[issue564] support command-not-found within grml's zsh on request?

[Michael Prokop]

Michael Prokop <mika at grml.org> added the comment:

[...]
> > function preexec() {
> >         command="${1%% *}"
> > }

> > function precmd() {
> >         (($?)) && [ -n "$command" ] && [ -x /usr/share/command-not-found/command-not-found ] && {
> >                 whence -- "$command" >& /dev/null ||
> >                         /usr/share/command-not-found/command-not-found -- "$command"
> >                 unset command
> >         }
> > }

> Okay, *if* we take a stab at this, I'm writing this from scratch.
> <yoda>This I don't like.</yoda>

Hehe ok :)

> > So when sourcing this file and invoking a command which isn't
> > present it displays which Debian package might provide the command.

> Might? So it's basically just guessing? Or does it actually consult
> the dpkg package database (which would be quite expensive, I think;
> .o( apt-file nautilus | grep bin/ | awk { whatever } )).

Might as in "if the command isn't in any Debian package it can't
help the user".

> > Demonstration (manually invoking
> > /usr/share/command-not-found/command-not-found though here):

> > % /usr/share/command-not-found/command-not-found nautilus
> > The program 'nautilus' is currently not installed.  To run 'nautilus' please ask your administrator to install the package 'nautilus'

> Okay, I get the notion.
> However:
>     a) How does that thing get it's data?

Via:

% file /var/cache/command-not-found/*
/var/cache/command-not-found/ftp.de.debian.org_debian_dists_unstable_contrib.db:           GNU dbm 1.x or ndbm database, little endian
/var/cache/command-not-found/ftp.de.debian.org_debian_dists_unstable_main.db:              GNU dbm 1.x or ndbm database, little endian
/var/cache/command-not-found/ftp.de.debian.org_debian_dists_unstable_non-free.db:          GNU dbm 1.x or ndbm database, little endian
/var/cache/command-not-found/www.debian-multimedia.org_dists_sid_main.db:                  GNU dbm 1.x or ndbm database, little endian
/var/cache/command-not-found/www.informatik.uni-koeln.de_fai_download_dists_lenny_main.db: GNU dbm 1.x or ndbm database, little endian

AFAICS.

>     b) How accurate are its predictions?

Very accurate AFAICS.

>     c) How well does it perform, if it's really accurate?

% zsh -f
% source /etc/zsh_command_not_found
% nautilus
zsh: command not found: nautilus
The program 'nautilus' is currently not installed.  To run 'nautilus' please ask your administrator to install the package 'nautilus
'
%

-> Works at least pretty well and fast on my system.

regards,
-mika-

----------
assignedto: ft
messages: 1627, 1628, 1629, 1630, 1631, 1636, 1637
nosy: ft, mika
priority: feature
status: chatting
title: support command-not-found within grml's zsh on request?
topic: configs, zsh

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GRML issue tracker <bts at bts.grml.org>
<http://bts.grml.org/grml/issue564>
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