extracting and creating ipk files - package

Question

ipk packages are the intallation packages used by opkg.
I'm trying to extract the contents of one of them and also create my own ipk.
I've read that I should be able to untar them but that is not true.
I've tried:
tar -zxvf mypack.ipk
and I get:
zip: stdin: not in gzip format
I've also tried:
tar -xvf mypack.ipk
and I get:
tar: This does not look like a tar archive
I've found that most of the information on the internet regarding ipk's are inaccurate.
My ipk was generated by bitbake. I'm having a hard time with bitbake and want to avoid using it.
Any ideas on how to extract and how to create ipk files? A simple template with a single package would be useful to have.

Answer 1

I figured it out.
You can extract the main package with the ar x command, then extract the control.tar.gz with the tar -zxf command.

Answer 2

I have tested "ar x package-name.ipk" command but it didn't help
I found bellow command which worked perfectly
tar zxpvf package-name.ipk
This extracts three files:
debian-binary
data.tar.gz
control.tar.gz
use the same command to open data.tar.gz and control.tar.gz files
for more information refer to
https://cognito.me.uk/computers/manual-extractioninstallation-of-ipk-packages-on-gargoyleopenwrt/

Answer 3

You need to create a control file, and then do some archiving using tar and ar. In my case, I was distributing just python scripts, so there was no architecture dependency. You should check the control and Makefile into version control, and delete all the other intermediate files.
Here are the contents of control
Package: my-thing-python
Version: 1.0
Description: python scripts for MyCompany
Section: extras
Priority: optional
Maintainer: John
License: CLOSED
Architecture: all
OE: my-thing-python
Homepage: unknown
Depends: python python-distutils python-pyserial python-curses python-mmap python-ctypes
Source: N/A
Here is my Makefile which sits in the same directory as all my python scripts.
all: my-thing-python.ipk
my-thing-python.ipk:
rm -rf ipk
mkdir -p ipk/opt/my-thing-python
cp *.py ipk/opt/my-thing-python
tar czvf control.tar.gz control
cd ipk; tar czvf ../data.tar.gz .; cd ..
echo 2.0 > debian-binary
ar r my-thing-python.ipk control.tar.gz data.tar.gz debian-binary
clean: FORCE
rm -rf ipk
rm -f control.tar.gz
rm -f data.tar.gz
rm -f my-thing-python.ipk
FORCE:

Answer 4

Extracting with these commands:
Extract the file by running the command:
ar -xv <.ipk file>
Extract the control.tar.gz file by running the command:
tar -zxvf control.tar.gz
data.tar.gz : untar by running the command:
tar –zxvf data.tar.gz

Answer 5

If you want a list of files in an ipk, you can do something like:
#!/bin/sh
for f
do
tar -x -z -f $f ./data.tar.gz -O | tar tvzf -
done
-O is extract to standard output.
ipk files used to be AR (like DPKG), but are now tgz.
I feel that some dpkg utility ought to cope with ipkg files, but I haven't found the right one.