From: Daniel Shahaf <d.s@daniel.shahaf.name>
To: Zsh Users <zsh-users@zsh.org>
Cc: Zach Riggle <zachriggle@gmail.com>
Subject: Re: Global Aliases, but as a function?
Date: Wed, 22 Dec 2021 20:14:39 +0000 [thread overview]
Message-ID: <20211222201439.GA1587@tarpaulin.shahaf.local2> (raw)
In-Reply-To: <CAH+w=7aLPhTT5znrLxNv9gHZWZGCpGfpHNXR4Fuu2j1tug2sMQ@mail.gmail.com>
Bart Schaefer wrote on Mon, Dec 20, 2021 at 17:55:15 -0800:
> You'd be looking at the third argument passed to preexec ("... the
> full text that is being executed") which you will have to take apart
> with something like cmdline=(${(z)3}) to figure out whether it's a
> simple command and whether one of the arguments is "--help".
>
If INTERACTIVE_COMMENTS is set then the taking apart should use ${(zZ+c+)}.
> Assuming it is just one command and has that argument, you've got the
> command name in $cmdline[1] (in my foregoing example) so you're going
> to create function with that name that ends by deleting itself; e.g.
> (naively again, ignoring the "is this a simple command" test):
>
> preexec() {
> local cmdline=(${(z)3})
> if [[ -n $cmdline[(R)--help] ]]; then
> function $cmdline[1] {
> $cmdline[1] "$@" | $LESS
> unfunction $cmdline[1]
The parameter «cmdline» will have been undefined by the time the inner
function runs, and the first line of the inner function would infinite
loop. Therefore:
.
eval "function ${(qq)cmdline[1]} {
unfunction -- ${(q)cmdline[1]}
${(q)cmdline[1]} "\$@" | …
}"
>
For the "is this a simple command?" test, my first sketch would be:
- No command separator tokens (';', '|', '||', etc.)
- First word's «type» is «command» [this rules out reserved words,
assignments, aliases, functions, parameter expansions, history
expansions…]
> }
> fi
> }
>
> And you're done. This works as long as $cmdline[1] isn't already
> defined as a different function, in which case you have to figure out
> how to save and restore that.
«functions -c»?
Cheers,
Daniel
prev parent reply other threads:[~2021-12-22 20:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-18 10:38 Zach Riggle
2021-12-18 22:40 ` Bart Schaefer
2021-12-20 18:42 ` Daniel Shahaf
2021-12-20 20:04 ` Bart Schaefer
2021-12-20 20:11 ` Roman Perepelitsa
2021-12-20 20:24 ` Bart Schaefer
2021-12-21 0:57 ` Zach Riggle
2021-12-21 0:56 ` Zach Riggle
2021-12-21 1:55 ` Bart Schaefer
2021-12-22 20:14 ` Daniel Shahaf [this message]
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