Zsh suffix alias alternative in bash

Question

In zsh I can open any file with a special suffix or extension like .log or .txt with a program with typing its file name only

$ alias -s txt=nano
$ word.txt 

That open the file word.txt with nano. How can I do this in bash?

Answer 1

How about exec zsh?

But this feature can actually be implemented in bash (since version 4.0; OSX users, see the previous paragraph). Kind of. When bash encounters a command that isn't found in the PATH, it runs a function called command_not_found_handle. You can write a function that attempts to open the file if it's a file in the current directory.

typeset -A extension_aliases
command_not_found_handle () {
  if [[ $# -eq 1 && -e $1 && $1 = *.* ]]; then
    local handler="${extension_aliases[${1##*.}]}"
    if [[ -n $local_handler ]]; then
      eval "$local_handler \"\$@\""
      return
    fi
  fi
  return 127
}

Instead of alias -s txt=nano, use extension_aliases[txt]=nano.

There are limitations to this approach. The file must be in the current directory, because command_not_found_handle is only invoked with a command name that doesn't contain a slash. Also you won't get completion for the file name.

It is a lot simpler to use existing mechanisms:

xdg-open word.txt

or on Debian and derivatives

see word.txt

You get many benefits: there's already a system database that maps extensions to programs, completion will work, and it doesn't require any special handling from the shell. It does require a bit more typing, but you can define a one-character alias for it (you'll need a space after it), or a key binding that inserts xdg-open at the beginning of the line:

bind -x '"\eo": READLINE_LINE="xdg-open $READLINE_LINE"; READLINE_POINT+=9'