# Being confused about libraries **URL:** \ **Category:** Ruby\ **Created:** [January 27, 2010, 1:21pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393 "2010-01-27T13:21:33Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 1:21pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/1 "2010-01-27T13:21:33Z")
Hello, When running gem I always need to add this lib and that lib (I’m using an ubuntu desktop linux). For example, for sqlite3, sometime I installed it: gem install sqlite3-ruby While some other time I installed it: apt-get install sqlite3 So what’s the relation between the system “sqlite3” and (most likely) ruby’s “sqlite3-ruby”? Thanks. Jenn. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 1:31pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/2 "2010-01-27T13:31:30Z")
On 27.01.2010 13:20, Ruby N. wrote: > So what’s the relation between the system “sqlite3” and (most likely) > ruby’s “sqlite3-ruby”? Ubuntu (and other distros) package gems within their own package management system. The reasons are many, but for example this allows more fine-grained dependency tracking than RubyGems provides, and allows the distribution to make a gem fit into the distribution’s file system layout. Another (side) benefit is that bugfixes are applied at the same time as the whole system updates. One step, instead of two. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 1:41pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/3 "2010-01-27T13:41:10Z")
Phillip G. wrote: > On 27.01.2010 13:20, Ruby N. wrote: > > > So what’s the relation between the system “sqlite3” and (most likely) > > ruby’s “sqlite3-ruby”? > > Ubuntu (and other distros) package gems within their own package > management system. That’s true, but the sqlite3 package isn’t a Ruby one: " A command line interface for SQLite 3 SQLite is a C library that implements an SQL database engine. Programs that link with the SQLite library can have SQL database access without running a separate RDBMS process. " The Ruby packages (for Ubuntu) are: libsqlite3-ruby1.8 libsqlite3-ruby1.9 Marvin ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 2:43pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/4 "2010-01-27T14:43:14Z")
Roger B. wrote: > Hi, > > On Wed, Jan 27, 2010 at 1:20 PM, Ruby N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > wrote: > > > So what’s the relation between the system “sqlite3” and (most likely) > > ruby’s “sqlite3-ruby”? > > Usually, the Ubuntu package is the library written in C (or some other > language) and the gem provides a ruby wrapper for these libraries. > That’s why you need both. Not exactly. If you “apt-get install libsqlite3-ruby”, then you get Ubuntu’s package containing the ruby library which talks to the C library (libsqlite3-0). The C library is automatically installed as a dependency. This is not a gem; the code is installed under ruby’s site library directory. If you install the gem (“gem install sqlite3-ruby”) then rubygems fetches, builds and installs its own version of this ruby library. In order for this to work, not only does the C library have to be present, but also the C library’s header files (libsqlite3-dev), the Ruby header files (ruby-dev) and the C compiler (build-essential) You only need one or other of these to access sqlite3 from ruby. The advantage of the gem approach is you can easily update it if a new version of the sqlite3-ruby gem is released. Ubuntu won’t update their package unless there’s a security issue, or until you move to the next version of Ubuntu. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 2:18pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/5 "2010-01-27T14:18:55Z")
Hi, On Wed, Jan 27, 2010 at 1:20 PM, Ruby N. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > So what’s the relation between the system “sqlite3” and (most likely) > ruby’s “sqlite3-ruby”? Usually, the Ubuntu package is the library written in C (or some other language) and the gem provides a ruby wrapper for these libraries. That’s why you need both. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 3:09pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/6 "2010-01-27T15:09:15Z")
On 27.01.2010 14:43, Brian C. wrote: > If you “apt-get install libsqlite3-ruby”, then you get Ubuntu’s package > containing the ruby library which talks to the C library (libsqlite3-0). > The C library is automatically installed as a dependency. This is not a > gem; the code is installed under ruby’s site library directory. While not the gem per se, it is the same code used as if you would do a sudo gem install sqlite3-ruby > The advantage of the gem approach is you can easily update it if a new > version of the sqlite3-ruby gem is released. Ubuntu won’t update their > package unless there’s a security issue, or until you move to the next > version of Ubuntu. The disadvantage of the gem approach is security: For one, RubyGems pretty much requires root access to some directories, for another, it makes no distinction between compile- and install-time, so the compiler runs as root, allowing me to potentially exploit a vulnerability in the compiler to get a backdoor installed. Or just do a “rm -rf /”, if I were unimaginative. RubyGems will happily overwrite anything in /usr/bin/, so I can include a /usr/bin/less file that grants me root access: [https://bugs.gentoo.org/show\_bug.cgi?id=278566](https://bugs.gentoo.org/show_bug.cgi?id=278566) And yes, the issue is known: [http://redmine.ruby-lang.org/issues/show/1800](http://redmine.ruby-lang.org/issues/show/1800) And unless you check certificates (against what? Is there a default keystore, like a “rubyist-keyring”?), you cannot verify the integrity of a package. So, trading convenience against security. Be aware of the risks that carries with it. Oddly this is less of an issue on Windows, since Ruby is self-contained there, and happily so, and wreaking a Windows isntall is exceptionally difficult by now. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 3:19pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/7 "2010-01-27T15:19:48Z")
I have the following sqite3 for ruby installed: $ gem list _sqlite3_ \*\*\* LOCAL GEMS \*\*\* dbd-sqlite3 (1.2.5) sqlite3 (0.0.6) sqlite3-ruby (1.2.5) And these system libraries: $ dpkg -l _sqlite3_ ii libsqlite3-0 3.6.16-1ubuntu1 SQLite 3 shared library ii libsqlite3-dev 3.6.16-1ubuntu1 SQLite 3 development files ii libsqlite3-ruby 1.2.4-2 SQLite3 interface for Ruby ii libsqlite3-ruby1.8 1.2.4-2 SQLite3 interface for Ruby 1.8 ii sqlite3 3.6.16-1ubuntu1 A command line interface for SQLite 3 So what’s the relations among them? Thanks again. ---
**Author:** ![rubynut](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/8e8cbc/32.png) [@rubynut](https://www.ruby-forum.com/u/rubynut)\ **Post date:** [January 27, 2010, 3:20pm UTC](https://www.ruby-forum.com/t/being-confused-about-libraries/182393/8 "2010-01-27T15:20:23Z")
On 27.01.2010 14:37, Ruby N. wrote: > ii libsqlite3-ruby1.8 1.2.4-2 > SQLite3 interface for Ruby 1.8 > ii sqlite3 3.6.16-1ubuntu1 > A command line interface for SQLite 3 libsqlite3-ruby\* is the sqlite3-ruby gem (the first one seems to be a meta package, once Ubuntu switches to Ruby 1.9 by default, so that 1.9 versions of gems get pulled by apt-get / synaptic). libsqlite3-0 and libsqlite3-dev are the plain old C based SQLite3 binaries and development packages, unrelated to Ruby, unless you build the native extension of the gem (which only needs the -dev package, technically speaking).