GNU Make: Batman's Grappling Hook for Programmers

GNU Make: Batman's Grappling Hook for Programmers

I gave a presentation about the ancient-but-ubiquitous GNU Make utility. Source code and Make examples are available on Github and slides are available here. Doran Barton again lent his expertise to the video production: …

OS X Time Machine on Synology NAS

OS X Time Machine on Synology NAS

Synology DiskStation Manager (DSM) allows you to back up a machine running Apple OS X via Time Machine to a Synology NAS device. This lets you back up many computers running OS X to a single NAS. OS X support for NAS devices has improved in recent years. Time Machine …

OS X El Capitan and the case of the missing disk space

OS X El Capitan and the case of the missing disk space

For several weeks I've had a 69 GB chunk of disk missing. No scanner could detect where it had gone (DaisyDisk, WhatSize, Finder, "About This Mac → Storage", Disk Utility (also in Recovery mode), command-line utilities df and du): they all indicated that there was only 18G left and none of …

Vivint Wireless vs Comcast/Xfinity

Vivint Wireless vs Comcast/Xfinity

[Edit: see bottom of post for updates!] Comcast has been pretty reliable and consistent at the "Blast!" plan: always around 50Mbs down and somewhere between 5 and 10Mbs up. Outages maybe once a year. Also reliable and consistent were unannounced price increases: $20 jumps every year or so when the …

An Illustrated Guide to SSH Tunnels

An Illustrated Guide to SSH Tunnels

SSH tunnels can provide secure connections through insecure or untrusted networks and may also be used to securely route through firewalls. About This Guide This guide began as a personal document to help me learn and remember how SSH tunnels work and has been several years incubating. If you find …

Create Disk Image from Folder in OS X

This will create a new disk image notes.dmg that when mounted will be named notes (from -volname). The image will hold up to 10 MB and once created will be populated from the existing ~/notes folder. The -format UDRW makes the image read-write. Omit -format to make a read-only …

tmux Notes

scroll mode tmux has a scroll mode where you can use page up/page down and arrows to scroll the buffer back. To enter scroll mode, C-b <page up>. To get out of scroll mode, <Esc>. Also C-b [ turns on scroll mode. sharing Poor man's screen …

procmail Notes

I don't mess with procmail much anymore, but maybe these will be useful to someone. Split a mailbox into separate files for each message: $ formail -s sh -c 'cat - > foo.$FILENO' < klez.file Resend a mailbox (foo) through a set of filters (rc.test): $ formail -s procmail …

Duplicate an SD Card in OS X

I made these notes as a result of my experimentation with a Raspberry Pi. I kept messing up the software on the SD card and needed to start over, but it took a long time to go through all of the RPi setup steps. By copying the partitions, I was …

Miscellaneous System Administration Notes

Some miscellaneous notes I may split out into separate posts later... don't bookmark this one. View open network connections on OS X sudo lsof -lnP +M -i4 The options: -l don't convert uids to login -n dont' convert network numbers to to hostnames -P don't convert port numbers to service …

Perl SSL Debugging

I just spent about 3 hours trying to figure out why a Mojolicious daemon wasn't permitting SSL connections. Here's what I checked: the server was accessible (iptables, routing, etc.) the port was accessible (I could set mojo's listen to http://*:443) and it would respond fine on my laptop the …