[Sat Dec 21 09:11:59 CST 2019]

A quick tip. I just had to rotate a bunch of PDF files and save them with the new rotation. Simply doing it inside a PDF viewer doesn't do the trick. It does change the rotation when you view it with the same app next time, but it doesn't truly change it on-file. In order to do this, you are better off using the pdftk utility, as recommended here. On my Debian stretch laptop, the following command worked fine to rotate it 180 degrees:

$ pdftk file.pdf cat 1south output file.pdf

{link to this entry}

[Fri Dec 13 15:22:20 CST 2019]

In case the presence of so many banners, pop-ups and ads are starting to bother you as much as me, you may be interested in this configuration trick to completely turn off images on Firefox. The key, perhaps, is that we don't truly need to completely turn off images altogether. As the article explains, by using "3" in the configuration, Firefox will stop displaying images from third-party sites, which fundamentally includes all annoying ads. Mind you, there are also plenty of websites these days that load images from servers in other domains, so you will also lose those. In any case, it's a personal choice. But, like I said, the excess of noise in most web pages is starting to become very annoying and distracting. Then, we wonder why attention deficit disorder is an issue. Sheesh! {link to this entry}

[Mon Dec 9 10:27:44 CST 2019]

I just needed to find out whether Bluetooth was enabled on my laptop from the shell. So, as usual, the first thing I did was search around the Web for ideas. That way, I encountered this suggestion to run the command dmesg | grep -i blue. That doesn't work. It shows things as initialized, even though it's truly not working as expected:

# dmesg | grep -i blue
[   49.856575] Bluetooth: Core ver 2.22
[   49.856588] Bluetooth: HCI device and connection manager initialized
[   49.856590] Bluetooth: HCI socket layer initialized
[   49.856592] Bluetooth: L2CAP socket layer initialized
[   49.856596] Bluetooth: SCO socket layer initialized
[   88.197640] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   88.197643] Bluetooth: BNEP filters: protocol multicast
[   88.197650] Bluetooth: BNEP socket layer initialized

Elsewhere, someone suggested running systemctl status bluetooth:

# systemctl status bluetooth
● bluetooth.service - Bluetooth service
   Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2019-12-09 06:06:29 CST; 4h 26min ago
     Docs: man:bluetoothd(8)
 Main PID: 3373 (bluetoothd)
   Status: "Running"
    Tasks: 1 (limit: 4915)
   CGroup: /system.slice/bluetooth.service
           └─3373 /usr/lib/bluetooth/bluetoothd

Dec 09 06:06:29 tangier systemd[1]: Starting Bluetooth service...
Dec 09 06:06:29 tangier bluetoothd[3373]: Bluetooth daemon 5.43
Dec 09 06:06:29 tangier systemd[1]: Started Bluetooth service.
Dec 09 06:06:29 tangier bluetoothd[3373]: Starting SDP server
Dec 09 06:06:29 tangier bluetoothd[3373]: Bluetooth management interface 1.14 initialized

Well, not really. That one tells me whether the Bluetooth service is enabled and initialized, but not whether things are truly working. So, what to do? The answer came from this other forum:

# hcitool dev
Devices:

In other words, it's not enabled on my laptop, which is what I sort of remembered already. I'm pretty sure I had disabled it in the BIOS sometime ago because, in general, I don't use it on the laptop. {link to this entry}