usr/src/lib/libc/port/gen/vis.c

   1 /*      $OpenBSD: vis.c,v 1.25 2015/09/13 11:32:51 guenther Exp $ */
   2 /*-
   3  * Copyright (c) 1989, 1993
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/types.h>
  32 #include <errno.h>
  33 #include <ctype.h>
  34 #include <limits.h>
  35 #include <string.h>
  36 #include <stdlib.h>
  37 #include <vis.h>
  38
  39 #define isoctal(c)      (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
  40 #define isvisible(c,flag)                                               \
  41         (((c) == '\\' || (flag & VIS_ALL) == 0) &&                      \
  42         (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) &&            \
  43         (((c) != '*' && (c) != '?' && (c) != '[' && (c) != '#') ||      \
  44                 (flag & VIS_GLOB) == 0) && isgraph((u_char)(c))) ||     \
  45         ((flag & VIS_SP) == 0 && (c) == ' ') ||                         \
  46         ((flag & VIS_TAB) == 0 && (c) == '\t') ||                       \
  47         ((flag & VIS_NL) == 0 && (c) == '\n') ||                        \
  48         ((flag & VIS_SAFE) && ((c) == '\b' ||                           \
  49                 (c) == '\007' || (c) == '\r' ||                         \
  50                 isgraph((u_char)(c))))))
  51
  52 /*
  53  * vis - visually encode characters
  54  */
  55 char *
  56 vis(char *dst, int c, int flag, int nextc)
  57 {
  58         if (isvisible(c, flag)) {
  59                 if ((c == '"' && (flag & VIS_DQ) != 0) ||
  60                     (c == '\\' && (flag & VIS_NOSLASH) == 0))
  61                         *dst++ = '\\';
  62                 *dst++ = c;
  63                 *dst = '\0';
  64                 return (dst);
  65         }
  66
  67         if (flag & VIS_CSTYLE) {
  68                 switch(c) {
  69                 case '\n':
  70                         *dst++ = '\\';
  71                         *dst++ = 'n';
  72                         goto done;
  73                 case '\r':
  74                         *dst++ = '\\';
  75                         *dst++ = 'r';
  76                         goto done;
  77                 case '\b':
  78                         *dst++ = '\\';
  79                         *dst++ = 'b';
  80                         goto done;
  81                 case '\a':
  82                         *dst++ = '\\';
  83                         *dst++ = 'a';
  84                         goto done;
  85                 case '\v':
  86                         *dst++ = '\\';
  87                         *dst++ = 'v';
  88                         goto done;
  89                 case '\t':
  90                         *dst++ = '\\';
  91                         *dst++ = 't';
  92                         goto done;
  93                 case '\f':
  94                         *dst++ = '\\';
  95                         *dst++ = 'f';
  96                         goto done;
  97                 case ' ':
  98                         *dst++ = '\\';
  99                         *dst++ = 's';
 100                         goto done;
 101                 case '\0':
 102                         *dst++ = '\\';
 103                         *dst++ = '0';
 104                         if (isoctal(nextc)) {
 105                                 *dst++ = '0';
 106                                 *dst++ = '0';
 107                         }
 108                         goto done;
 109                 }
 110         }
 111         if (((c & 0177) == ' ') || (flag & VIS_OCTAL) ||
 112             ((flag & VIS_GLOB) && (c == '*' || c == '?' || c == '[' || c == '#'))) {
 113                 *dst++ = '\\';
 114                 *dst++ = ((u_char)c >> 6 & 07) + '0';
 115                 *dst++ = ((u_char)c >> 3 & 07) + '0';
 116                 *dst++ = ((u_char)c & 07) + '0';
 117                 goto done;
 118         }
 119         if ((flag & VIS_NOSLASH) == 0)
 120                 *dst++ = '\\';
 121         if (c & 0200) {
 122                 c &= 0177;
 123                 *dst++ = 'M';
 124         }
 125         if (iscntrl((u_char)c)) {
 126                 *dst++ = '^';
 127                 if (c == 0177)
 128                         *dst++ = '?';
 129                 else
 130                         *dst++ = c + '@';
 131         } else {
 132                 *dst++ = '-';
 133                 *dst++ = c;
 134         }
 135 done:
 136         *dst = '\0';
 137         return (dst);
 138 }
 139
 140 /*
 141  * strvis, strnvis, strvisx - visually encode characters from src into dst
 142  *
 143  *      Dst must be 4 times the size of src to account for possible
 144  *      expansion.  The length of dst, not including the trailing NULL,
 145  *      is returned.
 146  *
 147  *      Strnvis will write no more than siz-1 bytes (and will NULL terminate).
 148  *      The number of bytes needed to fully encode the string is returned.
 149  *
 150  *      Strvisx encodes exactly len bytes from src into dst.
 151  *      This is useful for encoding a block of data.
 152  */
 153 int
 154 strvis(char *dst, const char *src, int flag)
 155 {
 156         char c;
 157         char *start;
 158
 159         for (start = dst; (c = *src);)
 160                 dst = vis(dst, c, flag, *++src);
 161         *dst = '\0';
 162         return (dst - start);
 163 }
 164
 165 int
 166 strnvis(char *dst, const char *src, size_t siz, int flag)
 167 {
 168         char *start, *end;
 169         char tbuf[5];
 170         int c, i;
 171
 172         i = 0;
 173         for (start = dst, end = start + siz - 1; (c = *src) && dst < end; ) {
 174                 if (isvisible(c, flag)) {
 175                         if ((c == '"' && (flag & VIS_DQ) != 0) ||
 176                             (c == '\\' && (flag & VIS_NOSLASH) == 0)) {
 177                                 /* need space for the extra '\\' */
 178                                 if (dst + 1 >= end) {
 179                                         i = 2;
 180                                         break;
 181                                 }
 182                                 *dst++ = '\\';
 183                         }
 184                         i = 1;
 185                         *dst++ = c;
 186                         src++;
 187                 } else {
 188                         i = vis(tbuf, c, flag, *++src) - tbuf;
 189                         if (dst + i <= end) {
 190                                 memcpy(dst, tbuf, i);
 191                                 dst += i;
 192                         } else {
 193                                 src--;
 194                                 break;
 195                         }
 196                 }
 197         }
 198         if (siz > 0)
 199                 *dst = '\0';
 200         if (dst + i > end) {
 201                 /* adjust return value for truncation */
 202                 while ((c = *src))
 203                         dst += vis(tbuf, c, flag, *++src) - tbuf;
 204         }
 205         return (dst - start);
 206 }
 207
 208 int
 209 stravis(char **outp, const char *src, int flag)
 210 {
 211         char *buf;
 212         int len, serrno;
 213
 214         buf = reallocarray(NULL, 4, strlen(src) + 1);
 215         if (buf == NULL)
 216                 return -1;
 217         len = strvis(buf, src, flag);
 218         serrno = errno;
 219         *outp = realloc(buf, len + 1);
 220         if (*outp == NULL) {
 221                 *outp = buf;
 222                 errno = serrno;
 223         }
 224         return (len);
 225 }
 226
 227 int
 228 strvisx(char *dst, const char *src, size_t len, int flag)
 229 {
 230         char c;
 231         char *start;
 232
 233         for (start = dst; len > 1; len--) {
 234                 c = *src;
 235                 dst = vis(dst, c, flag, *++src);
 236         }
 237         if (len)
 238                 dst = vis(dst, *src, flag, '\0');
 239         *dst = '\0';
 240         return (dst - start);
 241 }