cups-pdf-to-pdf: init at unstable-2021-12-22

Note that cups-pdf refuses to run without root privileges.
To use the binary, one has to either convince cups to
call it with root privileges, or install it suid root.

Also note that currently, this cups-pdf-fork produces
small pdfs with selectable text, as promised.
However, copying the text produces "garbled" text
(characters are randomly reassigned).
This is a known issue and I don't know how to fix it:

https://github.com/alexivkin/CUPS-PDF-to-PDF/issues/7

pkgs/misc/cups/drivers/cups-pdf-to-pdf/default.nix

···
+{ lib
+, stdenv
+, fetchFromGitHub
+, cups
+, coreutils
+}:
+
+stdenv.mkDerivation rec {
+  pname = "cups-pdf-to-pdf";
+  version = "unstable-2021-12-22";
+
+  src = fetchFromGitHub {
+    owner = "alexivkin";
+    repo = "CUPS-PDF-to-PDF";
+    rev = "c14428c2ca8e95371daad7db6d11c84046b1a2d4";
+    hash = "sha256-pa4PFf8OAFSra0hSazmKUfbMYL/cVWvYA1lBf7c7jmY=";
+  };
+
+  buildInputs = [ cups ];
+
+  postPatch = ''
+    sed -r 's|(gscall, size, ")cp |\1${coreutils}/bin/cp |' cups-pdf.c -i
+  '';
+
+  # gcc command line is taken from original cups-pdf's README file
+  # https://fossies.org/linux/cups-pdf/README
+  # however, we replace gcc with $CC following
+  # https://nixos.org/manual/nixpkgs/stable/#sec-darwin
+  buildPhase = ''
+    runHook preBuild
+    $CC -O9 -s cups-pdf.c -o cups-pdf -lcups
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+    install -Dt $out/lib/cups/backend cups-pdf
+    install -Dm 0644 -t $out/etc/cups cups-pdf.conf
+    install -Dm 0644 -t $out/share/cups/model *.ppd
+    runHook postInstall
+  '';
+
+  meta = with lib; {
+    description = "A CUPS backend that turns print jobs into searchable PDF files";
+    homepage = "https://github.com/alexivkin/CUPS-PDF-to-PDF";
+    license = licenses.gpl2Only;
+    maintainers = [ maintainers.yarny ];
+    longDescription = ''
+      cups-pdf is a CUPS backend that generates a PDF file for each print job and puts this file
+      into a folder on the local machine such that the print job's owner can access the file.
+
+      https://www.cups-pdf.de/
+
+      cups-pdf-to-pdf is a fork of cups-pdf which tries hard to preserve the original text of the print job by avoiding rasterization.
+
+      Note that in order to use this package, you have to make sure that the cups-pdf program is called with root privileges.
+    '';
+  };
+}

pkgs/top-level/all-packages.nix

···
 
   cups-dymo = callPackage ../misc/cups/drivers/dymo {};
 
+  cups-pdf-to-pdf = callPackage ../misc/cups/drivers/cups-pdf-to-pdf {};
+
   cups-toshiba-estudio = callPackage ../misc/cups/drivers/estudio {};
 
   cups-zj-58 =  callPackage ../misc/cups/drivers/zj-58 { };