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javabashenvironment-variablesjvm-arguments

Why is my environment variable incorrectly processed as a JVM option?

I want to use an environment variable as a JVM option when executing java -jar.

The command I want to execute it:

java -XX:onOutOfMemory='echo test' -jar foo.jar

When I run the above command as is, the jar will run.

(If you don't have the foo.jar, you will get an Error: Unable to access jarfile foo.jar error. But this still means that the option gets used correctly).

But when I create an environment variable containing the JVM option, and run the command using that variable.

OOM="-XX:onOutOfMemory='echo test'"
java $OOM -jar foo.jar

Than I get the following error:

Error: Could not find or load main class test'

It seems like the java command is ignoring the quotes around 'echo test'.

After looking for similar questions on SO and on other websites, I tried various variations of using quotes:

OOM="-XX:OnOutOfMemoryError=\"echo test\""
OOM='-XX:OnOutOfMemoryError="echo test"'
OOM=-XX:OnOutOfMemoryError="echo test"

But they all result in the same error.

An article from Oracle concerning JVM options, mentions using a semicolon:

-XX:OnOutOfMemoryError="<cmd args>; <cmd args>"

But the purpose of the semicolon is to separate multiple commands, not command and arguments. So this does not fix my problem.

Does anybody know how I can correctly move the -XX:onOutOfMemory='echo test' option into an environment variable?

Solution

  • When running java, you should quote $OOM

    Example:

    java "$OOM" -jar foo.jar

    See Why does my shell script choke on whitespace or other special characters? on Unix stackexchange for why this is needed.