Bash eval inside quotes - bash

I have a bash script which takes one parameter and does something like this:
ssh -t someserver "setenv DISPLAY $1; /usr/bin/someprogram"
How can I force bash to substitute in the $1 instead of passing the literal characters "$1" as the display variable?

Based on your comment on sehe's answer, it sounds like you just want the remote command to use the local X display — so that the program is running on your remote server (someserver) but being displayed on the machine you ran the ssh command on.
This can be done by just passing -X, e.g.
ssh -X someserver /usr/bin/someprogram
For some reason, this doesn't work with a few programs, for example evince. I'm not really sure why. I'm pretty sure that evince is the only app I've had trouble forwarding back over an SSH connection.
If this isn't what you're aiming to do, please explain.

Edit Are you aware of
ssh -X ...
ssh -Y ...
which already support X forwarding out of the box? Also look at
xhost +
in case you need to increase permissions to 'guests'.
If you want to forward non-standard X display address, you could always use
DISPLAY=localhost:3 ssh -XCt user#remote xterm
Bonus: to make ssh background after authentication, add '-f'
What locally? That should already work as shown. Remotely? escape the $: \$
However, I'm not sure where the command would be taking it's arguments ($1) from

Related

Here document is cutting off commands

I'm trying to connect to my server via SSH and issue some commands to it. For some reason it seems like the commands are getting cut "off".
Here is the code that does the putty connection as well as issuing the SSH commands:
./plink.exe ${USER}#${HOSTNAME} -pw ${PASS}<<SSH
cd /some/foo/bar
deploy_artifact.sh --instance development1 some_artifact.ear
APP_development1.sh restart
exit
SSH
For me it works, but on the machine of my colleague the issued SSH commands are getting cut off and thus are not interpreted correctly. For example deploy_artifact.sh is getting turned into ploy_artifact.sh (See the following the screenshot).
How can i prevent this? And what is causing this?
Thanks in advance for any help!
It appears the problem is with the plink and how it is used. The given example sends commands as a standard input, however I did not find in the plink manual any mention that it reads commands from the STDIN. It is better to avoid undocumented features, since they may not work correctly or the author may remove them without any notice. Instead, if you want to pass commands inline you should provide them as an argument, ie you either have to use a quoted text, or you can wrap heredoc in the "$(cat *heredoc* )" code, eg:
./plink.exe ${USER}#${HOSTNAME} -pw ${PASS} "$(cat <<SSH
cd /some/foo/bar
deploy_artifact.sh --instance development1 some_artifact.ear
APP_development1.sh restart
exit
SSH
)"
Or, you can keep the commands in a file and run the plink with the -m commands_file option.

Pass bash variable when sshing

I'm having some issues with multiple people running an application that requires port forwarding. I'd like to generate a random port number, ssh to the application server while passing that random number, and sed replace the default port with this one in a few different scripts.
So is there any way I can pass a bash variable through ssh or alternatively is there a better way to accomplish this?
If you know what you want to do with your variable, you can pass it to the remote host and run the commands on the same line:
ssh name#host "sed -i -e \"s/$myrandnumber/22/g\" file1 file2 file3"
$myvar will expand before the sshing happens, meaning it will be the value you set on the original machine, not the remote. You can make it a variable on the remote machine:
ssh name#host "export remotevar=$myrandnumber; bash -i"
But it'll only be available to the current session. If you just want the variable stored for some future date, then your best bet is writing to a file that will get sourced later, i.e.,
ssh name#host "echo \"myvar=$myrandnumber\" >> /etc/environment"

How can I ssh directly to a particular directory?

