command-not-found: sync with nixpkgs (#7499)

updates command-not-found.pl and adds fish compatibility

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

@@ -10,6 +10,24 @@ 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;
@@ -21,11 +39,24 @@ my $res = $dbh->selectall_arrayref(
     "select package from Programs where system = ? and name = ?",
     { Slice => {} }, $system, $program);
 
-if (!defined $res || scalar @$res == 0) {
+my $len = !defined $res ? 0 : scalar @$res;
+
+if ($len == 0) {
     print STDERR "$program: command not found\n";
-} elsif (scalar @$res == 1) {
+} elsif ($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;
@@ -34,6 +65,24 @@ 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.
@@ -41,5 +90,6 @@ 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;

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

@@ -18,21 +18,6 @@ let
   commandNotFound = pkgs.runCommand "command-not-found" { } ''
     install -Dm555 ${cnfScript} $out/bin/command-not-found
   '';
-
-  shInit = commandNotFoundHandlerName: ''
-    # This function is called whenever a command is not found.
-    ${commandNotFoundHandlerName}() {
-      local p=${commandNotFound}/bin/command-not-found
-      if [ -x $p -a -f ${cfg.dbPath} ]; then
-        # Run the helper program.
-        $p "$@"
-      else
-        echo "$1: command not found" >&2
-        return 127
-      fi
-    }
-  '';
-
 in
 {
   options.programs.command-not-found = {
@@ -50,8 +35,24 @@ in
   };
 
   config = lib.mkIf cfg.enable {
-    programs.bash.initExtra = shInit "command_not_found_handle";
+    programs.bash.initExtra = ''
-    programs.zsh.initContent = shInit "command_not_found_handler";
+      command_not_found_handle() {
+        '${commandNotFound}/bin/command-not-found' "$@"
+      }
+    '';
+
+    programs.zsh.initContent = ''
+      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
+    '';
 
     home.packages = [ commandNotFound ];
   };