Can't match the `java -version` using expr command

Question

I am using bash shell and expr command.Below is my scripts:

v=`java -version`

echo 'check java platform...'

echo `expr match "$v" 'java'`

Can't match java substring, just got 0. But if I use this : v='java version "1.6.0_34"' I got the correct result:4

Why? How to fix it?

user972946 · Accepted Answer · 2012-09-14 06:40:52Z

2

try this:

export v=`java -version 2>&1`
echo $v

answered Sep 14, 2012 at 6:40

user972946

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2 Comments

Thanks. Could explain a bit, any document?

I tried v=`java -version` and v has nothing, then it must be in stderr.