Changes between Version 1 and Version 2 of DissectingAPackage

Timestamp:

01/23/13 16:18:36 (12 years ago)

Author:

jdreed

Comment:

--

DissectingAPackage

@@ -1 +1 @@
 = Dissecting A Package =
 
-Now that we have a package, let's take a look inside it.
+Given a `.deb` package, the `dpkg-deb` command will tell us a bit about it:
+
+{{{
+$ dpkg-deb -I rpncalc_0.1_amd64.deb 
+ new debian package, version 2.0.
+ size 1854 bytes: control archive= 515 bytes.
+     304 bytes,    11 lines      control              
+     248 bytes,     4 lines      md5sums              
+ Package: rpncalc
+ Version: 0.1
+ Architecture: amd64
+ Maintainer: Jonathan Reed <jdreed@mit.edu>
+ Installed-Size: 30
+ Section: utils
+ Priority: extra
+ Description: Simple RPN calculator in bash
+  A simple RPN calculator, implemented in bash.
+  Not legal for trade.
+  This was taken from the O'Reilly bash cookbook.
+}}}
+
+Here we can see some basic information about the size, name, version, and other metadata.
+
+We can also extract the contents of the package into a temporary directory ("scratch"):
+
+{{{
+$ mkdir scratch
+$ dpkg-deb -x rpncalc_0.1_amd64.deb scratch
+$ cd scratch/
+$ ls
+usr
+$ tree
+.
+└── usr
+    ├── bin
+    │   └── rpncalc
+    └── share
+        └── doc
+            └── rpncalc
+                ├── changelog.gz
+                ├── copyright
+                └── README
+
+5 directories, 4 files
+}}}
+
+So now we have the contents in a temporary directory, and we could explore them and maybe try and run the binaries.
+
+Now let's dig a bit deeper into how the package is put together:
 
 A Debian package is merely a specialized version of an older archive format, known as `ar`.  The `ar` command is used to manipulate these types of archives.  Let's extract a `.deb` archive:
@@ -76 +124 @@
 }}}
 
-The control information contains metadata about the package.
+The control information contains metadata about the package.  The fields are largely self-explanatory -- we'll visit them in more detail later.
 
 
+