nixpkgs/modules/programs/bash/command-not-found.nix
Eelco Dolstra b89f941b20 Provide missing command suggestions, Ubuntu style
If the user tries to run a program that doesn't exist from Bash, the
program name is looked up in a database that maps to Nix package
names.  If it is found, we print out a message like:

  $ pdflatex
  The program ‘pdflatex’ is currently not installed. It is provided by
  several packages. You can install it by typing one of the following:
    nix-env -i tetex
    nix-env -i texlive-core

If the environment variable $NIX_AUTO_INSTALL is set, the command is
installed and executed automatically:

  $ hello --version
  The program ‘hello’ is currently not installed. It is provided by
  the package ‘hello’, which I will now install for you.
  installing `hello-2.8'
  hello (GNU hello) 2.8
  Copyright (C) 2011 Free Software Foundation, Inc. ...

To use this, you must currently manually put the SQLite programs
database in /var/lib/nixos/programs.sqlite.  In the future, this file
should be provided as part of the NixOS channel so it gets updated
automatically.  To get a test version:

  $ curl http://nixos.org/~eelco/programs.sqlite.xz | xz -d > /var/lib/nixos/programs.sqlite
2013-01-30 15:00:59 +01:00

49 lines
1.2 KiB
Nix

# This module provides suggestions of packages to install if the user
# tries to run a missing command in Bash. This is implemented using a
# SQLite database that maps program names to Nix package names (e.g.,
# "pdflatex" is mapped to "tetex").
{ config, pkgs, ... }:
with pkgs.lib;
let
commandNotFound = pkgs.substituteAll {
name = "command-not-found";
dir = "bin";
src = ./command-not-found.pl;
isExecutable = true;
inherit (pkgs) perl;
perlFlags = concatStrings (map (path: "-I ${path}/lib/perl5/site_perl ")
[ pkgs.perlPackages.DBI pkgs.perlPackages.DBDSQLite ]);
};
in
{
environment.interactiveShellInit =
''
# This function is called whenever a command is not found.
command_not_found_handle() {
local p=/run/current-system/sw/bin/command-not-found
if [ -x $p -a -f /var/lib/nixos/programs.sqlite ]; then
# Run the helper program.
$p "$1"
# Retry the command if we just installed it.
if [ $? = 126 ]; then
"$@"
fi
else
echo "$1: command not found" >&2
fi
}
'';
environment.systemPackages = [ commandNotFound ];
# TODO: tab completion for uninstalled commands! :-)
}