1 files changed, 95 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 00000000000..4d2a89b5158
--- /dev/null
+++ b/nixos/modules/programs/command-not-found/command-not-found.nix
@@ -0,0 +1,95 @@
+# 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" ] && [ -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 "$p" ] && [ -f '${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 ];
+  };
+
+}