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apt package

Finding the architecture that apt uses

Asked by Kiwinote

At the moment I am writing a program that needs to be able to detect the architecture of the installation. I know that there are many ways to do this, but because it is an apt-related program I would like to detect the architecture that apt uses. So far I have only found the file in /usr/share/doc/apt/examples/configure-index.gz that contains the line "Architecture "i386";". My question is: is this the official place where apt keeps its architecture configuration (in an example folder?) or is there a different place? Also it would be good to know whether this file has been in all releases since dapper, and whether it is still in gutsy.

Thanks,
Kiwinote

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Dennis Dirdjaja
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Markus Thielmann (thielmann) said : 		#1

In my opinion parsing "uname -a" would be the easiest method. It will work on all linux distributions. I'm unsure if it would work on BSD.

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Kiwinote (kiwinote) said : 		#2

I had seen that one, but it's not quite what I'm looking for. The thing is, is that "uname -m" gives a more complicated answer, ie i686 instead of i386. (I would also need a list of all possible replies, which I haven't yet found.) When apt downloads a program it downloads a i386 version, rather than a i686 one. What I'm looking for is the file/command/code that apt (so specifically apt) uses to decide which architecture of package to download. (It only needs to work on systems running apt)

Thanks,
Kiwinote

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Best Dennis Dirdjaja (dcd-ditsch) said : 		#3

Hi Kiwinote,

the default architecture is the architecture apt was compiled for. You can force another architecture by adding the parameter APT::Architecture in /etc/apt/apt.conf. In almost all cases, this would not be a good idea, though.

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Kiwinote (kiwinote) said : 		#4

Thanks, precisely what I was looking for. Hadn't yet made the connection between configure-index.gz and the man page of apt.conf. For anyone who visits this page via google, you can parse the result of "apt-cache -v" to find the installed architecture. (Ignore the status changes, I just wanted to post a custom thank-you message rather than a machine generated one)

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Kiwinote (kiwinote) said : 		#5

Thanks Dennis Dirdjaja, that solved my question.

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Benoit Pierre (benoit.pierre) said : 		#6

Simpler alternative: dpkg --print-architecture