fish_command_not_found - what to do when a command wasn't found¶
function fish_command_not_found ... end
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 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.
A simple handler:
function fish_command_not_found echo Did not find command $argv 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 end
Or the simple default handler:
function fish_command_not_found __fish_default_command_not_found_handler $argv end
This command was introduced in fish 3.2.0. Previous versions of fish used the "fish_command_not_found" 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 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 fish_command_not_found $argv end