Visit Our UNIX and Linux User Community

A script to change password for all other servers

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting A script to change password for all other servers
# 1  
Old 02-21-2017
A script to change password for all other servers

Hey Gurus,

I have this requirement to change the password for other servers remotely from one server. So, I installed public keys on all servers and wrote the following script to do the job. Something appears to be wrong with my loop, as it only changes one server and ignores the rest. I'm testing the script with a test data file with about 5 servers in it. The data file is the command-line argument to the script. Can you please tell me what's wrong and how to fix it?

As always, I truly appreciate this community effort. You guys are truly awesome; thank you very much.
##data file name is passed in as argument to .sh script
while  read -r line
        ##newPassword and username are placeholders
        ssh $line 'echo -e "TestPW\nTestPW" | passwd SomeUser'
done < "$filename"

Last edited by vbe; 02-21-2017 at 04:03 PM.. Reason: code tags please
# 2  
Old 02-21-2017

I think that this behaviour is being caused by the use of a 'while read' loop to drive the 'ssh' command. The way input is read in and processed in this particular script may not actually be what you'd expect. Instead of it looping nicely around, the entirety of your arguments end up being passed to 'ssh' in one glob, and it's just doing the first one.

Maybe try a 'for' loop instead ? So something like:

##data file name is passed in as argument to .sh script
for server in `cat $1`
        ##newPassword and username are placeholders
        ssh $server 'echo -e "TestPW\nTestPW" | passwd SomeUser'

See if that works, and let us know how you get on.
This User Gave Thanks to drysdalk For This Post:
# 3  
Old 02-21-2017
maybe -n option for ssh is missing as its a script... Otherwise ssh is tempted to read StdIN which here is void...
This User Gave Thanks to vbe For This Post:
# 4  
Old 02-21-2017
@drysdalk, I copied and pasted your version, it just hangs, I never get the prompt back.

@vbe, it does work just the way it is, but it only processes one server and not all in the list.

Thanks guys.
# 5  
Old 02-21-2017


Just checking, but are you running it with the filename as an argument ? e.g. ./ serverlist.txt or something like that ? The script takes the first argument ($1) as the filename to be read and processed.

I ask becasue if you were just running ./ on its own will never return a prompt, which is what you describe. In that usage case it would be sitting waiting for you to type in the input yourself, and would only proceed with execution after you did a Ctrl-D or otherwise indicated the end of input.

It's also possible of course that the issue is with the ssh or passwd parts of the script now as well. You may need different flags to passwd, something like passwd --stdin on a Red Hat-style system.
This User Gave Thanks to drysdalk For This Post:
# 6  
Old 02-21-2017
Yeah, I'm running it exactly like that,

root@testserver1# ./ pwchange.dat

and my pwchange.dat is formatted as follows:


With the while loop, it did read the pwchange.dat file, but it only changed the password for one server. And I got the prompt back.
With the for loop, ctrl-D does nothing, but ctrl-C breaks out of the script and give me the prompt back w/o doing anything.

Also, my environment is a mix of Solaris 10 and Linux (RHEL & SUSE). My script with the while loop does change one password, it changes either Solaris or Linux server. So, looks like the ssh & passwd commands are both OK.

Last edited by rbatte1; 02-22-2017 at 07:55 AM.. Reason: Added CODE tags
# 7  
Old 02-21-2017
So you havent tried ssh -n ... as I said ssh will read the first line but then it will expect things to coem from standard input unless you specify -n option

Previous Thread | Next Thread
Test Your Knowledge in Computers #917
Difficulty: Easy
Unix time is also known as Epoch time.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Shell script to set user password to never expire in UNIX servers

Hi, I have a requirement where in i need to write a shell script to set users password to never expire. I know the command which is used to perform the same .. which is chage command. But, could not figure out how to do the same in shell script. Could you please help me with the shell... (3 Replies)
Discussion started by: suren424
3 Replies

2. AIX

How to write a script to run without password on a batch of servers?

I need run a command such as ps -ef |grep xxx on a batch of servers, how to write a script to run it without password? don't need go in each server to check? Thanks (7 Replies)
Discussion started by: rainbow_bean
7 Replies

3. Shell Programming and Scripting

Script for login to servers with user name and password and execute commands

I am having the 15 servers which need to do the monitoring Hi I need a shell script, By which i can log in to multiple servers and execute the commands.. I need to specify the username and password in the scripts. Please help me to write the script so that it can login with username and... (5 Replies)
Discussion started by: nandan8a
5 Replies

4. Shell Programming and Scripting

Shell script to change the password on multiple servers in linux

Can any one please let me know the shell script to change the password for a particular user on multiple linux servers. (2 Replies)
Discussion started by: s_madras
2 Replies

5. Solaris

Change passwd for bulk servers using SSH script

Hi, I need to Change passwd for bulk servers using SSH script. I have one server, from which i can reach all the servers without password via SSH. There is some expect script, from which i can achieve it. Can any one help me out here. Thanks in advance. Vicky (1 Reply)
Discussion started by: vickyingle5
1 Replies

6. Shell Programming and Scripting

Script:Change password on 1000+ servers

Hello Folks Scenario : I have a linux box (expect tool installed) which connects to 1000+ other boxes (either Solaris or AIX or Linux ) with a specific id and password using SSH. I now wish to write a script (Shell and/or expect and/or Python) which will change this existing password to a... (1 Reply)
Discussion started by: ak835
1 Replies

7. Red Hat

Change password of linux servers remotely

Hi, I am very bad at scripting. I need help from scripting experts... I need to change password of around 100 linux remote servers. I have been given a script for changing the password that automates the task. however I do not understand the usage and meaning of the script, the script is an... (0 Replies)
Discussion started by: renuka
0 Replies

8. Shell Programming and Scripting

how to change root password using shell script with standard password

Hi Friends. I am new to scripting now i want to change the root password using the script with standard password. which is the easy scripting to learn for the beginner, Thanks in advance. (2 Replies)
Discussion started by: kurva
2 Replies

9. Shell Programming and Scripting

script to change passwords for the same user on multiple servers

I am trying to write a script to change passwords for the same user on multiple servers. My environment runs purely ssh / scp not rsh / rcp and therefore coping using rcp is not an option. I have been playing with expect to perform tasks but think there must be a better way. Has anyone got... (7 Replies)
Discussion started by: stolz
7 Replies

10. Shell Programming and Scripting

How to script to logon servers using id and password

Hey.. I am new in scripting.. I know a little bit of scripting.. I am facing some problem.. I need to create a script using which I may log on to a server (e.g. ftp) with ID and password.. thus copy a particular file to a local dir.. the commands required to do that I do know.. I am able to do it... (1 Reply)
Discussion started by: razeeev
1 Replies

Featured Tech Videos