/**
* Prints a string to an autobuffer, using JSON escape rules
* @param out pointer to output buffer
* @param txt string to print
* @param delimiter true if string must be enclosed in quotation marks
* @return -1 if an error happened, 0 otherwise
*/
static int
_json_printvalue(struct autobuf *out, const char *txt, bool delimiter) {
const char *ptr;
bool unprintable;
if (delimiter) {
if (abuf_puts(out, "\"") < 0) {
return -1;
}
}
else if (*txt == 0) {
abuf_puts(out, "0");
}
ptr = txt;
while (*ptr) {
unprintable = !str_char_is_printable(*ptr);
if (unprintable || *ptr == '\\' || *ptr == '\"') {
if (ptr != txt) {
if (abuf_memcpy(out, txt, ptr - txt) < 0) {
return -1;
}
}
if (unprintable) {
if (abuf_appendf(out, "\\u00%02x", (unsigned char)(*ptr++)) < 0) {
return -1;
}
}
else {
if (abuf_appendf(out, "\\%c", *ptr++) < 0) {
return -1;
}
}
txt = ptr;
}
else {
ptr++;
}
}
if (abuf_puts(out, txt) < 0) {
return -1;
}
if (delimiter) {
if (abuf_puts(out, "\"") < 0) {
return -1;
}
}
return 0;
}
/**
* Printable is defined as all ascii characters >= 32 except
* 127 and 255.
* @param value stringpointer
* @return true if string only contains printable characters,
* false otherwise
*/
bool
str_is_printable(const char *value) {
const unsigned char *_value;
_value = (const unsigned char *)value;
while (*_value) {
if (!str_char_is_printable(*_value)) {
return false;
}
_value++;
}
return true;
}
