lix/src/nix/ls.cc
Eelco Dolstra bbe97dff8b Make the Store API more type-safe
Most functions now take a StorePath argument rather than a Path (which
is just an alias for std::string). The StorePath constructor ensures
that the path is syntactically correct (i.e. it looks like
<store-dir>/<base32-hash>-<name>). Similarly, functions like
buildPaths() now take a StorePathWithOutputs, rather than abusing Path
by adding a '!<outputs>' suffix.

Note that the StorePath type is implemented in Rust. This involves
some hackery to allow Rust values to be used directly in C++, via a
helper type whose destructor calls the Rust type's drop()
function. The main issue is the dynamic nature of C++ move semantics:
after we have moved a Rust value, we should not call the drop function
on the original value. So when we move a value, we set the original
value to bitwise zero, and the destructor only calls drop() if the
value is not bitwise zero. This should be sufficient for most types.

Also lots of minor cleanups to the C++ API to make it more modern
(e.g. using std::optional and std::string_view in some places).
2019-12-10 22:06:05 +01:00

147 lines
4.2 KiB
C++

#include "command.hh"
#include "store-api.hh"
#include "fs-accessor.hh"
#include "nar-accessor.hh"
#include "common-args.hh"
#include "json.hh"
using namespace nix;
struct MixLs : virtual Args, MixJSON
{
std::string path;
bool recursive = false;
bool verbose = false;
bool showDirectory = false;
MixLs()
{
mkFlag('R', "recursive", "list subdirectories recursively", &recursive);
mkFlag('l', "long", "show more file information", &verbose);
mkFlag('d', "directory", "show directories rather than their contents", &showDirectory);
}
void listText(ref<FSAccessor> accessor)
{
std::function<void(const FSAccessor::Stat &, const Path &, const std::string &, bool)> doPath;
auto showFile = [&](const Path & curPath, const std::string & relPath) {
if (verbose) {
auto st = accessor->stat(curPath);
std::string tp =
st.type == FSAccessor::Type::tRegular ?
(st.isExecutable ? "-r-xr-xr-x" : "-r--r--r--") :
st.type == FSAccessor::Type::tSymlink ? "lrwxrwxrwx" :
"dr-xr-xr-x";
std::cout <<
(format("%s %20d %s") % tp % st.fileSize % relPath);
if (st.type == FSAccessor::Type::tSymlink)
std::cout << " -> " << accessor->readLink(curPath)
;
std::cout << "\n";
if (recursive && st.type == FSAccessor::Type::tDirectory)
doPath(st, curPath, relPath, false);
} else {
std::cout << relPath << "\n";
if (recursive) {
auto st = accessor->stat(curPath);
if (st.type == FSAccessor::Type::tDirectory)
doPath(st, curPath, relPath, false);
}
}
};
doPath = [&](const FSAccessor::Stat & st, const Path & curPath,
const std::string & relPath, bool showDirectory)
{
if (st.type == FSAccessor::Type::tDirectory && !showDirectory) {
auto names = accessor->readDirectory(curPath);
for (auto & name : names)
showFile(curPath + "/" + name, relPath + "/" + name);
} else
showFile(curPath, relPath);
};
auto st = accessor->stat(path);
if (st.type == FSAccessor::Type::tMissing)
throw Error(format("path '%1%' does not exist") % path);
doPath(st, path,
st.type == FSAccessor::Type::tDirectory ? "." : std::string(baseNameOf(path)),
showDirectory);
}
void list(ref<FSAccessor> accessor)
{
if (path == "/") path = "";
if (json) {
JSONPlaceholder jsonRoot(std::cout);
listNar(jsonRoot, accessor, path, recursive);
} else
listText(accessor);
}
};
struct CmdLsStore : StoreCommand, MixLs
{
CmdLsStore()
{
expectArg("path", &path);
}
Examples examples() override
{
return {
Example{
"To list the contents of a store path in a binary cache:",
"nix ls-store --store https://cache.nixos.org/ -lR /nix/store/0i2jd68mp5g6h2sa5k9c85rb80sn8hi9-hello-2.10"
},
};
}
std::string description() override
{
return "show information about a store path";
}
void run(ref<Store> store) override
{
list(store->getFSAccessor());
}
};
struct CmdLsNar : Command, MixLs
{
Path narPath;
CmdLsNar()
{
expectArg("nar", &narPath);
expectArg("path", &path);
}
Examples examples() override
{
return {
Example{
"To list a specific file in a NAR:",
"nix ls-nar -l hello.nar /bin/hello"
},
};
}
std::string description() override
{
return "show information about the contents of a NAR file";
}
void run() override
{
list(makeNarAccessor(make_ref<std::string>(readFile(narPath, true))));
}
};
static auto r1 = registerCommand<CmdLsStore>("ls-store");
static auto r2 = registerCommand<CmdLsNar>("ls-nar");