Antlr is a parser generator written in Java.
Execute these commands to download atlr .jar file in /usr/local/lib directory
cd /usr/local/lib curl -O http://www.antlr.org/download/antlr-4.5-complete.jar
add antlr4 to your class path.
alias antlr4='java -Xmx500M -cp "/usr/local/lib/antlr-4.5-complete.jar:$CLASSPATH" org.antlr.v4.Tool' alias grun='java org.antlr.v4.runtime.misc.TestRig'
java org.antlr.v4.Tool ANTLR Parser Generator Version 4.5 -o ___ specify output directory where all output is generated -lib ___ specify location of grammars, tokens files -atn generate rule augmented transition network diagrams ........... ...........
The above 3 commands (one export and two alias commands) needs to be run every time you start a new terminal. To solve this problem put the three commands in your .bashrc file like shown below.
Open the.bashrc file in any text editor
and add the three commands at the bottom of the file, Like shown in the image below
Note: bashrc is a script file that automatically executes whenever a new terminal is opened.