I often have to login to one of several servers and go to one of several directories on those machines. Currently I do something of this sort:
localhost ~]$ ssh somehost
Welcome to somehost!
somehost ~]$ cd /some/directory/somewhere/named/Foo
somehost Foo]$
I have scripts that can determine which host and which directory I need to get into but I cannot figure out a way to do this:
localhost ~]$ go_to_dir Foo
Welcome to somehost!
somehost Foo]$
Is there an easy, clever or any way to do this?
You can do the following:
ssh -t xxx.xxx.xxx.xxx "cd /directory_wanted ; bash --login"
This way, you will get a login shell right on the directory_wanted.
Explanation
-t Force pseudo-terminal allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services.
Multiple -t options force tty allocation, even if ssh has no local tty.
If you don't use -t then no prompt will appear.
If you don't add ; bash then the connection will get closed and return control to your local machine
If you don't add bash --login then it will not use your configs because its not a login shell
You could add
cd /some/directory/somewhere/named/Foo
to your .bashrc file (or .profile or whatever you call it) at the other host. That way, no matter what you do or where you ssh from, whenever you log onto that server, it will cd to the proper directory for you, and all you have to do is use ssh like normal.
Of curse, rogeriopvl's solution works too, but it's a tad bit more verbose, and you have to remember to do it every time (unless you make an alias) so it seems a bit less "fun".
My preferred approach is using the SSH config file (described below), but there are a few possible solutions depending on your usages.
Command Line Arguments
I think the best answer for this approach is christianbundy's reply to the accepted answer:
ssh -t example.com "cd /foo/bar; exec \$SHELL -l"
Using double quotes will allow you to use variables from your local machine, unless they are escaped (as $SHELL is here). Alternatively, you can use single quotes, and all of the variables you use will be the ones from the target machine:
ssh -t example.com 'cd /foo/bar; exec $SHELL -l'
Bash Function
You can simplify the command by wrapping it in a bash function. Let's say you just want to type this:
sshcd example.com /foo/bar
You can make this work by adding this to your ~/.bashrc:
sshcd () { ssh -t "$1" "cd \"$2\"; exec \$SHELL -l"; }
If you are using a variable that exists on the remote machine for the directory, be sure to escape it or put it in single quotes. For example, this will cd to the directory that is stored in the JBOSS_HOME variable on the remote machine:
sshcd example.com \$JBOSS_HOME
SSH Config File
If you'd like to see this behavior all the time for specific (or any) hosts with the normal ssh command without having to use extra command line arguments, you can set the RequestTTY and RemoteCommand options in your ssh config file.
For example, I'd like to type only this command:
ssh qaapps18
but want it to always behave like this command:
ssh -t qaapps18 'cd $JBOSS_HOME; exec $SHELL'
So I added this to my ~/.ssh/config file:
Host *apps*
RequestTTY yes
RemoteCommand cd $JBOSS_HOME; exec $SHELL
Now this rule applies to any host with "apps" in its hostname.
For more information, see http://man7.org/linux/man-pages/man5/ssh_config.5.html
I've created a tool to SSH and CD into a server consecutively – aptly named sshcd. For the example you've given, you'd simply use:
sshcd somehost:/some/directory/somewhere/named/Foo
Let me know if you have any questions or problems!
Based on additions to #rogeriopvl's answer, I suggest the following:
ssh -t xxx.xxx.xxx.xxx "cd /directory_wanted && bash"
Chaining commands by && will make the next command run only when the previous one was successful (as opposed to using ;, which executes commands sequentially). This is particularly useful when needing to cd to a directory performing the command.
Imagine doing the following:
/home/me$ cd /usr/share/teminal; rm -R *
The directory teminal doesn't exist, which causes you to stay in the home directory and remove all the files in there with the following command.
If you use &&:
/home/me$ cd /usr/share/teminal && rm -R *
