nixpkgs/pkgs/tools/backup/flockit/default.nix
Bas van Dijk 872d8fc5c9 flockit: init at 2012-08-11
The flockit library and tool exists solely because rsync doesn't have file
locking.

It's not used like a normal library; you don't link against it, and you don't
have to patch your source code to use it. It's inserted between your program and
its libraries by use of LD_PRELOAD.

For example:

  $ env LD_PRELOAD=$(nix-build -A pkgs.flockit)/lib/libflockit.so FLOCKIT_FILE_PREFIX=test rsync SRC DEST

Besides the library a handy executable is provided which can simplify the above to:

  $ $(nix-build -A pkgs.flockit)/bin/flockit test rsync SRC DEST

Also see the following blog post:
https://www.swiftstack.com/blog/2012/08/15/old-school-monkeypatching/
2017-08-06 00:38:29 +02:00

52 lines
1.6 KiB
Nix

{ stdenv, fetchFromGitHub }:
stdenv.mkDerivation rec {
name = "flockit-${version}";
version = "2012-08-11";
src = fetchFromGitHub {
owner = "smerritt";
repo = "flockit";
rev = "5c2b2092f8edcc8e3e2eb6ef66c968675dbfa686";
sha256 = "0vajck9q2677gpn9a4flkyz7mw69ql1647cjwqh834nrcr2b5164";
};
installPhase = ''
mkdir -p $out/lib $out/bin
cp ./libflockit.so $out/lib
(cat <<EOI
#!/bin/sh
env LD_PRELOAD="$out/lib/libflockit.so" FLOCKIT_FILE_PREFIX=\$1 \''${@:2}
EOI
) > $out/bin/flockit
chmod +x $out/bin/flockit
'';
meta = with stdenv.lib; {
description = "LD_PRELOAD shim to add file locking to programs that don't do it (I'm looking at you, rsync!)";
longDescription = ''
This library and tool exists solely because rsync doesn't have file locking.
It's not used like a normal library; you don't link against it, and you
don't have to patch your source code to use it. It's inserted between your
program and its libraries by use of LD_PRELOAD.
For example:
$ env LD_PRELOAD=$(nix-build -A pkgs.flockit)/lib/libflockit.so FLOCKIT_FILE_PREFIX=test rsync SRC DEST
Besides the library a handy executable is provided which can simplify the above to:
$ $(nix-build -A pkgs.flockit)/bin/flockit test rsync SRC DEST
Also see the following blog post:
https://www.swiftstack.com/blog/2012/08/15/old-school-monkeypatching/
'';
homepage = https://github.com/smerritt/flockit;
license = licenses.asl20;
platforms = platforms.linux;
maintainers = [ maintainers.basvandijk ];
};
}