How to input automatically when running a shell over SSH

Question

In my shell script I am running a command which is asking me for input   How can I give the command the input it needs automatically   For example    cat test sh ssh-copy-id tester 10 1 2 3   When running test sh    First  it will ask   Are you sure you want to continue connecting  yes no   Then  it will ask me to input the password   tester 10 1 2 3 s password    Is there a way to input this automatically

User · Accepted Answer

For general command-line automation  Expect is the classic tool  Or try pexpect if you re more comfortable with Python   Here s a similar question that suggests using Expect  Use expect in bash script to provide password to SSH command

User · Answer

There definitely is    Use the spawn  expect  and send commands   spawn test sh expect  Are you sure you want to continue connecting  yes no    send  yes    There are more examples all over Stack Overflow  see  Help with Expect within a bash script  You may need to install these commands first  depending on your system

User · Answer

For simple input  like two prompts and two corresponding fixed responses  you could also use a  here document   the syntax of which looks like this   test sh  lt  lt   y pasword     The  lt  lt  prefixes a pattern  in this case      Everything up to a line beginning with that pattern is interpreted as standard input  This approach is similar to the suggestion to pipe a multi-line echo into ssh  except that it saves the fork exec of the echo command and I find it a bit more readable  The other advantage is that it uses built-in shell functionality so it doesn t depend on expect

User · Answer

Also you can pipe the answers to the script   printf  y npassword n    sh test sh   where  n is escape-sequence

User · Answer

ssh-key with passphrase  with keychain  keychain is a small utility which manages ssh-agent on your behalf and allows the ssh-agent to remain running when the login session ends  On subsequent logins  keychain will connect to the existing ssh-agent instance  In practice  this means that the passphrase must be be entered only during the first login after a reboot  On subsequent logins  the unencrypted key from the existing ssh-agent instance is used  This can also be useful for allowing passwordless RSA DSA authentication in cron jobs without passwordless ssh-keys   To enable keychain  install it and add something like the following to    bash profile   eval keychain --agents ssh --eval id rsa From a security point of view  ssh-ident and keychain are worse than ssh-agent instances limited to the lifetime of a particular session  but they offer a high level of convenience  To improve the security of keychain  some people add the --clear option to their    bash profile keychain invocation  By doing this passphrases must be re-entered on login as above  but cron jobs will still have access to the unencrypted keys after the user logs out  The keychain wiki page has more information and examples   Got this info from   https   unix stackexchange com questions 90853 how-can-i-run-ssh-add-automatically-without-password-prompt  Hope this helps  I have personally been able to automatically enter my passphrase upon terminal launch by doing this   you can  of course  modify the script and fit it to your needs    edit the bashrc file to add this script   Check if the SSH agent is awake  if   -z   SSH AUTH SOCK      then exec ssh-agent bash -c  ssh-add    0  echo  The SSH agent was awakened  exit fi  Above line will start the expect script upon terminal launch     ssh exp   here s the content of this expect script     usr bin expect  set timeout 20  set passphrase  test   spawn    keyadding sh   expect  Enter passphrase for  the path of yourkey id rsa    send   passphrase r    interact   Here s the content of my keyadding sh script  you must put both scripts in your home folder  usually  home user      bin bash  ssh-add  the path of yourkey id rsa  exit 0   I would HIGHLY suggest encrypting the password on the  exp script as well as renaming this  exp file to something like term boot exp or whatever else for security purposes  Don t forget to create the files directly from the terminal using nano or vim  ex  nano    bashrc   nano term boot exp  and also a chmod  x script sh to make it executable  A chmod  r term boot exp would be also useful but you ll have to add sudo before   ssh exp in your bashrc file  So you ll have to enter your sudo password each time you launch your terminal  For me  it s more convenient than the passphrase cause I remember my admin  sudo  password by the hearth    Also  here s another way to do it I think   https   www cyberciti biz faq noninteractive-shell-script-ssh-password-provider   Will certainly change my method for this one when I ll have the time

[shell] How to input automatically when running a shell over SSH?

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