The command will fail after not finding the directory.
In my very specific case, I just wanted to execute a command in a remote host, inside a specific directory from a Jenkins slave machine:
ssh myuser#mydomain
cd /home/myuser/somedir
./commandThatMustBeRunInside_somedir
exit
But my machine couldn't perform the ssh (it couldn't allocate a pseudo-tty I suppose) and kept me giving the following error:
Pseudo-terminal will not be allocated because stdin is not a terminal
I could get around this issue passing "cd to dir + my command" as a parameter of the ssh command (to not have to allocate a Pseudo-terminal) and by passing the option -T to explicitly tell to the ssh command that I didn't need pseudo-terminal allocation.
ssh -T myuser#mydomain "cd /home/myuser/somedir; ./commandThatMustBeRunInside_somedir"
I use the environment variable CDPATH
going one step further with the -t idea. I keep a set of scripts calling the one below to go to specific places in my frequently visited hosts. I keep them all in ~/bin and keep that directory in my path.
#!/bin/bash
# does ssh session switching to particular directory
# $1, hostname from config file
# $2, directory to move to after login
# can save this as say 'con' then
# make another script calling this one, e.g.
# con myhost repos/i2c
ssh -t $1 "cd $2; exec \$SHELL --login"
My answer may differ from what you really want, but I write here as may be useful for some people. In my solution you have to enter into the directory once and then every new ssh session goes to the same dir (after the first logout).
How to ssh to the same directory you have been in your last login.
(I assume you use bash on the remote node.)
Add this line to your ~/.bash_logout on the remote node(!):
echo $PWD > ~/.bash_lastpwd
and these lines to the ~/.bashrc file (still on the remote node!)
if [ -f ~/.bash_lastpwd ]; then
cd $(cat ~/.bash_lastpwd)
fi
This way you save your current path on every logout and .bashrc put you into that directory after login.
ps: You can tweak it further like using the SSH_CLIENT variable to decide to go into that directory or not, so you can differentiate between local logins and ssh or even between different ssh clients.
Another way of going to directly after logging in is create "Alias". When you login into your system just type that alias and you will be in that directory.
Example : Alias = myfolder '/var/www/Folder'
After you log in to your system type that alias (this works from any part of the system)
this command if not in bashrc will work for current session. So you can also add this alias to bashrc to use that in future
$ myfolder => takes you to that folder
I know this has been answered ages ago but I found the question while trying to incorporate an ssh login in a bash script and once logged in run a few commands and log back out and continue with the bash script. The simplest way I found which hasnt been mentioned elsewhere because it is so trivial is to do this.
#!/bin/bash
sshpass -p "password" ssh user#server 'cd /path/to/dir;somecommand;someothercommand;exit;'
Connect With User
In case if you don't know this, you can use this to connect by specifying both user and host
ssh -t <user>#<Host domain / IP> "cd /path/to/directory; bash --login"
Example: ssh -t admin#test.com "cd public_html; bash --login"
You can also append the commands to be executed on every login by appending it in the double quotes with a ; before each command
Unfortunately, the suggested solution (of #rogeriopvl) doesn't work when you use multiple hops, so I found another one.
On remote machine add into ~/.bashrc the following:
[ "x$CDTO" != "x" ] && cd $CDTO
This allows you to specify the desired target directory on command line in this way:
ssh -t host1 ssh -t host2 "CDTO=/desired_directory exec bash --login"
Sure, this way can be used for a single hop too.
This solution can be combined with the usefull tip of #redseven for greater flexibilty (if no $CDTO, go to saved directory, if exists).
SSH itself provides a means of communication, it does not know anything about directories. Since you can specify which remote command to execute (this is - by default - your shell), I'd start there.
simply modify your home with the command:
usermod -d /newhome username

