archlinux

1. Installation guide
   1. USB Stick
   2. USB Booting
   3. Time and Network
   4. BIOS GPT scheme
      1. Partitioning
         1. Swap
      2. Filesystem
      3. Mount
   5. UEFI GPT scheme
      1. Disk Preparation
      2. Erase Disk
      3. GPT Table
      4. Partitioning
      5. ESP Filesystem
      6. LUKS
      7. LVM
      8. Filesystem
      9. Mounting
   6. Mirrors
   7. base group
   8. fstab
   9. Copy Keyfile
   10. Chroot
   11. Time
   12. Localization
   13. Network
   14. Initramfs by mkinitcpio
   15. root password
   16. Boot loader - Grub
   17. Reboot
2. General Settings
3. X
4. Time
5. pacman
   1. AUR
6. Xterm
   1. Copy and Paste
7. Alacritty
8. Resolution
   1. Virtual terminal
   2. Xorg
9. Fcitx
10. WPS
11. ALSA

Installation guide

1. Arch Linux has dropped support for i686 platforms. Only x86_64 now!
2. Download the latest ISO image from download link.
3. Install necessary packages. At least wpa_supplicant as the base group does not include that.

USB Stick

dd command will be used to create the bootable stick as it is more reliable and also the recommended method on the Wiki page. dd erases the whole USB stick and treats it as a hard drive.

Without explict notice, we assume the USB drive to be /dev/sdb. dd command is effective but dangerous as well. It take effects immediately without confirmation prompt. Therefore, please make sure you select the exact of= argument.

root@archiso / # fdisk -l; blkid; lsblk -f; findmnt
root@archiso / # dd bs=1M if=/path/to/archlinux.iso of=/dev/sdb status=progress oflag=sync

The optimal block size bs argument is determined by various factors (both hardware and software) on the system. Empirically, 1M or 4M is good enough.

To restore the USB stick as normal data storage, we should remove the ISO 9660 filesystem signature before re-partitioning and re-formating the USB drive by wipefs command. It only erase signatures of filesystem, raid or partition-table while leave filesystem itself untouched.

root@archiso / # wipefs --all /dev/sdb

USB Booting

Disable secure boot in BIOS setting as most Linux distributions do not buy digital certifits from Verisign.

If the USB stick refuses to load, then try the dd command once more. If directory /sys/firmware/efi/efivars exists, then it's booted in UEFI mode, otherwise it is in legacy BIOS mode.

By default, Arch ISO uses Zsh shell. To log all commands, set in ~/.zshrc the following to empty string:

HISTSIZE=-1
HISTFILESIZE=-1

And then run source .zshrc.

Within the Live system, we use Alt-arrow or Ctrl-Alt-Fx to switch virtual console and read installation guide there.

Time and Network

Once booted into the live system, check network connection and rectify system clock:

root@archiso ~ # ping www.archlinux.org
root@archiso ~ # timedatectl set-ntp true; timedatectl set-timezone Asia/Shanghai; timedatectl status

For wired/wireless network that require captive login or user agreement, refer to Using command line to connect to a wireless network with an http login and Connecting to a Wireless network with a captive portal. Also, please check network.

BIOS GPT scheme

1. Grub bootloader.
2. BIOS/GPT partitioning.
3. Single root partition plus extra swap file.

This booting schema is only used with VMs in VirtualBox.

Partitioning

Firstly, to identify disk devices:

root@archiso ~ # fdisk -l
root@archiso ~ # lsblk

For "Grub, BIOS/GPT" scheme, we must create the BIOS boot partition to hold Grub core.img. Around 1 MiB (2048 sectors) is enough. Partition number can be in any position order but has to be on the first 2 TiB of the disk. This partition should be flagged as bios_grub for parted, ef02 for gdisk, or select BIOS boot and partition type 4 for fdisk.

On the other hand, "Grub, BIOS/MBR" scheme uses post-MBR gap (after the 512B MBR and before the first partition) to store core.img. Usually this gap is 31 KiB. For complex modules in core.img, this space is limited. That can be resolved by pushing forward starting sector of the first parititon. For instance, partitioning tool can align at MiB boundaries, thus leaving enough post-MBR gap. So, it eliminates the bother to create BIOS boot partition.

