[Dovecot] understand the struct message_header_line

Timo...

Using the src/lib-mail/test-istream-header-filter.c as example, and following your tips to jump my desired header value, but i need to store the value from the Header filtered.

In the Exemple, the callback is this:

static void filter_callback(struct message_header_line *hdr, bool *matched, void *context ATTR_UNUSED) { if (hdr != NULL && hdr->name_offset == 0) { /* drop first header */ *matched = TRUE; } }

What i try to understand is how the structs work, it's save the entire header or every line from header call the callback function ?

hdr->name_offset is the size of elements in the struct ? (like a array of message_header_line)

The void *context ATTR_UNUSED i can pass what i want to change ? like a pointer to a variable ?