diff --git a/doc/manual/src/release-notes/rl-next.md b/doc/manual/src/release-notes/rl-next.md index c869b5e2f..c9753f9aa 100644 --- a/doc/manual/src/release-notes/rl-next.md +++ b/doc/manual/src/release-notes/rl-next.md @@ -1 +1,3 @@ # Release X.Y (202?-??-??) + +* Various nix commands can now read expressions from stdin with `--file -`. diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc index b7623d4ba..784117569 100644 --- a/src/libcmd/installables.cc +++ b/src/libcmd/installables.cc @@ -134,7 +134,9 @@ SourceExprCommand::SourceExprCommand() addFlag({ .longName = "file", .shortName = 'f', - .description = "Interpret installables as attribute paths relative to the Nix expression stored in *file*.", + .description = + "Interpret installables as attribute paths relative to the Nix expression stored in *file*. " + "If *file* is the character -, then a Nix expression will be read from standard input.", .category = installablesCategory, .labels = {"file"}, .handler = {&file}, @@ -695,7 +697,10 @@ std::vector> SourceExprCommand::parseInstallables( auto state = getEvalState(); auto vFile = state->allocValue(); - if (file) + if (file == "-") { + auto e = state->parseStdin(); + state->eval(e, *vFile); + } else if (file) state->evalFile(lookupFileArg(*state, *file), *vFile); else { auto e = state->parseExprFromString(*expr, absPath("."));