lib/libc/gen/vis.c

   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  * $FreeBSD: src/lib/libc/gen/vis.c,v 1.13 2003/10/30 12:41:50 phk Exp $
  34  * $DragonFly: src/lib/libc/gen/vis.c,v 1.6 2005/11/13 00:07:42 swildner Exp $
  35  */
  36
  37 #include <sys/types.h>
  38 #include <ctype.h>
  39 #include <limits.h>
  40 #include <stdio.h>
  41 #include <string.h>
  42 #include <vis.h>
  43
  44 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  45
  46 /*
  47  * vis - visually encode characters
  48  */
  49 char *
  50 vis(char *dst, int c, int flag, int nextc)
  51 {
  52         c = (unsigned char)c;
  53
  54         if (flag & VIS_HTTPSTYLE) {
  55                 /* Described in RFC 1808 */
  56                 if (!(isalnum(c) /* alpha-numeric */
  57                     /* safe */
  58                     || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
  59                     /* extra */
  60                     || c == '!' || c == '*' || c == '\'' || c == '('
  61                     || c == ')' || c == ',')) {
  62                         *dst++ = '%';
  63                         snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
  64                         dst += 2;
  65                         goto done;
  66                 }
  67         }
  68
  69         if ((flag & VIS_GLOB) &&
  70             (c == '*' || c == '?' || c == '[' || c == '#'))
  71                 ;
  72         else if (isgraph(c) ||
  73            ((flag & VIS_SP) == 0 && c == ' ') ||
  74            ((flag & VIS_TAB) == 0 && c == '\t') ||
  75            ((flag & VIS_NL) == 0 && c == '\n') ||
  76            ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
  77                 *dst++ = c;
  78                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  79                         *dst++ = '\\';
  80                 *dst = '\0';
  81                 return (dst);
  82         }
  83
  84         if (flag & VIS_CSTYLE) {
  85                 switch(c) {
  86                 case '\n':
  87                         *dst++ = '\\';
  88                         *dst++ = 'n';
  89                         goto done;
  90                 case '\r':
  91                         *dst++ = '\\';
  92                         *dst++ = 'r';
  93                         goto done;
  94                 case '\b':
  95                         *dst++ = '\\';
  96                         *dst++ = 'b';
  97                         goto done;
  98                 case '\a':
  99                         *dst++ = '\\';
 100                         *dst++ = 'a';
 101                         goto done;
 102                 case '\v':
 103                         *dst++ = '\\';
 104                         *dst++ = 'v';
 105                         goto done;
 106                 case '\t':
 107                         *dst++ = '\\';
 108                         *dst++ = 't';
 109                         goto done;
 110                 case '\f':
 111                         *dst++ = '\\';
 112                         *dst++ = 'f';
 113                         goto done;
 114                 case ' ':
 115                         *dst++ = '\\';
 116                         *dst++ = 's';
 117                         goto done;
 118                 case '\0':
 119                         *dst++ = '\\';
 120                         *dst++ = '0';
 121                         if (isoctal(nextc)) {
 122                                 *dst++ = '0';
 123                                 *dst++ = '0';
 124                         }
 125                         goto done;
 126                 }
 127         }
 128         if (((c & 0177) == ' ') || isgraph(c) || (flag & VIS_OCTAL)) {
 129                 *dst++ = '\\';
 130                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 131                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 132                 *dst++ = ((u_char)c & 07) + '0';
 133                 goto done;
 134         }
 135         if ((flag & VIS_NOSLASH) == 0)
 136                 *dst++ = '\\';
 137         if (c & 0200) {
 138                 c &= 0177;
 139                 *dst++ = 'M';
 140         }
 141         if (iscntrl(c)) {
 142                 *dst++ = '^';
 143                 if (c == 0177)
 144                         *dst++ = '?';
 145                 else
 146                         *dst++ = c + '@';
 147         } else {
 148                 *dst++ = '-';
 149                 *dst++ = c;
 150         }
 151 done:
 152         *dst = '\0';
 153         return (dst);
 154 }
 155
 156 /*
 157  * strvis, strvisx - visually encode characters from src into dst
 158  *
 159  *      Dst must be 4 times the size of src to account for possible
 160  *      expansion.  The length of dst, not including the trailing NUL,
 161  *      is returned.
 162  *
 163  *      Strvisx encodes exactly len bytes from src into dst.
 164  *      This is useful for encoding a block of data.
 165  */
 166 int
 167 strvis(char *dst, const char *src, int flag)
 168 {
 169         char c;
 170         char *start;
 171
 172         for (start = dst; (c = *src); )
 173                 dst = vis(dst, c, flag, *++src);
 174         *dst = '\0';
 175         return (dst - start);
 176 }
 177
 178 int
 179 strnvis(char *dst, const char *src, size_t len, int flag)
 180 {
 181         char *start, *end;
 182         char buf[5];
 183         int c, i;
 184
 185         i = 0;
 186         start = dst;
 187         end = start + len -1;
 188         for (; (c = *src) != '\0';) {
 189                 i = vis(buf, c, flag, *++src) - buf;
 190                 if (start + i > end) {
 191                         --src;
 192                         break;
 193                 }
 194                 memcpy(dst, buf, i);
 195                 dst += i;
 196         }
 197         if (len > 0)
 198                 *dst = '\0';
 199         if (dst + i > end) {
 200                 /* adjust return value for truncation */
 201                 while ((c = *src) != '\0')
 202                         dst += vis(buf, c, flag, *++src) - buf;
 203         }
 204         return (dst - start);
 205 }
 206
 207 int
 208 strvisx(char *dst, const char *src, size_t len, int flag)
 209 {
 210         int c;
 211         char *start;
 212
 213         for (start = dst; len > 1; len--) {
 214                 c = *src;
 215                 dst = vis(dst, c, flag, *++src);
 216         }
 217         if (len)
 218                 dst = vis(dst, *src, flag, '\0');
 219         *dst = '\0';
 220
 221         return (dst - start);
 222 }