Assuming you have a PDF and want to print that as a brochure or you want to print one A5 page two times on an A4 page. A useful tool for that is pdfjam, which you might already have installed. At least in Archlinux it is included in the texlive-core …

First of all, this is a very complex and powerful software. I was using shotwell to manage my photos over quite a long period, but it's capabilities are limited. Wherever you go, digiKam is recommended instead.

And well, this is true. The best things in digiKam so far are hierarchical …

Yesterday I had to convert some JPEG images with a white background into a PNG with a transparent background. While it is possible to do this by just replacing white with transparent, this also replaces white in other parts of the image where this is not intended. So the better …

If you want to save some files accessible over HTTP(S) to your computer and have to generate their paths with more than bash, saving with Python can be done as following

# With python3
from urllib.request import urlretrieve
urlretrieve(url, local_filename)

Just as a reminder: Adding status: draft to the header of a pelican source written in Markdown sets the draft mode.

(From the pelican docs)

Very handy list of needed commands: https://www.sslshopper.com/article-most-common-openssl-commands.html

This is especially useful if you hve to check details of a certificate, but also to check which certificate is serverd on non HHTP protocols.

As I am currently setting up a new mail server, I had to test the new server manually (As of now, the DNS records are not changed, so mail clients are problematic).

If you want to test plain text ports like standard postfix, go simply with telnet localhost 25. If …

Assuming you are using KVM as the libvirt backend:

1. Find location of harddrive in filesystem
2. Release and remove harddrive from VirtualBox (has not worked without this step)
3. Convert to raw image with VBoxManage clonehd --format RAW vboximage.vdi rawimage.raw
4. Convert to qcow2 image with qemu-img convert -f raw rawimage …

It has been a while since the last time I published something on this page. So I made some changes, from german to english, new layout and more as a notebook than a blog. We will see if this blog survives this time.

Debugging in Python is very easy with IPython, you don't need pdb or so, just do a simple

from IPython import embed

#Inside some functions
embed()

That's all.

Reference

See https://ipython.org/ipython-doc/3/api/generated/IPython.terminal.embed.html#IPython.terminal.embed.embed