Here is the partitioning steps:

root@archiso ~ # parted -a optimal /dev/sda
(parted) help
(parted) mktable gpt
(parted) unit s
(parted) print free
(parted) mkpart primary 0% 2047s        # 1MiB 2047s
(parted) set 1 bios_grub on
(parted) mkpart primary 2048s 100%
(parted) print free
(parted) quit

1. Tell parted to optimally align at 1MiB boundaries.

2. By default, GPT's free sector starts at 34s (equally 0%). Make BIOS boot partition be the very first parition which starts at 34s spanning to 2047s. parted reminds:

   Warning: The resulting partition is not properly aligned for best performance. Ignore/Cancel?

   Choose Ignore as this partition will not be regularly accessed. Performance issues can be disregarded though this is out of GPT alignment specifications.

3. The rest space is assigned to root starting at 2048s.

Swap

There is not any other separate partitions except that a swap file will be created. Swap partition bears NO advantages over swap file but could be shared among different systems. On the other hand, we can easily resize and plug/unplug a swap file on-the-fly.

Leave the swap file part after booting into new system.

Filesystem

There is no need to create file system for the partition bios_grub. Hence, just create an ext4 on the single root parition:

root@archiso ~ # mkfs.ext4 /dev/sda2

Mount

root@archiso ~ # mount /dev/sda2 /mnt

As there is only the root parition, we would not create any other mount points under /mnt, neither /home nor /boot.

UEFI GPT scheme

Almost all modern systems take UEFI booting schema. The old BIOS legacy mode discussed above is almost deprecated. To set the PC booting in only UEFI mode in BIOS setting (disable legacy BIOS). Also make sure the ISO is booted in UEFI mode.

Disk Preparation

1. If LVM, system encrytion (LUKS), or RAID is desired, do it now.
2. ESP could be any of FAT12, FAT16, FAT32 and VFAT (preferred).

We will erase partition or the whole drive before partitioning and formating.

Erase Disk

This section only covers normal mechanical disk drives. For SSDs, it is a different story.

We want to securely erase the disk by overwritting the entire drive with random data. There are a host of general methods available. But I choose the dm-crypt specific method here. Optionally, you could either erase just a single partition (i.e. /dev/sdXY) or the complete drive (i.e. /dev/sdX).

We first create a temporary dm-crypt container:

# erase a partition
root@archiso ~ # cryptsetup open /dev/sda1 --type plain --key-file /dev/urandom to_be_wiped
# erase a disk
root@archiso ~ # cryptsetup open /dev/sda --type plain --key-file /dev/urandom to_be_wiped

--key-file /dev/urandom is used as the encryption key. The container device is located at /dev/mapper/to_be_wipded. We can verify its existence by lsblk.

Next, we fill the container with zeros without the need of /dev/urandom:

root@archiso ~ # dd bs=1M if=/dev/zero of=/dev/mapper/to_be_wiped status=progress

For a large (i.e. a multi-terabyte disk) drive or partition, this may take hours or even a day.

Finally, close the temporary container:

root@archiso ~ # cryptsetup close /dev/mapper/to_be_wipded
root@archiso ~ # lsblk

GPT Table

Use parted to create GPT table:

root@archiso ~ # parted -a opt /dev/sda
(parted) mklabel gpt

Partitioning

For future compatability and scability, create an extra BIOS boot partition (for Grub). Additionally, I want the /boot partition also encrypted. This setup really makes the system complicated. Anyway, the practice and security improvement deserve it!

Here is the partitioning steps:

root@archiso ~ # parted -a opt /dev/sda
(parted) unit s/MiB
(parted) p free
(parted) mkpart primary 30s/40s 2047s
(parted) toggle 1 bios_grub
(parted) mkpart primary fat32 2048s/1MiB 551MiB
(parted) toggle 2 esp/boot
(parted) mkpart primary 551MiB 751MiB
(parted) mkpart primary 751MiB 100%
(parted) print free

1. As the Grub BIOS boot partition is not regularly accessed, there is no need to follow rigid alignment rules. It can just start at 34s (no alignment) or 40s (minimal alignment).

