The s6-fdholder-store program
s6-fdholder-store connects to a
fd-holding daemon listening on a
Unix domain socket, and gives it a copy of one of its open file
descriptors for the daemon to hold.
s6-fdholder-store [ -d fd ] [ -T fdtimeout ] [ -t timeout ] path id
- s6-fdholder-store executes into s6-ipcclient path
s6-fdholder-storec id. It does nothing else: it is just a
convenience program. The s6-ipcclient program connects
to a Unix socket at path, and the
s6-fdholder-storec program transmits the desired
file descriptor over the socket.
- It should be used to connect to a
s6-fdholderd daemon, which will store the
file descriptor given by the user.
- -d fd : store descriptor number fd.
By default, fd is 0 (i.e. the program's stdin will be stored).
s6-fdholder-store replaces its stdin with fd before executing into
- -T fdtimeout : the descriptor is stored with
an expiration time of fdtimeout milliseconds, which means the
s6-fdholderd daemon will close and get rid of
the descriptor after that time. By default, fdtimeout is 0, which
means infinite - no expiration time.
- -t timeout : if the operation cannot be
processed in timeout milliseconds, then fail with an error message.
Communications with the server should be near-instant, so this option is
only here to protect users against programming errors (connecting to the
wrong socket, for instance).
s6-ipcserver-socketbinder /tmp/mysocket s6-fdholder-store /service/fdholderd/s MYSOCKET
will open a Unix domain socket, bind it to /tmp/mysocket and
listen to incoming connections, then give it to a
s6-fdholderd instance listening on
/service/fdholderd/s, with no expiration date, with the
"MYSOCKET" identifier. Another program will be able to retrieve the
socket later, using s6-fdholder-retrieve.