jvmvik

# IRBRC tweaking for better productivity with Ruby 2+
# edit: ~/.irbrc

# save IRB history
require 'irb/ext/save-history'
#History configuration
IRB.conf[:SAVE_HISTORY] = 100
IRB.conf[:HISTORY_FILE] = "#{ENV['HOME']}/.irb-save-history"

# enable autocompletion

jvmvik

tmux shortcuts & cheatsheet

start new with session name:

tmux new -s master

attach to session by name:

tmux a -t myname

jvmvik

Linux Trick

List files and md5 associated

md5sum * */* 2>/dev/null > md5sum.md5

Remove log files passed

grep -lr "PASSED" $WORK_DIR/*/logs/*log | xargs rm

Inline ruby execution with standard library inclusion

jvmvik

Git Trick

Currated list of usefull complex command in git.

Find commmit missing on a branch in order to cherry-pick them.

Search in reverse order the hash of the commit missing on master from the dev branch.

git log origin/master..origin/dev --oneline --reverse  --pretty=format:"%h"
# copy/paste output in vscode to create a single line command like this:
git cherry-pick ef55b76d02f 1b85300d4fa a2197fe36d7 

jvmvik

OS realtime

• atop : network usage
• htop : cpu / memory / io usage
• lsof : filesystem handle per pid

Ruby

• rbspy : profile ruby application system call [https://github.com/rbspy/rbspy]

jvmvik

Ruby tricks

Best Ruby profiler

• Ruby spy : https://github.com/rbspy/rbspy

Documentation system

• yard is better than rdoc : https://yardoc.org/

Code

jvmvik

# Tmux 2.5 configuration file
#
# ~/.tmux.conf
#
# Enable scrooling with the mouse
#
# e-tmux-scrolling-in-iterm2/
set-window-option -g mode-mouse on
set-option -g mouse-select-pane on
set-option -g mouse-select-window on

jvmvik

Comments can be written like this.

# File should be named Makefile and then can be run as `make <target>`.
# Otherwise we use `make -f "filename" <target>`.

Warning - only use TABS to indent in Makefiles, never spaces!

Basics

jvmvik

Best command

lshosts - View static resource information about hosts in the cluster

bhosts — View resource and job information about server hosts in the cluster

lsid — View the cluster name

lsclusters — View cluster status and size

jvmvik

require 'mongo'

client = Mongo::Client.new("mongodb://localhost:27017", {database: 'test'})
db = client.db

# Show all collection
db.collection_names

# Count number of document
 db["searches"].count()