   GRUB embeds its core.img into this partition

2. It is recommended. to create the ESP with 550MiB.
3. When the unit used if MiB, the end of part 2 and the start of part 3 are both 551MiB. If using s unit, their relation should be +1.

Up to now, the partitions layout looks like:

/dev/sda1: BIOS boot
/dev/sda2: ESP
/dev/sda3: boot LUKS
/dev/sda4: '/', '/home', and '/swap' LUKS

ESP Filesystem

root@archiso ~ # mkfs.vfat -F32 /dev/sda2
root@archiso ~ # parted /dev/sda p free ; fdisk -l /dev/sda

1. BIOS boot partition shall not be formated or mounted. Just leave it alone.
2. Both sda3 and sda4 will be encrypted by LUKS, so there is no need to create filesystem at this stage.

LUKS

As Grub does not support LUKS2, use LUSK1 (--type luks1) on /dev/sda3 for /boot.

Firstly, we create a passphrase-protected file by gpg (namely arch-luks.gpg) that will be used to to encrypt the LUKS container.

root@archiso ~ # export GPG_TTY=$(tty)
root@archiso ~ # dd if=/dev/urandom bs=8388607 count=1 | gpg -v --symmetric --cipher-algo AES256 --armor --output ~/arch-luks.gpg

Why bs=8388607 count=1? Because the maximum key file size is 8192KiB. From the empirics of Gentoo installation, we should decrease the maximum value by 1.

Before anything else, make a backup of the key file (i.e. to a USB stick), as otherwise the Live environment would lose it upon reboot.

Next, we create the LUKS container:

root@archiso ~ # gpg --decrypt ~/arch-luks.gpg | cryptsetup luksFormat -v --type luks1 --cipher aes-xts-plain64 --key-size 512 --hash sha512 --key-file - --use-random /dev/sda3
root@archiso ~ # gpg --decrypt ~/arch-luks.gpg | cryptsetup luksFormat -v --type luks2 --cipher aes-xts-plain64 --key-size 512 --hash sha512 --key-file - --use-random /dev/sda4

luksFormat does not format the device, but sets up the header part of the LUKS container. Specially it encrypts the master key and embeds it into the header.

Master key is randomly choosen upon container creation and, encrypted and embedded in the header part.

It is the master key's job to encrypt the data on partition. Key file or passphrase is only used to encrypt/decrypt the master key.

For safety, add a fallback passphrase in addition to the key file. It always asks for an existing passphrase or key file before adding a new one.

root@archiso ~ # cryptsetup luksAddKey -v --key-file arch-luks --iter-time 5000 /dev/sda3 --key-slot 0
root@archiso ~ # cryptsetup luksAddKey -v --key-file arch-luks --iter-time 5000 /dev/sda4 --key-slot 0

Apart from luksAddKey, we can also luksRemoveKey, luksKillSlot etc.

We can use luksDump command to check the LUKS header:

root@archiso ~ # cryptsetup luksDump /dev/sda3
root@archiso ~ # cryptsetup luksDump /dev/sda4

It's better to backup the LUKS header:

root@archiso ~ # cryptsetup luksHeaderBackup /dev/sda3 --header-backup-file ~/sda3-luks-header.img
root@archiso ~ # cryptsetup luksHeaderBackup /dev/sda4 --header-backup-file ~/sda4-luks-header.img

Of course, we have a counterpart command luksHeaderRestore to restore header file. Once backuped, the the LUKS header may be deleted from the container. Details, refer to Arch wiki.

Once created, it is time to open the containers. The first open command, uses the fallback passphrase while the second uses key file.

root@archiso ~ # cryptsetup open /dev/sda3 cryptboot
root@archiso ~ # cryptsetup --key-file ~/arch-luks open /dev/sda4 cryptlvm
root@archiso ~ # lsblk
root@archiso ~ # ls -al /dev/mapper/

The open command asks for key file or passphrase to decrypt the master key in the LUKS header. The decrypted master key is then used to decrypte the LUKS container. The decrypted containers are now available at /dev/mapper/.

LVM

LUKS containers are ready for LVM containers on which we then create Arch Linux filesystem.

