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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/lib/libc/gen/vis.c,v 1.13 2003/10/30 12:41:50 phk Exp $
  30  * $DragonFly: src/lib/libc/gen/vis.c,v 1.6 2005/11/13 00:07:42 swildner Exp $
  31  */
  32
  33 #include <sys/types.h>
  34 #include <ctype.h>
  35 #include <limits.h>
  36 #include <stdio.h>
  37 #include <string.h>
  38 #include <vis.h>
  39
  40 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  41
  42 /*
  43  * vis - visually encode characters
  44  */
  45 char *
  46 vis(char *dst, int c, int flag, int nextc)
  47 {
  48         c = (unsigned char)c;
  49
  50         if (flag & VIS_HTTPSTYLE) {
  51                 /* Described in RFC 1808 */
  52                 if (!(isalnum(c) /* alpha-numeric */
  53                     /* safe */
  54                     || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
  55                     /* extra */
  56                     || c == '!' || c == '*' || c == '\'' || c == '('
  57                     || c == ')' || c == ',')) {
  58                         *dst++ = '%';
  59                         snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
  60                         dst += 2;
  61                         goto done;
  62                 }
  63         }
  64
  65         if ((flag & VIS_GLOB) &&
  66             (c == '*' || c == '?' || c == '[' || c == '#'))
  67                 ;
  68         else if (isgraph(c) ||
  69            ((flag & VIS_SP) == 0 && c == ' ') ||
  70            ((flag & VIS_TAB) == 0 && c == '\t') ||
  71            ((flag & VIS_NL) == 0 && c == '\n') ||
  72            ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
  73                 *dst++ = c;
  74                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  75                         *dst++ = '\\';
  76                 *dst = '\0';
  77                 return (dst);
  78         }
  79
  80         if (flag & VIS_CSTYLE) {
  81                 switch(c) {
  82                 case '\n':
  83                         *dst++ = '\\';
  84                         *dst++ = 'n';
  85                         goto done;
  86                 case '\r':
  87                         *dst++ = '\\';
  88                         *dst++ = 'r';
  89                         goto done;
  90                 case '\b':
  91                         *dst++ = '\\';
  92                         *dst++ = 'b';
  93                         goto done;
  94                 case '\a':
  95                         *dst++ = '\\';
  96                         *dst++ = 'a';
  97                         goto done;
  98                 case '\v':
  99                         *dst++ = '\\';
 100                         *dst++ = 'v';
 101                         goto done;
 102                 case '\t':
 103                         *dst++ = '\\';
 104                         *dst++ = 't';
 105                         goto done;
 106                 case '\f':
 107                         *dst++ = '\\';
 108                         *dst++ = 'f';
 109                         goto done;
 110                 case ' ':
 111                         *dst++ = '\\';
 112                         *dst++ = 's';
 113                         goto done;
 114                 case '\0':
 115                         *dst++ = '\\';
 116                         *dst++ = '0';
 117                         if (isoctal(nextc)) {
 118                                 *dst++ = '0';
 119                                 *dst++ = '0';
 120                         }
 121                         goto done;
 122                 }
 123         }
 124         if (((c & 0177) == ' ') || isgraph(c) || (flag & VIS_OCTAL)) {
 125                 *dst++ = '\\';
 126                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 127                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 128                 *dst++ = ((u_char)c & 07) + '0';
 129                 goto done;
 130         }
 131         if ((flag & VIS_NOSLASH) == 0)
 132                 *dst++ = '\\';
 133         if (c & 0200) {
 134                 c &= 0177;
 135                 *dst++ = 'M';
 136         }
 137         if (iscntrl(c)) {
 138                 *dst++ = '^';
 139                 if (c == 0177)
 140                         *dst++ = '?';
 141                 else
 142                         *dst++ = c + '@';
 143         } else {
 144                 *dst++ = '-';
 145                 *dst++ = c;
 146         }
 147 done:
 148         *dst = '\0';
 149         return (dst);
 150 }
 151
 152 /*
 153  * strvis, strvisx - visually encode characters from src into dst
 154  *
 155  *      Dst must be 4 times the size of src to account for possible
 156  *      expansion.  The length of dst, not including the trailing NUL,
 157  *      is returned.
 158  *
 159  *      Strvisx encodes exactly len bytes from src into dst.
 160  *      This is useful for encoding a block of data.
 161  */
 162 int
 163 strvis(char *dst, const char *src, int flag)
 164 {
 165         char c;
 166         char *start;
 167
 168         for (start = dst; (c = *src); )
 169                 dst = vis(dst, c, flag, *++src);
 170         *dst = '\0';
 171         return (dst - start);
 172 }
 173
 174 int
 175 strnvis(char *dst, const char *src, size_t len, int flag)
 176 {
 177         char *start, *end;
 178         char buf[5];
 179         int c, i;
 180
 181         i = 0;
 182         start = dst;
 183         end = start + len -1;
 184         for (; (c = *src) != '\0';) {
 185                 i = vis(buf, c, flag, *++src) - buf;
 186                 if (start + i > end) {
 187                         --src;
 188                         break;
 189                 }
 190                 memcpy(dst, buf, i);
 191                 dst += i;
 192         }
 193         if (len > 0)
 194                 *dst = '\0';
 195         if (dst + i > end) {
 196                 /* adjust return value for truncation */
 197                 while ((c = *src) != '\0')
 198                         dst += vis(buf, c, flag, *++src) - buf;
 199         }
 200         return (dst - start);
 201 }
 202
 203 int
 204 strvisx(char *dst, const char *src, size_t len, int flag)
 205 {
 206         int c;
 207         char *start;
 208
 209         for (start = dst; len > 1; len--) {
 210                 c = *src;
 211                 dst = vis(dst, c, flag, *++src);
 212         }
 213         if (len)
 214                 dst = vis(dst, *src, flag, '\0');
 215         *dst = '\0';
 216
 217         return (dst - start);
 218 }