else { 182 dst--; 183 i = 2; 184 break; 185 } 186 } 187 src++; 188 } else { 189 i = vis(tbuf, c, flag, *++src) - tbuf; 190 if (dst + i <= end) { 191 memcpy(dst, tbuf, i); 192 dst += i; 193 } else { 194 src--; 195 break; 196 } 197 } 198 } 199 if (siz > 0) 200 *dst = '\0'; 201 if (dst + i > end) { 202 /* adjust return value for truncation */ 203 while ((c = *src)) 204 dst += vis(tbuf, c, flag, *++src) - tbuf; 205 } 206 return (dst - start); 207 } 208 209 int 210 strvisx(char *dst, const char *src, size_t len, int flag) 211 { 212 char c; 213 char *start; 214 215 for (start = dst; len > 1; len--) { 216 c = *src; 217 dst = vis(dst, c, flag, *++src); 218 } 219 if (len) 220 dst = vis(dst, *src, flag, '\0'); 221 *dst = '\0'; 222 return (dst - start); 223 } 224 225 #endif 226