shell script not printing value

Question

I am a newbie in shell programming trying to run the below script. I am unsuccessful in printing the value assigned to the hadoop_home variable in the below example. Please help me in understanding my mistake.

#!/bin/sh
echo "Holaaaa"
hadoop_home= echo "$HADOOP_HOME"
java_home= echo "$JAVA_HOME"
echo "Printing variable values"
echo "${hadoop_home}"
echo "${java_home}"

On executing the above shell, it prints

Holaaaa
/usr/hdp/2.6.0.1-152/hadoop/
/usr/lib/jvm/java-1.7.0-openjdk-amd64/jre/
Printing variable values

The variable value in hadoop_home and java_home is empty. Why is it empty and how can I get the values assigned to these variables?

John Kugelman · Accepted Answer · 2018-04-17 19:19:59Z

3

Assignments must not have spaces around the =. To capture the output of a command use $(cmd).

hadoop_home=$(echo "$HADOOP_HOME")

This can be simplified to:

hadoop_home=$HADOOP_HOME

answered Apr 17, 2018 at 19:19

John Kugelman

365k70 gold badges555 silver badges600 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Atom Over a year ago

Thank you. Removing space after '=' and adding $HADOOP_HOME solved the issue for me.

Comforse · Accepted Answer · 2018-04-17 19:23:03Z

1

Remove the echo and the double quotes from around the variables.

The echo command just prints to the standard output, it does not assign any values to the variables in your case as you are not in the standard output. You can capture the result though with a slight change:

$(echo "$HADOOP_HOME")

edited Apr 17, 2018 at 19:23

answered Apr 17, 2018 at 19:17

Comforse

2,0664 gold badges27 silver badges43 bronze badges

1 Comment

Atom Over a year ago

Thank you. I accepted John answer because removing spaces has solved my problem completely. Thank you for your response

Collectives™ on Stack Overflow

shell script not printing value

2 Answers 2

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related