From a local node, retrieve the date from server A and set that time on server B. When ntpd is not an option and you need to get closest clock sync between two nodes Replace SRC_SRV with yout source server and DST_SRV with your destination server. You must have ssh access to both and sudo access to the the destination to set the date. Show Sample Output

Only requires one `exit` to close session.

man NetworkManager.conf ... none: NetworkManager will not modify resolv.conf. This implies rc-manager unmanaged Show Sample Output

Added gdb & other usefull stuff Show Sample Output

Trims left over file system data from SSD. This can be set as a mount option, but then IO performance decreases. I prefer to trim in a batch either on boot or every few weeks. Show Sample Output

Does the same but shows nicely progress in real time with correct Size in %. But also needs the packages sudo,dd,pv and dialog.

In this example, I’m creating a wrapper for apt-get that assumes yes every time — but the command could be anything.

2d - is a shortcut for a period back in time Show Sample Output

Clear Cached Memory on Ubuntu based distributions, and also display memory status. Please do not use this on a production machine unless you really really know what you are doing. Echo 3 is a kinder way of purging the memory, you can also use 'echo 2' or 'echo 1' if #1 You know what you are doing, and #2 refer to number 1 :-)

an alternative to this one with only 2 processes https://www.commandlinefu.com/commands/view/25844/quickly-add-a-new-user-to-all-groups-the-default-user-is-in

In July 2008, there was an uproar over Foxconn motherboards feeding Linux installs incorrect ACPI information (http://ubuntu-virginia.ubuntuforums.org/showthread.php?t=869249). Foxconn has gladly corrected their mistake, but make sure it's not happening on your motherboard! After running the command, just view the 'dsdt.dsl' in any editor you like. Show Sample Output

sudo pmset -a hibernatemode 1 sets hiberate on. sudo pmset -a hibernatemode 0 sets hibernate off. from the pmset man page: 0001 (bit 0) enables hibernation; causes OS X to write memory state to hibernation image at sleep time. On wake (without bit 1 set) OS X will resume from the hibernation image. Bit 0 set (without bit 1 set) causes OS X to write memory state and immediately hibernate at sleep time. I often change my MacBook's sleep state. So I created a function for bash to make it a little easier. Usage: hibernate (on | off) "hibernate on" will set your laptop to hibernate if the lid is closed. "hibernate off" will set your laptop to sleep if the lid is closed. ### note : "proper" indentation isn't preserved on the website function hibernate() { case "${1}" in on) sudo pmset -a hibernatemode 1 echo Hibernate mode on. ;; off) sudo pmset -a hibernatemode 0 echo Hiberate mode off. ;; *) echo "I'm sorry Dave, but I can't do that." ;; esac } To make things easier, add the proper line in your /etc/sudoers file so that your user may invoke pmset without a password. Here's how mine looks: bwayne luna = NOPASSWD: /usr/bin/pmset Don't forget that you must edit sudoers with `sudo visudo` from Terminal.app, and not by another text editor. Sorry this is so Mac OS specific. Show Sample Output

If you don't save the rule set it won't be applied during a reboot

This will change the ownership of /../../somedirectory as well as all its subdirectories so they will be be owned by user2 - typically used when a directory is owned by root:root

It is safe when there is "PermitEmptyPasswords no" in /etc/ssh/sshd_config. This command is useful when there is no need to have a password.

Tail all logs that are opened by all java processes. This is helpful when you are on a new environment and you do not know where the logs are located. Instead of java you can put any process name. This command does work only for Linux. The list of all log files opened by java process: sudo ls -l $(eval echo "/proc/{$(echo $(pgrep java)|sed 's/ /,/')}/fd/")|grep log|sed 's/[^/]* //g'

This command works at least in 9.04+