prun [-EIOstv][-B base][-c cpus][-e err][-i in][-m block|cyclic]
     [-n procs][-N nodes][-o out][-p partition][-P project]
     [-R flags] program [args...]
prun -p root | -r [-tv]
     [-H hostnamelist][-B base][-N nodes][-R flags] program [args...]
prun -f procfile [-EItv][-e err][-i in][-o out][-p partition][-P project]
prun -h

Run a parallel program
Flags:
	-B <value>	base node
	-c <value>	number of cpus per process
	-e err		set stderr mode
	-E 		'explain' a procfile (only with -f option)
	-f <procfile>	use procfile
	-h 		print this info
	-i in		set stdin mode
	-I 		allocate CPUs immediately or fail
	-n <value>	number of processes to run
	-N <value>	number of nodes to allocate
	-m block|cyclic	process to node mapping
	-o out		set stdout mode
	-O 		allow resources to be overcommited
			for example more processes than cpus
	-p <partition>	partition to use
	-P <project>	project to use
	-r 		rsh mode (admin use only)
	-s 		print stats as job exits
	-R <flags>	set resource request flag. <flags> can be:
			    cluster=cluster | cluster-member=member
			    hwbcast=0|1
			    immediate=0|1
			    maxcpus=n
			    mincpus=n
			    pty=0|1
			    samecpus=0|1
			    rails=n (1<=n<=32)
			    railmask=mask
	-t 		prefix output with process number
	-v 		enable reporting

Resources are allocated (and freed) for the job, unless previously
assigned using allocate. The default process distribution is block.

Stdio for a parallel program is controlled by three stdio modes one
each for stdin (-i), stdout (-o) and stderr (-e). These modes control
how input to prun is directed to the application processes and how
their output on stdout/stderr is processed by prun. The supported
stdio modes are:
	all	all processes send/receive
	none	no processes send/receive
	{rank}	only process {rank} can send/receive
	file	processes read/write from/to file.{rank}

The default modes are stdin=0, stdout=all, stderr=all, i.e. stdin is
directed to process 0 and output on stdout/stderr from all processes
is returned to prun.

'prun -p root ...' and 'prun -r ...' are equivalent in that -p root
implies rsh mode and -r implies -p root.  In both cases the partition,
will be root, rsh mode will be set and 1 process per node will run.
By default -N will be set to all nodes.

Procfile line format should be one of the following:
number			hostname[:path] executable arguments
lowrank;highrank;step	hostname[:path] executable arguments
number			index[:path] executable arguments
lowrank;highrank;step	index[:path] executable arguments