I want to run the same set of Unix commands on multiple machines. I am aware of ssh and something like the below. I want to write a shell script to do this. I have access to bash and ksh and I'm on Linux Red Hat 5.
ssh root#ip "echo \$HOME"
However, I have 2 questions:
I keep getting prompted for a password. How can I have it not prompt me and enter the password automatically?
How can I execute multiple commands?
You should use key based authentification, possibly coupled with ssh-agent to remember key passphrase.
You can invoke sh -c as the command, and pass it a string containing the list of command to execute. ssh invoke a shell on the remote machine, so you can pass a list of command as a string.
For example:
$ ssh user#ip "echo 'Hello world'; whoami; cd / ; ls"
Use ssh-agent to set up authentication for all commands. Or put your multiple commands into a single shell script.
Send a list of commands to the remote shell. Possible solutions:
use ", escape line breaks to format code and end each substatement with ;.
Disadvantage: " should not be used inside the command list.
ssh user#ip "\
echo 'Hallo sir, how are you doing?';\
whoami;\
cd /;\
ls\
"
use ' and format code with regular line breaks.
Disadvantage: ' should not be used inside the command list.
ssh user#ip '
echo "Hallo sir, how are you doing?"
whoami
cd /
ls
'
Note: using " or ' inside the respective statements will not necessarily result in an error. Though you may get unsuspected results.
Related
I am having problems running SSH from a shell script once I send the script into the background. The error is "expected more tokens" I read on line that I could nest the SSH call in a bash command as follows, but doing so prompts for a password, and even when I enter the correct password (which I don't want to do) it won't work.
This prompts for password from the command line
bash -c "ssh NJ\\NJDSSINFADM#dc01nj2dwifdv02.nj.core.him pmcmds DFD_ETIME wf_TEST"
This works from the command line or script in the foreground, but not when I run the script in the background
ssh NJ\\NJDSSINFADM#dc01nj2dwifdv02.nj.core.him pmcmds DFD_ETIME wf_TEST
Don't use let to assign variables with strings. It treats the value as an arithmetic expression, and your value is not intended to be treated that way.
jstat=$(echo $jstat|sed -e 's/[^0-9]//g')
You also don't need to use an external command to remove characters from a string, you can use the parameter expansion operator for substitution.
jstat=${jstat//[^0-9]/}
See the Bash Manual for an explanation of this syntax.
I'm new to linux scripting. I want to copy file from remote server to current server(executing or client server),required cert & key files are already installed on my server(client server). below commands work when I execute it individually in sequence but, after Integrating into a .sh script it doesnt!
--My Script--
lftp -u username,xxx -p 2121 remoteServer.net;
set ssl:cert-file /abc/def/etc/User_T.p12;
set ssl:key-file abc/def/etc/User_T.p12.pwd;
lftp -e 'set net:timeout 10; get /app/home/atm/feed.txt -o /com/data/';
man lftp:
-f script_file
Execute commands in the file and exit. This option must be used
alone without other arguments (except --norc).
-c commands
Execute the given commands and exit. Commands can be separated
with a semicolon, `&&' or `||'. Remember to quote the commands
argument properly in the shell. This option must be used alone
without other arguments (except --norc).
Use "here document" feature of the shell:
lftp <<EOF
set...
open...
get...
EOF
Thanks lav for your suggestion, I found that my script was not executing second line so added continuation like
<< SCRIPT
& ended script with SCRIPT
removed all semi colon... Its working
I've recently started using bash to automate a windows rescue disk with chntpw. I'm trying to set up the program to use the expect command to listen for certain chntpw dialog questions and input the right answers without any user input. For some reason after setting up the bash script to use #!/usr/bin/expect rather than #!/bin/bash then many standard terminal commands are no longer understood.
I'm running the script by typing this into terminal:
user#kali:~/Desktop/projects/breezee$ bash breezee1.sh
The terminal output is as follows:
BREEZEE 1.0
Welcome to BREEZEE
breezee1.sh: line 9: fdisk: command not found
[Select] /dev/:
Here is my code:
#!/usr/bin/expect
clear
echo "BREEZEE 1.0"
echo "Welcome to BREEZEE"
fdisk -l
#list partitions
echo -n "[Select] /dev/:"
#ask user to choose primary windows partition
read sda
clear
echo /dev/$sda selected
umount /dev/$sda
sudo ntfsfix /dev/$sda
sudo mount -t ntfs-3g -o remove_hiberfile /dev/$sda /mnt/
cd /mnt/Windows/System32/config
clear
chntpw -l SAM #list accounts on windows partition
chntpw -u Administrator SAM
#now supply chntpw with values to run the password clear (this answers the prompts)
expect '> '
send '1\r'
expect '> '
send '2\r'
expect '> '
send '3\r'
expect ': '
send 'y\r'
expect '> '
send 'q\r'
expect ': '
send 'y\r'
clear
echo "Operation Successfull!"
