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

    openssl speed md5
    kharthigeyan · 2019-11-07 16:30:30 0
  • Http server on port other than 8000 Show Sample Output

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

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Socksify any program to avoid restrictive firwalls
Require: - tsocks (deb pkg) - A working SOCKS proxy. It's easy with ssh: $ ssh -N -D localhost:1080 your.home.pc -p 443 - tsocks configuration in your /etc/tsocks.conf (for the previous): server = server_port = 1080

git diff of files that have been staged ie 'git add'ed

To find the count of each open file on a system (that supports losf)

Encrypt and password-protect execution of any bash script, Version 2
(Please see sample output for usage) Use any script name (the read command gets it) and it will be encrypted with the extension .crypt, i.e.: myscript --> myscript.crypt You can execute myscript.crypt only if you know the password. If you die, your script dies with you. If you modify the startup line, be careful with the offset calculation of the crypted block (the XX string). Not difficult to make script editable (an offset-dd piped to a gpg -d piped to a vim - piped to a gpg -c directed to ), but not enough space to do it on a one liner. Sorry for the chmod on parentheses, I dont like "-" at the end. Thanks flatcap for the subshell abbreviation to /dev/null

Destroy all disks on system simultaneously
This command will use the fdisk utility to find all block devices on your system, and overwrite them with data from the /dev/urandom non-blocking random number generator. CAUTION: This will irrevocably erase EVERY SINGLE physical block storage device visible to the fdisk utility, including plugged USB devices, RAID sets, LVM, etc.

command line calculator
simple function , floating point number is supported.

Check if system is 32bit or 64bit

Find files with at least one exec bit set

Show highlighted text with full terminal width
Show a full terminal line inverted with custom text.

Identify differences between directories (possibly on different servers)
This can be much faster than downloading one or both trees to a common servers and comparing the files there. After, only those files could be copied down for deeper comparison if needed.

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