Running a Program on a Remote Server Using SSH

How do you run a program on a remote server using ssh?

For this example we'll have two servers, one named Johnny and another named Cash. Both are running openssh. Our goal is to have a program on Johnny login to Cash and run a program on Cash. To make the task a little more complex we'll be using different users on each machine.

The first thing we'll need to do is generate public and private keys on Johnny. So, logged into Johnny as user 'boy' we create public and private keys by creating them in the .ssh directory as follows:


Johnny$> pwd


/home/boy/.ssh


Johnny$> ssh-keygen -t rsa -f sue


Generating public/private rsa key pair.


Enter passphrase (empty for no passphrase):


Enter same passphrase again:


Your identification has been saved in sue.


Your public key has been saved in sue.pub.


The key fingerprint is:


8d:e9:c0:g1:c7:1f:e3:b3:2f:38:12:aa:b5:3b:2e:b3 boy@Johnny


Johnny$>

In the example above we picked an arbitrary name, sue, to identify the files that hold the generated keys. When prompted to enter a passphrase (twice) we simply hit enter twice.

As the output of ssh-keygen indicates, the public key has been saved in a file named sue.pub.

The output of ssh-keygen implies, but doesn't indicate directly, that the private key is in a file named sue (Yes, a user named boy created a file named sue.)


Johnny$>ls -l


-rwx------ 1 sue suegrp 887 Oct 17 14:27 sue


-rwx------ 1 sue suegrp 223 Oct 17 14:27 sue.pub

The private key file, sue, will remain on Johnny for the reaminder of this exercise, but the public key must be moved to the remote server, Cash. Note that the .ssh directory itself, as well as the sue and sue.pub files should have permissions of 700.

Now you'll need to ftp the sue.pub file from Johnny to Cash. The user on Cash that we'll login as is user 'named'.


Johnny$> ftp Cash


Connected to Cash


220 Cash - Propery of Xyz. - Authorized users only


Name (Cash:boy): named


331 Password required for named.


Password:


230-Last unsuccessful login: Fri Oct 17 13:12:55 2003 on ftp from Johnny 230-Last login: Fri Oct 17 16:02:11 2003 on /dev/pts/1 from Johnny


230 User named logged in.


ftp> cd .ssh


ftp> mput sue.pub


mput sue.pub? y


200 PORT command successful.


150 Opening data connection for sue.pub.


226 Transfer complete.


224 bytes sent in 0.000781 seconds (280.1 Kbytes/s)


local: sue.pub remote: sue.pub


ftp>bye


221 Goodbye.


Johnny$>

Now we'll telnet into Cash and concatenate the sue.pub file into /home/named/.ssh/authorized_keys file.


Cash$> pwd


/home/named/.ssh


Cash$> cat sue.pub >> authorized_keys


Cash$> exit


Connection closed.


Johnny$>

Let's recap what we've done so far.

1) We've created public and private keys on Johnny.

2) We've ftp'd the public key file, sue.pub, from Johnny to Cash.

3) We've telnetted to Cash, and concatenated the contents of sue.pub into authorized_keys

We're now ready to manually login from Johnny to Cash using ssh.


Johnny$> ssh -i /home/boy/.ssh/sue named@Cash


The authenticity of host 'Cash (xxx.yyy.zzz.aaa)' can't be established.


RSA key fingerprint is 65:11:7d:ef:ed:a3:cc:34:d1:b5:ba:c9:16:22:31:23.


Are you sure you want to continue connecting (yes/no)? yes


================================================================


*** NOTICE TO ALL USERS ***


================================================================


Cash$>exit< /p>


Connection to Cash closed.


Johnny$>

Now on Johnny, create a shell script called 'boynamedsue.sh' with the following one line of contents and chmod the script to 777.

ssh -i /home/boy/.ssh/sue named@Cash /usr/bin/ls -l

Next, execute the script on Johnny.


Johnny$> boynamedsue.sh


================================================================


*** NOTICE TO ALL USERS ***


================================================================


-rwxrwxr-x 1 named namedgrp 10020 Oct 17 14:35 namedfile1.txt


-rw-r--r-- 1 named namedgrp 680 Aug 14 16:18 namedfile.html


-rw------- 1 named namedgrp 1148 Aug 18 09:51 mbox


drwxr-xr-x 2 named namedgrp 512 Jun 17 13:38 old


Johnny$>

You just executed a program on Johnny, that logged into Cash and ran a program (unix 'ls -l').

The next step you'll want to take is to replace the '/usr/bin/ls -l' command in the boynamedsue.sh program with the path and name of the program that you want to run.

About The Author

C.S. Deam is a small business owner. His eBook Computer Nuggets: Non-Techie Internet Tips For In-Laws, Out-Laws, and the Rest of Society is a great gift for non-techie family members and is available at www.linkertonpublishing.com where you can sign up for FREE E-Courses & Newsletters to help you on your path to self-employment.

eco-friendly cleaning service Buffalo Grove ..
In The News:

