How to translate "\r\n" string in Lua script with Wireshark

Question

I have written a Lua script to analyze some protocols. I wanna split long strings, so I need to split them into lines.

But when I try to use "\r\n" , there shows "\r\n" in wireshark , not new line. For example , I write code like below, but there shows "value \12\r\r\n". This means that "\\" is translated to "\" successful , but 0x0d and "\r\n" it's not translated?

local normalized_value = '\\'.."12"..string.char(0x0d).."\r\n" 

How to make this work?

Answer 1

Finnaly , I found this in source code of Wireshark. Yes, wireshark ignored these symbols. You can find it in print.c

static void
print_escaped_csv(FILE *fh, const char *unescaped_string)
{
    const char *p;

    if (fh == NULL || unescaped_string == NULL) {
        return;
    }

    for (p = unescaped_string; *p != '\0'; p++) {
        switch (*p) {
        case '\b':
            fputs("\\b", fh);
            break;
        case '\f':
            fputs("\\f", fh);
            break;
        case '\n':
            fputs("\\n", fh);
            break;
        case '\r':
            fputs("\\r", fh);
            break;
        case '\t':
            fputs("\\t", fh);
            break;
        default:
            fputc(*p, fh);
        }
    }
}

So I decided to build my own version