nixpkgs/nixos/modules/programs/command-not-found/command-not-found.nix
rnhmjoj 61b7cab481
treewide: use perl.withPackages when possible
Since 03eaa48 added perl.withPackages, there is a canonical way to
create a perl interpreter from a list of libraries, for use in script
shebangs or generic build inputs. This method is declarative (what we
are doing is clear), produces short shebangs[1] and needs not to wrap
existing scripts.

Unfortunately there are a few exceptions that I've found:

  1. Scripts that are calling perl with the -T switch. This makes perl
  ignore PERL5LIB, which is what perl.withPackages is using to inform
  the interpreter of the library paths.

  2. Perl packages that depends on libraries in their own path. This
  is not possible because perl.withPackages works at build time. The
  workaround is to add `-I $out/${perl.libPrefix}` to the shebang.

In all other cases I propose to switch to perl.withPackages.

[1]: https://lwn.net/Articles/779997/
2021-03-31 21:35:37 +02:00

96 lines
2.5 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, lib, pkgs, ... }:
with lib;
let
cfg = config.programs.command-not-found;
commandNotFound = pkgs.substituteAll {
name = "command-not-found";
dir = "bin";
src = ./command-not-found.pl;
isExecutable = true;
inherit (cfg) dbPath;
perl = pkgs.perl.withPackages (p: [ p.DBDSQLite p.StringShellQuote ]);
};
in
{
options.programs.command-not-found = {
enable = mkOption {
type = types.bool;
default = true;
description = ''
Whether interactive shells should show which Nix package (if
any) provides a missing command.
'';
};
dbPath = mkOption {
default = "/nix/var/nix/profiles/per-user/root/channels/nixos/programs.sqlite" ;
description = ''
Absolute path to programs.sqlite.
By default this file will be provided by your channel
(nixexprs.tar.xz).
'';
type = types.path;
};
};
config = mkIf cfg.enable {
programs.bash.interactiveShellInit =
''
# This function is called whenever a command is not found.
command_not_found_handle() {
local p=${commandNotFound}/bin/command-not-found
if [ -x $p -a -f ${cfg.dbPath} ]; then
# Run the helper program.
$p "$@"
# Retry the command if we just installed it.
if [ $? = 126 ]; then
"$@"
else
return 127
fi
else
echo "$1: command not found" >&2
return 127
fi
}
'';
programs.zsh.interactiveShellInit =
''
# This function is called whenever a command is not found.
command_not_found_handler() {
local p=${commandNotFound}/bin/command-not-found
if [ -x $p -a -f ${cfg.dbPath} ]; then
# Run the helper program.
$p "$@"
# Retry the command if we just installed it.
if [ $? = 126 ]; then
"$@"
else
return 127
fi
else
# Indicate than there was an error so ZSH falls back to its default handler
echo "$1: command not found" >&2
return 127
fi
}
'';
environment.systemPackages = [ commandNotFound ];
};
}