Commands using printf (206)

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Show all detected mountable Drives/Partitions/BlockDevices
Yields entries in the form of "/dev/hda1" etc. Use this if you are on a new system and don't know how the storage hardware (ide, sata, scsi, usb - with ever changing descriptors) is connected and which partitions are available. Far better than using "fdisk -l" on guessed device descriptors.

backup system over ssh, exlucde common dirs

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"

Produce 10 copies of the same string

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"

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

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)

Video Google download
Download google video with wget. Or, if you wish, pass video URL to ie mplayer to view as stream. 1. VURL: replace with url. I.e. http://video.google.com/videoplay?docid=12312312312312313# 2. OUPUT_FILE : optionally change to a more suited name. This is the downloaded file. I.e. foo.flv # Improvements greatly appreciated. (close to my first linux command after ls -A :) ) Breakedown pipe by pipe: 1. wget: html from google, pass to stdout 2. grep: get the video url until thumbnailUrl (not needed) 3. grep: Strip off everything before http:// 4. sed: urldecode 5. echo: hex escapes 6. sed: stipr of tailing before thumbnailUrl 7. wget: download. Here one could use i.e. mplayer or other...

Change the From: address on the fly for email sent from the command-line
It's very common to have cron jobs that send emails as their output, but the From: address is whatever account the cron job is running under, which is often not the address you want replies to go to. Here's a way to change the From: address right on the command line. What's happening here is that the "--" separates the options to the mail client from options for the sendmail backend. So the -f and -F get passed through to sendmail and interpreted there. This works on even on a system where postfix is the active mailer - looks like postfix supports the same options. I think it's possible to customize the From: address using mutt as a command line mailer also, but most servers don't have mutt preinstalled.

Localize provenance of current established connections
Sample command to obtain a list of geographic localization for established connections, extracted from netstat. Need geoiplookup command ( part of geoip package under CentOS)


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