command-not-found: Add ZSH Support

2 files changed, 119 insertions, 0 deletions

diff --git a/nixos/modules/programs/command-not-found/command-not-found.nix b/nixos/modules/programs/command-not-found/command-not-found.nix
new file mode 100644
index 000000000000..bead2dcdcf90
--- /dev/null
+++ b/nixos/modules/programs/command-not-found/command-not-found.nix
@@ -0,0 +1,71 @@
+# 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
+
+  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
+
+{
+
+  programs.bash.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 /nix/var/nix/profiles/per-user/root/channels/nixos/programs.sqlite ]; then
+          # Run the helper program.
+          $p "$1"
+          # 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=/run/current-system/sw/bin/command-not-found
+        if [ -x $p -a -f /nix/var/nix/profiles/per-user/root/channels/nixos/programs.sqlite ]; then
+          # Run the helper program.
+          $p "$1"
+
+          # Retry the command if we just installed it.
+          if [ $? = 126 ]; then
+            "$@"
+          fi
+	else
+          # Indicate than there was an error so ZSH falls back to its default handler
+	  return 127
+        fi
+      }
+    '';
+
+  environment.systemPackages = [ commandNotFound ];
+
+  # TODO: tab completion for uninstalled commands! :-)
+
+}
diff --git a/nixos/modules/programs/command-not-found/command-not-found.pl b/nixos/modules/programs/command-not-found/command-not-found.pl
new file mode 100644
index 000000000000..916649059d37
--- /dev/null
+++ b/nixos/modules/programs/command-not-found/command-not-found.pl
@@ -0,0 +1,48 @@
+#! @perl@/bin/perl -w @perlFlags@
+
+use strict;
+use DBI;
+use DBD::SQLite;
+use Config;
+
+my $program = $ARGV[0];
+
+my $dbPath = "/nix/var/nix/profiles/per-user/root/channels/nixos/programs.sqlite";
+
+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);
+
+if (!defined $res || scalar @$res == 0) {
+    print STDERR "$program: command not found\n";
+} elsif (scalar @$res == 1) {
+    my $package = @$res[0]->{package};
+    if ($ENV{"NIX_AUTO_INSTALL"} // "") {
+        print STDERR <<EOF;
+The program ‘$program’ is currently not installed. It is provided by
+the package ‘$package’, which I will now install for you.
+EOF
+        ;
+        exit 126 if system("nix-env", "-i", $package) == 0;
+    } else {
+        print STDERR <<EOF;
+The program ‘$program’ is currently not installed. You can install it by typing:
+  nix-env -i $package
+EOF
+    }
+} else {
+    print STDERR <<EOF;
+The program ‘$program’ is currently not installed. It is provided by
+several packages. You can install it by typing one of the following:
+EOF
+    print STDERR "  nix-env -i $_->{package}\n" foreach @$res;
+}
+
+exit 127;