yaowenqiang

\n
=============  HOST:  ==========\n
\n
           local_ip:  %{local_ip}\n
         local_port:  %{local_port}\n
          remote_ip:  %{remote_ip}\n
        remote_port:  %{remote_port}\n
\n
=======  CONNECTION:  ==========\n
\n

yaowenqiang

Here's a list of mildly interesting things about the C language that I learned mostly by consuming Clang's ASTs. Although surprises are getting sparser, I might continue to update this document over time.

There are many more mildly interesting features of C++, but the language is literally known for being weird, whereas C is usually considered smaller and simpler, so this is (almost) only about C.

1. Combined type and variable/field declaration, inside a struct scope [https://godbolt.org/g/Rh94Go]

struct foo {
   struct bar {
 int x;

yaowenqiang

Super Guide to the split-window tmux Subcommand (and Beyond)

Guide overview

tmux, like other great software, is deceptive. On the one hand, it's fairly easy to get set up and start using right away. On the other hand, it's difficult to take advantage of tmux's adanced power features without spending some quality alone time with the manual. But the problem with manuals is that they aren't geared toward beginners. They are geared toward helping seasoned developers and computer enthusiasts quickly obtain the

yaowenqiang

Top HN posts

1. Ask HN: What books changed the way you think about almost everything?

2. Ask HN: What are the best MOOCs you've taken?

3. Ask HN: How to self-learn electronics?

4. Ask HN: Successful one-person online businesses?

yaowenqiang

Presto Specific

• Don’t SELECT *, Specify explicit column names (columnar store)
• Avoid large JOINs (filter each table first)
  • In PRESTO tables are joined in the order they are listed!!
  • Join small tables earlier in the plan and leave larger fact tables to the end
  • Avoid cross joins or 1 to many joins as these can degrade performance
• Order by and group by take time
  • only use order by in subqueries if it is really necessary
• When using GROUP BY, order the columns by the highest cardinality (that is, most number of unique values) to the lowest.

yaowenqiang

Saved HN stories

Generated using the hn2md.py script.

1. Stop Using Std::endl [video]
2. Memory Access Patterns Are Important (2012)
3. Deep Reinforcement Learning Explained

yaowenqiang

function drips(){
    docker ps -q | xargs -n 1 docker inspect --format '{{ .NetworkSettings.IPAddress }} {{ .Name }}' | sed 's/ \// /'
}

yaowenqiang

# /etc/systemd/system/mysql_exporter.service

[Unit]
Description=Mysql Exporter
Wants=network-online.target
After=network-online.target


[Service]
User=root

yaowenqiang

# Install tmux on Centos release 6.5

# install deps
yum install gcc kernel-devel make ncurses-devel

# DOWNLOAD SOURCES FOR LIBEVENT AND MAKE AND INSTALL
curl -OL https://github.com/libevent/libevent/releases/download/release-2.0.22-stable/libevent-2.0.22-stable.tar.gz
tar -xf libevent-2.0.22-stable.tar.gz
cd libevent-2.0.22-stable
./configure --prefix=/usr/local

yaowenqiang

You are doing JSON APIs wrong.

When you use JSON to call an API - not a REST API, but something like JSON-RPC - you will usually want to encode one of several possible messages.

Your request body looks like this:

{
 "type": "MessageWithA",