Linq Read Inserted Id of a Record
Suppose we have the following code sinppets:
private BlogDataContext db = new BlogDataContext ();
...
article.Created = DateTime.UtcNow;
article.Modified = DateTime.UtcNow;
db.Articles.InsertOnSubmit(article);
db.SubmitChanges( );
The ID of the article is automatically generated. How do we get the Id of the newly inserted record?
It turns out that the article is updated with the value of Id after the method SubmitChanges( ) is invoked. So, we can just get the Id this way:
int id = article.Id;
Credit: Read inserted Id from LINQ
Convert wav to m4a with GNU/Linux
There are probably a gazillion ways to do this. I use FAAC, Freeware Advanced Audio Coder, to do this job.
It works very well:
faac originalfile.wav -o outputfile.m4a
FIXED: extconf.rb:8:in `require’: no such file to load — mkmf (LoadError)
While reading Linux Journal Issue 181 today, I stumbled upon a section explaining about running Ruby on Rails on Apache using an Apache module called Phusion Passenger, also known as mod_rails.
To install Passenger, I followed the instruction provided in the magazine:
sudo gem install passenger
Unxpectedly, I got the following error:
Building native extensions. This could take a while...
ERROR: Error installing passenger:
ERROR: Failed to build gem native extension.
/usr/bin/ruby1.8 extconf.rb
extconf.rb:8:in `require': no such file to load -- mkmf (LoadError)
from extconf.rb:8
Gem files will remain installed in /usr/lib/ruby/gems/1.8/gems/fastthread-1.0.7 for inspection.
Results logged to /usr/lib/ruby/gems/1.8/gems/fastthread-1.0.7/ext/fastthread/gem_make.out
What’s happening? What did I do wrong?
According to a blog post by Al Hoang, a Ruby dev package needed to be installed. Well, I wouldn’t have a clue about this!
So, to FIX this, I need to install ruby1.8-dev:
$ sudo apt-get install ruby1.8-dev
...
Now, I’m ready to install Passenger gem:
$ sudo gem install passenger
Building native extensions. This could take a while...
Successfully installed passenger-2.2.4
1 gem installed
Installing ri documentation for passenger-2.2.4...
Installing RDoc documentation for passenger-2.2.4...
Copy hard disks or partitions using dd
Warning: The following is for personal note only, and is not meant to be a tutorial or guide.
On Debian server at work, we have /home reside on /dev/hda6 and I want to move to a new hard disk /dev/hdb.
First, I need to format /dev/hdb using fdisk. Then use dd to copy the content from /dev/hda6 to /dev/hdb1, the newly createdd ext3 partition.
# dd if=/dev/hda6 of=/dev/hdb1 bs=1024
The above commands instruct dd to read the content from /dev/hda6 and write it to /dev/hdb1. bs=1024 sets the block size to 1024 bytes.
dd takes a while depends on how big is your hard disk. Then, there is one final step to do — to re-size /dev/hdb1 to its maximum capacity.
# e2fsck -f /dev/hdb1
Now we can resize the file system in /dev/dhb1 partition. If we don’t specify the size, then resize2fs will assume the largest:
# resize2fs /dev/hdb1
# fsck -n /dev/hb1
Pidgin – old version of libpurple and unknown protocol
Aaaahhh… I fixed the Pidgin problem with Unknow protocol just 5 minutes after the previous post was made. I’m going to write how I found out the problem and how it has been fixed. If you’re interested, keep reading.
In the previous post, I mentioned that I would removed the Pidgin package completely including its configuration file (# apt-get –purge remove pidgin.) I did and followed by re-installation of Pidgin, unfortunately, it didn’t fix anything.
Then I checked the About dialog (Help -> About), and I noticed the libpurple 2.5.4 under Pidgin 2.5.6. This must be the source of the problem! But I remember libpurple has been upgraded to 2.5.6 and it said so in Aptitude. So what could be possibly wrong?
A while back, I have installed Pidgin from source code, however I was quite sure that it has been properly removed — I went into the Pidgin source and execute # make uninstall.Well, according to this Bug #385639, libpurple is still present in /usr/local/
kenno@san7:/usr/local/lib
$ ls
finch libpurple.so.0 pkgconfig site_ruby
gnt libpurple.so.0.5.4 purple-2 xemacs
libpurple-client.so.0 perl python2.4
libpurple-client.so.0.5.4 pidgin python2.5
kenno@san7:/usr/local/lib
So, I need to remove these unwated libraries manually:
kenno@san7:/usr/local/lib
$ sudo rm libpurple*
Now, let’s run Pidgin again…and… that’s it. The problem has been fixed!
For the record, I have upgraded Pidgin to 2.5.8 (unstable package at the time of this post is written) and everything works as expected. Now, I’m back to a happy Pidgin user.
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