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. 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 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #if defined(LIBC_SCCS) && !defined(lint) 35 static char rcsid[] = "$OpenBSD: vis.c,v 1.7 2001/08/13 15:30:23 millert Exp $"; 36 #endif /* LIBC_SCCS and not lint */ 37 38 #include <sys/types.h> 39 #include <limits.h> 40 #include <ctype.h> 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) && \ 50 ((c) == '\b' || (c) == '\007' || (c) == '\r'))) 51 52 /* 53 * vis - visually encode characters 54 */ 55 char * 56 vis(dst, c, flag, nextc) 57 register char *dst; 58 int c, nextc; 59 register int flag; 60 { 61 if (isvisible(c)) { 62 *dst++ = c; 63 if (c == '\\' && (flag & VIS_NOSLASH) == 0) 64 *dst++ = '\\'; 65 *dst = '\0'; 66 return (dst); 67 } 68 69 if (flag & VIS_CSTYLE) { 70 switch(c) { 71 case '\n': 72 *dst++ = '\\'; 73 *dst++ = 'n'; 74 goto done; 75 case '\r': 76 *dst++ = '\\'; 77 *dst++ = 'r'; 78 goto done; 79 case '\b': 80 *dst++ = '\\'; 81 *dst++ = 'b'; 82 goto done; 83 #ifdef __STDC__ 84 case '\a': 85 #else 86 case '\007': 87 #endif 88 *dst++ = '\\'; 89 *dst++ = 'a'; 90 goto done; 91 case '\v': 92 *dst++ = '\\'; 93 *dst++ = 'v'; 94 goto done; 95 case '\t': 96 *dst++ = '\\'; 97 *dst++ = 't'; 98 goto done; 99 case '\f': 100 *dst++ = '\\'; 101 *dst++ = 'f'; 102 goto done; 103 case ' ': 104 *dst++ = '\\'; 105 *dst++ = 's'; 106 goto done; 107 case '\0': 108 *dst++ = '\\'; 109 *dst++ = '0'; 110 if (isoctal(nextc)) { 111 *dst++ = '0'; 112 *dst++ = '0'; 113 } 114 goto done; 115 } 116 } 117 if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) { 118 *dst++ = '\\'; 119 *dst++ = ((u_char)c >> 6 & 07) + '0'; 120 *dst++ = ((u_char)c >> 3 & 07) + '0'; 121 *dst++ = ((u_char)c & 07) + '0'; 122 goto done; 123 } 124 if ((flag & VIS_NOSLASH) == 0) 125 *dst++ = '\\'; 126 if (c & 0200) { 127 c &= 0177; 128 *dst++ = 'M'; 129 } 130 if (iscntrl(c)) { 131 *dst++ = '^'; 132 if (c == 0177) 133 *dst++ = '?'; 134 else 135 *dst++ = c + '@'; 136 } else { 137 *dst++ = '-'; 138 *dst++ = c; 139 } 140 done: 141 *dst = '\0'; 142 return (dst); 143 } 144 145 /* 146 * strvis, strnvis, strvisx - visually encode characters from src into dst 147 * 148 * Dst must be 4 times the size of src to account for possible 149 * expansion. The length of dst, not including the trailing NULL, 150 * is returned. 151 * 152 * Strnvis will write no more than siz-1 bytes (and will NULL terminate). 153 * The number of bytes needed to fully encode the string is returned. 154 * 155 * Strvisx encodes exactly len bytes from src into dst. 156 * This is useful for encoding a block of data. 157 */ 158 int 159 strvis(dst, src, flag) 160 register char *dst; 161 register const char *src; 162 int flag; 163 { 164 register char c; 165 char *start; 166 167 for (start = dst; (c = *src);) 168 dst = vis(dst, c, flag, *++src); 169 *dst = '\0'; 170 return (dst - start); 171 } 172 173 int 174 strnvis(dst, src, siz, flag) 175 register char *dst; 176 register const char *src; 177 size_t siz; 178 int flag; 179 { 180 register char c; 181 char *start, *end; 182 183 for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) { 184 if (isvisible(c)) { 185 *dst++ = c; 186 if (c == '\\' && (flag & VIS_NOSLASH) == 0) { 187 /* need space for the extra '\\' */ 188 if (dst < end) 189 *dst++ = '\\'; 190 else { 191 dst--; 192 break; 193 } 194 } 195 src++; 196 } else { 197 /* vis(3) requires up to 4 chars */ 198 if (dst + 3 < end) 199 dst = vis(dst, c, flag, *++src); 200 else 201 break; 202 } 203 } 204 *dst = '\0'; 205 if (dst >= end) { 206 char tbuf[5]; 207 208 /* adjust return value for truncation */ 209 while ((c = *src)) 210 dst += vis(tbuf, c, flag, *++src) - tbuf; 211 } 212 return (dst - start); 213 } 214 215 int 216 strvisx(dst, src, len, flag) 217 register char *dst; 218 register const char *src; 219 register size_t len; 220 int flag; 221 { 222 register char c; 223 char *start; 224 225 for (start = dst; len > 1; len--) { 226 c = *src; 227 dst = vis(dst, c, flag, *++src); 228 } 229 if (len) 230 dst = vis(dst, *src, flag, '\0'); 231 *dst = '\0'; 232 return (dst - start); 233 } 234