How can I automate running commands remotely over SSH to multiple servers in parallel?

I've searched around a bit for similar questions, but other than running one command or perhaps a few command with items such as:
ssh user#host -t sudo su -
However, what if I essentially need to run a script on (let's say) 15 servers at once. Is this doable in bash? In a perfect world I need to avoid installing applications if at all possible to pull this off. For argument's sake, let's just say that I need to do the following across 10 hosts:
Deploy a new Tomcat container
Deploy an application in the container, and configure it
Configure an Apache vhost
Reload Apache
I have a script that does all of that, but it relies on me logging into all the servers, pulling a script down from a repo, and then running it. If this isn't doable in bash, what alternatives do you suggest? Do I need a bigger hammer, such as Perl (Python might be preferred since I can guarantee Python is on all boxes in a RHEL environment thanks to yum/up2date)? If anyone can point to me to any useful information it'd be greatly appreciated, especially if it's doable in bash. I'll settle for Perl or Python, but I just don't know those as well (working on that). Thanks!
You can run a local script as shown by che and Yang, and/or you can use a Here document:
ssh root#server /bin/sh <<\EOF
wget http://server/warfile # Could use NFS here
cp app.war /location
command 1
command 2
/etc/init.d/httpd restart
EOF
Often, I'll just use the original Tcl version of Expect. You only need to have that on the local machine. If I'm inside a program using Perl, I do this with Net::SSH::Expect. Other languages have similar "expect" tools.
The issue of how to run commands on many servers at once came up on a Perl mailing list the other day and I'll give the same recommendation I gave there, which is to use gsh:
http://outflux.net/unix/software/gsh
gsh is similar to the "for box in box1_name box2_name box3_name" solution already given but I find gsh to be more convenient. You set up a /etc/ghosts file containing your servers in groups such as web, db, RHEL4, x86_64, or whatever (man ghosts) then you use that group when you call gsh.
[pdurbin#beamish ~]$ gsh web "cat /etc/redhat-release; uname -r"
www-2.foo.com: Red Hat Enterprise Linux AS release 4 (Nahant Update 7)
www-2.foo.com: 2.6.9-78.0.1.ELsmp
www-3.foo.com: Red Hat Enterprise Linux AS release 4 (Nahant Update 7)
www-3.foo.com: 2.6.9-78.0.1.ELsmp
www-4.foo.com: Red Hat Enterprise Linux Server release 5.2 (Tikanga)
www-4.foo.com: 2.6.18-92.1.13.el5
www-5.foo.com: Red Hat Enterprise Linux Server release 5.2 (Tikanga)
www-5.foo.com: 2.6.18-92.1.13.el5
[pdurbin#beamish ~]$
You can also combine or split ghost groups, using web+db or web-RHEL4, for example.
I'll also mention that while I have never used shmux, its website contains a list of software (including gsh) that lets you run commands on many servers at once. Capistrano has already been mentioned and (from what I understand) could be on that list as well.
Take a look at Expect (man expect)
I've accomplished similar tasks in the past using Expect.
You can pipe the local script to the remote server and execute it with one command:
ssh -t user#host 'sh' < path_to_script
This can be further automated by using public key authentication and wrapping with scripts to perform parallel execution.
You can try paramiko. It's a pure-python ssh client. You can program your ssh sessions. Nothing to install on remote machines.
See this great article on how to use it.
To give you the structure, without actual code.
Use scp to copy your install/setup script to the target box.
Use ssh to invoke your script on the remote box.
pssh may be interesting since, unlike most solutions mentioned here, the commands are run in parallel.
(For my own use, I wrote a simpler small script very similar to GavinCattell's one, it is documented here - in french).
Have you looked at things like Puppet or Cfengine. They can do what you want and probably much more.
For those that stumble across this question, I'll include an answer that uses Fabric, which solves exactly the problem described above: Running arbitrary commands on multiple hosts over ssh.
Once fabric is installed, you'd create a fabfile.py, and implement tasks that can be run on your remote hosts. For example, a task to Reload Apache might look like this:
from fabric.api import env, run
env.hosts = ['host1#example.com', 'host2#example.com']
def reload():
""" Reload Apache """
run("sudo /etc/init.d/apache2 reload")
Then, on your local machine, run fab reload and the sudo /etc/init.d/apache2 reload command would get run on all the hosts specified in env.hosts.
You can do it the same way you did before, just script it instead of doing it manually. The following code remotes to machine named 'loca' and runs two commands there. What you need to do is simply insert commands you want to run there.
che#ovecka ~ $ ssh loca 'uname -a; echo something_else'
Linux loca 2.6.25.9 #1 (blahblahblah)
something_else
Then, to iterate through all the machines, do something like:
