From 03ae5e64592d6d62f30158ccfa804f1b4135a596 Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Mon, 8 May 2017 18:39:33 +0200 Subject: [PATCH] Add "nix edit" command This is a little convenience command that opens the Nix expression of the specified package. For example, nix edit nixpkgs.perlPackages.Moose opens in $EDITOR (at the right line number for some editors). This requires the package to have a meta.position attribute. --- src/nix/edit.cc | 75 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 src/nix/edit.cc diff --git a/src/nix/edit.cc b/src/nix/edit.cc new file mode 100644 index 000000000..632b55577 --- /dev/null +++ b/src/nix/edit.cc @@ -0,0 +1,75 @@ +#include "command.hh" +#include "shared.hh" +#include "eval.hh" +#include "attr-path.hh" + +#include + +using namespace nix; + +struct CmdEdit : InstallablesCommand +{ + std::string name() override + { + return "edit"; + } + + std::string description() override + { + return "open the Nix expression of a Nix package in $EDITOR"; + } + + Examples examples() override + { + return { + Example{ + "To open the Nix expression of the GNU Hello package:", + "nix edit nixpkgs.hello" + }, + }; + } + + void run(ref store) override + { + auto state = getEvalState(); + + for (auto & i : installables) { + auto v = i->toValue(*state); + + Value * v2; + try { + auto dummyArgs = state->allocBindings(0); + v2 = findAlongAttrPath(*state, "meta.position", *dummyArgs, *v); + } catch (Error &) { + throw Error("package ‘%s’ has no source location information", i->what()); + } + + auto pos = state->forceString(*v2); + debug("position is %s", pos); + + auto colon = pos.rfind(':'); + if (colon == std::string::npos) + throw Error("cannot parse meta.position attribute ‘%s’", pos); + + std::string filename(pos, 0, colon); + int lineno = std::stoi(std::string(pos, colon + 1)); + + auto editor = getEnv("EDITOR", "cat"); + + Strings args{editor}; + + if (editor.find("emacs") != std::string::npos || + editor.find("nano") != std::string::npos || + editor.find("vim") != std::string::npos) + args.push_back(fmt("+%d", lineno)); + + args.push_back(filename); + + execvp(editor.c_str(), stringsToCharPtrs(args).data()); + + throw SysError("cannot run editor ‘%s’", editor); + } + } +}; + +static RegisterCommand r1(make_ref());