At this stage, we only care about /dev/mapper/cryptlvm as there is no LVM requirement on /dev/mapper/cryptboot.

root@archiso ~ # pvcreate /dev/mapper/cryptlvm ; pvdisplay -v -m
root@archiso ~ # vgcreate volgrp /dev/mapper/cryptlvm ; vgdisplay -v
root@archiso ~ # lvcreate --size 16G volgrp --name swap
root@archiso ~ # lvcreate --size 60G volgrp --name root
root@archiso ~ # lvcreate --size 250G volgrp --name home ; lvdisplay -v -m
root@archiso ~ # ls -al /dev/{mapper,volgrp}

1. Create a physical volume /dev/mapper/cryptlvm on top of the LUKS container.
2. Create a volume group volgrp and add the physical volume into it. We can add more, if multiple physical volumes exist.

3. Create logical volumes within volgrp.

   For futher compatibility, leave some volgrp space unallocated. Size of logical volumes can be ajusted on the fly.

Created logical volmes' symbolic links reside in two equivalent locations, namely /dev/mapper/ and /dev/volgrp/.

Filesystem

Format the logical volumes.

root@archiso ~ # mkswap /dev/volgrp/swap
root@archiso ~ # mkfs.ext4 /dev/volgrp/root
root@archiso ~ # mkfs.ext4 /dev/volgrp/home

Recall that, we have not create filesystem for the decrypted cryptboot yet. Just create filesystem on top LUKS container directly without LVM.

root@archiso ~ # mkfs.ext2 /dev/mapper/cryptboot
root@archiso ~ # lsblk

Mounting

root@archiso ~ # blkid
root@archiso ~ # swapon /dev/volgrp/swap
root@archiso ~ # mount /dev/volgrp/root /mnt
root@archiso ~ # mkdir /mnt/home; mount /dev/volgrp/home /mnt/home
#
root@archiso ~ # mkdir /mnt/boot; mount /dev/mapper/cryptboot /mnt/boot
#
root@archiso ~ # mkdir /mnt/efi; mount /dev/sda2 /mnt/efi
#
root@archiso ~ # lsblk

1. Before mounting, we should use blkid to check relevant partition and filesystem are correctly prepared.
2. LUKS boot partition can be mounted directly as we have already create the filesystem on it.

Mirrors

Get a state-of-the-art copy from mirrorlist generator:

curl -vo mirrorlist https://www.archlinux.org/mirrorlist/?country=all&protocol=http&protocol=https&ip_version=4&ip_version=6

Edit /etc/pacman.d/mirrorlist and place geographically closest mirrors on top.

base group

# base
root@archiso ~ # pacstrap /mnt base base-devel
# optional
root@archiso ~ # pacstrap /mnt nano

1. This will install all packages from base and base-devel to the root partition. Around 200 MiB packages will be downloaded and 700 MiB disk space consumed. Ignore the warning on locale failure that will be handled after chroot.

   base and base-devl are meta packages. Check Meta package and package group.

2. The base group does not even has a text editor. So we install nano explicitly here. Other groups or individual packages can also be appended to the pacstrap command. However, we'd better install only necessary packages at this stage. Of course, we can install packages within chroot by pacman or when the OS is completely installed.

fstab

root@archiso ~ # genfstab -U /mnt >> /mnt/etc/fstab
root@archiso ~ # cat /mnt/etc/fstab

1. -U and -L use UUID and label respectively.

Attention that, the separate cryptboot container is also included in /etc/fstab. To support automount of /boot partition after booting, we can resort to /mnt/etc/crypttab:

# /mnt/etc/crypttab
cryptboot	/dev/sda2	/efi/arch-luks	cipher=aes-xts-plain64:sha512,size=512

Copy Keyfile

Before chrooting, copy the key file to ESP partition.

root@archiso ~ # cp ~/arch-luks.gpg /mnt/efi/

Chroot

root@archiso ~ # arch-chroot /mnt

Much simpler than that of Gentoo. The shell prompt becomes [root@archiso /#] and the default shell becomes Bash.