for box in box1_name box2_name box3_name
do
ssh $box 'commmands_to_run_everywhere'
done
In order to make this ssh thing work without entering passwords all the time, you'll need to set up key authentication. You can read about it at IBM developerworks.
You can run the same command on several servers at once with a tool like cluster ssh. The link is to a discussion of cluster ssh on the Debian package of the day blog.
Well, for step 1 and 2 isn't there a tomcat manager web interface; you could script that with curl or zsh with the libwww plug in.
For SSH you're looking to:
1) not get prompted for a password (use keys)
2) pass the command(s) on SSH's commandline, this is similar to rsh in a trusted network.
Other posts have shown you what to do, and I'd probably use sh too but I'd be tempted to use perl like ssh tomcatuser#server perl -e 'do-everything-on-one-line;' or you could do this:
either scp the_package.tbz tomcatuser#server:the_place/.
ssh tomcatuser#server /bin/sh <<\EOF
define stuff like TOMCAT_WEBAPPS=/usr/local/share/tomcat/webapps
tar xj the_package.tbz or rsync rsync://repository/the_package_place
mv $TOMCAT_WEBAPPS/old_war $TOMCAT_WEBAPPS/old_war.old
mv $THE_PLACE/new_war $TOMCAT_WEBAPPS/new_war
touch $TOMCAT_WEBAPPS/new_war [you don't normally have to restart tomcat]
mv $THE_PLACE/vhost_file $APACHE_VHOST_DIR/vhost_file
$APACHECTL restart [might need to login as apache user to move that file and restart]
EOF
You want DSH or distributed shell, which is used in clusters a lot. Here is the link: dsh
You basically have node groups (a file with lists of nodes in them) and you specify which node group you wish to run commands on then you would use dsh, like you would ssh to run commands on them.
dsh -a /path/to/some/command/or/script
It will run the command on all the machines at the same time and return the output prefixed with the hostname. The command or script has to be present on the system, so a shared NFS directory can be useful for these sorts of things.
Creates hostname ssh command of all machines accessed.
by Quierati
http://pastebin.com/pddEQWq2
#Use in .bashrc
#Use "HashKnownHosts no" in ~/.ssh/config or /etc/ssh/ssh_config
# If known_hosts is encrypted and delete known_hosts
[ ! -d ~/bin ] && mkdir ~/bin
for host in `cut -d, -f1 ~/.ssh/known_hosts|cut -f1 -d " "`;
do
[ ! -s ~/bin/$host ] && echo ssh $host '$*' > ~/bin/$host
done
[ -d ~/bin ] && chmod -R 700 ~/bin
export PATH=$PATH:~/bin
Ex Execute:
$for i in hostname{1..10}; do $i who;done
There is a tool called FLATT (FLexible Automation and Troubleshooting Tool) that allows you to execute scripts on multiple Unix/Linux hosts with a click of a button. It is a desktop GUI app that runs on Mac and Windows but there is also a command line java client.
You can create batch jobs and reuse on multiple hosts.
Requires Java 1.6 or higher.
Although it's a complex topic, I can highly recommend Capistrano.
I'm not sure if this method will work for everything that you want, but you can try something like this:
$ cat your_script.sh | ssh your_host bash
Which will run the script (which resides locally) on the remote server.
Just read a new blog using setsid without any further installation/configuration besides the mainstream kernel. Tested/Verified under Ubuntu14.04.
While the author has a very clear explanation and sample code as well, here's the magic part for a quick glance:
#----------------------------------------------------------------------
# Create a temp script to echo the SSH password, used by SSH_ASKPASS
#----------------------------------------------------------------------
SSH_ASKPASS_SCRIPT=/tmp/ssh-askpass-script
cat > ${SSH_ASKPASS_SCRIPT} <<EOL
#!/bin/bash
echo "${PASS}"
EOL
chmod u+x ${SSH_ASKPASS_SCRIPT}
# Tell SSH to read in the output of the provided script as the password.
# We still have to use setsid to eliminate access to a terminal and thus avoid
# it ignoring this and asking for a password.
export SSH_ASKPASS=${SSH_ASKPASS_SCRIPT}
......
......
# Log in to the remote server and run the above command.
# The use of setsid is a part of the machinations to stop ssh
# prompting for a password.
setsid ssh ${SSH_OPTIONS} ${USER}#${SERVER} "ls -rlt"
Easiest way I found without installing or configuring much software is using plain old tmux. Say you have 9 linux servers. Pick a box as your main. Start a tmux session:
tmux
Then create 9 split tmux panes by doing this 8 times:
ctrl-b + %
Now SSH into each box in each pane. You'll need to know some tmux shortcuts. To navigate, press:
ctrl+b <arrow-keys>
Once your logged in to all your boxes on each pane. Now turn on pane synchronization where it lets you type the same thing into each box:
ctrl+b :setw synchronize-panes on
now when you press any keys, it will show up on every pane. to turn it off, just make on to off. to cycle resize panes, press ctrl+b < space-bar >.
This works alot better for me since I need to see each terminal output as sometimes servers crash or hang for whatever reason when downloading or upgrade software. Any issues, you can just isolate and resolve individually.

