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  * 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 sccsid[] = "@(#)vis.c       8.1 (Berkeley) 7/19/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/gen/vis.c,v 1.11 2002/08/19 17:14:58 jmallett Exp $");
  39
  40 #include <sys/types.h>
  41 #include <limits.h>
  42 #include <ctype.h>
  43 #include <stdio.h>
  44 #include <vis.h>
  45
  46 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  47
  48 /*
  49  * vis - visually encode characters
  50  */
  51 char *
  52 vis(dst, c, flag, nextc)
  53         char *dst;
  54         int c, nextc;
  55         int flag;
  56 {
  57         c = (unsigned char)c;
  58
  59         if (flag & VIS_HTTPSTYLE) {
  60                 /* Described in RFC 1808 */
  61                 if (!(isalnum(c) /* alpha-numeric */
  62                     /* safe */
  63                     || c == '$' || c == '-' || c == '_' || c == '.' || c == '+'
  64                     /* extra */
  65                     || c == '!' || c == '*' || c == '\'' || c == '('
  66                     || c == ')' || c == ',')) {
  67                         *dst++ = '%';
  68                         snprintf(dst, 4, (c < 16 ? "0%X" : "%X"), c);
  69                         dst += 2;
  70                         goto done;
  71                 }
  72         }
  73
  74         if (isgraph(c) ||
  75            ((flag & VIS_SP) == 0 && c == ' ') ||
  76            ((flag & VIS_TAB) == 0 && c == '\t') ||
  77            ((flag & VIS_NL) == 0 && c == '\n') ||
  78            ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
  79                 *dst++ = c;
  80                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  81                         *dst++ = '\\';
  82                 *dst = '\0';
  83                 return (dst);
  84         }
  85
  86         if (flag & VIS_CSTYLE) {
  87                 switch(c) {
  88                 case '\n':
  89                         *dst++ = '\\';
  90                         *dst++ = 'n';
  91                         goto done;
  92                 case '\r':
  93                         *dst++ = '\\';
  94                         *dst++ = 'r';
  95                         goto done;
  96                 case '\b':
  97                         *dst++ = '\\';
  98                         *dst++ = 'b';
  99                         goto done;
 100                 case '\a':
 101                         *dst++ = '\\';
 102                         *dst++ = 'a';
 103                         goto done;
 104                 case '\v':
 105                         *dst++ = '\\';
 106                         *dst++ = 'v';
 107                         goto done;
 108                 case '\t':
 109                         *dst++ = '\\';
 110                         *dst++ = 't';
 111                         goto done;
 112                 case '\f':
 113                         *dst++ = '\\';
 114                         *dst++ = 'f';
 115                         goto done;
 116                 case ' ':
 117                         *dst++ = '\\';
 118                         *dst++ = 's';
 119                         goto done;
 120                 case '\0':
 121                         *dst++ = '\\';
 122                         *dst++ = '0';
 123                         if (isoctal(nextc)) {
 124                                 *dst++ = '0';
 125                                 *dst++ = '0';
 126                         }
 127                         goto done;
 128                 }
 129         }
 130         if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
 131                 *dst++ = '\\';
 132                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 133                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 134                 *dst++ = ((u_char)c & 07) + '0';
 135                 goto done;
 136         }
 137         if ((flag & VIS_NOSLASH) == 0)
 138                 *dst++ = '\\';
 139         if (c & 0200) {
 140                 c &= 0177;
 141                 *dst++ = 'M';
 142         }
 143         if (iscntrl(c)) {
 144                 *dst++ = '^';
 145                 if (c == 0177)
 146                         *dst++ = '?';
 147                 else
 148                         *dst++ = c + '@';
 149         } else {
 150                 *dst++ = '-';
 151                 *dst++ = c;
 152         }
 153 done:
 154         *dst = '\0';
 155         return (dst);
 156 }
 157
 158 /*
 159  * strvis, strvisx - visually encode characters from src into dst
 160  *
 161  *      Dst must be 4 times the size of src to account for possible
 162  *      expansion.  The length of dst, not including the trailing NUL,
 163  *      is returned.
 164  *
 165  *      Strvisx encodes exactly len bytes from src into dst.
 166  *      This is useful for encoding a block of data.
 167  */
 168 int
 169 strvis(dst, src, flag)
 170         char *dst;
 171         const char *src;
 172         int flag;
 173 {
 174         char c;
 175         char *start;
 176
 177         for (start = dst; (c = *src); )
 178                 dst = vis(dst, c, flag, *++src);
 179         *dst = '\0';
 180         return (dst - start);
 181 }
 182
 183 int
 184 strvisx(dst, src, len, flag)
 185         char *dst;
 186         const char *src;
 187         size_t len;
 188         int flag;
 189 {
 190         int c;
 191         char *start;
 192
 193         for (start = dst; len > 1; len--) {
 194                 c = *src;
 195                 dst = vis(dst, c, flag, *++src);
 196         }
 197         if (len)
 198                 dst = vis(dst, *src, flag, '\0');
 199         *dst = '\0';
 200
 201         return (dst - start);
 202 }