To log all commands, set the following in ~/.bashrc empty string or negative integer:

# ~/.bashrc
HISTSIZE=-1
HISTFILESIZE=-1

Time

[root@archiso /#] ln -sf /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

# On VirtualBox
[root@archiso /#] hwclock -w/--systohc

Localization

Mainly, we will modify two files /etc/locale.gen and /etc/locale.conf.

Uncomment the following lines from /etc/locale.gen:

en_US.UTF-8 UTF-8
zh_CN.UTF-8 UTF-8
zh_CN.GB18030 GB18030

Generate the locale:

[root@archiso / #] grep '^[^#]'/etc/locale.gen

[root@archiso / #] locale-gen
[root@archiso / #] locale -a

[root@archiso / #] echo LANG=en_US.UTF-8 >> /etc/locale.conf

Here we set system-wide locale to en_US.UTF-8. For per-user locale, leave it to ~/.config/locale.conf.

To set customized keymap permanently, edit (create) /etc/vconsole.conf:

[root@archiso / #] echo 'KEYMAP=emacs' >> /etc/vconsole.conf

Check /usr/share/keymaps/i386/qwerty for predefined keymaps. Switch to a keymap temporarily:

root@archiso ~ # loadkeys emacs

Attention, this only affects keyboard layout in virtual console. X keyboard layout is discuessed here.

Network

Set hostname:

# Create /etc/hostname
[root@archiso / #] echo "myhostname" >> /etc/hostname

Update /etc/hosts:

127.0.0.1	localhost
::1		localhost
127.0.1.1	myhostname.localdomain	myhostname

The third line in the request uses 127.0.1.1 instead of 127.0.0.1. It does not matter which one is used, actually. But hostname resolution provide some information.

Install NetworkManager:

[root@archiso / #] pacman -S networkmanager

NetworkManager has built-in DHCP client, so we don't need to install dhcpcd. Aslo, it will pull in wpa_supplicant. To configure wpa_supplicant.conf, check Gentoo Installation.

Initramfs by mkinitcpio

# /etc/mkinitcpio.conf
MODULES=(vfat)
HOOKS=(base udev autodetect modconf block filesystems keyboard fsck keymap encrypt lvm2)

1. Add vfat module, otherwise initramfs fails load the key file.
2. This is a busybox based initramfs configuration. It is different from systemd init booting process, which is the next phase.
3. Use mkinitpico -H <hook-name> to check hooks info. Use mkinitcpio -L to list available hooks.
4. Remove consolefont hook as it is unnecessary.

Before creating the new initramfs, we should install lvm2, otherwise mkinitcpio cannot find the hook:

[root@archiso / #] pacman -S lvm2

Now we will re-create the initramfs to include the new hooks, though pacstrap above already created it upon installation of linux package (pulled in by the base group).

[root@archiso / #] mkinitcpio -P

mkinitcpio will install generate two images, a default and a fallback that skips the autodetect hook thus including a full range of mostly-unneeded modules. Obviously, the fallback image is much bigger in size than the default one as it attempts to pull in as many modules as possible. Therefore, fallback image generation usually reports missing firmware. If the system does not have such hardware, it can be safely ignored. Otherwise, just install the relevant modules like 'wd719x-firmware'.

root password

[root@archiso / #] passwd

Boot loader - Grub

[root@archiso / #] pacman -S grub efibootmgr intel-ucode

1. efibootmgr is used by the GRUB installation script to write boot entries to NVRAM.
2. intel-ucode is used to apply CPU stability and security updates during boot.

Since the boot partition is encrypted by LUKS, so we should enable encryption option for Grub.

# /etc/default/grub
GRUB_ENABLE_CRYPTODISK=y

This option is used by grub-install to generate core.img. Then we set the kernel parameters so that initramfs can unlock (using encrypt hook) the encrypted swap, root, home partitions. For the arguments format, check mkinitcpio -H encrypt before editing /etc/default/grub.

# /etc/default/grub

# or PARTUUID
GRUB_CMDLINE_LINUX="cryptdevice=UUID=of-sda4:cryptlvm cryptkey=UUID=of-sda2:auto:/arch-luks resume=UUID=of-volgrp-swap root=UUID=of-volgrp-root"
# or /dev/mapper/volgrp-root
GRUB_CMDLINE_LINUX="cryptdevice=/dev/sda4:cryptlvm cryptkey=/dev/sda2:vfat:/arch-luks resume=/dev/volgrp/swap root=/dev/mapper/volgrp-root"

1. It is error-prone to input UUID/PARTUUID without GUI, we can replace UUID with the device pathname.

2. Please make sure the key file is located under ESP partition.

   If you forget the copy the key file before choorting, just exit the chroot, copy key file, and re-enter.

