高浩亮 haolian9

I recently happened upon a very interesting implementation of popen() (different API, same idea) called popen-noshell using clone(2), and so I opened an issue requesting use of vfork(2) or posix_spawn() for portability. It turns out that on Linux there's an important advantage to using clone(2). I think I should capture the things I wrote there in a better place. A gist, a blog, whatever.

This is not a paper. I assume reader familiarity with fork() in particular and Unix in general, though, of course, I link to relevant wiki pages, so if the unfamiliar reader is willing to go down the rabbit hole, they should be able to come ou

Understanding the Memory Layout of Linux Executables

Required tools for playing around with memory:

hexdump
objdump
readelf
xxd
gcore

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

I have not implemented any below solutions. But I think the first reference is good

References:

Php-FPM

Php fpm is the new way to setup php to run with your webserver. Php-fpm is a fastcgi process manager for php that is totally separate from the webserver. The webserver communicates with fpm through a socket and passes the name of the script to execute. So fpm can run with any web server that is fastcgi compatible.

I recently moved from my old shared hosting to linode. Linode provides linux vps hosting at economic prices. However the servers are totally unmanaged are just raw linux machines that have shell access. So through the shell you have to setup everything including the web server, php and the web files.

So this time I decided to go with the combination of nginx and php-fpm. I had multiple sites to setup on this new webserver. Nginx deals with these through separate server blocks (aka vhost in apache). However there was another thing needed. Php on each site should run with its own user and not the nginx common user named www-data.

Running each site with its own uid/gid is more secure and

Table Of Content

Skip to the relevant sections if needed.

2-min tutorial to do it the quick-and-dirty-way
Concepts for resolving Git conflicts
Setting up different editors / tool for using git mergetool
- Finding out what mergetool editors are supported
mergetool simple code example for vimdiff
- Resolving conflict from a Git pull
Other great references and tutorials

	package main

	import (
	"fmt"
	)

	func partition(a []int, lo, hi int) int {
	// Select the highest index or right most element in the array
	// as the pivot.
	p := a[hi]

	## Pre-requisite: You have to know your last commit message from your deleted branch.
	git reflog
	# Search for message in the list
	# a901eda HEAD@{18}: commit: <last commit message>

	# Now you have two options, either checkout revision or HEAD
	git checkout a901eda
	# Or
	git checkout HEAD@{18}

	#!/bin/bash

	web_service='nginx'
	config_file="/usr/local/etc/le-renew-webroot.ini"

	le_path='/opt/letsencrypt'
	exp_limit=30;

	if [ ! -f $config_file ]; then
	echo "[ERROR] config file does not exist: $config_file"

	// I had problems getting mouse movement events working in ncurses, but after
	// some research, it seems as if this is how you can do it. The magic is in the
	// printf("\033[?1003h\n") which was the missing piece in the puzzle for me
	// (see console_codes(4) for more information). 1003 means here that all events
	// (even position updates) will be reported.
	//
	// This seems to work in at least three X-based terminals that I've tested:
	// xterm, urxvt and gnome-terminal. It doesn't work when testing in a "normal"
	// terminal, with GPM enabled. Perhaps something for the next gist version? :)