Re: [Qemu-devel] Re: Machine-readable or parseable qemu output

[Jamie Lokier <jamie@shareable.org>]

Although it's nice to have a monitor which is human-readable, many
programs have a separate monitor _program_ which connects over a unix
socket to the running app.  For example, Bind has rndc, ntpd has
ntpdc, apache has apachectl, and Samba has smbcontrol.

This gives all the benefits of a machine-accessible monitor, including
asynchronous events, waiting for long commands (like migrate) while
still doing useful things (like change the CD while migrating? :-)

It's much more scriptable to have a separate program, and you still
have a nice text UI with line-editing, help, etc.  Possibly a nicer
UI, since it's not limited to telnet/serial.

For QEMU, maybe it would work to define a machine-accessible socket
protocol, and move the current QEMU monitor code to a separate app
which connects over that protocol?  If QEMU is invoked with arguments
asking for the current monitor over e.g. a socket, telnet socket or
serial port, it'd be easy for QEMU to fork/exec the monitor app.  The
same app would be invokable from scripts.

-- Jamie