3. Kernel parameter

   resume is used to suspend to disk. root is optional as long as grub-mkconfig is used to generate the boot menu.

4. mkinitpico by default, doe not support gpg hook. Therefore, we cannot use a gpg-procted key file unless mkinitcpio-gnupg is adopted. However, using a gpg-protected key file does not add security level compared to passphrase as the protected key file is also protected by passphrase. Hence, we use file arch-luks directly.

Once the configured, we can install the bootloader to ESP partition:

[root@archiso / #] grub-install --target=x86_64-efi --efi-directory=/efi --bootloader-id=GRUB --recheck --modules="part_gpt"

Attention that, there is no /dev/sda argument as that is for legacy BIOS booting.

Then, generate boot menu:

[root@archiso / #] pacman -S os-prober
[root@archiso / #] grub-mkconfig -o /boot/grub/grub.cfg

In order for Grub to find Windows 10 system, please turn off Fast Startup. Also make sure os-prober* is installed. By the way, /boot and /efi must also be mounted.

If the grub-mkconfig hangs there, probably read LVM need access to /run/lvm under new root and use the suggested hack.

root@archiso ~ # mkdir /mnt/hostlvm
root@archiso ~ # mount --bind /run/lvm /mnt/hostlvm
root@archiso ~ # arch-chroot /mnt
root@archiso ~ # ln -s /hostlvm /run/lvm

The following is for BIOS/GPT schema:

[root@archiso / #] pacman -S grub intel-ucode
[root@archiso / #] grub-install --target=i386-pc /dev/sda
[root@archiso / #] grub-mkconfig -o /boot/grub/grub.cfg

Although we install x86_64 Arch Linux, the --target should be i386-pc due to BIOS booting scheme.

Reboot

[root@archiso / #] cp .bash_history /path/to/usb-stick/bash.log (optionally as it remains after reboot but maybe overriden)
[root@archiso / #] exit/Ctrl-D
root@archiso ~ # cp .zsh_history /path/to/usb-stick/zsh.log
root@archiso ~ # umount -R /mnt
root@archiso ~ # reboot

We'd better unmount all partitions under /mnt to determine busy partitions and diagnose with fuser.

General Settings

Check Post-installation.

1. Enable NetworkManager

   # optional on desktop as networkmanager will detect Wi-Fi interface and ask for Wi-Fi password
   [root@host ~]# wpa_passphrase ssid psk > /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
      
   [root@host ~]# systemctl enable/start NetworkManager
   

2. New user account

3. Swap file

   Optional if swap partition is created.

   [root@host ~]# dd bs=1M count=1024 if=/dev/zero of=/swapfile
   [root@host ~]# chmod 600 /swapfile
   [root@host ~]# mkswap /swapfile
   [root@host ~]# swapon /swapfile
   [root@host ~]# swapon --show
   [root@host ~]# free -h
   

   Finally, addan entry to /etc/fstab:

   /swapfile none swap defaults 0 0

   1. We must use the exact swap file path instead of UUID or Label.
   2. To cease manual operation bother, try systemd-swap that automates swap management.

X

X.

Time

Refer to Linux Time.

pacman

/etc/pacman.conf sets almost everything regarding pacman, like database, cache, log, repos etc.

pacman has two data warehouses:

1. main repo. the synced database that stores package metadata (pacman -S).

   ~ $ tar -tzpvf /var/lib/pacman/sync/core.db
   

2. local repo. the locally installed packages (pacman -Q).

