General form for Linux system call

syscall.cpp

// Signal handling.... sigh
template<typename F> inline
int syscall(F f) {
    int result{};
    do {
        result = f();
    } while ( result == -1 && errno == EINTR );
    return result;
}


// Using it
void open_shut(const char *pathname) {
  int opened = syscall([&]() { return open(pathname, O_CREAT | O_CLOEXEC); });
  if ( opened >= 0 ) {
    // Use the file descripter  
    syscall([&]() { return close(opened); });
  } else {
    // Couldn't open, no need to close
  }
}