jcberthon

class String
  def to_boolean
    return true   if self == true   || self =~ (/(true|t|yes|y|1)$/i)
    return false  if self == false  || self.nil? || self.empty? || self =~ (/(false|f|no|n|0)$/i)
    raise ArgumentError.new("invalid value for Boolean: \"#{self}\"")
  end
end

jcberthon

# Source: http://www.dzone.com/snippets/identify-duplicates-array
module Enumerable
  
  # Returns any duplicates entry if found
  # Usage: <enumerable>.report_duplicate
  def report_duplicate
    inject({}) {|h,v| h[v]=h[v].to_i+1; h}.reject{|k,v| v==1}.keys
  end
end

jcberthon

#!/bin/sh

### BEGIN INIT INFO
# Provides:          nothing
# Required-Start:    $all
# Default-Start:     3 5
# Default-Stop:      4
# Short-Description: single_line_description
# Description:       multiline_description
### END INIT INFO

jcberthon

#!/usr/bin/env bash
# call with `mount.sh true` for debug messages

home_vols=( "/Volumes/NFS_mount" ) # if more than one mountpoint then order is important
home_router_mac="0:23:46:9d:e:f7" # use code below to identify this data
mounts=( `mount | grep /Volumes | awk {'print$3'}` )

router_ip=`netstat -rnf inet | grep default | awk {'print$2'}`
router_mac=`netstat -rnf inet | grep -v link | grep -w ^$router_ip | awk {'print$2'}`
#echo $router_mac #for current router's MAC address

jcberthon

docker images --quiet --filter=dangling=true | xargs --no-run-if-empty docker rmi

jcberthon

# The examples below are given with the hostname github.com.
# Just change the hostname to one of your known hosts.
# These commands are particularly usefull if your ~/.ssh/known_hosts file is
# hashed!

# To display the fingerprint in its default form
ssh-keygen -l -F github.com

# To choose the algorithm for displaying the fingerprint (valid option for OpenSSH 7.2 are: `md5` or `sha256`)
ssh-keygen -l -E sha256 -F github.com

jcberthon

NetworkManager WiFi Power Saving

NetworkManager supports WiFi powersaving but the function is rather undocumented.

From the source code: wifi.powersave can have the following value:

• NM_SETTING_WIRELESS_POWERSAVE_DEFAULT (0): use the default value
• NM_SETTING_WIRELESS_POWERSAVE_IGNORE (1): don't touch existing setting
• NM_SETTING_WIRELESS_POWERSAVE_DISABLE (2): disable powersave

jcberthon

Source: https://access.redhat.com/articles/199563

This program will insert an actual leap second and may cause issues on unpatched systems. It is strongly recommended to use this in a test environment.

Build

gcc leap-a-day.c -o leap-a-day -lrt

Usage

jcberthon

#!/bin/bash
# Copyright 2017-2018 Jean-Christophe Berthon
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software

jcberthon

$ sudo docker-containerd-ctr pprof --debug-socket /run/docker/containerd/docker-containerd-debug.sock goroutines
goroutine 1916106 [running]:
runtime/pprof.writeGoroutineStacks(0x55e3880d1be0, 0xc420200540, 0x0, 0x0)
	/usr/local/go/src/runtime/pprof/pprof.go:608 +0xa9
runtime/pprof.writeGoroutine(0x55e3880d1be0, 0xc420200540, 0x2, 0x30, 0x55e387c98c00)
	/usr/local/go/src/runtime/pprof/pprof.go:597 +0x46
runtime/pprof.(*Profile).WriteTo(0x55e3880bd6c0, 0x55e3880d1be0, 0xc420200540, 0x2, 0xc420200540, 0xc42035e9c0)
	/usr/local/go/src/runtime/pprof/pprof.go:310 +0x3ad
net/http/pprof.handler.ServeHTTP(0xc42011c6d1, 0x9, 0x55e3880dc720, 0xc420200540, 0xc42019ff00)