From d7a9e5346ce61876658c840acc22768bcfc882f1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <theophane.hufschmitt@tweag.io>
Date: Mon, 12 Jun 2023 08:52:24 +0200
Subject: [PATCH] Redirect some Nix command outputs to a pager

Make `nix search`, `nix flake show` and `nix flake metadata` pipe their
output into a pager to make their result easier to visualise.
---
 src/nix/flake.cc  | 3 +++
 src/nix/search.cc | 1 +
 2 files changed, 4 insertions(+)

diff --git a/src/nix/flake.cc b/src/nix/flake.cc
index 1eea52e15..6d225043f 100644
--- a/src/nix/flake.cc
+++ b/src/nix/flake.cc
@@ -167,6 +167,8 @@ struct CmdFlakeMetadata : FlakeCommand, MixJSON
         auto lockedFlake = lockFlake();
         auto & flake = lockedFlake.flake;
 
+        RunPager pager;
+
         if (json) {
             nlohmann::json j;
             if (flake.description)
@@ -1128,6 +1130,7 @@ struct CmdFlakeShow : FlakeCommand, MixJSON
             Activity act(*logger, lvlInfo, actUnknown,
                 fmt("evaluating '%s'", concatStringsSep(".", attrPathS)));
 
+            std::optional<RunPager> pager = json ? std::nullopt : std::optional<RunPager>(RunPager());
             try {
                 auto recurse = [&]()
                 {
diff --git a/src/nix/search.cc b/src/nix/search.cc
index c92ed1663..cc437c9cb 100644
--- a/src/nix/search.cc
+++ b/src/nix/search.cc
@@ -63,6 +63,7 @@ struct CmdSearch : InstallableValueCommand, MixJSON
 
     void run(ref<Store> store, ref<InstallableValue> installable) override
     {
+        RunPager pager;
         settings.readOnlyMode = true;
         evalSettings.enableImportFromDerivation.setDefault(false);