chntpw -l SAM #list accounts on windows partition
In short, I'm trying to use standard bash/terminal commands alongside the expect commands. I'm probably going about this all wrong, so please correct me as I've been troubleshooting this for about three days and haven't gotten far :(
When you specify the application that should run your script, you can only use the scripting language that application will understand.
Clearly, Expect is not bash, and does not understand bash commands.
i suggest you separate those two scripts. Write the first part for !#/bin/bash, the second for Expect. Make the first script invoke the second script and redirect it to chntpw.
expect uses tcl not bash. So you can write your script in TCL when you use #!/usr/bin/expect.
For example, echo "BREEZEE 1.0" should be written as:
puts "BREEZEE 1.0"
And you should use exp_send instead of send.
From expect manual:
exp_send is an alias for send. If you are using Expectk or some other variant of Expect in the Tk environment, send is defined by Tk for an entirely different purpose. exp_send is provided for compatibility between environments. Similar aliases are provided for other Expect's other send commands.
I trying to create a .sh file that execute things like "pwd" or "ls" command.
My problem its when i execute the .sh file.
Its seems not recognize the tasks
I tried to use echo
Example : echo 'lsApps' or echo "lsApps"
but it prints the name of the task instead execute the comand
for example i want to execute a .ssh file that makes a pwd
VAR_1=pwd
echo $VAR_1
but it prints me pwd instead the current path ...
Any idea?
echo is used to print on the screen (man page reference). If you do echo 'IsApps' it will take it as a string and print it. If you want to execute a command you can just do it by doing IsApps (acutes not quotes, acute is usually below the escape key). This will execute the command and show the output on the screen. If you want to store the output of the command in a variable, you can do
<variable_name>=`IsApps`
This will store the output in the variable. Note that there is no space between variable name and the command. Also, those are not quotes but instead acutes. To print the variable on screen you can use echo by doing echo $<variable_name>
If you don't want to see the output at all. You can do
IsApps > /dev/null
this will execute the command but you will not see any stdout on your screen.
As far as ssh is concerned, do ssh-keygen and then ssh-copy-id user#remote_ip to set ssh keys so that you don't have to enter your password with ssh. Once you have done that, you can use ssh user#remote_ip in your shell script.
I need to execute multiple commands on remote machine, and use ssh to do so,
ssh root#remote_server 'cd /root/dir; ./run.sh'
In the script, I want to pass a local variable $argument when executing run.sh, like
ssh root#remote_server 'cd /root/dir; ./run.sh $argument'
It does not work, since in single quote $argument is not interpreted the expected way.
Edit: I know double quote may be used, but is there any side effects on that?
You can safely use double quotes here.
ssh root#remote_server "cd /root/dir; ./run.sh $argument"
This will expand the $argument variable. There is nothing else present that poses any risk.
If you have a case where you do need to expand some variables, but not others, you can escape them with backslashes.
$ argument='-V'
$ echo "the variable \$argument is $argument"
would display
the variable $argument is -V
You can always test with double quotes to discover any hidden problems that might catch you by surprise. You can always safely test with echo.
Additionally, another way to run multiple commands is to redirect stdin to ssh. This is especially useful in scripts, or when you have more than 2 or 3 commands (esp. any control statements or loops)
$ ssh user#remoteserver << EOF
> # commands go here
> pwd
> # as many as you want
> # finish with EOF
> EOF
output, if any, of commands will display
$ # returned to your current shell prompt
If you do this on the command line, you'll get a stdin prompt to write your commands. On the command line, the SSH connection won't even be attempted until you indicate completion with EOF. So you won't see results as you go, but you can Ctrl-C to get out and start over. Whether on the command line or in a script, you wrap up the sequence of commands with EOF. You'll be returned to your normal shell at that point.
You could run xargs on the remote side:
$ echo "$argument" | ssh root#remote_server 'cd /root/dir; xargs -0 ./run.sh'
This avoids any quoting issues entirely--unless your argument has null characters in it, I suppose.