Start of new Nix command-line interface

src/nix/hash.cc

@@ -0,0 +1,140 @@
+#include "command.hh"
+#include "hash.hh"
+#include "legacy.hh"
+#include "shared.hh"
+
+using namespace nix;
+
+struct CmdHash : Command
+{
+    enum Mode { mFile, mPath };
+    Mode mode;
+    bool base32 = false;
+    bool truncate = false;
+    HashType ht = htSHA512;
+    Strings paths;
+
+    CmdHash(Mode mode) : mode(mode)
+    {
+        mkFlag(0, "base32", "print hash in base-32", &base32);
+        mkFlag(0, "base16", "print hash in base-16", &base32, false);
+        mkHashTypeFlag("type", &ht);
+        expectArgs("paths", &paths);
+    }
+
+    std::string name() override
+    {
+        return mode == mFile ? "hash-file" : "hash-path";
+    }
+
+    std::string description() override
+    {
+        return mode == mFile
+            ? "print cryptographic hash of a regular file"
+            : "print cryptographic hash of the NAR serialisation of a path";
+    }
+
+    void run() override
+    {
+        for (auto path : paths) {
+            Hash h = mode == mFile ? hashFile(ht, path) : hashPath(ht, path).first;
+            if (truncate && h.hashSize > 20) h = compressHash(h, 20);
+            std::cout << format("%1%\n") %
+                (base32 ? printHash32(h) : printHash(h));
+        }
+    }
+};
+
+static RegisterCommand r1(make_ref<Command, CmdHash>(CmdHash::mFile));
+static RegisterCommand r2(make_ref<Command, CmdHash>(CmdHash::mPath));
+
+struct CmdToBase : Command
+{
+    bool toBase32;
+    HashType ht = htSHA512;
+    Strings args;
+
+    CmdToBase(bool toBase32) : toBase32(toBase32)
+    {
+        mkHashTypeFlag("type", &ht);
+        expectArgs("strings", &args);
+    }
+
+    std::string name() override
+    {
+        return toBase32 ? "to-base32" : "to-base16";
+    }
+
+    std::string description() override
+    {
+        return toBase32
+            ? "convert a hash to base-32 representation"
+            : "convert a hash to base-32 representation";
+    }
+
+    void run() override
+    {
+        for (auto s : args) {
+            Hash h = parseHash16or32(ht, s);
+            std::cout << format("%1%\n") %
+                (toBase32 ? printHash32(h) : printHash(h));
+        }
+    }
+};
+
+static RegisterCommand r3(make_ref<Command, CmdToBase>(false));
+static RegisterCommand r4(make_ref<Command, CmdToBase>(true));
+
+/* Legacy nix-hash command. */
+static int compatNixHash(int argc, char * * argv)
+{
+    HashType ht = htMD5;
+    bool flat = false;
+    bool base32 = false;
+    bool truncate = false;
+    enum { opHash, opTo32, opTo16 } op = opHash;
+    Strings ss;
+
+    parseCmdLine(argc, argv, [&](Strings::iterator & arg, const Strings::iterator & end) {
+        if (*arg == "--help")
+            showManPage("nix-hash");
+        else if (*arg == "--version")
+            printVersion("nix-hash");
+        else if (*arg == "--flat") flat = true;
+        else if (*arg == "--base32") base32 = true;
+        else if (*arg == "--truncate") truncate = true;
+        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 == "--to-base16") op = opTo16;
+        else if (*arg == "--to-base32") op = opTo32;
+        else if (*arg != "" && arg->at(0) == '-')
+            return false;
+        else
+            ss.push_back(*arg);
+        return true;
+    });
+
+    if (op == opHash) {
+        CmdHash cmd(flat ? CmdHash::mFile : CmdHash::mPath);
+        cmd.ht = ht;
+        cmd.base32 = base32;
+        cmd.truncate = truncate;
+        cmd.paths = ss;
+        cmd.run();
+    }
+
+    else {
+        CmdToBase cmd(op == opTo32);
+        cmd.args = ss;
+        cmd.ht = ht;
+        cmd.run();
+    }
+
+    return 0;
+}
+
+static RegisterLegacyCommand s1("nix-hash", compatNixHash);