Shell: Multiple commands via ssh / subshell

Question

Hello,
I have this script:
#!/bin/sh
SP_CONFIG=/home/flindner/spider/spFackrellB2+innerBox.conf
ssh flindner@yoko "ssh yuka << 'ENDSSH'
MESH=`awk '/OUTFILENAME/ {getline; print}' $SP_CONFIG`
ENDSSH"
executed with sh -x
florian@horus ~ % sh -x ./remote_spider_test.sh
+ SP_CONFIG=/home/flindner/spider/spFackrellB2+innerBox.conf
++ awk '/OUTFILENAME/ {getline; print}' /home/flindner/spider/spFackrellB2+innerBox.conf
awk: fatal: cannot open file `/home/flindner/spider/spFackrellB2+innerBox.conf' for reading (No such file or directory)
+ ssh flindner@yoko 'ssh yuka << '\''ENDSSH'\''
MESH=
ENDSSH'
But when I execute the awk command on the machine yuka it works just fine:
flindner@yuka:~> awk '/OUTFILENAME/ {getline; print}' /home/flindner/spider/spFackrellB2+innerBox.conf
meshFackrellB2+innerBox.msh
Therefore I think that somehow awk is being executed on my local machine and not on either one on the remote machines (I would be running on yoko too).
Why is that? How can I execute it on yoko like it was intented? Other commands played just well, I suspect the problem is connected to the subshell execution of awk.
Thanks a lot!

Answer 1

The problem here is that the shell will evaluate the string inside "" before running the command. that means the awk-line will run locally. Try using ' instead of " around the  ssh yuka ... ENDSSH.  Single quotes will prevent the shell from evaluating anything inside like variables or subshell stuff. Also use $( .. ) instead of ` `, because its more readable
Last edited by seiichiro0185 (2011-09-19 14:11:15)