Implement autocomplete

[reduardo7]

Example: https://unix.stackexchange.com/a/291867/22180

Here is basic guide.

Lets have an example of script called admin.sh to which you would like to have autocomplete working.

#!/usr/bin/bash

while [ $# -gt 0 ]; do
  arg=$1

  case $arg in
    option_1)
     # do_option_1
    ;;
    option_2)
     # do_option_1
    ;;
    shortlist)
      echo option_1 option_2 shortlist
    ;;
    *)
     echo Wrong option
    ;;
  esac
  
  shift
done

Note option shortlist. Calling script with this option will print out all possible options for this script.

And here you have the autocomplete.sh script:

#!/usr/bin/bash

_script() {
  _script_commands=$(/path/to/your/admin.sh shortlist)

  local cur prev
  COMPREPLY=()
  cur="${COMP_WORDS[COMP_CWORD]}"
  COMPREPLY=( $(compgen -W "${_script_commands}" -- ${cur}) )
  return 0
}

complete -o nospace -F _script /path/to/your/admin.sh

Note that the last argument to complete is the name of the script you want to add autocompletion to. All you need to do is to add your autocomplete script to ~/.bashrc or /etc/bash_completion.d as:

source /full-path/to/your/autocomplete.sh

# or

. /full-path/to/your/autocomplete.sh

Finally, make them executable:

chmod a+x admin.sh autocomplete.sh

Source: https://askubuntu.com/a/483149/24155