push sheeet

nixos/modules/programs/command-not-found/command-not-found.nix

@@ -0,0 +1,84 @@
+# 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,
+  ...
+}:
+
+let
+  cfg = config.programs.command-not-found;
+  commandNotFound = pkgs.replaceVarsWith {
+    name = "command-not-found";
+    dir = "bin";
+    src = ./command-not-found.pl;
+    isExecutable = true;
+    replacements = {
+      inherit (cfg) dbPath;
+      perl = pkgs.perl.withPackages (p: [
+        p.DBDSQLite
+        p.StringShellQuote
+      ]);
+    };
+  };
+
+in
+
+{
+  options.programs.command-not-found = {
+
+    enable = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = ''
+        Whether interactive shells should show which Nix package (if
+        any) provides a missing command.
+
+        Requires nix-channels to be set and downloaded (sudo nix-channels --update.)
+
+        See also nix-index and nix-index-database as an alternative for flakes-based systems.
+
+        Additionally, having the env var NIX_AUTO_RUN set will automatically run the matching package, and with NIX_AUTO_RUN_INTERACTIVE it will confirm the package before running.
+      '';
+    };
+
+    dbPath = lib.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 = lib.types.path;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    programs.bash.interactiveShellInit = ''
+      command_not_found_handle() {
+        '${commandNotFound}/bin/command-not-found' "$@"
+      }
+    '';
+
+    programs.zsh.interactiveShellInit = ''
+      command_not_found_handler() {
+        '${commandNotFound}/bin/command-not-found' "$@"
+      }
+    '';
+
+    # NOTE: Fish by itself checks for nixos command-not-found, let's instead makes it explicit.
+    programs.fish.interactiveShellInit = ''
+      function fish_command_not_found
+         "${commandNotFound}/bin/command-not-found" $argv
+      end
+    '';
+
+    environment.systemPackages = [ commandNotFound ];
+  };
+
+}

nixos/modules/programs/command-not-found/command-not-found.pl

@@ -0,0 +1,95 @@
+#! @perl@/bin/perl -w
+
+use strict;
+use DBI;
+use DBD::SQLite;
+use String::ShellQuote;
+use Config;
+
+my $program = $ARGV[0];
+
+my $dbPath = "@dbPath@";
+
+if (! -e $dbPath) {
+    print STDERR "$program: command not found\n";
+    print STDERR "\n";
+    print STDERR "command-not-found: Missing package database\n";
+    print STDERR "command-not-found is a tool for searching for missing packages.\n";
+    print STDERR "No database was found, this likely means the database hasn't been generated yet.\n";
+    print STDERR "This tool requires nix-channels to generate the database for the `nixos` channel.\n";
+    print STDERR "\n";
+    print STDERR "If you are using nix-channels you can run:\n";
+    print STDERR "    sudo nix-channels --update\n";
+    print STDERR "\n";
+    print STDERR "If you are using flakes, see nix-index and nix-index-database.\n";
+    print STDERR "\n";
+    print STDERR "If you would like to disable this message you can set:\n";
+    print STDERR "    programs.command-not-found.enable = false;\n";
+    exit 127;
+}
+
+my $dbh = DBI->connect("dbi:SQLite:dbname=$dbPath", "", "")
+    or die "cannot open database `$dbPath'";
+$dbh->{RaiseError} = 0;
+$dbh->{PrintError} = 0;
+
+my $system = $ENV{"NIX_SYSTEM"} // $Config{myarchname};
+
+my $res = $dbh->selectall_arrayref(
+    "select package from Programs where system = ? and name = ?",
+    { Slice => {} }, $system, $program);
+
+my $len = !defined $res ? 0 : scalar @$res;
+
+if ($len == 0) {
+    print STDERR "$program: command not found\n";
+} elsif ($len == 1) {
+    my $package = @$res[0]->{package};
+    if ($ENV{"NIX_AUTO_RUN"} // "") {
+        if ($ENV{"NIX_AUTO_RUN_INTERACTIVE"} // "") {
+            while (1) {
+                print STDERR "'$program' from package '$package' will be run, confirm? [yn]: ";
+                chomp(my $comfirm = <STDIN>);
+                if (lc $comfirm eq "n") {
+                    exit 0;
+                } elsif (lc $comfirm eq "y") {
+                    last;
+                }
+            }
+        }
+        exec("nix-shell", "-p", $package, "--run", shell_quote("exec", @ARGV));
+    } else {
+        print STDERR <<EOF;
+The program '$program' is not in your PATH. You can make it available in an
+ephemeral shell by typing:
+  nix-shell -p $package
+EOF
+    }
+} else {
+    if ($ENV{"NIX_AUTO_RUN"} // "") {
+        print STDERR "Select a package that provides '$program':\n";
+        for my $i (0 .. $len - 1) {
+            print STDERR "  [", $i + 1, "]: @$res[$i]->{package}\n";
+        }
+        my $choice = 0;
+        while (1) { # exec will break this loop
+            no warnings "numeric";
+            print STDERR "Your choice [1-${len}]: ";
+            # 0 can be invalid user input like non-number string
+            # so we start from 1
+            $choice = <STDIN> + 0;
+            if (1 <= $choice && $choice <= $len) {
+                exec("nix-shell", "-p", @$res[$choice - 1]->{package},
+                    "--run", shell_quote("exec", @ARGV));
+            }
+        }
+    } else {
+        print STDERR <<EOF;
+The program '$program' is not in your PATH. It is provided by several packages.
+You can make it available in an ephemeral shell by typing one of the following:
+EOF
+        print STDERR "  nix-shell -p $_->{package}\n" foreach @$res;
+    }
+}
+
+exit 127;