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#include "hash.hh"
#include "shared.hh"
#include "download.hh"
#include "store-api.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "common-opts.hh"
#include "attr-path.hh"
#include <iostream>
using namespace nix;
/* If ‘uri’ starts with ‘mirror://’, then resolve it using the list of
mirrors defined in Nixpkgs. */
string resolveMirrorUri(EvalState & state, string uri)
{
if (string(uri, 0, 9) != "mirror://") return uri;
string s(uri, 9);
auto p = s.find('/');
if (p == string::npos) throw Error("invalid mirror URI");
string mirrorName(s, 0, p);
Value vMirrors;
state.eval(state.parseExprFromString("import <nixpkgs/pkgs/build-support/fetchurl/mirrors.nix>", "."), vMirrors);
state.forceAttrs(vMirrors);
auto mirrorList = vMirrors.attrs->find(state.symbols.create(mirrorName));
if (mirrorList == vMirrors.attrs->end())
throw Error(format("unknown mirror name ‘%1%’") % mirrorName);
state.forceList(*mirrorList->value);
if (mirrorList->value->listSize() < 1)
throw Error(format("mirror URI ‘%1%’ did not expand to anything") % uri);
string mirror = state.forceString(*mirrorList->value->listElems()[0]);
return mirror + (hasSuffix(mirror, "/") ? "" : "/") + string(s, p + 1);
}
int main(int argc, char * * argv)
{
return handleExceptions(argv[0], [&]() {
initNix();
initGC();
HashType ht = htSHA256;
std::vector<string> args;
Strings searchPath;
bool printPath = getEnv("PRINT_PATH") != "";
bool fromExpr = false;
string attrPath;
std::map<string, string> autoArgs_;
parseCmdLine(argc, argv, [&](Strings::iterator & arg, const Strings::iterator & end) {
if (*arg == "--help")
showManPage("nix-prefetch-url");
else if (*arg == "--version")
printVersion("nix-prefetch-url");
else if (*arg == "--type") {
string s = getArg(*arg, arg, end);
ht = parseHashType(s);
if (ht == htUnknown)
throw UsageError(format("unknown hash type ‘%1%’") % s);
}
else if (*arg == "--print-path")
printPath = true;
else if (*arg == "--attr" || *arg == "-A") {
fromExpr = true;
attrPath = getArg(*arg, arg, end);
}
else if (parseAutoArgs(arg, end, autoArgs_))
;
else if (parseSearchPathArg(arg, end, searchPath))
;
else if (*arg != "" && arg->at(0) == '-')
return false;
else
args.push_back(*arg);
return true;
});
if (args.size() > 2)
throw UsageError("too many arguments");
store = openStore();
EvalState state(searchPath);
Bindings & autoArgs(*evalAutoArgs(state, autoArgs_));
/* If -A is given, get the URI from the specified Nix
expression. */
string uri;
if (!fromExpr) {
if (args.empty())
throw UsageError("you must specify a URI");
uri = args[0];
} else {
Path path = resolveExprPath(lookupFileArg(state, args.empty() ? "." : args[0]));
Value vRoot;
state.evalFile(path, vRoot);
Value & v(*findAlongAttrPath(state, attrPath, autoArgs, vRoot));
state.forceAttrs(v);
auto urls = v.attrs->find(state.symbols.create("urls"));
if (urls == v.attrs->end())
throw Error("attribute set does not contain a ‘urls’ attribute");
state.forceList(*urls->value);
if (urls->value->listSize() < 1)
throw Error("‘urls’ list is empty");
uri = state.forceString(*urls->value->listElems()[0]);
}
/* Figure out a name in the Nix store. */
auto name = baseNameOf(uri);
if (name.empty())
throw Error(format("cannot figure out file name for ‘%1%’") % uri);
/* If an expected hash is given, the file may already exist in
the store. */
Hash hash, expectedHash(ht);
Path storePath;
if (args.size() == 2) {
expectedHash = parseHash16or32(ht, args[1]);
storePath = makeFixedOutputPath(false, ht, expectedHash, name);
if (store->isValidPath(storePath))
hash = expectedHash;
else
storePath.clear();
}
if (storePath.empty()) {
auto actualUri = resolveMirrorUri(state, uri);
if (uri != actualUri)
printMsg(lvlInfo, format("‘%1%’ expands to ‘%2%’") % uri % actualUri);
/* Download the file. */
auto result = downloadFile(actualUri);
/* Copy the file to the Nix store. FIXME: if RemoteStore
implemented addToStoreFromDump() and downloadFile()
supported a sink, we could stream the download directly
into the Nix store. */
AutoDelete tmpDir(createTempDir(), true);
Path tmpFile = (Path) tmpDir + "/tmp";
writeFile(tmpFile, result.data);
/* FIXME: inefficient; addToStore() will also hash
this. */
hash = hashString(ht, result.data);
if (expectedHash != Hash(ht) && expectedHash != hash)
throw Error(format("hash mismatch for ‘%1%’") % uri);
storePath = store->addToStore(name, tmpFile, false, ht);
}
if (!printPath)
printMsg(lvlInfo, format("path is ‘%1%’") % storePath);
std::cout << printHash16or32(hash) << std::endl;
if (printPath)
std::cout << storePath << std::endl;
});
}
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