====== Devuan Management ======

Some are applicable to any APT-based distro.

//**Note:** To remove translations,//<code>$ cd /etc ; echo "Acquire::Languages { \"none\"; };" > apt/apt.conf.d/99translation ; cd - >/dev/null</code>

//**Note:** To automatically update system essentials,//<code>$ apt install unattended-upgrades ; dpkg-reconfigure --priority=low unattended-upgrades</code>

===== Upgrading =====

To do an upgrade:

  * Modify ''/etc/apt/sources.list'' and replace the release codenames <code># sed -i 's/old_release/new_release/g' /etc/apt/sources.list</code>
    * skip ''-i'' option for a dry-run
  * Update package list <code># apt update</code>
  * Upgrade distribution <code># apt dist-upgrade</code>
  * To make sure EVERYTHING is upgraded (avoids old packages held back)
    * <code># apt full-upgrade</code>
  * Do house cleaning <code>
# apt autoremove
# apt clean</code>

That should do it!

===== List Installed Packages =====

Using ''apt'' tool <code>$ apt list --installed 2>/dev/null | grep installed</code> 
Note that apt will issue a warning when piping its output in shell. Hence, the need to redirect ''stderr'' to ''/dev/null''. We can further grep away the packages that were automatically installed.

Using the basic ''dpkg'' tool <code>$ dpkg --get-selections | sed -n 's/^\([^\t]*\)\t.*$/\1/ p'</code> 
This version, however, only provides package name. To extract similar output from ''apt'' (assuming output was redirected into a file called ''temp.txt''), run <code>$ cat temp.txt | sed -n 's|^\(.*\)/.*$|\1| p'</code>

===== Adding More Repo =====

Get proper signature key from that source (''*.asc'' file) and add to system using ''apt-key''.
<code># cat <key-file.asc> | apt-key add - </code>

Create a listing file for source URL in ''/etc/apt/sources.list.d/''.
<code># echo "deb [arch=?] <new-repo-url> <version> main" > /etc/apt/sources.list.d/new-repo.list</code>

After doing an ''apt update'', should be able to ''apt install <pkg>''...

===== Reconfigure Package =====

Basically, run a ''dpkg-reconfigure <pkg>''

e.g. To change timezone <code># dpkg-reconfigure tzdata</code>

===== Search package for specific binary =====

  * There is a  specific tool for that <code># apt install apt-file</code>
  * Update the package/file mapping database <code># apt-file update</code>
  * Search for "top" <code># apt-file search --regexp '/top$'</code>

===== Avoiding marking package as manually installed  =====

  * Use dry-run (simulation) option ''-s'' <code># apt install -s <pg1> ... <pkgN> 2>/dev/null|grep manually</code>
  * Removed the package(s) displayed from your install list and re-run without ''-s''

===== GRUB Stuffs =====

To prevent GRUB from looking for other OS every time it is updated:
  * edit ''/etc/default/grub'' and insert <code>GRUB_DISABLE_OS_PROBER=true</code>
  * run update-grub

To add a custom entry:
  * add a menuentry in ''/etc/grub.d/40_custom''
  * uses the same menuentry format as in ''/boot/grub/grub.cfg''
    * e.g. to boot my Slackware partition I can insert <code grub>
menuentry 'Slackware' --class slackware --class gnu-linux --class gnu --class os $menuentry_id_option 'my1part-<uuid>' {
	insmod part_gpt
	insmod ext2
	set root='hd0,gpt4'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt4 --hint-efi=hd0,gpt4 --hint-baremetal=ahci0,gpt4  <uuid>
	else
	  search --no-floppy --fs-uuid --set=root 4d95a526-2518-4fd6-a904-f7bd2729145d
	fi
	linux /boot/vmlinuz-huge-4.4.240 root=/dev/sda4
}
</code>
    * use ''initrd'' (after ''linux'' line) to specify an initrd/initramfs
    * of course, <uuid> should be a valid filesystem uuid 
  * run update-grub

===== KVM Stuffs =====

If KVM group is missing, simply create one...
<code># [ -z "$(cat /etc/group|grep kvm)" ] && addgroup --gid 125 kvm</code>