[root@host ~ #] pacman -Ss regex                       # search for pkg
[root@host ~ #] pacman -Si pkg                         # show pkg info
[root@host ~ #] pacman -Sg grp                         # show group info
[root@host ~ #] pacman -S pkg1 pkg2                    # install pkg1 and pkg2

[root@host ~ #] pacman -Sy archlinux-keyring           # upgrade keyring first
[root@host ~ #] pacman -Syu                            # roll the system
[root@host ~ #] pacman -Syu pkg                        # roll the system and install pgk
                                                       
[root@host ~ #] pacman -Qs pkg                         # search for locally installed pkg 
[root@host ~ #] pacman -Qi pkg                         # show locally installed pkg info
[root@host ~ #] pacman -Qe                             # list explicitly installed pkgs
                      
[root@host ~ #] pactree pkg                            # show dependency

[root@host ~ #] pacman -F /path/to/file                # pathname in main repo
[root@host ~ #] pacman -Qo /path/to/file               # pathname in local repo
                                                       
[root@host ~ #] pacman -D --asdeps pkg                 # mark a package as non-explicitly installed
[root@host ~ #] pacman -D --asexplicit pkg             # mark a package as explicitly installed
                                                       
[root@host ~ #] pacman -R pkg                          # remove pkg but leave dependencies alone
[root@host ~ #] pacman -R grp
[root@host ~ #] pacman -Rs pkg                         # remove pkg and orphan dependencies; report error: argument '-' specified with empty stdin when no orphans

[root@host ~ #] pacman -Qtd                            # query orphaned packages
[root@host ~ #] pacman -Qtdq | pacman -Rns -           # remove orphaned packages

[root@host ~ #] paccache -ruk0                         # clean downloaded packages
[root@host ~ #] pacman -Scc                            # more aggressive

AUR

Use wps-office-cn as an example.

# get the PKGBUILD file
~ $ git \
-c 'url.https://aur.archlinux.org/wps-office-cn.git.insteadOf=https://aur.archlinux.org/wps-office-cn.git' \
clone --depth=1 \
https://aur.archlinux.org/wps-office-cn.git

# build the package
~ $ cd wps-office-cn$
~ $ makepkg -sirc

# install the package
~ $ sudo pacman -U wps-office-cn-11.1.0.11698-1-x86_64.pkg.tar.zst

wpspdf relies on libtiff5.

To upgrade the package, repeat the above procedures.

Xterm

Install xterm package. Add the following into ~/.Xresources:

XTerm.termName: xterm-256color
XTerm.vt100.locale: true
XTerm.vt100.metaSendsEscape: true
XTerm.vt100.reverseVideo: true

XTerm.vt100.backarrowKey: false
XTerm.ttyModes: erase ^?

XTerm.bellIsUrgent: true

XTerm.vt100.faceName: DejaVu Sans Mono:style=Book:antialias=true
XTerm.vt100.faceNameDoublesize: WenQuanYi WenQuanYi Bitmap Song
XTerm.vt100.faceSize: 10

XTerm.vt100.translations: #override \n\
    Ctrl Shift <Key>C: copy-selection(CLIPBOARD) \n\
    Ctrl Shift <Key>V: insert-selection(CLIPBOARD)

To take these settings into effect immediately:

[root@host ~ #] xrdb -merge ~/.Xresources
# -or-
[root@host ~ #] xrdb ~/.Xresources

xrdb without the -merge option will reload .Xresources, replacing current settings.

Copy and Paste

X11 has two kinds of buffers, namely PRIMARY and CLIPBOARD.

To copy/paste to/from the CLIPBOARD , we select (highlight) text, press Ctrl-C and Ctrl-V. Selected text will be copied to PRIMARY buffer automatically. To paste from PRIMARY, press the middle mouse button. Shift-insert also pastes from PRIMARY, but support only by terminal emulators. Implicitly, PRIMARY buffer lives a short period and will be replaced with new selection.

Literally, we use paste and insert, buffer and selection interchangeably.

The actual buffer and key shortcut used are determined by X application. When it comes to Xterm, selection goes to PRIMARY by default. However, we can set selection to CLIPBOARD by Ctrl-MiddbleMouse and enable Select to Clipboard. Alternatively, we can adjust ~/.Xresources:

# ~/.Xresources
XTerm.vt100.selectToClipboard: true/false

Such settings will abandom the PRIMARY buffer. Instead, we add copy/paste shortcuts:

# ~/.Xresources
XTerm.vt100.translations: #override \n\
    Ctrl Shift <Key>C: copy-selection(CLIPBOARD) \n\
    Ctrl Shift <Key>V: insert-selection(CLIPBOARD)

Notice that each key binding line must be separated by \n\.

