---
author: Alvie Rahman
date: \today
title: Linux
tags:
- linux
uuid: 8ef11516-4afd-4f80-abb8-bdce045e8b65
---

# user stuff

## add user to group

```bash
usermod -a -G group user
```

## change primary user group

```bash
usermod -g group user
```

# help i think my device shut down after deleting the current kernel and before installing the second (no entries in systemd-boot/grub/<bootloader>)

0. boot into a live usb of current disto
1. mount the root partition to `/mnt` and the boot partition to the appropriate folder (check
   fstab which should be in `/mnt/etc/fstab`, if it says `/efi`, mount it to `/mnt/efi`)
2. chroot into the mounted filesystem:

   on arch based systems you can simply run:

   ```
   arch-chroot /mnt
   ```

   on non arch based systems[^1]:

   ```
   mount -t proc /proc /mnt/proc/
   mount -t sysfs /sys /mnt/ys/
   mount --rbind /dev /mnt/dev/
   # only if using uefi
   mount --rbind /sys/firmware/efi/efivars /mnt/sys/firmware/efi/efivars/
   # for internet access
   cp /etc/resolv.conf /mnt/etc/resolv.conf
   chroot /mnt /bin/bash
   ```
3. the system can now be force updated/kernel images can be generated

   on arch based systems[^2]:

   ```
   # reinstall all current packages
   pacman -Qqen > /root/pkgs.txt # list all installed packages
   pacman -S $(< /root/pkgs.txt) # reinstall all installed packages
   rm /root/pkgs.txt # clean up

   # reinstall dependencies (if there are issues)
   pacman -Qqdn > /root/deps.txt # list all installed dependencies
   pacman -S $(< /root/deps.txt) # reinstall all installed dependencies
   rm /root/deps.txt # clean up
   ```

[^1]: https://wiki.archlinux.org/title/Chroot [wayback machine](https://web.archive.org/web/20240121115548/https://wiki.archlinux.org/title/Chroot)
[^2]: https://bbs.archlinux.org/viewtopic.php?id=193174 [wayback machine](https://web.archive.org/web/20240129153400/https://bbs.archlinux.org/viewtopic.php?id=193174)