1 files changed, 77 insertions, 0 deletions
diff --git a/nix/buildManPages/default.nix b/nix/buildManPages/default.nix
new file mode 100644
index 0000000000..83cf548c77
--- /dev/null
+++ b/nix/buildManPages/default.nix
@@ -0,0 +1,77 @@
+{ depot, ... }:
+
+let
+  inherit (depot.third_party)
+    lib
+    gzip
+    mandoc
+    coreutils
+    ;
+
+  inherit (depot.nix)
+    runExecline
+    getBins
+    ;
+
+  bins = getBins mandoc [ "mandoc" ]
+      // getBins gzip   [ "gzip" ]
+      // getBins coreutils [ "mkdir" "ln" "cp" ]
+      ;
+
+  defaultGzip = true;
+
+  basename = gzip: { name, section, ... }:
+    "${name}.${toString section}${lib.optionalString gzip ".gz"}";
+
+  manDir = { section, ... }:
+    "\${out}/share/man/man${toString section}";
+
+  target = gzip: args:
+    "${manDir args}/${basename gzip args}";
+
+  buildManPage =
+    { requireLint ? false
+    , gzip ? defaultGzip
+    , ...
+    }:
+    { content
+    , ...
+    }@page: let
+      source = builtins.toFile (basename false page) content;
+    in runExecline (basename gzip page) {} ([
+      (if requireLint then "if" else "foreground") [
+        bins.mandoc "-mdoc" "-T" "lint" source
+      ]
+      "importas" "out" "out"
+    ] ++ (if gzip then [
+      "redirfd" "-w" "1" "$out"
+      bins.gzip "-c" source
+    ] else [
+      bins.cp "--reflink=auto" source "$out"
+    ]));
+
+  buildManPages =
+    name:
+    { derivationArgs ? {}
+    , gzip ? defaultGzip
+    , ...
+    }@args:
+    pages:
+    runExecline "${name}-man-pages" {
+      inherit derivationArgs;
+    } ([
+      "importas" "out" "out"
+    ] ++ lib.concatMap ({ name, section, content }@page: [
+      "if" [ bins.mkdir "-p" (manDir page) ]
+      "if" [
+        bins.ln "-s"
+        (buildManPage args page)
+        (target gzip page)
+      ]
+    ]) pages);
+
+in {
+  __functor = _: buildManPages;
+
+  single = buildManPage;
+}