connectat —
    initiate a connection on a socket
Standard C Library (libc, -lc)
The
    connectat()
    system call initiates a connection on the socket s.
    When passed the special value AT_FDCWD in the
    fd parameter, the behavior is identical to a call to
    connect(2).
    Otherwise, connectat() works like the
    connect(2)
    system call with two exceptions:
  - It is limited to sockets in the PF_LOCAL domain.
    
  
- If the file path stored in the sun_path field of the
      sockaddr_un structure is a relative path, it is located relative to the
      directory associated with the file descriptor
    fd.
The connectat() function returns the
    value 0 if successful; otherwise the value -1 is returned and
    the global variable errno is set to indicate the
    error.
The connectat() system call may fail with
    the same errors as the
    connect(2)
    system call or with the following errors:
  - [EBADF]
- The sun_path field does not specify an absolute path
      and the fd argument is neither
      AT_FDCWDnor a valid file descriptor.
- [ENOTDIR]
- The sun_path field is not an absolute path and
      fd is neither AT_FDCWDnor a
      file descriptor associated with a directory.
The connectat was developed by
    Pawel Jakub Dawidek
    <pawel@dawidek.net>
    under sponsorship from the FreeBSD Foundation.