David Tomaschik Matir

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

⚠️ Content below I now consider obsolete. My latest guide is now located here: Technical guide for using YubiKey series 4 for GPG and SSH. Please consult that resource instead.

Quick GPG Smartcard Guide

Opening and closing an SSH tunnel in a shell script the smart way

I recently had the following problem:

From an unattended shell script (called by Jenkins), run a command-line tool that accesses the MySQL database on another host.
That tool doesn't know that the database is on another host, plus the MySQL port on that host is firewalled and not accessible from other machines.

We didn't want to open the MySQL port to the network, but it's possible to SSH from the Jenkins machine to the MySQL machine. So, basically you would do something like

ssh -L 3306:localhost:3306 remotehost

TMUX - Single window group, multiple session.

So I have been using tmux for a while and have grown to like it and have since added many many customizations to it. Now once you start getting the hang of it, you'll naturally want to do more with the tool.

Now tmux has a concept of window-group and session and if you are like me you'll want multiple session that connects to the same window group instead of a new window group every time. Basically I just need different views into the same set of windows that I have already created, I don't want to create a new set of windows every time I fire up my terminal.

This is the default case if you simply use the tmux command as your login shell, effectively creating a new group of windows every time you start tmux.

This is less than ideal because, if you are like me, you fire up one-off terminals all the time and you don't want all those one-off jobs to stay running in the background. Plus sometimes you need information fro

	## IPv6 Tests
	http://[::ffff:169.254.169.254]
	http://[0:0:0:0:0:ffff:169.254.169.254]

	## AWS
	# Amazon Web Services (No Header Required)
	# from http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html#instancedata-data-categories
	http://169.254.169.254/latest/meta-data/iam/security-credentials/dummy
	http://169.254.169.254/latest/user-data
	http://169.254.169.254/latest/user-data/iam/security-credentials/[ROLE NAME]

	// Just before switching jobs:
	// Add one of these.
	// Preferably into the same commit where you do a large merge.
	//
	// This started as a tweet with a joke of "C++ pro-tip: #define private public",
	// and then it quickly escalated into more and more evil suggestions.
	// I've tried to capture interesting suggestions here.
	//
	// Contributors: @r2d2rigo, @joeldevahl, @msinilo, @_Humus_,
	// @YuriyODonnell, @rygorous, @cmuratori, @mike_acton, @grumpygiant,