xieyunzi

Terminal Colors

There exists common confusion about terminal colors. This is what we have right now:

• Plain ASCII
• ANSI escape codes: 16 color codes with bold/italic and background
• 256 color palette: 216 colors + 16 ANSI + 24 gray (colors are 24-bit)
• 24-bit true color: "888" colors (aka 16 milion)

xieyunzi

from scapy.all import *

def main():
    """
    """
    packet = IP(dst="192.168.100.123")/TCP()/"from scapy packet"
    send(packet)


def packet_with_seq_n():

xieyunzi

If you are getting this in gdb on macOS while trying to run a program:

Unable to find Mach task port for process-id 57573: (os/kern) failure (0x5).
 (please check gdb is codesigned - see taskgated(8))

1. Open Keychain Access
2. In menu, open Keychain Access > Certificate Assistant > Create a certificate
3. Give it a name (e.g. gdbc)

xieyunzi

This is a little trick I use to spin up the packages instalation on Debian/Ubuntu boxes in Vagrant.

I add a simple function that checks if a directory named something similar to ~/.vagrant.d/cache/apt/opscode-ubuntu-12.04/partial (it may have another path in Windows or MacOS) and create the directory if it doesn't already exist.

def local_cache(basebox_name)
  cache_dir = Vagrant::Environment.new.home_path.join('cache', 'apt', basebox_name)
  partial_dir = cache_dir.join('partial')
  partial_dir.mkdir unless partial_dir.exist?
 cache_dir

xieyunzi

const copyToClipboard = str => {
  const el = document.createElement('textarea');  // Create a <textarea> element
  el.value = str;                                 // Set its value to the string that you want copied
  el.setAttribute('readonly', '');                // Make it readonly to be tamper-proof
  el.style.position = 'absolute';                 
  el.style.left = '-9999px';                      // Move outside the screen to make it invisible
  document.body.appendChild(el);                  // Append the <textarea> element to the HTML document
  const selected =            
    document.getSelection().rangeCount > 0        // Check if there is any content selected previously
      ? document.getSelection().getRangeAt(0)     // Store selection if found

xieyunzi

Lisp interpreter in 90 lines of C++

I've enjoyed reading Peter Norvig's recent articles on Lisp. He implements a Scheme interpreter in 90 lines of Python in the first, and develops it further in the second.

Just for fun I wondered if I could write one in C++. My goals would be

1. A Lisp interpreter that would complete Peter's Lis.py test cases correctly...
2. ...in no more than 90 lines of C++.

Although I've been thinking about this for a few weeks, as I write this I have not written a line of the code. I'm pretty sure I will achieve 1, and 2 will be... a piece of cake!

xieyunzi

// inplace merge sort
// http://thomas.baudel.name/Visualisation/VisuTri/inplacestablesort.html
(function () {
  "use strict";

  var floor = Math.floor;

  function lower(a, from, to, value, compare) {
    while (to > from) {
      var middle = from + floor((to - from) / 2);

xieyunzi

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#

xieyunzi

import code; code.interact(local=dict(globals(), **locals()))

xieyunzi

// this is the background code...

// listen for our browerAction to be clicked
chrome.browserAction.onClicked.addListener(function (tab) {
	// for the current tab, inject the "inject.js" file & execute it
	chrome.tabs.executeScript(tab.ib, {
		file: 'inject.js'
	});
});