CODEWITHSUNDEEP
bashssh
TaylorOtwell
TaylorOtwell

Reputation: 7337

Passing Bash Command Through SSH - Executing Variable Capture

I am passing the following command straight through SSH:

ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server@111.111.111.111 'bash -s' << EOF
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
        echo "" | sudo -S service php5-fpm reload
fi
EOF

I get the following error:

[2015-02-25 22:45:23] local.INFO: bash: line 1: syntax error near unexpected token `('
bash: line 1: ` FPM_EXISTS=root      2378  0.0  0.9 342792 18692 ?        Ss   17:41   0:04 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)

It's like it is trying to execute the output of ps aux | grep php-fpm instead of just capturing git the variable. So, if I change the command to try to capture ls, it acts like it tries to execute that as well, of course returning "command not found" for each directory.

If I just paste the contents of the Bash script into a file and run it it works fine; however, I can't seem to figure out how to pass it through SSH.

Any ideas?

Upvotes: 3

Views: 283

Answers (2)

hek2mgl
hek2mgl

Reputation: 158270

You need to wrap starting EOF in single quotes. Otherwise ps aux | grep php-fpm would get interpreted by the local shell.

The command should look like this:

ssh ... server@111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=$(ps aux | grep php-fpm)
if [ ! -z "$FPM_EXISTS" ]
then
        echo "" | sudo -S service php5-fpm reload
fi
EOF

Check this: http://tldp.org/LDP/abs/html/here-docs.html (Section 19.7)

Btw, I would encourage you to use $() instead of backticks consequently for command substitution because of the ability to nest them. You will have more fun, believe me. Check this for example: What is the benefit of using $() instead of backticks in shell scripts?

Upvotes: 9

Tim Groeneveld
Tim Groeneveld

Reputation: 9049

You should wrap the EOF in single quotes.

ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server@111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
        echo "" | sudo -S service php5-fpm reload
fi
EOF

Upvotes: 5

Related Questions