Start a command on the destination. By default it is not possible to
redirect I/O. If the command is successfully started, a positive
spawn ID is returned. If the spawn fails, a negative value will be
returned. Once the command has started, you can interact with it
using remote_expect and remote_wait procedures.
remote_spawn dest commandline args
destThe destination.
commandlineThe command to execute.
argsIf the optional keyword readonly is specified, input to the
command may be redirected.