gen/vis.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * Copyright (c) 1989, 1993
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58
  59 #include <sys/types.h>
  60 #include <limits.h>
  61 #include <ctype.h>
  62 #include <vis.h>
  63
  64 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  65
  66 /*
  67  * vis - visually encode characters
  68  */
  69 char *
  70 vis(dst, c, flag, nextc)
  71         register char *dst;
  72         int c, nextc;
  73         register int flag;
  74 {
  75         if ((u_int)c <= UCHAR_MAX && isgraph(c) ||
  76            ((flag & VIS_SP) == 0 && c == ' ') ||
  77            ((flag & VIS_TAB) == 0 && c == '\t') ||
  78            ((flag & VIS_NL) == 0 && c == '\n') ||
  79            ((flag & VIS_SAFE) && (c == '\b' || c == '\007' || c == '\r'))) {
  80                 *dst++ = c;
  81                 if (c == '\\' && (flag & VIS_NOSLASH) == 0)
  82                         *dst++ = '\\';
  83                 *dst = '\0';
  84                 return (dst);
  85         }
  86
  87         if (flag & VIS_CSTYLE) {
  88                 switch(c) {
  89                 case '\n':
  90                         *dst++ = '\\';
  91                         *dst++ = 'n';
  92                         goto done;
  93                 case '\r':
  94                         *dst++ = '\\';
  95                         *dst++ = 'r';
  96                         goto done;
  97                 case '\b':
  98                         *dst++ = '\\';
  99                         *dst++ = 'b';
 100                         goto done;
 101 #if __STDC__
 102                 case '\a':
 103 #else
 104                 case '\007':
 105 #endif
 106                         *dst++ = '\\';
 107                         *dst++ = 'a';
 108                         goto done;
 109                 case '\v':
 110                         *dst++ = '\\';
 111                         *dst++ = 'v';
 112                         goto done;
 113                 case '\t':
 114                         *dst++ = '\\';
 115                         *dst++ = 't';
 116                         goto done;
 117                 case '\f':
 118                         *dst++ = '\\';
 119                         *dst++ = 'f';
 120                         goto done;
 121                 case ' ':
 122                         *dst++ = '\\';
 123                         *dst++ = 's';
 124                         goto done;
 125                 case '\0':
 126                         *dst++ = '\\';
 127                         *dst++ = '0';
 128                         if (isoctal(nextc)) {
 129                                 *dst++ = '0';
 130                                 *dst++ = '0';
 131                         }
 132                         goto done;
 133                 }
 134         }
 135         if (((c & 0177) == ' ') || (flag & VIS_OCTAL)) {
 136                 *dst++ = '\\';
 137                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 138                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 139                 *dst++ = ((u_char)c & 07) + '0';
 140                 goto done;
 141         }
 142         if ((flag & VIS_NOSLASH) == 0)
 143                 *dst++ = '\\';
 144         if (c & 0200) {
 145                 c &= 0177;
 146                 *dst++ = 'M';
 147         }
 148         if (iscntrl(c)) {
 149                 *dst++ = '^';
 150                 if (c == 0177)
 151                         *dst++ = '?';
 152                 else
 153                         *dst++ = c + '@';
 154         } else {
 155                 *dst++ = '-';
 156                 *dst++ = c;
 157         }
 158 done:
 159         *dst = '\0';
 160         return (dst);
 161 }
 162
 163 /*
 164  * strvis, strvisx - visually encode characters from src into dst
 165  *
 166  *      Dst must be 4 times the size of src to account for possible
 167  *      expansion.  The length of dst, not including the trailing NULL,
 168  *      is returned.
 169  *
 170  *      Strvisx encodes exactly len bytes from src into dst.
 171  *      This is useful for encoding a block of data.
 172  */
 173 int
 174 strvis(dst, src, flag)
 175         register char *dst;
 176         register const char *src;
 177         int flag;
 178 {
 179         register char c;
 180         char *start;
 181
 182         for (start = dst; c = *src;)
 183                 dst = vis(dst, c, flag, *++src);
 184         *dst = '\0';
 185         return (dst - start);
 186 }
 187
 188 int
 189 strvisx(dst, src, len, flag)
 190         register char *dst;
 191         register const char *src;
 192         register size_t len;
 193         int flag;
 194 {
 195         int c;
 196         char *start;
 197
 198         for (start = dst; len > 1; len--) {
 199                 c = *src;
 200                 dst = vis(dst, c, flag, *++src);
 201         }
 202         if (len)
 203                 dst = vis(dst, *src, flag, '\0');
 204         *dst = '\0';
 205
 206         return (dst - start);
 207 }