Combining/Merging Pictures with ImageMagick

• Left-to-Right:

  bash

  convert +append -background black image1.jpg image2.jpg output.jpg

• Top-to-Bottom:

  bash

  convert -append -background black image1.jpg image2.jpg output.jpg

• EXAMPLE of merging photos with borders and centered position:-

  bash

  convert +append -background black -border 1 -bordercolor white -gravity center image1.jpg image2.jpg output.jpg

Rujukan: ImageMagick

Connect to WiFi with wpa_supplicant

This is somehow a primitive method for connecting to a wireless network but I just prefer doing it this way. Please refer to step number (i) and (ii) if you are running it for the first time. Otherwise, skip to step number (iii).

As root :

1. Ensure that wifi is unblocked:-

   bash

   rfkill unblock wifi

2. Enable wpa_supplicant.service and dhcpcd.service:-

   bash

   systemctl enable --now wpa_supplicant.service && \
     systemctl enable --now dhcpcd.service

3. Connect with wpa_supplicant:-

   bash

   wpa_supplicant -B -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf

4. Totally kill the wpa_supplicant process should you need to connect to a different network:-

   bash

   killall wpa_supplicant

Repeat step number 4 above with different configuration of the network details.

Provided below is an example of a simple valid wpa_supplicant.conf file:-

ctrl_interface=/run/wpa_supplicant
update_config=1
ap_scan=1
fast_reauth=1
country=MY

network={
  ssid="MYSSID"
  psk="passphrase"
}

Rujukan: wpa_supplicant | ArchWiki

Displaying Codes Behind A Symbol In Pygments

The good thing about syntax highlighting with Pygments is that we do not have to use HTML Escape in order to display a character/symbol in our codes.
However, I believe that there may be times when we need to present the code behind such character/symbol in our highlighted codes. So, here is the tip to have this purpose done:
Let’s say we need to have this character code shown in our highlighted codes. All we need to do is to replace the <&> symbol with its HTML escape which is <&>. In this case, the code behind the symbol used in this example is <⌘>. So in our code writing, we should type it this way; <⌘>.

Rujukan: place of interest sign (U+2318)

Grub2 Menuentry for Chainloading FreeBSD-UEFI

menuentry 'FreeBSD 11.1' {
  insmod ufs2
  set root=(hd0,gpt10)
  chainloader /boot/boot1.efi
}

Rujukan: fighting with grub2

Mengatasi Kegagalan Git Ketika Menambah Submodule

Saya terima ralat ketika cuba menambah submodule public untuk git melalui baris perintah berikut:

git submodule add -b master git@github.com-web:saya/saya.github.io.git public

Ralat yang diterima adalah:

Cloning into '$HOME/hugo/blog/public'...
Enter passphrase for key '$HOME/.ssh/id_ed25519_web': 
warning: You appear to have cloned an empty repository.
fatal: 'origin/master' is not a commit and a branch 'master' cannot be created from it
Unable to checkout submodule 'public'

Saya berhasil selesaikan masalah ini melalui pembacaan di halaman [Git push: “fatal ‘origin’ does not appear to be a git repository - fatal Could not read from remote repository.”]

Langkah-langkah yang perlu dibuat adalah:

1. Periksa sekiranya origin ada ditetapkan dengan menjalankan baris perintah seperti di bawah:-

   bash

   git remote -v

   Jika tiada apa-apa input yang keluar, tinggalkan langkah kedua dan teruskan dengan langkah ketiga diikuti langkah-langkah berikutnya.
   

   Sekiranya dapat output sebagaimana di bawah, teruskan dengan langkah kedua sehingga akhir.
   

   origin	git@github.com-blog:saya/blog.git (fetch)
   origin	git@github.com-blog:saya/blog.git (push)

   
   

2. Singkirkan tetapan remote yang lama dengan baris perintah berikut:-

   bash

   git remote remove origin

3. Kemudian, bolehlah menambah remote yang betul dengan:-

   bash

   git remote add origin git@github.com-blog:saya/blog.git

4. Dan akhir sekali, tambahkan submodule:-

   bash

   git submodule add -b master git@github.com-web:saya/saya.github.io.git public

   Maklum balas yang sepatutnya diterima adalah seperti ini:
   

   Adding existing repo at 'public' to the index