Re: [PATCH v3 7/8] sub-process: move sub-process functions into separate files

> +Types
> +-----
> +
> +'int(*subprocess_start_fn)(struct subprocess_entry *entry)'::
> +
> +	User-supplied function to initialize the sub-process.  This is
> +	typically used to negoiate the interface version and capabilities.
> +
> +
> +Functions
> +---------
> +
> +`subprocess_start`::
> +
> +	Start a subprocess and add it to the subprocess hashmap.
> +
> +`subprocess_stop`::
> +
> +	Kill a subprocess and remove it from the subprocess hashmap.
> +
> +`subprocess_find_entry`::
> +
> +	Find a subprocess in the subprocess hashmap.
> +
> +`subprocess_get_child_process`::
> +
> +	Get the underlying `struct child_process` from a subprocess.
> +
> +`subprocess_read_status`::
> +
> +	Helper function to read packets looking for the last "status=<foo>"
> +	key/value pair.

> diff --git a/sub-process.c b/sub-process.c
> new file mode 100644
> index 0000000000..2c4d27c193
> --- /dev/null
> +++ b/sub-process.c
> @@ -0,0 +1,116 @@
> +/*
> + * Generic implementation of background process infrastructure.
> + */
> +#include "sub-process.h"
> +#include "sigchain.h"
> +#include "pkt-line.h"
> + ...
> +void subprocess_exit_handler(struct child_process *process)
> +{