sindresorhus

var xhr = function() {
    var xhr = new XMLHttpRequest();
    return function( method, url, callback ) {
        xhr.onreadystatechange = function() {
            if ( xhr.readyState === 4 ) {
                callback( xhr.responseText );
            }
        };
        xhr.open( method, url );
        xhr.send();

tensorfields

#!/bin/bash
# Returns the IP address of a running KVM guest VM
# Assumes a working KVM/libvirt environment
#
# Install:
#   Add this bash function to your ~/.bashrc and `source ~/.bashrc`.
# Usage: 
#   $ virt-addr vm-name
#   192.0.2.16
#

ccstone

————————————————————————————————————————————————————————————————————————————————————————————————————
BBEdit / BBEdit-Lite / TextWrangler Regular Expression Guide              Modified: 2018/08/10 01:19
————————————————————————————————————————————————————————————————————————————————————————————————————

NOTES: 

The PCRE engine (Perl Compatible Regular Expressions) is what BBEdit and TextWrangler use.

Items I'm unsure of are marked '# PCRE?'.  The list while fairly comprehensive is not complete.

julianlam

Provisioning and usage of unprivileged LXC containers via indirect login or script

As I've discovered, managing LXC containers is fairly straightforward, but when building out a system for provisioning out user maintained instances of NodeBB, it was imperative that unprivileged LXC containers were used, so that in the event of shell breakout from NodeBB followed by privilege escalation of the saas user, the root user in the LXC container would only be an unprivileged user on the host machine.

During the course of development, I ran into numerous blockers when it came to managing LXC containers in unexpected circumstances. Namely:

• Using LXC in a subshell is not directly supported. This usually happens under one of the following two circumstances:
  • After switching users via su or executing lxc-* commands as another user via sudo
  • Executing lxc-* commands via a program, application, or script. In my case, a Node.js application.

kevteljeur

#!/bin/bash
# Returns the IP address of a running KVM guest VM
# Assumes a working KVM/libvirt environment
#
# Install:
#   Add this bash function to your ~/.bashrc and `source ~/.bashrc`.
# Usage: 
#   $ virt-addr vm-name
#   192.0.2.16
#