devshell: add prePrompt option

2 files changed, 6 insertions, 0 deletions

diff --git a/example/flake.nix b/example/flake.nix
index 86accf7..0479e01 100644
--- a/example/flake.nix
+++ b/example/flake.nix
@@ -37,6 +37,10 @@
           DATABASE_URL = "postgresql:///${PGDATABASE}?host=${PGHOST}";
         };
 
+        prePrompt = ''
+          echo "<C-d> to exit this development shell."
+        '';
+
         shell = null;
       };
     }
diff --git a/lib/mk-dev-shell.nix b/lib/mk-dev-shell.nix
index fe2ac02..cc7d940 100644
--- a/lib/mk-dev-shell.nix
+++ b/lib/mk-dev-shell.nix
@@ -2,6 +2,7 @@ flake:
 { pkgs
 , tools ? []
 , envVars ? {}
+, prePrompt ? ""
 , shell ? null
 }:
 
@@ -16,6 +17,7 @@ in pkgs.mkShell {
     ${shellLib.ifSomeAttrs envVars shellLib.printEnvVars}
     ${shellLib.ifSomeList tools shellLib.printBins}
     echo
+    ${prePrompt}
 
     ${if (shell != null) then shell else shellLib.startUserShell}
     exit $?