|Home||Switchboard||Unix Administration||Red Hat||TCP/IP Networks||Neoliberalism||Toxic Managers|
May the source be with you, but remember the KISS principle ;-)
Bigger doesn't imply better. Bigger often is a sign of obesity, of lost control, of overcomplexity, of cancerous cells
|News||SSH||Recommended Links||Private and Public key managemen||Mini-tutorial||FAQs|
While any command executed by ssh is executed "on the other side of the pond" at remote server, the output is channeled to the host on which ssh command is entered. That creates very interesting opportunities
First a very simple example
ssh email@example.com 'tail -100 /var/log/messages' | egrep 'Terminal|Serious|Aborted'
ssh firstname.lastname@example.org "cat /var/log/messages" | grep 'su\['
Even more interesting possibilities exist if you analyze proxy logs or logs of the Apache webserver.
Of course all those examples require to provide password for the server. To avoid it you can use password-less SSH login
If we put this command in a loop so that it executed for each server we manage we will get a simple monitoring system that can help us to detect abnormal situation.
But the most interesting trick with using ssh in pipes is so called "ssh tar pipe". Like r-tools ssh supports cross computer pipes:
tar cvzf - . | rsh xxx.xxx.xxx.xxx "( cd $dir; tar xzf - )"or
tar cvzf - . | ssh xxx.xxx.xxx.xxx "( cd $dir; tar xzf - )"
This is also possible to do the same in the reverse direction
ssh xxx.xxx.xxx.xxx "( cd $dir; tar cvzf - )" | tar xzf -The same idea can be implemented using cpio instead of pipe. In this case you can transfer hard links, which is a problem for tar.
June 15, 2007 | Spikelab
Command Compression Fileset Time scp No Small 0:01:53 scp No Large 0:10:10 scp Yes Small 0:02:46 scp Yes Large 0:14:11 tar | ssh No Small 0:00:24 tar | ssh No Large 0:03:18 tar | ssh Yes ssh Small 0:01:09 tar | ssh Yes ssh Large 0:11:33 tar | ssh Yes tar gz Small 0:00:18 tar | ssh Yes tar gz Large 0:01:57 tar | nc No Small 0:00:21 tar | nc No Large 0:03:24 tar | nc Yes tar gz Small 0:00:20 tar | nc Yes tar gz Large 0:01:16
Copying files (keeping permissions with tar)
ssh remote_host "tar -cf - -C srcdir ." | tar xpf - -C destdir
Backing up/compressing mysql db.
mysqldump | bzip2 | ssh remotehost backup.sh -
Or how about this one from freesbsd handbook, remote backups using dump.
/sbin/dump -0uan -f - /usr | gzip -2 | ssh \
email@example.com dd of=/mybigfiles/dump-usr-l0.gz
You could also copy/restore a partition this way through ssh.
ssh -NLf localport:remotehost:remoteport remotehost
ssh is an indispensable unix tool: remote cvs, rsync, remote X forwarding,
scp, sftp just to name a few, can't live without ssh :)
On Fri, Jul 19, 2002 at 11:40:48AM -0700, tedu wrote:
> Generically, here's my question. I'd like to know how to set up some pipe between two networked computers sent via ssh channel. Such that
> host1$ echo hi > ssh_pipe_file
> host2$ cat ssh_pipe_file
> would happen.
> Specifically, I'm trying to transfer audio data from a host with a player
> to a host with a sound card. Maybe there's a simpler way to do just this?
I have used nc(1) (netcat) to do that exact job. It would be easy to
set up ssh to forward a port and then use netcat to pipe the data over
the encrypted pipe.
> Hi, > > I am relatively new to ssh and I'd like to know if it is possible to do > the following: > > I want to force the VNC server to only accept connection thru an ssh > secure pipe. [chop] > The right-hand side of the drawing I have sorted out. The server side is > still a mystery. How do I convince VNC to only use and ssh pipe and > refuse connection from any other tcp port? I think you can say "vnc -localhost" so that it only accepts connection from the local host, if the ssh pipe ends at the same machine as the one where the ssh pipe ends. Of course, VNC will still accept unenctypted connections from the localhost, but not from remote hosts. Incompetence disclaimer: I haven't tried, and I don't know much about the gearworks of TCP and tunneling. So I don't know whether my logic is sound, and whether it'll actuelly work.
Google matched content
Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers : Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism : The Iron Law of Oligarchy : Libertarian Philosophy
War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda : SE quotes : Language Design and Programming Quotes : Random IT-related quotes : Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce : Bernard Shaw : Mark Twain Quotes
Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 : Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law
Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds : Larry Wall : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS : Programming Languages History : PL/1 : Simula 67 : C : History of GCC development : Scripting Languages : Perl history : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history
The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month : How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite
Most popular humor pages:
Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor
The Last but not Least
Copyright © 1996-2018 by Dr. Nikolai Bezroukov. www.softpanorama.org was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) in the author free time and without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.
This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...
|You can use PayPal to make a contribution, supporting development of this site and speed up access. In case softpanorama.org is down you can use the at softpanorama.info|
The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the author present and former employers, SDNP or any other organization the author may be associated with. We do not warrant the correctness of the information provided or its fitness for any purpose.
Last modified: September 12, 2017