diff --git a/nix/writeExecline/OWNERS b/nix/writeExecline/OWNERS new file mode 100644 index 000000000..a742d0d22 --- /dev/null +++ b/nix/writeExecline/OWNERS @@ -0,0 +1,3 @@ +inherited: true +owners: + - Profpatsch diff --git a/nix/writeExecline/default.nix b/nix/writeExecline/default.nix new file mode 100644 index 000000000..0916e2d58 --- /dev/null +++ b/nix/writeExecline/default.nix @@ -0,0 +1,67 @@ +{ pkgs, lib, ... }: + +# Write an execline script, represented as nested nix lists. +# Everything is escaped correctly. +# https://skarnet.org/software/execline/ + +# TODO(Profpatsch) upstream into nixpkgs + +let + # replaces " and \ to \" and \\ respectively and quote with " + # e.g. + # a"b\c -> "a\"b\\c" + # a\"bc -> "a\\\"bc" + escapeExeclineArg = arg: + ''"${builtins.replaceStrings [ ''"'' ''\'' ] [ ''\"'' ''\\'' ] (toString arg)}"''; + + # Escapes an execline (list of execline strings) to be passed to execlineb + # Give it a nested list of strings. Nested lists are interpolated as execline + # blocks ({}). + # Everything is quoted correctly. + # + # Example: + # escapeExecline [ "if" [ "somecommand" ] "true" ] + # == ''"if" { "somecommand" } "true"'' + escapeExecline = execlineList: lib.concatStringsSep " " + (let + go = arg: + if builtins.isString arg then [(escapeExeclineArg arg)] + else if builtins.isPath arg then [(escapeExeclineArg "${arg}")] + else if lib.isDerivation arg then [(escapeExeclineArg arg)] + else if builtins.isList arg then [ "{" ] ++ builtins.concatMap go arg ++ [ "}" ] + else abort "escapeExecline can only hande nested lists of strings, was ${lib.generators.toPretty {} arg}"; + in builtins.concatMap go execlineList); + +in + +name: +{ + # "var": substitute readNArgs variables and start $@ + # from the (readNArgs+1)th argument + # "var-full": substitute readNArgs variables and start $@ from $0 + # "env": don’t substitute, set # and 0…n environment vaariables, where n=$# + # "none": don’t substitute or set any positional arguments + # "env-no-push": like "env", but bypass the push-phase. Not recommended. + argMode ? "var", + # Number of arguments to be substituted as variables (passed to "var"/"-s" or "var-full"/"-S" + readNArgs ? 0, +}: +# Nested list of lists of commands. +# Inner lists are translated to execline blocks. +argList: + +let + env = + if argMode == "var" then "s${toString readNArgs}" + else if argMode == "var-full" then "S${toString readNArgs}" + else if argMode == "env" then "" + else if argMode == "none" then "P" + else if argMode == "env-no-push" then "p" + else abort ''"${toString argMode}" is not a valid argMode, use one of "var", "var-full", "env", "none", "env-no-push".''; + +in + # TODO(Profpatsch): rewrite `writeScript` with `runExecline` + pkgs.writeScript name '' + #!${pkgs.execline}/bin/execlineb -W${env} + ${escapeExecline argList} + '' diff --git a/third_party/default.nix b/third_party/default.nix index 4c29ba480..c13b8f1b3 100644 --- a/third_party/default.nix +++ b/third_party/default.nix @@ -59,6 +59,7 @@ let cudatoolkit darwin dockerTools + execline fetchFromGitHub fetchgit fetchurl @@ -130,6 +131,7 @@ let thttpd tree which + writeScript writeShellScript writeShellScriptBin writeText