Add convenience function for connecting to a Unix domain socket

Author: edolstra

src/libstore/uds-remote-store.cc

@@ -84,9 +84,7 @@ ref<RemoteStore::Connection> UDSRemoteStore::openConnection()
     auto conn = make_ref<Connection>();
 
     /* Connect to a daemon that does the privileged work for us. */
-    conn->fd = createUnixDomainSocket();
-
-    nix::connect(toSocket(conn->fd.get()), path);
+    conn->fd = nix::connect(path);
 
     conn->from.fd = conn->fd.get();
     conn->to.fd = conn->fd.get();

src/libutil/include/nix/util/unix-domain-socket.hh

@@ -9,6 +9,8 @@
 #endif
 #include <unistd.h>
 
+#include <filesystem>
+
 namespace nix {
 
 /**
@@ -80,4 +82,9 @@ void bind(Socket fd, const std::string & path);
  */
 void connect(Socket fd, const std::string & path);
 
+/**
+ * Connect to a Unix domain socket.
+ */
+AutoCloseFD connect(const std::filesystem::path & path);
+
 }

src/libutil/unix-domain-socket.cc

@@ -114,4 +114,11 @@ void connect(Socket fd, const std::string & path)
     bindConnectProcHelper("connect", ::connect, fd, path);
 }
 
+AutoCloseFD connect(const std::filesystem::path & path)
+{
+    auto fd = createUnixDomainSocket();
+    nix::connect(toSocket(fd.get()), path);
+    return fd;
+}
+
 }