StringEscape.c

   1 #include <stddef.h>
   2 #include <assert.h>
   3 #include <stdlib.h>
   4
   5 //FIXME out gets silently truncated if outsize is too small
   6
   7 size_t escape(char* in, char* out, size_t outsize) {
   8         size_t l = 0;
   9         while(*in && l + 3 < outsize) {
  10                 switch(*in) {
  11                 case '\a': /* 0x07 */
  12                 case '\b': /* 0x08 */
  13                 case '\t': /* 0x09 */
  14                 case '\n': /* 0x0a */
  15                 case '\v': /* 0x0b */
  16                 case '\f': /* 0x0c */
  17                 case '\r': /* 0x0d */
  18                 case '\"': /* 0x22 */
  19                 case '\'': /* 0x27 */
  20                 case '\?': /* 0x3f */
  21                 case '\\': /* 0x5c */
  22                         *out++ = '\\';
  23                         l++;
  24                         switch(*in) {
  25                         case '\a': /* 0x07 */
  26                                 *out = 'a'; break;
  27                         case '\b': /* 0x08 */
  28                                 *out = 'b'; break;
  29                         case '\t': /* 0x09 */
  30                                 *out = 't'; break;
  31                         case '\n': /* 0x0a */
  32                                 *out = 'n'; break;
  33                         case '\v': /* 0x0b */
  34                                 *out = 'v'; break;
  35                         case '\f': /* 0x0c */
  36                                 *out = 'f'; break;
  37                         case '\r': /* 0x0d */
  38                                 *out = 'r'; break;
  39                         case '\"': /* 0x22 */
  40                                 *out = '\"'; break;
  41                         case '\'': /* 0x27 */
  42                                 *out = '\''; break;
  43                         case '\?': /* 0x3f */
  44                                 *out = '\?'; break;
  45                         case '\\': /* 0x5c */
  46                                 *out = '\\'; break;
  47                         }
  48                         break;
  49                 default:
  50                         *out = *in;
  51                 }
  52                 in++;
  53                 out++;
  54                 l++;
  55         }
  56         *out = 0;
  57         return l;
  58 }
  59
  60 size_t unescape(char* in, char *out, size_t outsize) {
  61         size_t l = 0;
  62         while(*in && l + 1 < outsize) {
  63                 switch (*in) {
  64                         case '\\':
  65                                 ++in;
  66                                 assert(*in);
  67                                 switch(*in) {
  68                                         case 'a':
  69                                                 *out = '\a';
  70                                                 break;
  71                                         case 'b':
  72                                                 *out = '\b';
  73                                                 break;
  74                                         case 't':
  75                                                 *out='\t';
  76                                                 break;
  77                                         case 'n':
  78                                                 *out='\n';
  79                                                 break;
  80                                         case 'v':
  81                                                 *out='\v';
  82                                                 break;
  83                                         case 'f':
  84                                                 *out = '\f';
  85                                                 break;
  86                                         case 'r':
  87                                                 *out='\r';
  88                                                 break;
  89                                         case '"':
  90                                                 *out='"';
  91                                                 break;
  92                                         case '\'':
  93                                                 *out = '\'';
  94                                                 break;
  95                                         case '?':
  96                                                 *out = '\?';
  97                                                 break;
  98                                         case '\\':
  99                                                 *out='\\';
 100                                                 break;
 101                                         // FIXME add handling of hex and octal
 102                                         default:
 103                                                 abort();
 104                                 }
 105                                 break;
 106                         default:
 107                                 *out=*in;
 108                 }
 109                 in++;
 110                 out++;
 111                 l++;
 112         }
 113         *out = 0;
 114         return l;
 115 }