Since sometimes we forget (or can't be bothered) with doing a --help or doing a man <command> having bash completion is great.
in this example, I am using a script that I've made which is a simple script that has the following commands.
With bash completion, after typing the command (vm.sh) and pressing tab it will automatically show the commands create destroy list-vol list-vm console vnc reset
Then after the command, pressing tab will output the list of all servers available.
To break it down,
$word contains the current command
$prev contains the previous command, so if it is selected, what the next command can be e.g. in this case
if prev=console then the next command can be <servername>
in this example, I am using a script that I've made which is a simple script that has the following commands.
vm.sh --help
create [servername] If option=console, then display console immediately
destroy [servername] Delete a VM
list-vol List all disks for all VMs
list-vm List VMs and status
console [servername] Access console of server
vnc [servername] List VNC port for VM
reset [servername] Restart VM
With bash completion, after typing the command (vm.sh) and pressing tab it will automatically show the commands create destroy list-vol list-vm console vnc reset
Then after the command, pressing tab will output the list of all servers available.
# bash completion for vm.sh
# pks - 20130926
# Now with extra flash bastard bits
# Press tab to view list of available servers after the command
_vm.sh () # By convention, the function name
{ #+ starts with an underscore.
local cmd_="$1##*/}"
# word that is being completed
local word=${COMP_WORDS[COMP_CWORD]}
# entire line being completed
local line=${COMP_LINE}
# exclusion pattern
local xpat='|*mqueue*'
_get_comp_words_by_ref -n : cur prev
# previous command
prev="${COMP_WORDS[COMP_CWORD-1]}"
COMPREPLY=() # Array variable storing the possible completions.
case "$prev" in
create|destroy|console|vnc|reset)
servers=`vm.sh list-vm | awk '{print $2}' | grep web | xargs -n1`
COMPREPLY=( $( compgen -W '$servers' -- "$cur" ) )
return 0
;;
esac
case "$word" in
*)
COMPREPLY=( $( compgen -W 'create destroy list-vol list-vm console \
vnc reset' -- $cur ) );;
esac
return 0
}
_complete ()
{
COMPREPLY=
}
complete -F _vm.sh vm.sh
# Local variables:
# mode: shell-script
# sh-basic-offset: 4
# sh-indent-comment: t
# indent-tabs-mode: nil
# End:
# ex: ts=4 sw=4 et filetype=sh
To break it down,
$word contains the current command
$prev contains the previous command, so if it is selected, what the next command can be e.g. in this case
if prev=console then the next command can be <servername>
