+// ----------------------------------------------------------------------------
+// functions to convert between ISO-8859-1 and UTF-8
+// ----------------------------------------------------------------------------
+
+char *getUTF8FromLatin1(char *latin1)
+{
+ int max_utf8_size = 2 * strlen(latin1) + 1;
+ char *utf8 = checked_calloc(max_utf8_size);
+ unsigned char *src = (unsigned char *)latin1;
+ unsigned char *dst = (unsigned char *)utf8;
+
+ while (*src)
+ {
+ if (*src < 128) // pure 7-bit ASCII
+ {
+ *dst++ = *src;
+ }
+ else if (*src >= 160) // non-ASCII characters
+ {
+ *dst++ = 194 + (*src >= 192);
+ *dst++ = 128 + (*src & 63);
+ }
+ else // undefined in ISO-8859-1
+ {
+ *dst++ = '?';
+ }
+
+ src++;
+ }
+
+ // only use the smallest possible string buffer size
+ utf8 = checked_realloc(utf8, strlen(utf8) + 1);
+
+ return utf8;
+}
+
+char *getLatin1FromUTF8(char *utf8)
+{
+ int max_latin1_size = strlen(utf8) + 1;
+ char *latin1 = checked_calloc(max_latin1_size);
+ unsigned char *src = (unsigned char *)utf8;
+ unsigned char *dst = (unsigned char *)latin1;
+
+ while (*src)
+ {
+ if (*src < 128) // pure 7-bit ASCII
+ {
+ *dst++ = *src++;
+ }
+ else if (src[0] == 194 &&
+ src[1] >= 128 && src[1] < 192) // non-ASCII characters
+ {
+ *dst++ = src[1];
+ src += 2;
+ }
+ else if (src[0] == 195 &&
+ src[1] >= 128 && src[1] < 192) // non-ASCII characters
+ {
+ *dst++ = src[1] + 64;
+ src += 2;
+ }
+
+ // all other UTF-8 characters are undefined in ISO-8859-1
+
+ else if (src[0] >= 192 && src[0] < 224 &&
+ src[1] >= 128 && src[1] < 192)
+ {
+ *dst++ = '?';
+ src += 2;
+ }
+ else if (src[0] >= 224 && src[0] < 240 &&
+ src[1] >= 128 && src[1] < 192 &&
+ src[2] >= 128 && src[2] < 192)
+ {
+ *dst++ = '?';
+ src += 3;
+ }
+ else if (src[0] >= 240 && src[0] < 248 &&
+ src[1] >= 128 && src[1] < 192 &&
+ src[2] >= 128 && src[2] < 192 &&
+ src[3] >= 128 && src[3] < 192)
+ {
+ *dst++ = '?';
+ src += 4;
+ }
+ else if (src[0] >= 248 && src[0] < 252 &&
+ src[1] >= 128 && src[1] < 192 &&
+ src[2] >= 128 && src[2] < 192 &&
+ src[3] >= 128 && src[3] < 192 &&
+ src[4] >= 128 && src[4] < 192)
+ {
+ *dst++ = '?';
+ src += 5;
+ }
+ else if (src[0] >= 252 && src[0] < 254 &&
+ src[1] >= 128 && src[1] < 192 &&
+ src[2] >= 128 && src[2] < 192 &&
+ src[3] >= 128 && src[3] < 192 &&
+ src[4] >= 128 && src[4] < 192 &&
+ src[5] >= 128 && src[5] < 192)
+ {
+ *dst++ = '?';
+ src += 6;
+ }
+ else
+ {
+ *dst++ = '?';
+ src++;
+ }
+ }
+
+ // only use the smallest possible string buffer size
+ latin1 = checked_realloc(latin1, strlen(latin1) + 1);
+
+ return latin1;
+}
+
+
+// ----------------------------------------------------------------------------
+// functions for JSON handling
+// ----------------------------------------------------------------------------
+
+char *getEscapedJSON(char *s)
+{
+ int max_json_size = 2 * strlen(s) + 1;
+ char *json = checked_calloc(max_json_size);
+ unsigned char *src = (unsigned char *)s;
+ unsigned char *dst = (unsigned char *)json;
+ char *escaped[256] =
+ {
+ ['\b'] = "\\b",
+ ['\f'] = "\\f",
+ ['\n'] = "\\n",
+ ['\r'] = "\\r",
+ ['\t'] = "\\t",
+ ['\"'] = "\\\"",
+ ['\\'] = "\\\\",
+ };
+
+ while (*src)
+ {
+ if (escaped[*src] != NULL)
+ {
+ char *esc = escaped[*src++];
+
+ while (*esc)
+ *dst++ = *esc++;
+ }
+ else
+ {
+ *dst++ = *src++;
+ }
+ }
+
+ // only use the smallest possible string buffer size
+ json = checked_realloc(json, strlen(json) + 1);
+
+ return json;
+}
+
+