Passing variables in remote ssh command

Question

I want to be able to run a command from my machine using ssh and pass through the environment variable $BUILD_NUMBER

Here's what I'm trying:

ssh [email protected] '~/tools/run_pvt.pl $BUILD_NUMBER'

$BUILD_NUMBER is set on the machine making the ssh call and since the variable doesn't exist on the remote host, it doesn't get picked up.

How do I pass the value of $BUILD_NUMBER

Answer 1

Variables in single-quotes are not evaluated. Use double quotes:

ssh [email protected] "~/tools/run_pvt.pl $BUILD_NUMBER"

The shell will expand variables in double-quotes, but not in single-quotes. This will change into your desired string before being passed to the ssh command.

Answer 2

If you use

ssh [email protected] "~/tools/run_pvt.pl $BUILD_NUMBER"

instead of

ssh [email protected] '~/tools/run_pvt.pl $BUILD_NUMBER'

your shell will interpolate the $BUILD_NUMBER before sending the command string to the remote host.