1 /* $OpenBSD: vis.c,v 1.23 2014/11/17 19:48:27 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 #include <sys/types.h> 32 #include <errno.h> 33 #include <ctype.h> 34 #include <limits.h> 35 #include <string.h> 36 #include <stdlib.h> 37 #include <vis.h> 38 39 #define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7') 40 #define isvisible(c,flag) \ 41 (((c) == '\\' || (flag & VIS_ALL) == 0) && \ 42 (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \ 43 (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') || \ 44 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) || \ 45 ((flag & VIS_SP) == 0 && (c) == ' ') || \ 46 ((flag & VIS_TAB) == 0 && (c) == '\t') || \ 47 ((flag & VIS_NL) == 0 && (c) == '\n') || \ 48 ((flag & VIS_SAFE) && ((c) == '\b' || \ 49 (c) == '\007' || (c) == '\r' || \ 50 isgraph((u_char)(c)))))) 51 52 /* 53 * vis - visually encode characters 54 */ 55 char * 56 vis(char *dst, int c, int flag, int nextc) 57 { 58 if (isvisible(c, flag)) { 59 *dst++ = c; 60 if (c == '\\' && (flag & VIS_NOSLASH) == 0) 61 *dst++ = '\\'; 62 *dst = '\0'; 63 return (dst); 64 } 65 66 if (flag & VIS_CSTYLE) { 67 switch(c) { 68 case '\n': 69 *dst++ = '\\'; 70 *dst++ = 'n'; 71 goto done; 72 case '\r': 73 *dst++ = '\\'; 74 *dst++ = 'r'; 75 goto done; 76 case '\b': 77 *dst++ = '\\'; 78 *dst++ = 'b'; 79 goto done; 80 case '\a': 81 *dst++ = '\\'; 82 *dst++ = 'a'; 83 goto done; 84 case '\v': 85 *dst++ = '\\'; 86 *dst++ = 'v'; 87 goto done; 88 case '\t': 89 *dst++ = '\\'; 90 *dst++ = 't'; 91 goto done; 92 case '\f': 93 *dst++ = '\\'; 94 *dst++ = 'f'; 95 goto done; 96 case ' ': 97 *dst++ = '\\'; 98 *dst++ = 's'; 99 goto done; 100 case '\0': 101 *dst++ = '\\'; 102 *dst++ = '0'; 103 if (isoctal(nextc)) { 104 *dst++ = '0'; 105 *dst++ = '0'; 106 } 107 goto done; 108 } 109 } 110 if (((c & 0177) == ' ') || (flag & VIS_OCTAL) || 111 ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) { 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((u_char)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(char *dst, const char *src, int flag) 154 { 155 char c; 156 char *start; 157 158 for (start = dst; (c = *src);) 159 dst = vis(dst, c, flag, *++src); 160 *dst = '\0'; 161 return (dst - start); 162 } 163 164 int 165 strnvis(char *dst, const char *src, size_t siz, int flag) 166 { 167 char *start, *end; 168 char tbuf[5]; 169 int c, i; 170 171 i = 0; 172 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 173 if (isvisible(c, flag)) { 174 i = 1; 175 *dst++ = c; 176 if (c == '\\' && (flag & VIS_NOSLASH) == 0) { 177 /* need space for the extra '\\' */ 178 if (dst < end) 179 *dst++ = '\\'; 180 else { 181 dst--; 182 i = 2; 183 break; 184 } 185 } 186 src++; 187 } else { 188 i = vis(tbuf, c, flag, *++src) - tbuf; 189 if (dst + i <= end) { 190 memcpy(dst, tbuf, i); 191 dst += i; 192 } else { 193 src--; 194 break; 195 } 196 } 197 } 198 if (siz > 0) 199 *dst = '\0'; 200 if (dst + i > end) { 201 /* adjust return value for truncation */ 202 while ((c = *src)) 203 dst += vis(tbuf, c, flag, *++src) - tbuf; 204 } 205 return (dst - start); 206 } 207 208 int 209 stravis(char **outp, const char *src, int flag) 210 { 211 char *buf; 212 int len, serrno; 213 214 buf = reallocarray(NULL, 4, strlen(src) + 1); 215 if (buf == NULL) 216 return -1; 217 len = strvis(buf, src, flag); 218 serrno = errno; 219 *outp = realloc(buf, len + 1); 220 if (*outp == NULL) { 221 *outp = buf; 222 errno = serrno; 223 } 224 return (len); 225 } 226 227 int 228 strvisx(char *dst, const char *src, size_t len, int flag) 229 { 230 char c; 231 char *start; 232 233 for (start = dst; len > 1; len--) { 234 c = *src; 235 dst = vis(dst, c, flag, *++src); 236 } 237 if (len) 238 dst = vis(dst, *src, flag, '\0'); 239 *dst = '\0'; 240 return (dst - start); 241 } 242