vac: A simple bash command that activates virtualenv

vac.sh

# This setup defines a new command `vac` that activates a virtualenv. You can also add autocompletion to this command.
# Prereq: All venv directories must be in the same place, I place mine under `~/venvs`

# Function to activate virtualenv. Place this in your `.bashrc` file.
```
vac() {
    # activates a virutalenv environment
    # eg: vactivate llama_farm
    source "$HOME/venvs/$1/bin/activate"
}
```

# If you want autocompletion with the `vac` command, add the following to a file
# `~/.local/share/bash-completion/completions/vac-completion`
# auto completions for the `vac` command.
```
_vac_completions() 
{
    local cur prev envs
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"
    # list all envs, I place mine in a folder ~/venvs
    envs=$(ls $HOME/venvs)

    COMPREPLY=( $(compgen -W "${envs}" -- ${cur}) )
    return 0
    
}
complete -F _vac_completions vac
```

# Then add this file to your `.bashrc` too:
`source ~/.local/share/bash-completion/completions/vac-completion`

# Now your setup is complete!

# Ref: https://askubuntu.com/a/345150