Rusty Razor Blade » tips

Open New Terminal Tip

jon — Mon, 05 Dec 2011 23:37:08 +0000

I tend to open up several terminals when working on a project, so I usually want them to start in the same directory I’ve been working with. Stick this in your ~/.bash_profile to have your new terminal windows automatically cd to the directory you last used.

export PROMPT_COMMAND='echo `pwd` > ~/.lastpwd' cd `cat ~/.lastpwd `

Multiple Filetypes in Vim

jon — Wed, 27 Apr 2011 23:11:36 +0000

I’m finding this useful as I work with snipmate and have defined custom snippets for solr config files. I still want to use the XML filetype, but I have no real use for the solr fields outside of editing the schema.xml file.

set filetype=xml.solr

Booya.

SSH with multiple hops

jon — Tue, 19 Apr 2011 01:25:28 +0000

Excellent question on superuser.com with a fantastic answer. If anyone needs to jump through multiple servers via ssh (or any other protocol) take a look at this answer.

ssh -L 9999:localhost:9999 host1 ssh -L 9999:localhost:1234 -N host2

Using iWatch to Automatically Run Unit Tests (Linux)

jon — Thu, 24 Feb 2011 02:13:37 +0000

iWatch is a perl script that uses inotify to monitor files directories. It’s similar to the watch tool, which can do all sorts of stuff if the files or directories it’s watching are modified or affected in pretty much any way at all.

Install iWatch

apt-get install iwatch

I’ve got this 1 liner in a file to quickly watch my directory and execute a PHP unit test .

#!/bin/bash
iwatch -c "phpunit $1" -t ‘.*php$’ -r -v -x ./.git -e modify .

I run this with a my argument (a unit test) and then sit there and code away. When I save, it detects the change and automatically runs my test. It’s pretty awesome.

Running Erlang Code from the Command Line

jon — Fri, 09 Jul 2010 18:31:31 +0000

This was really useful for me in scripting TextEdit to run my unit tests, as Erlide has been crashing every time I use it.

erl -run mymodule myfunc -run init stop -noshell

http://www.trapexit.org/Running_Erlang_Code_From_The_Command_Line

Textmate – Stop ._ Backup Files

jon — Mon, 15 Feb 2010 04:08:46 +0000

Pretty sure this stops TextMate from creating the ridiculous backup files in my network shares.

defaults write com.macromates.textmate OakDocumentDisableFSMetaData 1

Linux/OSX: find out what network ports are in use

jon — Tue, 05 Jan 2010 19:21:07 +0000

To get a quick idea of what ports you have open on your local box, you can use nmap.

~ jhaddad$ nmap localhost
Starting Nmap 5.00 ( http://nmap.org ) at 2010-01-05 11:06 PST
Interesting ports on localhost (127.0.0.1):
Not shown: 499 closed ports, 492 filtered ports
PORT STATE SERVICE
80/tcp open http
88/tcp open kerberos-sec
548/tcp open afp
631/tcp open ipp
3306/tcp open mysql
3325/tcp open unknown
5900/tcp open vnc
9000/tcp open cslistener
10000/tcp open snet-sensor-mgmt

For more detailed information, try netstat:

netstat -an

You’ll get a breakdown of every socket open on your machine – useful for figuring out who’s connected and from where.

The OSX version of netstat lacks a few options – such as the useful ‘-p’ option to display the process id (PID) – which can be useful combined with kill to get rid of unwanted connections – for instance,an SSH tunnel accidentally left open.

MacBook Air Battery Drain While Sleeping

jon — Fri, 11 Dec 2009 19:54:53 +0000

I bought a MacBook Air in June this year, refurbished. I didn’t really use it a lot for day to day work, and when I didn’t use it I was charging it. It was very convenient – it weighs practically nothing and has almost no impact on me while traveling. When I cut back on using it, I noticed a few things.

When I’d leave it unplugged for a few days, the battery would be dead. After a bit of testing I noticed I was losing roughly 25% of my battery life overnight if it wasn’t unplugged.
It started creaking when I’d open it. I was genuinely concerned it would just fall apart when I was trying to open it.

Obviously both of these things suck, so after a bit I brought it to the Apple store. They pretty much replaced everything in it – battery, logic board, screen bezel, hinges, and gave it back to me. So problem #2 was solved, but for some reason I kept seeing the battery issue.

I brought it back Monday of this week. The guy there (Ryan) explained to me that since I wasn’t up to date w/ my software, the tech guys would basically just give it back and refuse to work on it. He suggested resetting the PRAM and calibrating the battery. He also didn’t seem to think that losing 25% battery overnight was weird, even though I’ve owned 2 MacBook Pros and 2 iBooks that never had this issue – I could leave my MacBook Pro unplugged for days and it would only lose a few %.

I did these things, but it didn’t make a difference. It was only after a ton of looking around that someone suggested turning off bluetooth.

After turning off bluetooth, I let the laptop sit overnight in sleep. I checked it the next morning, and it was only down 4% from the night before. Huge improvement. I think I could have accomplished the same thing if I turned off the “Allow Bluetooth devices to wake this computer” setting, but since I’m not using it, I’d rather just disable it.

Anyway, if anyone knows anything else about this issue, I’m interested to find out more. I like the Air as a “sit on the couch and browse the web” laptop, hate it for doing any sort of IDE development. Also not great for playing Scrabble on Facebook – it can’t hold the entire board on the screen. Lame.

Interesting Programmer Links

jon — Tue, 21 Apr 2009 19:47:08 +0000

Peeping into memcached.

Really interesting read about how to examine what’s stored in memcached.

Peep uses ptrace to freeze a running memcached server, dump the internal key metadata, and return the server to a running state. If you have a good host ejection mechanism in your client, such as in the Twitter libmemcached builds, you won’t even have to change the production server pool. The instance is not restarted, and no data is lost.

Quick look at MySQL 5.4

Highlights include scalability improvements, subquery optimizations and join improvements, improved stored procedure management, out parameters in prepared statements, and new information schema additions.

EasyVMX

EasyVMX lets you create empty VMWare images. Very useful when coupled with the VMWare player.

For the next 5 days you can get Jira 5 user license for $5.

I used Jira about 3 years ago at Infosearch Media, which I don’t think exists any more. Anyway, it trounced bugzilla then and still does.

A cool rundown on what you can do with the information schema in MySQL.

I like this post, it makes a few really cool points. It explains how to get a list of all tables and their engine and how to get a list of foreign keys in your schema. Very cool.

Q4M, a Queue storage engine

Q4M looks like a pretty cool storage engine that aims to address twitter-like features. I’ll be trying this out for myself in the near future.

Q4M (Queue for MySQL) is a message queue licensed under GPL that works as a pluggable storage engine of MySQL 5.1, designed to be robust, fast, flexible. It is already in production quality, and is used by several web services (see Users of Q4M).

Compiling libjpeg on 64 bit Centos

jon — Mon, 07 Jul 2008 22:14:55 +0000

I ran into an issue just now compiling libjpeg on 64 bit CentOS. I found this very helpful post that gives a workaround using a config.guess file from libtool. For some reason, I didn’t have the folder he suggested, but I did have the alternative (automake).

cp /usr/share/automake-1.9/config.guess .
cp /usr/share/automake-1.9/config.sub .

I copied the above files into my jpeg-6b directory, and

./configure –enable-shared –enable-static

worked correctly.