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-rw-r--r--src/nix-prefetch-url/local.mk7
-rw-r--r--src/nix-prefetch-url/nix-prefetch-url.cc210
2 files changed, 217 insertions, 0 deletions
diff --git a/src/nix-prefetch-url/local.mk b/src/nix-prefetch-url/local.mk
new file mode 100644
index 000000000000..3e7735406af0
--- /dev/null
+++ b/src/nix-prefetch-url/local.mk
@@ -0,0 +1,7 @@
+programs += nix-prefetch-url
+
+nix-prefetch-url_DIR := $(d)
+
+nix-prefetch-url_SOURCES := $(d)/nix-prefetch-url.cc
+
+nix-prefetch-url_LIBS = libmain libexpr libstore libutil libformat
diff --git a/src/nix-prefetch-url/nix-prefetch-url.cc b/src/nix-prefetch-url/nix-prefetch-url.cc
new file mode 100644
index 000000000000..73a2845e07a5
--- /dev/null
+++ b/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -0,0 +1,210 @@
+#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_;
+        bool unpack = false;
+        string name;
+
+        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 (*arg == "--unpack")
+                unpack = true;
+            else if (*arg == "--name")
+                name = 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);
+
+            /* Extract the URI. */
+            auto attr = v.attrs->find(state.symbols.create("urls"));
+            if (attr == v.attrs->end())
+                throw Error("attribute set does not contain a ‘urls’ attribute");
+            state.forceList(*attr->value);
+            if (attr->value->listSize() < 1)
+                throw Error("‘urls’ list is empty");
+            uri = state.forceString(*attr->value->listElems()[0]);
+
+            /* Extract the hash mode. */
+            attr = v.attrs->find(state.symbols.create("outputHashMode"));
+            if (attr == v.attrs->end())
+                printMsg(lvlInfo, "warning: this does not look like a fetchurl call");
+            else
+                unpack = state.forceString(*attr->value) == "recursive";
+
+            /* Extract the name. */
+            if (name.empty()) {
+                attr = v.attrs->find(state.symbols.create("name"));
+                if (attr != v.attrs->end())
+                    name = state.forceString(*attr->value);
+            }
+        }
+
+        /* Figure out a name in the Nix store. */
+        if (name.empty())
+            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(unpack, ht, expectedHash, name);
+            if (store->isValidPath(storePath))
+                hash = expectedHash;
+            else
+                storePath.clear();
+        }
+
+        if (storePath.empty()) {
+
+            auto actualUri = resolveMirrorUri(state, uri);
+
+            /* Download the file. */
+            auto result = downloadFile(actualUri, DownloadOptions());
+
+            AutoDelete tmpDir(createTempDir(), true);
+            Path tmpFile = (Path) tmpDir + "/tmp";
+            writeFile(tmpFile, result.data);
+
+            /* Optionally unpack the file. */
+            if (unpack) {
+                printMsg(lvlInfo, "unpacking...");
+                Path unpacked = (Path) tmpDir + "/unpacked";
+                createDirs(unpacked);
+                if (hasSuffix(baseNameOf(uri), ".zip"))
+                    runProgram("unzip", true, {"-qq", tmpFile, "-d", unpacked}, "");
+                else
+                    // FIXME: this requires GNU tar for decompression.
+                    runProgram("tar", true, {"xf", tmpFile, "-C", unpacked}, "");
+
+                /* If the archive unpacks to a single file/directory, then use
+                   that as the top-level. */
+                auto entries = readDirectory(unpacked);
+                if (entries.size() == 1)
+                    tmpFile = unpacked + "/" + entries[0].name;
+                else
+                    tmpFile = unpacked;
+            }
+
+            /* FIXME: inefficient; addToStore() will also hash
+               this. */
+            hash = unpack ? hashPath(ht, tmpFile).first : hashString(ht, result.data);
+
+            if (expectedHash != Hash(ht) && expectedHash != hash)
+                throw Error(format("hash mismatch for ‘%1%’") % uri);
+
+            /* 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. */
+            storePath = store->addToStore(name, tmpFile, unpack, ht);
+
+            assert(storePath == makeFixedOutputPath(unpack, ht, hash, name));
+        }
+
+        if (!printPath)
+            printMsg(lvlInfo, format("path is ‘%1%’") % storePath);
+
+        std::cout << printHash16or32(hash) << std::endl;
+        if (printPath)
+            std::cout << storePath << std::endl;
+    });
+}