A Blog about Skateboarding, Technology, and Entrepreneurship

Error Installing Gnuplot on Mac OS X - ld: symbol(s) not found

admin — Thu, 29 Jul 2010 14:35:33 +0000

This morning I was trying to install Gnuplot from source because I wanted generate some graphs for ApacheBench. I’m currently benchmarking one of our Rails applications using Nginx w/ Mongrels against Phusion Passenger (Nginx flavor). When “make”ing Gnuplot I received the following error:

Undefined symbols:
“_rl_ding”, referenced from:
_alert in mouse.o
“_rl_complete_with_tilde_expansion”, referenced from:
_main in plot.o
“_history_list”, referenced from:
_write_history_list in history.o
“_rl_reset_after_signal”, referenced from:
_main in plot.o
ld: symbol(s) not found
collect2: ld returned 1 exit status
make[3]: *** [gnuplot] Error 1
make[2]: *** [all-recursive] Error 1
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2

After reading a comment here I found out that the -–with-readline=builtin option needs to be include when configuring Gnuplot. So you should run the following before “make”ing:

./configure -–with-readline=builtin

That got me going and hopefully it will do the same for you!

Dealing with Git: Your branch is behind ‘origin/master’ by xx commits

admin — Tue, 27 Jul 2010 21:38:50 +0000

If you’re new to Git you may be working on a branch and realize that you’ve fallen out of synch with the master. In the case of Subversion you can normally do “svn up” and be good to go. In the case git you’ll normally do a “git fetch” and then a “git status” shows the following:

Your branch is behind ‘origin/master’ by 12 commits, and can be fast-forwarded.

To sync your branch with the master you can issue the following command:

git merge master

and you should now have all the latest changes from master.

My Collection of Firefox Shopping Add-ons

admin — Tue, 15 Jun 2010 02:49:34 +0000

I wanted to share what I’ve found to be some of my favorite shopping add-ons for Firefox. I put together this collection of shopping add-ons that can either save you money or help you search quicker. My favorite is PriceBlink, which finds cheaper prices for the product you’re currently viewing on a retailer’s site. It also includes coupons and shipping costs.

Be sure to vote for my shopping collection and share it with family and friends!

https://addons.mozilla.org/en-US/firefox/collection/ultimate-shopping-add-ons

Firefox Extension Development and XPath Replace Function

dennis — Sat, 22 May 2010 00:58:26 +0000

If you’re doing Firefox extension development you may be surprised by the lack of the XPath replace function. I definitely was. After looking through the list of supported Firefox XPath functions I found that the translate function did the trick. Here’s a list of supported Firefox Xpath functions for future reference:

https://developer.mozilla.org/en/XPath/Functions

Merging a Single Subversion Commit from Trunk to Branch

dennis — Tue, 26 Jan 2010 17:23:56 +0000

I’m posting way too much about SVN these days, but these are mainly for my personal recollection. Hopefully you’ll find them useful too. Here’s the scenario: you’re working on a branch and you want to merge a single commit from trunk into the branch. The first thing you need to do is find the revision number that you want to merge. Let’s say it’s 11259. Your SVN merge command will look like this:

svn merge -r 11258:11259 –dry-run https://myrepo.com/trunk

Notice the “–dry-run” parameter. This will display a list of files impacted, but won’t actually make the change. When you’re ready for primetime just remove the –dry-run param:

svn merge -r 11258:11259 https://myrepo.com/trunk

Running a Single Test File in Rails

dennis — Wed, 11 Nov 2009 20:13:27 +0000

There are cases where you don’t want to run your entire Rails test suite. From your Rails application directory run the following command:

ruby -I lib:test test/integration/dealer_admin_test.rb

A small but useful tidbit.

Problems with MySQL Gem and Rake on Snow Leopard

dennis — Tue, 22 Sep 2009 20:15:19 +0000

I recently got a new MacBook Pro and had problems creating a new database for my Rails app on Snow Leopard. Running rake db:create left me with the following useless error:

Couldn’t create database for {”username”=>”root”, “adapter”=>”mysql”, “database”=>”delete_me”, “password”=>nil, “socket”=>”/tmp/mysql.sock”}, charset: utf8, collation: utf8_unicode_ci (if you set the charset manually, make sure you have a matching collation)

Although I could manually access MySQL via command line and create the necessary databases, rake continually failed. It turns out that the MySQL gem needed to be compiled for a 64-bit OS as mentioned in this post:

http://weblog.rubyonrails.org/2009/8/30/upgrading-to-snow-leopard

The key command to run is:

sudo env ARCHFLAGS=”-arch x86_64″ gem install mysql — –with-mysql-config=/usr/local/mysql/bin/mysql_config

Then you should be able to run your rake tasks and ultimately get Rails talking to your MySQL database.

Magento Unexpectedly Prompts to Download index.php

dennis — Fri, 11 Sep 2009 22:15:00 +0000

This was a new one for me. I was installing Magento today on Ubuntu Hardy (8.04.3 LTS to be exact) and ran into a problem where accessing the base Magento install URL would prompt to download the index.php file. The odd thing was that I could access the index.php directly and it would work just fine. This was running under Apache 2.2. It turns out that Apache needed my DirectoryIndex to be specified, which is strange because this hasn’t been a problem with other installations. At any rate, I updated my default config file located in /etc/apache2/sites-available with the following lines just before the closing VirtualHost tag:

DirectoryIndex index.php index.html

I then restarted apache (sudo /etc/init.d/apache2 restart) and was good to go.

SVN List Comment and Files Changed for a Certain Revision

dennis — Tue, 18 Aug 2009 18:25:39 +0000

I’m spending a lot of time with the SVN command line right now because we’re trying to get a product release out the door. One thing that I’ve found handy is the ability to get the comments and list of files changed for a certain revision number. This is fairly commonplace for SVN GUI tools, but it took me a bit to find out how to do this via command line. Here’s how you do it:

svn log -v -r 7447 https://yoursvnurl.com

You can remove the URL if you’re running this command from your local copy.

SVN Current Revision Number and Commit Log Between Two Revisions

dennis — Wed, 05 Aug 2009 16:19:56 +0000

Just a quick post if you’d like to get a history of SVN commits between an older revision and your current working copy. Get the current revision number from your local copy:

svnversion .

Then get a commit history between and older version and your current version:

svn log -r 6885:8485

Where the number before the colon is your old version and the one after is your current.