How to use SSH to run a local shell script on a remote machine?

I have to run a local shell script (windows/Linux) on a remote machine.
I have SSH configured on both machine A and B. My script is on machine A which will run some of my code on a remote machine, machine B.
The local and remote computers can be either Windows or Unix based system.
Is there a way to run do this using plink/ssh?
If Machine A is a Windows box, you can use Plink (part of PuTTY) with the -m parameter, and it will execute the local script on the remote server.
plink root#MachineB -m local_script.sh
If Machine A is a Unix-based system, you can use:
ssh root#MachineB 'bash -s' < local_script.sh
You shouldn't have to copy the script to the remote server to run it.
This is an old question, and Jason's answer works fine, but I would like to add this:
ssh user#host <<'ENDSSH'
#commands to run on remote host
ENDSSH
This can also be used with su and commands which require user input. (note the ' escaped heredoc)
Since this answer keeps getting bits of traffic, I would add even more info to this wonderful use of heredoc:
You can nest commands with this syntax, and that's the only way nesting seems to work (in a sane way)
ssh user#host <<'ENDSSH'
#commands to run on remote host
ssh user#host2 <<'END2'
# Another bunch of commands on another host
wall <<'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
You can actually have a conversation with some services like telnet, ftp, etc. But remember that heredoc just sends the stdin as text, it doesn't wait for response between lines
I just found out that you can indent the insides with tabs if you use <<-END!
ssh user#host <<-'ENDSSH'
#commands to run on remote host
ssh user#host2 <<-'END2'
# Another bunch of commands on another host
wall <<-'ENDWALL'
Error: Out of cheese
ENDWALL
ftp ftp.example.com <<-'ENDFTP'
test
test
ls
ENDFTP
END2
ENDSSH
(I think this should work)
Also see
http://tldp.org/LDP/abs/html/here-docs.html
Also, don't forget to escape variables if you want to pick them up from the destination host.
This has caught me out in the past.
For example:
user#host> ssh user2#host2 "echo \$HOME"
prints out /home/user2
while
user#host> ssh user2#host2 "echo $HOME"
prints out /home/user
Another example:
user#host> ssh user2#host2 "echo hello world | awk '{print \$1}'"
prints out "hello" correctly.
This is an extension to YarekT's answer to combine inline remote commands with passing ENV variables from the local machine to the remote host so you can parameterize your scripts on the remote side:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'
# commands to run on remote host
echo $ARG1 $ARG2
ENDSSH
I found this exceptionally helpful by keeping it all in one script so it's very readable and maintainable.
Why this works. ssh supports the following syntax:
ssh user#host remote_command
In bash we can specify environment variables to define prior to running a command on a single line like so:
ENV_VAR_1='value1' ENV_VAR_2='value2' bash -c 'echo $ENV_VAR_1 $ENV_VAR_2'
That makes it easy to define variables prior to running a command. In this case echo is our command we're running. Everything before echo defines environment variables.
So we combine those two features and YarekT's answer to get:
ssh user#host ARG1=$ARG1 ARG2=$ARG2 'bash -s' <<'ENDSSH'...
In this case we are setting ARG1 and ARG2 to local values. Sending everything after user#host as the remote_command. When the remote machine executes the command ARG1 and ARG2 are set the local values, thanks to local command line evaluation, which defines environment variables on the remote server, then executes the bash -s command using those variables. Voila.
<hostA_shell_prompt>$ ssh user#hostB "ls -la"
That will prompt you for password, unless you have copied your hostA user's public key to the authorized_keys file on the home of user .ssh's directory. That will allow for passwordless authentication (if accepted as an auth method on the ssh server's configuration)
I've started using Fabric for more sophisticated operations. Fabric requires Python and a couple of other dependencies, but only on the client machine. The server need only be a ssh server. I find this tool to be much more powerful than shell scripts handed off to SSH, and well worth the trouble of getting set up (particularly if you enjoy programming in Python). Fabric handles running scripts on multiple hosts (or hosts of certain roles), helps facilitate idempotent operations (such as adding a line to a config script, but not if it's already there), and allows construction of more complex logic (such as the Python language can provide).
