strange behaviour : export CLASSPATH=$(JARS=(./lib/*.jar); IFS=:; echo “${JARS[*]}”)

Question

export CLASSPATH=$(JARS=(./lib/*.jar); IFS=:; echo "${JARS[*]}")

If I put this line in a bash_script.sh and do

chmod +x bash_script.sh

and then run

./bash_script.sh

it gives the error.

Syntax error: "(" unexpected (expecting ")")

How ever I am able to run this thing directly from the prompt and get the expected result. as

$ export CLASSPATH=$(JARS=(./lib/*.jar); IFS=:; echo "${JARS[*]}")

I was wondering what is the reason for this strange behaviour.

Answer 1

将#!/bin/bash添加为第一行，以强制其在bash shell中运行。

Answer 2

Make sure you have #!/bin/bash at the top of your shell script. Array syntax VAR=(...) is a bash-ism. It won't work in plain sh ( #!/bin/sh ).

By the way, that looks like a line from my answer here . If so, I encourage you to use my updated solution rather than this.

There's no need to manually build the classpath list. Java supports a convenient wildcard syntax for directories containing jar files.

 java -cp "$LIB/*" 

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