Commands by kharthigeyan (2)

  • Measure the cpu performance: In-case if the cpu is thermal throttling then you can find it using this command. Check the first line of the output. Example: Doing md5 for 3s on 16 size blocks: 11406892 md5's in 2.98s ? #(When cpu is not throttling) Doing md5 for 3s on 16 size blocks: 110692 md5's in 2.98s ?? #(When cpu is thermal throttling) Practical use case: Once we had cooling outage in data center which caused thermal throttling in some of the worker nodes. We used this tool to prove that some servers are not performing well because of the cpu thermal throttling. Show Sample Output


    8
    openssl speed md5
    kharthigeyan · 2019-11-07 16:30:30 2
  • Http server on port other than 8000 Show Sample Output


    0
    python -m SimpleHTTPServer 8080
    kharthigeyan · 2019-02-12 14:53:57 0

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This command can be used to extract the IP address of the network.
can be used within a script to configure iptables for example: iface=$2 inet_ip=`ifconfig "$iface" | grep inet | cut -d: -f2 | cut -d ' ' -f1` ipt="sudo /sbin/iptables" ......................... ---------------------------------------------------------------------------------------------------------------- $ipt -A INPUT -i $iface ! -f -p tcp -s $UL -d $inet_ip --sport 1023: --dport 3306 -m state --state NEW,ESTABLISHED -j ACCEPT ---------------------------------------------------------------------------------------------------------------- ----------------------------------------------------------------------------------------------------------------- $ipt -A OUTPUT -o $iface -p tcp -s $inet_ip -d $UL --sport 3306 --dport 1023: -m state --state ESTABLISHED,RELATED -j ACCEPT -----------------------------------------------------------------------------------------------------------------

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

When was your OS installed?
Show time and date when you installed your OS.

Find files of two different extensions and copy them to a directory

Generate White Noise
This command will generate white noise through your speakers (assuming you have sound enabled). It's good for staying focused, privacy, coping with tinnitus, etc. I use it to test that the sound works.

Find usb device
I often use it to find recently added ou removed device, or using find in /dev, or anything similar. Just run the command, plug the device, and wait to see him and only him

View user activity per directory.
View all files opened by a user in specified directory. The +D option makes lsof search all sub-directories to complete depth, while ignoring symbolic links.

Find files and calculate size of result in shell
Find files and calculate size with stat of result in shell

Day of the week of your birthday over the years.
Do you ever want to know which day of week was your birhday! Now you can check that with this command, just set your birh date at the beginning (My bday in the example) and the dates will be revealed. ;)

SVN Clean
Removes all unversioned files and folders from an svn repository. Also: $ svn status --no-ignore | grep ^I | awk '{print $2}' | xargs rm -rf will remove those files which svn status ignores. Handy to add to a script which is in your path so you can run it from any repository (a la 'svn_clean.sh').


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