Resolving permission issue with Tomcat

When you download and start running catalins.sh, you might get following error.

The BASEDIR environment variable is not defined correctly
This environment variable is needed to run this program

To resolve this;
1) Check $CATALINA_HOME and $JAVA_HOME set properly.

2) Check whether the relevant files in $CATALINA_HOME/bin have necessary permissions required for execution.

$ chmod u+x catalina.sh
$ chmod +x ./setclasspath.sh
$ chmod +x ./startup.sh
$ chmod +x ./shutdown.sh