Re: what can be global aliases used for?

[Roman Perepelitsa <roman.perepelitsa@xxxxxxxxx>]

On Fri, Feb 17, 2023 at 3:59 PM Sebastian Gniazdowski
<sgniazdowski@xxxxxxxxx> wrote:
>
> I'm trying to get the suspected capabilities out of global aliases. Currently I'm using them for:
> - macro-like labels for exporting patterns like EMPTYSTR being [[:space:][:INVALID:]]# roughly, to a single place,
> - macro-like SNIP_EMULATE_OPTIONS_ZERO that invokes emulate, setopt and 0=...
>
> I wonder what else can global aliases do?

Global aliases are unhygienic macros. It's rarely a good idea to use
unhygienic macros in the code you share with others. If you must use
an unhygienic macro in shared code, give it a long and ugly name to
avoid clashes.

EMPTYSTR can be a parameter. You would have to use $~EMPTYSTR but
you'll avoid most of the pitfalls of unhygienic macros.

SNIP_EMULATE_OPTIONS_ZERO can also be a parameter, which you can use
via `eval $SNIP_EMULATE_OPTIONS_ZERO`. I do something like this in
zsh4humans:

typeset -gr _z4h_opt='emulate -L zsh &&
  setopt typeset_silent pipe_fail extended_glob &&
  setopt prompt_percent no_prompt_subst no_prompt_bang &&
  setopt no_bg_nice no_aliases || return'

function foo() {
  eval "$_z4h_opt"
  # do stuff
}

function bar() {
  eval "$_z4h_opt"
  # do stuff
}

Roman.