Step 1 :
Find your .bashrc file

Step 2 :
(.bashrc is found in root directory)
(You can type cd in the terminal and hit enter to get to root and use ls -la to see list of files in directory)
– Edit your .bashrc file. Use whatever editing tool of your choice.
or you can just edit in the terminal with the below command :
nano .bashrc
Once you are in the file proceed to step 3.

Step 3 :
Go to the bottom of you .bashrc file and look for something along the lines of the below :

 
 
export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion

Step 4 :
Add a comment above the snippet indicated above so it looks like this.

#Custom Bash Commands
# Commands will be listed here...

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion

Step 5 :
Add your commands. 1 per line! use semi-colon ( ; ) to run multiple commands in succession

#Custom Bash Commands
alias my_custom_bash_command="do something in bash code"
alias my_custom_bash_command2="do something in bash code"
alias my_custom_bash_command3="do something in bash code"
alias my_custom_bash_command4="do something in bash code"

export NVM_DIR="$HOME/.nvm"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"  # This loads nvm
[ -s "$NVM_DIR/bash_completion" ] && \. "$NVM_DIR/bash_completion"  # This loads nvm bash_completion