yihong0618

-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

yihong0618

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;

yihong0618

// =============================================================================
// XNU kperf/kpc demo
// Available for Intel/Apple M1, macOS/iOS, with root privileges
//
// XNU source (since xnu 2422.1.72):
// https://github.com/apple/darwin-xnu/blob/main/osfmk/kern/kpc.h
// https://github.com/apple/darwin-xnu/blob/main/bsd/kern/kern_kpc.c
//
// System Private frameworks (since macOS 10.11, iOS 8.0):
// /System/Library/PrivateFrameworks/kperf.framework

yihong0618

import sys,os
import curses

def draw_menu(stdscr):
    k = 0
    cursor_x = 0
    cursor_y = 0

    # Clear and refresh the screen for a blank canvas
    stdscr.clear()