Gentoo

Portage

Directories

The default ebuild folder is /var/db/repos/gentoo/
The package.mask file is is at /var/db/repos/gentoo/profiles/package.mask
Portage stores source files in /var/cache/distfiles/
The standard directory for documentations is /usr/share/doc/
Explicitly installed packages are listed in /var/lib/portage/world
The common configuration file for merging is at /etc/portage/make.conf

Cheat sheet

Action	Command
Update the repository	`emerge --sync`
Search for software	`emerge --search [keyword]` `emerge --searchdesc [keyword]`
Install software	`emerge --ask gui-wm/sway`
Check dependencies	`emerge --pretend sway`
Only download sources	`emerge --fetchonly sway`
View USE flags	`emerge -vp gui-wm/sway`
Mark package as removable	`emerge --deselect sway`
Update installed packages	`emerge --update --ask @world`
+ their dependencies	`--deep`
+ their build dependencies	`--with-bdeps=y`
+ account for USE changes	`--newuse`
Remove deselected/unneeded packages	`emerge --depclean --ask`
Query a variable	`portageq envvar USE`
List all installed packages	`portageq match / ""`

Updating packages

Update the repository with emerge --sync, then emerge --update --ask @world

Removing unneeded packages

Manually deselect the packages to remove with emerge --deselect, or make the desired changes to USE flags
Update with dependencies: emerge --update --deep --newuse --ask @world
Remove unneeded packages: emerge --depclean --ask

Accepting licenses

A package's license will be shown by results of emerge --search
The ACCEPT_LICENSE variable is defined in /etc/portage/make.conf
Acceptance of licenses for individual packages can be done in /etc/portage/package.license
Individual licenses are stored in /var/db/repos/gentoo/licenses/
License groups are stored in var/db/repos/gentoo/profiles/license_groups

License Group	Summary
@GPL-COMPATIBLE	GPL, BSD, MIT, Apache-2.0, zlib, unicode, ...
@FSF-APPROVED	Apache-1.0, openssl, IBM, PHP-3.01, ...
@OSI-APPROVED	GPL, BSD, MIT, zlib, ...
@MISC-FREE	Unapproved but follow the Free Software Definition
@FREE-SOFTWARE	@FSF-APPROVED + @OSI-APPROVED + @MISC-FREE
@FSF-APPROVED-OTHER	"free documentation" or "works of practical use besides software and documentation"
@MISC-FREE-DOCS	Not listed under @FSF-APPROVED-OTHER but still follow the free definition
@FREE-DOCUMENTS	@FSF-APPROVED-OTHER + @MISC-FREE-DOCS
@FREE	@FREE-SOFTWARE + @FREE-DOCUMENTS
@BINARY-REDISTRIBUTABLE	At the very least allows free redistribution in binary form
@EULA	Tries to take away your rights

Network

The hostname is defined at /etc/conf.d/hostname

# hostname
hostname="oldboy"

You can define several fields under /etc/conf.d/net

# dns domain name
dns_domain_lo="home"
# ip interface
config_eno1="192.168.1.141 netmask 255.255.255.0 brd 192.168.1.255"
routes_eno1="default via 192.168.1.1"

Linux

Fonts are in /usr/share/fonts/
Update environment variables for the current session with env-update and source /etc/profile

Find all available modules by running

find /lib/modules/`uname -r` -type f -iname '*.o' -or -iname '*.ko'

Find all detected CPU vulnerabilities by running

tail -n +1 /sys/devices/system/cpu/vulnerabilities/*

To load modules automatically on boot, list them in /etc/modprobe.d/*.conf files.

Configure the kernel with make menuconfig
Build the kernel by doing make -j5 && make modules_install -j5

OpenRC

To add a service to a runlevel (sysinit, boot, default):

rc-update add <service_name> <runlevel>

To manage a service (start, stop, restart):

rc-service <service_name> <command>

Timezone and Locale

To update the system's timezone

# check available timezones
ls /usr/share/zoneinfo
# select and configure a timezone
echo "Europe/Stockholm" >/etc/timezone
emerge --config sys-libs/timezone-data

To install a locale

# check available locales
less /usr/share/i18n/SUPPORTED
# add a locale
echo "en_GB.UTF-8 UTF-8" >>/etc/locale.gen
# install locales in /etc/locale.gen
locale-gen
# manage current locale
eselect locale