diff options
| -rw-r--r-- | src/nix/eval.cc | 55 | ||||
| -rw-r--r-- | tests/pure-eval.sh | 8 |
2 files changed, 59 insertions, 4 deletions
diff --git a/src/nix/eval.cc b/src/nix/eval.cc index 8da81d667..0f02919de 100644 --- a/src/nix/eval.cc +++ b/src/nix/eval.cc @@ -3,6 +3,7 @@ #include "shared.hh" #include "store-api.hh" #include "eval.hh" +#include "eval-inline.hh" #include "json.hh" #include "value-to-json.hh" #include "progress-bar.hh" @@ -13,6 +14,7 @@ struct CmdEval : MixJSON, InstallableCommand { bool raw = false; std::optional<std::string> apply; + std::optional<Path> writeTo; CmdEval() { @@ -24,6 +26,13 @@ struct CmdEval : MixJSON, InstallableCommand .labels = {"expr"}, .handler = {&apply}, }); + + addFlag({ + .longName = "write-to", + .description = "write a string or attrset of strings to 'path'", + .labels = {"path"}, + .handler = {&writeTo}, + }); } std::string description() override @@ -66,7 +75,7 @@ struct CmdEval : MixJSON, InstallableCommand auto state = getEvalState(); - auto v = installable->toValue(*state).first; + auto [v, pos] = installable->toValue(*state); PathSet context; if (apply) { @@ -77,13 +86,51 @@ struct CmdEval : MixJSON, InstallableCommand v = vRes; } - if (raw) { + if (writeTo) { + stopProgressBar(); + + if (pathExists(*writeTo)) + throw Error("path '%s' already exists", *writeTo); + + std::function<void(Value & v, const Pos & pos, const Path & path)> recurse; + + recurse = [&](Value & v, const Pos & pos, const Path & path) + { + state->forceValue(v); + if (v.type == tString) + // FIXME: disallow strings with contexts? + writeFile(path, v.string.s); + else if (v.type == tAttrs) { + if (mkdir(path.c_str(), 0777) == -1) + throw SysError("creating directory '%s'", path); + for (auto & attr : *v.attrs) + try { + if (attr.name == "." || attr.name == "..") + throw Error("invalid file name '%s'", attr.name); + recurse(*attr.value, *attr.pos, path + "/" + std::string(attr.name)); + } catch (Error & e) { + e.addTrace(*attr.pos, hintfmt("while evaluating the attribute '%s'", attr.name)); + throw; + } + } + else + throw TypeError("value at '%s' is not a string or an attribute set", pos); + }; + + recurse(*v, pos, *writeTo); + } + + else if (raw) { stopProgressBar(); std::cout << state->coerceToString(noPos, *v, context); - } else if (json) { + } + + else if (json) { JSONPlaceholder jsonOut(std::cout); printValueAsJSON(*state, true, *v, jsonOut, context); - } else { + } + + else { state->forceValueDeep(*v); logger->cout("%s", *v); } diff --git a/tests/pure-eval.sh b/tests/pure-eval.sh index 43a765997..561ca53fb 100644 --- a/tests/pure-eval.sh +++ b/tests/pure-eval.sh @@ -16,3 +16,11 @@ nix eval --expr 'assert 1 + 2 == 3; true' [[ $(nix eval --impure --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x") == 123 ]] (! nix eval --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; })).x") nix eval --expr "(import (builtins.fetchurl { url = file://$(pwd)/pure-eval.nix; sha256 = \"$(nix hash-file pure-eval.nix --type sha256)\"; })).x" + +rm -rf $TEST_ROOT/eval-out +nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ x = "foo" + "bar"; y = { z = "bla"; }; }' +[[ $(cat $TEST_ROOT/eval-out/x) = foobar ]] +[[ $(cat $TEST_ROOT/eval-out/y/z) = bla ]] + +rm -rf $TEST_ROOT/eval-out +(! nix eval --store dummy:// --write-to $TEST_ROOT/eval-out --expr '{ "." = "bla"; }') |