linuxLookupNameFromDnsSearch

fn linuxLookupNameFromDnsSearch(
    gpa: Allocator,
    addrs: *ArrayList(LookupAddr),
    canon: *ArrayList(u8),
    name: []const u8,
    family: posix.sa_family_t,
    port: u16,
) !void {
    var rc: ResolvConf = undefined;
    rc.init(gpa) catch return error.ResolveConfParseFailed;
    defer rc.deinit();

    // Count dots, suppress search when >=ndots or name ends in
    // a dot, which is an explicit request for global scope.
    var dots: usize = 0;
    for (name) |byte| {
        if (byte == '.') dots += 1;
    }

    const search = if (dots >= rc.ndots or mem.endsWith(u8, name, "."))
        ""
    else
        rc.search.items;

    var canon_name = name;

    // Strip final dot for canon, fail if multiple trailing dots.
    if (mem.endsWith(u8, canon_name, ".")) canon_name.len -= 1;
    if (mem.endsWith(u8, canon_name, ".")) return error.UnknownHostName;

    // Name with search domain appended is setup in canon[]. This both
    // provides the desired default canonical name (if the requested
    // name is not a CNAME record) and serves as a buffer for passing
    // the full requested name to name_from_dns.
    try canon.resize(gpa, canon_name.len);
    @memcpy(canon.items, canon_name);
    try canon.append(gpa, '.');

    var tok_it = mem.tokenizeAny(u8, search, " \t");
    while (tok_it.next()) |tok| {
        canon.shrinkRetainingCapacity(canon_name.len + 1);
        try canon.appendSlice(gpa, tok);
        try linuxLookupNameFromDns(gpa, addrs, canon, canon.items, family, rc, port);
        if (addrs.items.len != 0) return;
    }

    canon.shrinkRetainingCapacity(canon_name.len);
    return linuxLookupNameFromDns(gpa, addrs, canon, name, family, rc, port);
}