arch

# recover from broken arch
rm /var/lib/pacman/db.lck
pacman -S linux # after chrooting

# caution: dont use grub from other bootloaders to boot arch
# It always safe to use arch grub

# users and groups
# create new group
sudo groupadd groupname

# add user to group
# need to logout and relogin to take effect
sudo usermod -aG mygroup username

# add group owner to directory
sudo chown :newgroup /path/to/directory

# see all users
cat /etc/passwd

# remove user
sudo userdel username

# add users
sudo useradd users -mG wheel username

# create swap file
# Use dd to create a swap file the size of your choosing. For example, creating a 512 MiB swap file:
dd if=/dev/zero of=/swapfile bs=1M count=512 status=progress

chmod 0600 /swapfile

mkswap -U clear /swapfile

swapon /swapfile
# finally  edit your fstab

# Setup Static IP during installation for network acess
# the live cd makes use of the following for network configuration and dns resolution
systemd-networkd.service
systemd-resolved.service

# create the following file /etc/systemd/network/20-wired.network
# susbtitute with your correct interface id, static ip address, Gateway and DNS
```
[Match]
Name=enp1s0

[Network]
Address=10.1.10.9/24
Gateway=10.1.10.1
DNS=10.1.10.1
```

# After installation if there is still no internet access.
# Make sure there is a proper /etc/resolv.conf file setup

# Alternate set of instructions for setting up static IP
# Set IP address and subnet mask
sudo ip addr add <IP>/<SUBNET> dev <INTERFACE>

# Set default gateway
sudo ip route add default via <GATEWAY>

# Set DNS server
echo "nameserver <DNS>" | sudo tee /etc/resolv.conf > /dev/null

# install deb apps on arch
# install debtap from AUR
sudo debtap -u
debtap -Q  package_name.deb
sudo pacman -U package_name.pkg

# sysreq enable all features
Write the following into /etc/sysctl.d/50-default.conf
kernel.sysrq = 1

# extract rpm file on arch
rpmextract.sh /path/to/rpm

# open sudoers file with vimdiff
VISUAL=vimdiff sudoedit /etc/sudoers /etc/sudoers.pacnew

# switch kernel
install the package from pacman; update grub