Alacritty

xterm is really outdated, use Alacritty on Arch Linux.

However, Alacritty sets ENV variable TERM to alacritty which would break remote shell (e.g. SSH) like below.

WARNING: terminal is not fully functional

For general compatibility, we can configure Alacritty and set ENV TERM to xterm-256color.

# /usr/share/doc/alacritty/example/alacritty.yml
# /.config/alacritty/alacritty.yml

env:
  TERM: xterm-256color

Resolution

Virtual terminal

VirtualBox might fail to detect correct screen resolution for virtual terminal (console). Similar to Android-x86 post, we should add custom kernel parameter through Grub bootloader.

In Grub menu, press e, and then F2. You are now in command line prompt, type vbeinfo to list possible resolutions. The one prefixed with * is the default. Choose a desired one (i.e. 1366x768) and press ESC. Append video=1366x768 to linux line and press F10. If none of the listed values meet requirement, we can try vboxmanage setextradata:

~ $ VBoxManage setextradata archlinux "CustomVideoMode1" "1300x730x24"

The newly created value will be listed by vbeinfo. To make the desired resolution permanent, we can edit /etc/default/grub:

GRUB_CMDLINE_LINUX_DEFAULT="quiet video=1300x730"

We can also set Grub's resolution by:

GRUB_GFXMODE="1366x768x24" (for Grub menu itself)

Do not forget to update the Grub menu:

[root@host ~ #] grub-mkconfig -o /boot/grub/grub.cfg

Xorg

Most of the time, Xorg resolution works out of box. Command line tool xrandr and Xorg.conf can be used to set Xorg resolution.

Query resolution:

user@host ~ $ xrandr

The entry with star * means current resolution while with + means default preferred resolution. Set resolution:

user@host ~ $ echo $DISPLAY
user@host ~ $ xrandr --display :0 --output VGA-1 --mode 1366x768

We can put the commands into ~/.xinitrc or ~/.config/awesome/autostart.sh. Alternatively, create Xorg.conf /etc/X11/xorg.conf.d/10-resolution.conf:

Section "Monitor"
  Identifier "VGA-1"
  Modeline "1368x768_60.00"   85.25  1368 1440 1576 1784  768 771 781 798 -hsync +vsync
  Option "PreferredMode" "1368x768_60.00"
EndSection

Section "Screen"
  Identifier "Screen 0"
  Monitor "VGA-1"
  DefaultDepth 24
  SubSection "Display"
    Depth 24
  EndSubSection
EndSection

You can get the Identifier value from xrandr output.

Fcitx

Check Fcitx:

user@host ~ $ pacman -S fcitx-im fcitx-configtool

Then, append run fcitx-autostart into ~/.config/awesome/autostart.sh and relaunch awesome.

If some QT applications cannot input Chinese, ensure the following packages are available.

user@host ~ $ pacman -Qi fcitx-qt5
user@host ~ $ pacman -Qi fcitx-qt6

WPS

WPS on Linux has two version, namely wps-office-cn and wps-office. The CN version has much more features!

~ $ git clone https://aur.archlinux.org/wps-office-cn.git
~ $ cd wps-office-cn
~ $ makepkg
~ $ sudo pacman -U wps-office-cn-11.1.0.10702-1-x86_64.pkg.tar.zst

To display math symbols, we need to install AUR ttf-wps-fonts.

After closing WPS, the background process refuses to exit:

~ $ sudo chmod -x /usr/lib/office6/wpsoffice
~ $ sudo chmod -x /usr/lib/office6/wpscloudsvr

However, remove the excution permission may disallow WPS login. It's a trade-off.

ALSA

Assume the system has multiple audio cards, we may have adjust the default card.

First, identify the card list.

~ $ aplay -l

~ $ cat /proc/asound/cards

Then, update ~/.config/alsa/asoundrc.

defaults.pcm.card 0
defaults.ctl.card 0

Re-login and try alsamixer and speaker-test.