A new phone return scam targets recent buyers with fake carrier calls. Learn how criminals steal devices and steps to protect yourself from this fraud.
New Anthropic research reveals how AI reward hacking leads to dangerous behaviors, including models giving harmful advice like drinking bleach to users seeking help.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Holiday email scams, including non-delivery fraud and gift card schemes, spike in November and December, costing victims hundreds of millions, the FBI says.
Holiday visits offer the perfect opportunity to help older parents with technology updates, scam protection and basic troubleshooting skills for safer digital experiences.
Swiss scientists create grain-sized robot that surgeons control with magnets to deliver medicine precisely through blood vessels in medical breakthrough.
Researchers exploited WhatsApp's API vulnerability to scrape 3.5 billion phone numbers. Learn how this massive data breach happened and protect yourself.
Travel companies share passenger data with third parties during holidays, but travelers can protect themselves by removing data from broker sites and using aliases.
Xpeng's humanoid robot moves so realistically that crowds believed it was fake, marking a major advancement in robotics technology ahead of 2026 commercial launch.
Researchers discover phishing scam using invisible characters to evade email security, with protection tips including password managers and two-factor authentication.
iPhone and Android users can reduce battery drain and data usage by restricting Background App Refresh to Wi-Fi connections instead of mobile networks.
Scammers nearly stole an Apple account by exploiting the support system with authentic-looking tickets and phone calls, users can protect themselves with safety steps.
FoloToy restored sales of its AI teddy bear Kumma after a weeklong suspension following safety group findings of risky and inappropriate responses to children.
Threat intelligence firm Synthient uncovers one of the largest password exposures ever, prompting immediate security recommendations.
Viral video shared by Elon Musk shows Tesla's Optimus humanoid robots performing tasks from cooking to construction, garnering over 58.5 million views on social media.
Chinese hackers used Anthropic's Claude AI to launch autonomous cyberattacks on 30 organizations worldwide, marking a major shift in cybersecurity threats.
Apple's new Sleep Score feature gives you a rating for your nightly rest quality. Learn how to set it up on your Apple Watch and iPhone today.
Essential phone settings to enable before losing your device, including Find My network, location services and security features for iPhone and Android.
The Fox News AI Newsletter gives readers the latest AI technology advancements, covering the challenges and opportunities AI presents.
Cybersecurity research shows weak passwords remain a major threat, with simple patterns and number sequences putting millions of accounts at risk.
New Android malware BankBot YNRK silences phones, steals banking data and drains crypto wallets automatically. Learn how this advanced threat works.
FDA approves first human trial for Paradromics' brain-computer interface that could restore speech for paralyzed patients through neural technology.
New phishing platform QRR targets Microsoft 365 users across 1,000 domains in 90 countries. Learn how to spot fake login pages and protect your accounts.
OpenTable now uses AI to track your dining habits and share insights with restaurants. Learn what data they collect and how to protect your privacy.
Google's discontinued Nest thermostats still secretly upload home data to company servers despite losing smart features, raising serious privacy concerns.

Microsoft CRM Customization ? Programming Closed Email Activity

Microsoft CRM is CRM answer from Microsoft and attempt to... Read More

The Top 5 Wrong Reasons For Not Hiring Testers

Considering whether or not your software company should hire a... Read More

Microsoft CRM Data Import FAQ

Microsoft CRM has built-in conversion tool, however you should probably... Read More

Microsoft Great Plains PM: Payables Management

Microsoft Business Solutions Great Plains is marketed for mid-size companies... Read More

Is Software Tester a Most Infamous Person in a Software Project Team?

The fact that a software tester is a most infamous... Read More

MicroWorld Releases New Version of MailScan Ver. 4.5 - Antivirus and Content Security Software

MicroWorld Technologies, Inc. the leading solutions provider in the area... Read More

SQL: Querying Microsoft Great Plains ? Overview for Database Administrator/Developer

Looks like Microsoft Great Plains becomes more... Read More

Software Review: Xsitepro Total Site Management Software

It's not very often I get excited about a software... Read More

Causes of ERP Failures

ERP is the acronym of Enterprise Resource Planning. Multi-module ERP... Read More

Adware and Spyware

What is 'adware'?Adware is basically software or scripts that are... Read More

Free Program Removes Spyware not Detected by Premium Security Scan

What is Spyware?Spyware monitors your surfing habits and sends the... Read More

Enterprise Resource Planning Overview

ERP (Enterprise Resource Planning) Overview covers What is ERP, Brief... Read More

Microsoft Great Plains eCommerce: overview for developer

Microsoft Business Solutions Great Plains was designed back in the... Read More

New Web-Based HR Tool is Max From NAS, Hannibal, and InfoLink

Three highly respected names in Human Resources have joined forces... Read More

Ukraine: a Prospective Player on the World Software Outsourcing Market

The destruction of the Soviet Union about 15 years ago,... Read More

Keep Your Software Simple! A Review of EditPlus

I like my software simple. If it's too complex or... Read More

What Stands Behind The Software Description?

With thousands of web pages added to the Net every... Read More

MCP Market News: Microsoft SQL Server & SQL Reporting Services

Are you ready? SQL Server 2005, the next-generation data management... Read More

Screenplay and Script Writing Software

When it comes to screenplay software each screenwriter needs to... Read More

Crystal Reports For Microsoft Navision - Overview For Programmer/IT Specialist

Let us give you - developer some hints in the... Read More

Intro to UNIX Shells

A UNIX Shell is in simplest terms, a command line... Read More

MSN Messenger Is A Sweet Way To Communicate

MSN messenger is a pretty cool invention. I mean I'm... Read More

Spyware - The Internet Devil Of Our Times!

Spyware and Adware infest over 90 percent of computers in... Read More

What is Preventive Maintenance Software?

Preventive Maintenance (PM) is defined as scheduled work done on... Read More

Microsoft Great Plains Logistics & Warehouse Management ? Implementation & Customization Highlights

Logistics automation is often considered as barcoding extension to Sales... Read More

express cleaning service Arlington Heights ..