cat ./script.sh | ssh <user>#<host>
chmod +x script.sh
ssh -i key-file root#111.222.3.444 < ./script.sh
Try running ssh user#remote sh ./script.unx.
Assuming you mean you want to do this automatically from a "local" machine, without manually logging into the "remote" machine, you should look into a TCL extension known as Expect, it is designed precisely for this sort of situation. I've also provided a link to a script for logging-in/interacting via SSH.
https://www.nist.gov/services-resources/software/expect
http://bash.cyberciti.biz/security/expect-ssh-login-script/
ssh user#hostname ". ~/.bashrc;/cd path-to-file/;. filename.sh"
highly recommended to source the environment file(.bashrc/.bashprofile/.profile). before running something in remote host because target and source hosts environment variables may be deffer.
I use this one to run a shell script on a remote machine (tested on /bin/bash):
ssh deploy#host . /home/deploy/path/to/script.sh
if you wanna execute command like this
temp=`ls -a`
echo $temp
command in `` will cause errors.
below command will solve this problem
ssh user#host '''
temp=`ls -a`
echo $temp
'''
If the script is short and is meant to be embedded inside your script and you are running under bash shell and also bash shell is available on the remote side, you may use declare to transfer local context to remote. Define variables and functions containing the state that will be transferred to the remote. Define a function that will be executed on the remote side. Then inside a here document read by bash -s you can use declare -p to transfer the variable values and use declare -f to transfer function definitions to the remote.
Because declare takes care of the quoting and will be parsed by the remote bash, the variables are properly quoted and functions are properly transferred. You may just write the script locally, usually I do one long function with the work I need to do on the remote side. The context has to be hand-picked, but the following method is "good enough" for any short scripts and is safe - should properly handle all corner cases.
somevar="spaces or other special characters"
somevar2="!##$%^"
another_func() {
mkdir -p "$1"
}
work() {
another_func "$somevar"
touch "$somevar"/"$somevar2"
}
ssh user#server 'bash -s' <<EOT
$(declare -p somevar somevar2) # transfer variables values
$(declare -f work another_func) # transfer function definitions
work # call the function
EOT
The answer here (https://stackoverflow.com/a/2732991/4752883) works great if
you're trying to run a script on a remote linux machine using plink or ssh.
It will work if the script has multiple lines on linux.
**However, if you are trying to run a batch script located on a local
linux/windows machine and your remote machine is Windows, and it consists
of multiple lines using **
plink root#MachineB -m local_script.bat
wont work.
Only the first line of the script will be executed. This is probably a
limitation of plink.
Solution 1:
To run a multiline batch script (especially if it's relatively simple,
consisting of a few lines):
If your original batch script is as follows
cd C:\Users\ipython_user\Desktop
python filename.py
you can combine the lines together using the "&&" separator as follows in your
local_script.bat file:
https://stackoverflow.com/a/8055390/4752883:
cd C:\Users\ipython_user\Desktop && python filename.py
After this change, you can then run the script as pointed out here by
#JasonR.Coombs: https://stackoverflow.com/a/2732991/4752883 with:
`plink root#MachineB -m local_script.bat`
Solution 2:
If your batch script is relatively complicated, it may be better to use a batch
script which encapsulates the plink command as well as follows as pointed out
here by #Martin https://stackoverflow.com/a/32196999/4752883:
rem Open tunnel in the background
start plink.exe -ssh [username]#[hostname] -L 3307:127.0.0.1:3306 -i "[SSH
key]" -N
rem Wait a second to let Plink establish the tunnel
timeout /t 1
rem Run the task using the tunnel
"C:\Program Files\R\R-3.2.1\bin\x64\R.exe" CMD BATCH qidash.R
rem Kill the tunnel
taskkill /im plink.exe
This bash script does ssh into a target remote machine, and run some command in the remote machine, do not forget to install expect before running it (on mac brew install expect )
#!/usr/bin/expect
set username "enterusenamehere"
set password "enterpasswordhere"
set hosts "enteripaddressofhosthere"
spawn ssh $username#$hosts
expect "$username#$hosts's password:"
