create file with given size (filled with zeros)
dd if=/dev/zero of=FILENAME bs=1024k count=MEGABYTES #or truncate -s 2M FILE
replace string in dir
grep -rl STRING1 . | xargs ^Cd -i 's/STRING1/STRING2/g'
Note: This replaces STRING1 to STRING2 even in hidden dirs, which can mess up your .git/index
non interactive gdb to run & backtrace
set confirm off can turn off the "Quit anyway? (y or n)" question.
gdb EXECUTABLE -ex "set width 1000" -ex "thread apply all bt" -ex run -ex bt -ex "set confirm off" -ex quit
direct rendering without root
If as a non-root user even thou GLX module is loaded:
user $ cat /var/log/Xorg.0.log | grep -i glx LoadModule: "glx"
you don't have direct rendering:
user $ glxinfo | grep direct direct rendering: Yes
But you do have it as a root, you might want to add the user to the correct group:
root $ gpasswd -a [USERNAME] video
Export/apply git diff as patch
git diff > save.patch patch -p1 < save.patch
Link: Stackoverflow
getting rid of consolekit and policykit
systemd makes them redundant, getting rid of them is pretty easy:
edit /etc/pam.d/system-auth and enable pam_systemd.so:
session optional pam_systemd.so
and re-emerge pambase
USE=-consolekit emerge pambase
and sincle polkit is used by upower and udisks (automount) and these 2 is used by kdelibs, you may want ot rebuild kdelibs too:
USE="-upower -udisks" emerge kdelibs
link: gentoo wiki
start DHCP at boot with systemd
migrating from openRC was smooth and automatic, except starting the DHCP.
To play with runlevels, issue this commands:
systemctl enable dhcpcd systemctl disable dhcpcd
They seem to translate to creating/deleting symlinks:
ln -s '/usr/lib64/systemd/system/dhcpcd.service' '/etc/systemd/system/multi-user.target.wants/dhcpcd.service' rm '/etc/systemd/system/multi-user.target.wants/dhcpcd.service'
update all packages under same category (for example KDE) with emerge
from eix --help:
-#, --only-names --pure-packages with format/ -I, --installed Next expression only matches installed packages. -C, --category category
The emerge command:
emerge -av $(eix -I#C kde-base)
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