close function not being recognized - C++

I have the following piece of code in a file called `RaftLog.cc`: ``` #include <algorithm> #include <fcntl.h> #include <sys/stat.h> namespace LogCabin { namespace Server { namespace RaftConsensusInternal { namespace FilesystemUtil = Storage::FilesystemUtil; namespace { bool fileToProto(const std::string& path, google::protobuf::Message& out) { int fd = open(path.c_str(), O_RDONLY); if (fd == -1) return false; else close(fd); FilesystemUtil::FileContents file(path); // more code down here, not useful to the problem. ``` However, when I compile I have: ``` build/Server/RaftLog.cc: In function ‘bool LogCabin::Server::RaftConsensusInternal::{anonymous}::fileToProto(const string&, google::protobuf::Message&)’: build/Server/RaftLog.cc:43:17: error: ‘close’ was not declared in this scope build/Server/RaftLog.cc: In function ‘void LogCabin::Server::RaftConsensusInternal::{anonymous}::protoToFile(google::protobuf::Message&, const string&)’: build/Server/RaftLog.cc:76:13: error: ‘close’ was not declared in this scope In file included from ./Server/RaftConsensus.h:17:0, ``` I don't know why the `close()` function does not get included by `#include <fcntl.h>`. May someone please help me? Also let me know if I should include more code.