send -- "$password\n"
expect "$"
send -- "somecommand on target remote machine here\n"
sleep 5
expect "$"
send -- "exit\n"
You can use runoverssh:
sudo apt install runoverssh
runoverssh -s localscript.sh user host1 host2 host3...
-s runs a local script remotely
Useful flags:
-g use a global password for all hosts (single password prompt)
-n use SSH instead of sshpass, useful for public-key authentication
If it's one script it's fine with the above solution.
I would set up Ansible to do the Job. It works in the same way (Ansible uses ssh to execute the scripts on the remote machine for both Unix or Windows).
It will be more structured and maintainable.
It is unclear if the local script uses locally set variables, functions, or aliases.
If it does this should work:
myscript.sh:
#!/bin/bash
myalias $myvar
myfunction $myvar
It uses $myvar, myfunction, and myalias. Let us assume they is set locally and not on the remote machine.
Make a bash function that contains the script:
eval "myfun() { `cat myscript.sh`; }"
Set variable, function, and alias:
myvar=works
alias myalias='echo This alias'
myfunction() { echo This function "$#"; }
And "export" myfun, myfunction, myvar, and myalias to server using env_parallel from GNU Parallel:
env_parallel -S server -N0 --nonall myfun ::: dummy
Extending answer from #cglotr. In order to write inline command use printf, it useful for simple command and it support multiline using char escaping '\n'
example :
printf "cd /to/path/your/remote/machine/log \n tail -n 100 Server.log" | ssh <user>#<host> 'bash -s'
See don't forget to add bash -s
I created a solution that works better for me by combining the use of a heredoc from Yarek T's answer with the piped cat method from cglotr's answer along with some other tricks for non-interactive login (using sshpass), using variables from the local and remote host in the script, and enabling sudo commands. The code is longer just because it includes some additional tricks that are likely desired, but the original questioner didn't ask for them.
The problem I have with Yarek's answer is that all the warnings and commands in the heredoc print to the screen. The problem I have with cglotr's answer is that is requires a script file and a complex command with additional interaction to execute the script. With my solution, I write a script that does everything by simply calling the script with the remote host IP address as the first argument like this:
./MYSCRIPT REMOTE_IP_ADDRESS
The script to be run on the remote host is saved to a variable within the script on the local host using a heredoc so that you don't need to do any quote escaping. Then, the variable containing the script is echo piped to sshpass. Be sure to indent the commands with tabs and not spaces (you'll get spaces instead of tabs when you copy the code). Here is an example of the remote script within the local script.
!/bin/bash
# Input argument 1 should be the target host IP address (required)
RX_IP="/(\b25[0-5]|\b2[0-4][0-9]|\b[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}/"
IS_IP=$(echo $1 | sed -nr "${RX_IP}p" | wc -l)
if (( $IS_IP )); then
USERNAME=remoteuser
HOSTNAME=$1
# Export the SSH password to environment variable for sshpass and sudo.
# The space before the command prevents saving the command to history.
export SSHPASS=mypassword;
while read -r -d '' SCRIPT <<-EOS
# Enable sudo commands with the following command.
# The space before echo prevents saving the command to history.
echo $SSHPASS | sudo -Sv
# Do stuff here. Escape variables to be be accessed on the remote host.
# For example, escape print variable in an awk command:
# This command lists all USB block device partitions.
ls -l /dev /dev/mapper | awk '/^b/ && /sd[a-z][1-9]/ {print \$10}'
exit
EOS
echo "$SCRIPT" | sshpass -e ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null ${USERNAME}#${HOSTNAME} &>/dev/null
echo 'DONE'
else
echo "Missing IP address of target host."
echo "Usage: ./SCRIPT_NAME IP_ADDRESS
fi
You need to install sshpass on the local host like this (for Debian based distros).
sudo apt install sshpass
There is another approach ,you can copy your script in your host with scp command then execute it easily .
First, copy the script over to Machine B using scp
[user#machineA]$ scp /path/to/script user#machineB:/home/user/path
Then, just run the script
[user#machineA]$ ssh user#machineB "/home/user/path/script"
This will work if you have given executable permission to the script.

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