pvcreate /dev/sdc
vgcreate hadoopvg /dev/sdc
lvcreate -L 60G -n hadooplv hadoopvg
lvcreate -l 100%FREE -n reply hadoopvg
mkfs.xfs /dev/hadoopvg/hadooplv
mkfs.xfs /dev/hadoopvg/repolv
mkdir /{hadoop,repo}
mount /dev/hadoopvg/hadooplv /hadoop
mount /dev/hadoopvg/repolv /repo
from: https://unix.stackexchange.com/questions/30759/whats-a-good-example-of-piping-commands-together
Problem
Let’s say the command conky stopped responding on my desktop, and I want to kill it manually. I know a little bit of Unix, so I know that what I need to do is execute the command kill <PID>. In order to retrieve the PID, I can use ps or top or whatever tool my Unix distribution has given me. But how can I do this in one command?
Answer
$ ps aux | grep conky | grep -v grep | awk '{print $2}' | xargs kill
DISCLAIMER: This command only works in certain cases. Don’t copy/paste it in your terminal and start using it, it could kill processes unsuspectingly. Rather learn how to build it.
How it works
1- ps aux
This command will output the list of running processes and some info about them. The interesting info is that it’ll output the PID of each process in its 2nd column. Here’s an extract from the output of the command on my box:
$ ps aux
rahmu 1925 0.0 0.1 129328 6112 ? S 11:55 0:06 tint2
rahmu 1931 0.0 0.3 154992 12108 ? S 11:55 0:00 volumeicon
rahmu 1933 0.1 0.2 134716 9460 ? S 11:55 0:24 parcellite
rahmu 1940 0.0 0.0 30416 3008 ? S 11:55 0:10 xcompmgr -cC -t-5 -l-5 -r4.2 -o.55 -D6
rahmu 1941 0.0 0.2 160336 8928 ? Ss 11:55 0:00 xfce4-power-manager
rahmu 1943 0.0 0.0 32792 1964 ? S 11:55 0:00 /usr/lib/xfconf/xfconfd
rahmu 1945 0.0 0.0 17584 1292 ? S 11:55 0:00 /usr/lib/gamin/gam_server
rahmu 1946 0.0 0.5 203016 19552 ? S 11:55 0:00 python /usr/bin/system-config-printer-applet
rahmu 1947 0.0 0.3 171840 12872 ? S 11:55 0:00 nm-applet --sm-disable
rahmu 1948 0.2 0.0 276000 3564 ? Sl 11:55 0:38 conky -q
2- grep conky
I’m only interested in one process, so I use grep to find the entry corresponding to my program conky.
$ ps aux | grep conky
rahmu 1948 0.2 0.0 276000 3564 ? Sl 11:55 0:39 conky -q
rahmu 3233 0.0 0.0 7592 840 pts/1 S+ 16:55 0:00 grep conky
3- grep -v grep
As you can see in step 2, the command ps outputs the grep conky process in its list (it’s a running process after all). In order to filter it, I can run grep -v grep. The option -v tells grep to match all the lines excluding the ones containing the pattern.
$ ps aux | grep conky | grep -v grep
rahmu 1948 0.2 0.0 276000 3564 ? Sl 11:55 0:39 conky -q
NB: I would love to know a way to do steps 2 and 3 in a single grep call.
4- awk '{print $2}'
Now that I have isolated my target process. I want to retrieve its PID. In other words I want to retrieve the 2nd word of the output. Lucky for me, most (all?) modern unices will provide some version of awk, a scripting language that does wonders with tabular data. Our task becomes as easy as print $2.
$ ps aux | grep conky | grep -v grep | awk '{print $2}'
1948
5- xargs kill
I have the PID. All I need is to pass it to kill. To do this, I will use xargs.
xargs kill will read from the input (in our case from the pipe), form a command consisting of kill <items> (<items> are whatever it read from the input), and then execute the command created. In our case it will execute kill 1948. Mission accomplished.
sed -i ‘s/Xm\(s\|x\)[[:digit:]]*m/Xmx\12048m/g’ /usr/lib/idea/bin/idea.vmoptions /usr/lib/idea/bin/idea64.vmoptions
This line will replace
-Xms???m and -Xmx???m to the following in files: idea.vmoptions and idea64.vmoptions
-Xms2048m
-Xmx2048m
lsb_release -afrom: https://www.digitalocean.com/community/tutorials/how-to-install-java-with-apt-get-on-ubuntu-16-04
From: https://github.com/franzwong/til/blob/master/java/silent-install-oracle-jdk8-ubuntu.md
Problem: During installation of Oracle JDK 8 on Ubuntu, we need to agree on license agreement manually.
Solution: Installing Java Automatically (With Silent Option)
Shell script:
sudo apt-get install -y python-software-properties debconf-utils
sudo add-apt-repository -y ppa:webupd8team/java
sudo apt-get update
echo "oracle-java8-installer shared/accepted-oracle-license-v1-1 select true" | sudo debconf-set-selections
sudo apt-get install -y oracle-java8-installer
Ansible:
---
- name: Add apt repository
apt_repository:
repo: 'ppa:webupd8team/java'
state: present
update_cache: yes
- name: Accept license
debconf:
name: 'oracle-java8-installer'
question: 'shared/accepted-oracle-license-v1-1'
value: 'true'
vtype: 'select'
- name: Install java
apt: name={{ item }} state=present
with_items:
- oracle-java8-installer
- ca-certificates
- oracle-java8-set-default
from: https://www.cyberciti.biz/faq/check-ram-size-from-desktop-redhat/
cat /proc/meminfo
free -m
free -g
free -k
vmstat -s
top
zip -r {filename.zip} *.txt
this example packages all txt files in the current folder into a zip file named by {filename.zip}. Replace it with your output zip filename.
{ echo “some command”; sleep 1; } | telnet localhost 13333
(note: you need a short sleep here because the remote command may take some time to process or the early SIGHUP is not taken gracefully by the telnet)
from: http://xmodulo.com/how-to-install-apache-ant-on-centos.html
$ wget http://www.us.apache.org/dist/ant/binaries/apache-ant-1.10.1-bin.tar.gz
$ sudo tar xvfvz apache-ant-1.10.1-bin.tar.gz -C /opt
$ sudo ln -s /opt/apache-ant-1.10.1 /opt/ant
$ sudo sh -c ‘echo ANT_HOME=/opt/ant >> /etc/environment’
$ sudo ln -s /opt/ant/bin/ant /usr/bin/ant
From: https://www.cyberciti.biz/faq/howto-set-date-time-from-linux-command-prompt/
$ sudo timedatectl set-time YYYY-MM-DD
For example set the current date to 2015-12-01 (1st, Dec, 2015):
# timedatectl set-time '2015-12-01'
# timedatectl
Altar Moss 