show , append enviroment variables

Show all enviroment variables

Command:env

 

Show local environment variables

Command:set

 

Append environment variables

The most common usage is to append directories that contain executable files  into environment variable PATH

Editing  .bashrc(or .bash_profile) file in your home directory is good choice. Then you can execute command: source .bashrc, to force it to take effect.

For example:

  #Add hadoop and java environment:

JAVA_HOME=/usr/local/jdk1.6.0_13

export PATH=$JAVA_HOME/bin:$PATH

 

#hadoop

export HADOOP_JAR=$HADOOP_HOME/hadoop-0.19.1-core.jar

export HADOOP_ROOT=/usr/local/hadoop/hadoop-0.19.1

export HADOOP_HOME=$HADOOP_ROOT

export HADOOP_CONF_DIR=$HOME/hadoop_conf

export JAVA_HOME=/usr/local/jdk1.6.0_13

export PATH=$HADOOP_HOME/bin:$HOME/online/hive/hive-lib/bin:$JAVA_HOME/bin:$HOME/bin:$HOME/online/bin:$PATH