When fish tries to execute a command and can't find it, it invokes this function.
It can print a message to tell you about it, and it often also checks for a missing package that would include the command.
Fish ships multiple handlers for various operating systems and chooses from them when this function is loaded,
or you can define your own.
It receives the full commandline as one argument per token, so $argv[1] contains the missing command.
When you leave ``fish_command_not_found`` undefined (e.g. by adding an empty function file) or explicitly call ``__fish_default_command_not_found_handler``, fish will just print a simple error.
Example
-------
A simple handler:
::
function fish_command_not_found
echo Did not find command $argv[1]
end
> flounder
Did not find command flounder
Or the handler for OpenSUSE's command-not-found::
function fish_command_not_found
/usr/bin/command-not-found $argv[1]
end
Or the simple default handler::
function fish_command_not_found
__fish_default_command_not_found_handler $argv
end
Backwards compatibility
-----------------------
This command was introduced in fish 3.2.0. Previous versions of fish used the "fish_command_not_found" :ref:`event <event>` instead.
To define a handler that works in older versions of fish as well, define it the old way::
function __fish_command_not_found_handler --on-event fish_command_not_found
echo COMMAND WAS NOT FOUND MY FRIEND $argv[1]
end
in which case fish will define a ``fish_command_not_found`` that calls it,
or define a wrapper::
function fish_command_not_found
echo "G'day mate, could not find your command: $argv"
end
function __fish_command_not_found_handler --on-event fish_command_not_found
