penglei penglei

Using strace and lsof to debug blocked processes

You can use strace on a specific pid to figure out what a specific process is doing, e.g.:

strace -fp <pid>

You might see something like:

select(9, [3 5 8], [], [], {0, 999999}) = 0 (Timeout)

测试平台：DigitalOcean VPS ubuntu14.04 x64, strongswan5.2.2

运行以下命令请使用root权限

一：安装strongswan

由于ubuntu软件仓库中strongswan版本较低，因此从官网源码编译安装

apt-get install build-essential     #编译环境
aptitude install libgmp10 libgmp3-dev libssl-dev pkg-config libpcsclite-dev libpam0g-dev     #编译所需要的软件

GitHub Flavored Asciidoc (GFA)

Go Tar incompatibility

This gist demonstrates a bug in Go's archive/tar handling of tar files. Under certain conditions, tar files generated with Go 1.7 and before cannot be correctly read with Go 1.8+. While first encountered in Docker, which makes heavy use of tar files, this gist attempts to make a minimal reproduction without the Docker code base.

To reproduce this, you'll need respective versions of Go installed in /usr/local/go1.7.6 and /usr/local/go1.8.3. Other methods of version

GPG - SSH setup

Generating the master key

Here we create the master key. We want only Certify capability: we use the master key only to create the subkeys, Sign - Encrypt - Authenticate capabilities will be assigned to the subkeys.

Run the following command to start the master key generation process. Select the set your own capabilities creation process (type 8)

  ▶ gpg --full-generate-key --expert

ANSI Escape Sequences

Standard escape codes are prefixed with Escape:

Ctrl-Key: ^[
Octal: \033
Unicode: \u001b
Hexadecimal: \x1B
Decimal: 27

	curl --include \
	--no-buffer \
	--header "Connection: Upgrade" \
	--header "Upgrade: websocket" \
	--header "Host: example.com:80" \
	--header "Origin: http://example.com:80" \
	--header "Sec-WebSocket-Key: SGVsbG8sIHdvcmxkIQ==" \
	--header "Sec-WebSocket-Version: 13" \
	http://example.com:80/

	#! /usr/bin/env stack
	-- stack --resolver lts-18.8 script

	{-# LANGUAGE OverloadedStrings #-}

	{-
	This is a handy illustration of converting between five of the commonly-used
	string types in Haskell (String, ByteString, lazy ByteString, Text and lazy
	Text).

	# configuration for osx clipboard support


	set-option -g default-command "reattach-to-user-namespace -l sh"