What is the cleanest way to ssh and run multiple commands in Bash

Question

I already have an ssh agent set up  and I can run commands on an external server in Bash script doing stuff like  ssh blah server  quot ls  pwd  quot   Now  what I d really like to do is run a lot of long commands on an external server  Enclosing all of these in between quotation marks would be quite ugly  and I d really rather avoid ssh ing multiple times just to avoid this  So  is there a way I can do this in one go enclosed in parentheses or something  I m looking for something along the lines of  ssh blah server      ls some folder       someaction sh     pwd     Basically  I ll be happy with any solution as long as it s clean  Edit To clarify  I m talking about this being part of a larger bash script  Other people might need to deal with the script down the line  so I d like to keep it clean  I don t want to have a bash script with one line that looks like  ssh blah server  quot ls some folder    someaction sh  some params   pwd    some other action  other params   quot   because it is extremely ugly and difficult to read

User · Answer

For anyone stumbling over here like me - I had success with escaping the semicolon and the newline:

First step: the semicolon. This way, we do not break the ssh command:

ssh <host> echo test\;ls
                    ^ backslash!

Listed the remote hosts /home directory (logged in as root), whereas

ssh <host> echo test;ls
                    ^ NO backslash

listed the current working directory.

Next step: breaking up the line:

                      v another backslash!
ssh <host> echo test\;\
ls

This again listed the remote working directory - improved formatting:

ssh <host>\
  echo test\;\
  ls

If really nicer than here document or quotes around broken lines - well, not me to decide...

(Using bash, Ubuntu 14.04 LTS.)

User · Answer

To match your sample code  you can wrap your commands inside single or double qoutes  For example  ssh blah server     ls   pwd

User · Answer

SSH and Run Multiple Commands in Bash   Separate commands with semicolons within a string  passed to echo  all piped into the ssh command   For example   echo  df -k uname -a    ssh 192 168 79 134  Pseudo-terminal will not be allocated because stdin is not a terminal  Filesystem     1K-blocks    Used Available Use  Mounted on  dev sda2       18274628 2546476  14799848  15    tmpfs             183620      72    183548   1   dev shm  dev sda1         297485   39074    243051  14   boot Linux newserv 2 6 32-431 el6 x86 64  1 SMP Sun Nov 10 22 19 54 EST 2013 x86 64 x86 64 x86 64 GNU Linux

User · Answer

How about a Bash Here Document   ssh otherhost  lt  lt  EOF   ls some folder       someaction sh  some params    pwd     some other action  other params  EOF   To avoid the problems mentioned by  Globalz in the comments  you may be able to  depending what you re doing on the remote site  get away with replacing the first line with  ssh otherhost  bin bash  lt  lt  EOF   Note that you can do variable substitution in the Here document  but you may have to deal with quoting issues  For instance  if you quote the  limit string   ie  EOF in the above   then you can t do variable substitutions  But without quoting the limit string  variables are substituted  For example  if you have defined  NAME above in your shell script  you could do  ssh otherhost  bin bash  lt  lt  EOF touch   tmp   NAME   EOF   and it would create a file on the destination otherhost with the name of whatever you d assigned to  NAME  Other rules about shell script quoting also apply  but are too complicated to go into here

User · Answer

For simple commands you can use  ssh  lt ssh args gt  command1   amp  amp   command2  or ssh  lt ssh args gt  command1   amp   amp  command2

User · Answer

Edit your script locally  then pipe it into ssh  e g   cat commands-to-execute-remotely sh   ssh blah server   where commands-to-execute-remotely sh looks like your list above   ls some folder   someaction sh pwd

User · Answer

This can also be done as follows  Put your commands in a script  let s name it commands-inc sh     bin bash ls some folder   someaction sh pwd   Save the file  Now run it on the remote server   ssh user remote  bash -s   lt   path to commands-inc sh   Never failed for me

User · Answer

I see two ways   First you make a control socket like this    ssh -oControlMaster yes -oControlPath    ssh ssh- r- h- p  lt yourip gt    and run your commands   ssh -oControlMaster no -oControlPath    ssh ssh- r- h- p  lt yourip gt  -t  lt yourcommand gt    This way you can write an ssh command without actually reconnecting to the server   The second would be to dynamically generate the script  scping it and running

User · Answer

The easiest way to configure your system to use single ssh sessions by default with multiplexing   This can be done by creating a folder for the sockets   mkdir    ssh controlmasters   And then adding the following to your  ssh configuration   Host       ControlMaster auto     ControlPath    ssh controlmasters  r  h  p socket     ControlMaster auto     ControlPersist 10m   Now  you do not need to modify any of your code  This allows multiple calls to ssh and scp without creating multiple sessions  which is useful when there needs to be more interaction between your local and remote machines   Thanks to  terminus s answer  http   www cyberciti biz faq linux-unix-osx-bsd-ssh-multiplexing-to-speed-up-ssh-connections  and https   en wikibooks org wiki OpenSSH Cookbook Multiplexing

User · Answer

Not sure if the cleanest for long commands but certainly the easiest   ssh user host  cmd1  cmd2  cmd3

User · Answer

Put all the commands on to a script and it can be run like  ssh  lt remote-user gt   lt remote-host gt   bash -s   lt   remote-commands sh

User · Answer

This works well for creating scripts  as you do not have to include other files     bin bash ssh  lt my user gt   lt my host gt   quot bash -s quot   lt  lt  EOF       here you just type all your commmands  as you can see  i e      touch  tmp test1      touch  tmp test2      touch  tmp test3  EOF    you can use    which bash  -s  instead of my  quot bash -s quot  as well   but bash is usually being found in a standard location   so for easier memorizing it i leave that out   since i dont fat-finger my  PATH that bad so it cant even find  bin bash

User · Answer

The posted answers using multiline strings and multiple bash scripts did not work for me    Long multiline strings are hard to maintain   Separate bash scripts do not maintain local variables     Here is a functional way to ssh and run multiple commands while keeping local context   LOCAL VARIABLE test  run remote         echo   LOCAL VARIABLE      ls some folder         someaction sh  some params        some other action  other params     ssh otherhost    set   run remote

[bash] What is the cleanest way to ssh and run multiple commands in Bash?

Examples related to bash

Examples related to unix

Examples related to ssh