04-22-2020
man bash is your friend:
Quote:
Here Documents
This type of redirection instructs the shell to read input from the current source until a line containing only delimiter (with no trailing blanks)
is seen. All of the lines read up to that point are then used as the standard input (or file descriptor n if n is specified) for a command.
The format of here-documents is:
[n]<<[-]word
here-document
delimiter
No parameter and variable expansion, command substitution, arithmetic expansion, or pathname expansion is performed on word. If any part of word is quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion, the character sequence \<newline> is ignored, and \ must be used to quote the characters \, $, and `.
You are in a dilemma here: you want the
IP variable expanded locally, but the other variables expanded remotely. For the first, you can't have the "word" quoted, but it must be unquoted, so, for the second, you need to apply the escapes for the
$ signs.
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
I am trying to search and remove files from a list of servers. I want to find every occurence of this file on each machine and then remove it. If I execute the find command on the remote machine I would like to be able to pipe the output to xargs and remove the file. Does anyone know hat would be... (1 Reply)
Discussion started by: sewood
1 Replies
2. Shell Programming and Scripting
Hi All,
i have two machines like x and y . my requirement is i should connect to machine Y from x through ssh connection . and do some operation such as copy and move and delete files in Y machine .
i tried with this code but it is doing in machine x only . and i need to exit from Y when... (1 Reply)
Discussion started by: rateeshkumar
1 Replies
3. Shell Programming and Scripting
Hello to all
Background info:
Local machine : Linux, /bin/bash
Remote machine (for the user used for ssh) : SunOs, /bin/ksh
(so we have different OS, different Shells)
My problem :
From the local host i execute
$ var=bla
$ result=$(ssh -q user@remote-machine "
> echo \"this is... (12 Replies)
Discussion started by: black_fender
12 Replies
4. UNIX for Dummies Questions & Answers
how to use ssh to run shell script on a remote machine?
ssh user@remote sh ./script.unx
i ran the above command
./script.unx HAS NOHUP COMMAND IN ITS BODY, I AM GETTING ERROR AS NOHUP NOT FOUND...
i tried to run that script from remote server, its working fine
do ineed to set... (6 Replies)
Discussion started by: only4satish
6 Replies
5. Shell Programming and Scripting
Hello,
I am running into few issues, please suggest me what I am missing.
I am running this script on a linux host.
Main idea of this script is to, login to each host via ssh and get uid of user, service user that I trying to run this script, has already deployed ssh keys and provide sudo... (8 Replies)
Discussion started by: bobby320
8 Replies
6. Shell Programming and Scripting
Hi,
I'm trying to automate a couple of mounts. (I would do this in fstab, but the auto feature causes the virtual machine I'm running in to freeze when it boots up) If the machine I'm trying to connect to is OFF, I get the host unreachable error and then the bash script stops. The problem is... (3 Replies)
Discussion started by: jdilts
3 Replies
7. Red Hat
I want to SSH to 192.168.1.15 Server from my machine, my ip was 192.168.1.99
Source Destination was UP, with IP 192.168.1.15.
This is LAN Network there are 30 Machine's Connected to the network and working fine, I'm Playing around the local machine's because I need to apply the same rules in... (2 Replies)
Discussion started by: babinlonston
2 Replies
8. Linux
How to execute a script in remote machine through ssh
I have a script test.sh which does some backup activity in remote machine. Wanted to keep backup also in remote machine.
ssh -l username <remote machine> "commands to be exceuted as ; separted"
but how to put the script in the place of... (5 Replies)
Discussion started by: sanvel
5 Replies
9. Shell Programming and Scripting
Geeks,
Could you please help me out in my script and identify the missing piece. I need to check/get the exit status of a remote command executed on remote host through script and send out an email when process/processes is/are not running on any/all server(s).
Here's the complete... (5 Replies)
Discussion started by: lovesaikrishna
5 Replies
10. Shell Programming and Scripting
Hi,
My goal is to connect from unix server A to windows server B and call a bat file on windows.
I am able to succeed in remoting to windows and executing a command, the issue i am facing is the shell scrip is exiting without making sure of bat file success.
