Function parse_string

lib/cJSON.c:524–712

Parse the input text into an unescaped cstring, and populate item. */

/* Parse the input text into an unescaped cstring, and populate item. */
static const unsigned char *parse_string(cJSON *item, const unsigned char *str, const unsigned char **ep)
{
    const unsigned char *ptr = str + 1;
    const unsigned char *end_ptr = str + 1;
    unsigned char *ptr2 = NULL;
    unsigned char *out = NULL;
    size_t len = 0;
    unsigned uc = 0;
    unsigned uc2 = 0;

    /* not a string! */
    if (*str != '\"')
    {
        *ep = str;
        goto fail;
    }

    while ((*end_ptr != '\"') && *end_ptr)
    {
        if (*end_ptr++ == '\\')
        {
            if (*end_ptr == '\0')
            {
                /* prevent buffer overflow when last input character is a backslash */
                goto fail;
            }
            /* Skip escaped quotes. */
            end_ptr++;
        }
        len++;
    }

    /* This is at most how long we need for the string, roughly. */
    out = (unsigned char*)cJSON_malloc(len + 1);
    if (!out)
    {
        goto fail;
    }
    item->valuestring = (char*)out; /* assign here so out will be deleted during cJSON_Delete() later */
    item->type = cJSON_String;

    ptr = str + 1;
    ptr2 = out;
    /* loop through the string literal */
    while (ptr < end_ptr)
    {
        if (*ptr != '\\')
        {
            *ptr2++ = *ptr++;
        }
        /* escape sequence */
        else
        {
            ptr++;
            switch (*ptr)
            {
                case 'b':
                    *ptr2++ = '\b';