Commands by justinf (2)

  • Quick OneLiner to sniff for ICMP traffic, proof of concept socket code. Needs root privs to run. Show Sample Output

    echo "exec(\"import socket, os\nwhile True:\n\tprint (socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP)).recvfrom(65565)\")" | sudo python
    justinf · 2015-05-24 08:19:55 0
  • If you've upgraded to OS X 10.10.x the OS installer should be on your system, otherwise its a free download (~ 5 GB). Added bonus, the above command does not require the USB pre-formatted. Show Sample Output

    sudo /Applications/Install\ OS\ X\ --volume /Volumes/Untitled --applicationpath /Applications/Install\ OS\ X\ --nointeraction
    justinf · 2015-05-24 08:03:41 0

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Prints new content of files
Useful to e.g. keep an eye on several logfiles.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Debug your makefile
Say your dependencies specified in your Makefile (or dates on your source files) is causing 'make' to skip some source-files (that it should not) or on the other other end, if it is causing make to always build some source-files regardless of dates of target, then above command is handy to find out what 'make' thinks of your date v/s target date-wise or what dependencies are in make's view-point. The egrep part removes the extra noise, that you might want to avoid.

move messages directly from one IMAP inbox to another
This one-liner was useful in helping someone I know to get off of MS Exchange. `mailutil` proved to be a much better alternative than `fetchmail` or `getmail` in this case. It quickly moved all mails to the destination server (a simple Dovecot/Maildir setup), with no need to convert back and forth between mbox/maildir on the user's own system.

AWK Calculator

Rename files in batch

Create a bash script from last commands
In order to write bash-scripts, I often do the task manually to see how it works. I type ### at the start of my session. The function fetches the commands from the last occurrence of '###', excluding the function call. You could prefix this with a here-document to have a proper script-header. Delete some lines, add a few variables and a loop, and you're ready to go. This function could probably be much shorter...

Remove a file whose name begins with a dash ( - ) character
Using the redundant ./ directory information prevents the dash from occurring at the beginning of the filename, and being interpreted as an option of the rm command. Also works using: $ rm -- -filename

parted - scripted partitioning (of all multipathed SAN LUNs)
`multipath -ll` requires Device Mapper multipath.conf configuration. And of course, replace "3PARdata,VV" with your disk array's SCSI vendor,LUN name. - GPT partition table allows you to create >2TB partitions

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