Can you please help me in... (4 Replies)
Discussion started by: pxp018
4 Replies
LEARN ABOUT MOJAVE
ssh-copy-id
SSH-COPY-ID(1) BSD General Commands Manual SSH-COPY-ID(1)
NAME
ssh-copy-id -- use locally available keys to authorise logins on a remote machine
SYNOPSIS
ssh-copy-id [-f] [-n] [-i [identity_file]] [-p port] [-o ssh_option] [user@]hostname
ssh-copy-id -h | -?
DESCRIPTION
ssh-copy-id is a script that uses ssh(1) to log into a remote machine (presumably using a login password, so password authentication should
be enabled, unless you've done some clever use of multiple identities). It assembles a list of one or more fingerprints (as described below)
and tries to log in with each key, to see if any of them are already installed (of course, if you are not using ssh-agent(1) this may result
in you being repeatedly prompted for pass-phrases). It then assembles a list of those that failed to log in, and using ssh, enables logins
with those keys on the remote server. By default it adds the keys by appending them to the remote user's ~/.ssh/authorized_keys (creating
the file, and directory, if necessary). It is also capable of detecting if the remote system is a NetScreen, and using its 'set ssh pka-dsa
key ...' command instead.
The options are as follows:
-i identity_file
Use only the key(s) contained in identity_file (rather than looking for identities via ssh-add(1) or in the default_ID_file). If the
filename does not end in .pub this is added. If the filename is omitted, the default_ID_file is used.
Note that this can be used to ensure that the keys copied have the comment one prefers and/or extra options applied, by ensuring that
the key file has these set as preferred before the copy is attempted.
-f Forced mode: doesn't check if the keys are present on the remote server. This means that it does not need the private key. Of
course, this can result in more than one copy of the key being installed on the remote system.
-n do a dry-run. Instead of installing keys on the remote system simply prints the key(s) that would have been installed.
-h, -? Print Usage summary
-p port, -o ssh_option
These two options are simply passed through untouched, along with their argument, to allow one to set the port or other ssh(1)
options, respectively.
Rather than specifying these as command line options, it is often better to use (per-host) settings in ssh(1)'s configuration file:
ssh_config(5).
Default behaviour without -i, is to check if 'ssh-add -L' provides any output, and if so those keys are used. Note that this results in the
comment on the key being the filename that was given to ssh-add(1) when the key was loaded into your ssh-agent(1) rather than the comment
contained in that file, which is a bit of a shame. Otherwise, if ssh-add(1) provides no keys contents of the default_ID_file will be used.
The default_ID_file is the most recent file that matches: ~/.ssh/id*.pub, (excluding those that match ~/.ssh/*-cert.pub) so if you create a
key that is not the one you want ssh-copy-id to use, just use touch(1) on your preferred key's .pub file to reinstate it as the most recent.
EXAMPLES
If you have already installed keys from one system on a lot of remote hosts, and you then create a new key, on a new client machine, say, it
can be difficult to keep track of which systems on which you've installed the new key. One way of dealing with this is to load both the new
key and old key(s) into your ssh-agent(1). Load the new key first, without the -c option, then load one or more old keys into the agent,
possibly by ssh-ing to the client machine that has that old key, using the -A option to allow agent forwarding:
user@newclient$ ssh-add
user@newclient$ ssh -A old.client
user@oldl$ ssh-add -c
... prompt for pass-phrase ...
user@old$ logoff
user@newclient$ ssh someserver
now, if the new key is installed on the server, you'll be allowed in unprompted, whereas if you only have the old key(s) enabled, you'll be
asked for confirmation, which is your cue to log back out and run
user@newclient$ ssh-copy-id -i someserver
The reason you might want to specify the -i option in this case is to ensure that the comment on the installed key is the one from the .pub
file, rather than just the filename that was loaded into you agent. It also ensures that only the id you intended is installed, rather than
all the keys that you have in your ssh-agent(1). Of course, you can specify another id, or use the contents of the ssh-agent(1) as you pre-
fer.
Having mentioned ssh-add(1)'s -c option, you might consider using this whenever using agent forwarding to avoid your key being hijacked, but
it is much better to instead use ssh(1)'s ProxyCommand and -W option, to bounce through remote servers while always doing direct end-to-end
authentication. This way the middle hop(s) don't get access to your ssh-agent(1). A web search for 'ssh proxycommand nc' should prove
enlightening (N.B. the modern approach is to use the -W option, rather than nc(1)).
SEE ALSO
ssh(1), ssh-agent(1), sshd(8)
BSD
June 17, 2010 BSD