APT ( Advanced Packaging Tool )

APT ( Advanced Packaging Tool )

apt-get   -------> APT package handling tool
apt-get install (package name) ----------> To install any software and package


apt-get install firefox


apt-get autoremove package name
apt-get remove package name --------------> To remove package

* aptitude :-> high-level interface to the package manager This command use
                      for.

                    install any software or find any software.

aptitude search ( package name ) ----> search any package
aptitude install ( package name )  -----> To install any package
aptitude remove ( package name ) ----> To remove any package


If you want to install any binary package like java in a binary formate then give package execute permission. After that [ ./java ] is command.
./java

Check java install or not :

dpkg -query -l | grep java

This command show you that the java install or not check java package install or not.

env : run a program in a modified environment
         This command run for to check environment or path is correct or not.

export JAVA_HOME = /opt/java
export = command
JAVA_HOME = variable
/opt/java = file location

export JAVA_HOME = /opt/java
export ANT_HOME = /opt/ant  ----> [ ANT is a compiler ]
echo $ JAVA_HOME
echo $ANT_HOME -----> To check variable export or not.

vim /etc/profile ----> insert line

export JAVA_HOME = /opt/java
export ANT_HOME = /opt/ant
export PATH = $PATH:${JAVA_HOME}/bin:${ANT_HOME}/bin ---> restart pc

But if you don't want to reboot pc then run
   [ source /etc/profile ]  -----> command use for execute variable .