gen/FreeBSD/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  * 4. 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
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)vis.c       8.1 (Berkeley) 7/19/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD: src/lib/libc/gen/vis.c,v 1.14 2007/01/09 00:27:56 imp Exp $");
  35
  36 #include <sys/types.h>
  37 #include <limits.h>
  38 #include <ctype.h>
  39 #include <stdio.h>
  40 #include <vis.h>
  41
  42 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  43
  44 /*
  45  * vis - visually encode characters
  46  */
  47 char *
  48 vis(dst, c, flag, nextc)
  49         char *dst;
  50         int c, nextc;
  51         int flag;
  52 {
  53         c = (unsigned char)c;
  54
  55         if (flag & VIS_HTTPSTYLE) {
  56                 /* Described in RFC 1808 */
  57                 if (!(isalnum(c) /* alpha-numeric */
  58                     /* safe */
  59                     || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
  60                     /* extra */
  61                     || c == '!' || c == '*' || c == '\'' || c == '('
  62                     || c == ')' || c == ',')) {
  63                         *dst++ = '%';
  64                         snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
  65                         dst += 2;
  66                         goto done;
  67                 }
  68         }
  69
  70         if ((flag & VIS_GLOB) &&
  71             (c == '*' || c == '?' || c == '[' || c == '#'))
  72                 ;
  73         else if (isgraph(c) ||
  74            ((flag & VIS_SP) == 0 && c == ' ') ||
  75            ((flag & VIS_TAB) == 0 && c == '\t') ||
  76            ((flag & VIS_NL) == 0 && c == '\n') ||
  77            ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
  78                 *dst++ = c;
  79                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  80                         *dst++ = '\\';
  81                 *dst = '\0';
  82                 return (dst);
  83         }
  84
  85         if (flag & VIS_CSTYLE) {
  86                 switch(c) {
  87                 case '\n':
  88                         *dst++ = '\\';
  89                         *dst++ = 'n';
  90                         goto done;
  91                 case '\r':
  92                         *dst++ = '\\';
  93                         *dst++ = 'r';
  94                         goto done;
  95                 case '\b':
  96                         *dst++ = '\\';
  97                         *dst++ = 'b';
  98                         goto done;
  99                 case '\a':
 100                         *dst++ = '\\';
 101                         *dst++ = 'a';
 102                         goto done;
 103                 case '\v':
 104                         *dst++ = '\\';
 105                         *dst++ = 'v';
 106                         goto done;
 107                 case '\t':
 108                         *dst++ = '\\';
 109                         *dst++ = 't';
 110                         goto done;
 111                 case '\f':
 112                         *dst++ = '\\';
 113                         *dst++ = 'f';
 114                         goto done;
 115                 case ' ':
 116                         *dst++ = '\\';
 117                         *dst++ = 's';
 118                         goto done;
 119                 case '\0':
 120                         *dst++ = '\\';
 121                         *dst++ = '0';
 122                         if (isoctal(nextc)) {
 123                                 *dst++ = '0';
 124                                 *dst++ = '0';
 125                         }
 126                         goto done;
 127                 }
 128         }
 129         if (((c & 0177) == ' ') || isgraph(c) || (flag & VIS_OCTAL)) {
 130                 *dst++ = '\\';
 131                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 132                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 133                 *dst++ = ((u_char)c & 07) + '0';
 134                 goto done;
 135         }
 136         if ((flag & VIS_NOSLASH) == 0)
 137                 *dst++ = '\\';
 138         if (c & 0200) {
 139                 c &= 0177;
 140                 *dst++ = 'M';
 141         }
 142         if (iscntrl(c)) {
 143                 *dst++ = '^';
 144                 if (c == 0177)
 145                         *dst++ = '?';
 146                 else
 147                         *dst++ = c + '@';
 148         } else {
 149                 *dst++ = '-';
 150                 *dst++ = c;
 151         }
 152 done:
 153         *dst = '\0';
 154         return (dst);
 155 }
 156
 157 /*
 158  * strvis, strvisx - visually encode characters from src into dst
 159  *
 160  *      Dst must be 4 times the size of src to account for possible
 161  *      expansion.  The length of dst, not including the trailing NUL,
 162  *      is returned.
 163  *
 164  *      Strvisx encodes exactly len bytes from src into dst.
 165  *      This is useful for encoding a block of data.
 166  */
 167 int
 168 strvis(dst, src, flag)
 169         char *dst;
 170         const char *src;
 171         int flag;
 172 {
 173         char c;
 174         char *start;
 175
 176         for (start = dst; (c = *src); )
 177                 dst = vis(dst, c, flag, *++src);
 178         *dst = '\0';
 179         return (dst - start);
 180 }
 181
 182 int
 183 strvisx(dst, src, len, flag)
 184         char *dst;
 185         const char *src;
 186         size_t len;
 187         int flag;
 188 {
 189         int c;
 190         char *start;
 191
 192         for (start = dst; len > 1; len--) {
 193                 c = *src;
 194                 dst = vis(dst, c, flag, *++src);
 195         }
 196         if (len)
 197                 dst = vis(dst, *src, flag, '\0');
 198         *dst = '\0';
 199
 200         return (dst - start);
 201 }