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.\" The following requests are required for all man pages.
.Dd February 19, 2000
.Dt JSH 1
.Sh NAME
.Nm jsh
.Nd run scheduled commands on remote machines
.Sh SYNOPSIS
.Nm
.Op Fl aei
.Op Fl l Ar username
.Op Fl p Ar port
.Op Fl o Ar port
.Op Fl h Ar hostname
.Op Ar command ...
.Sh DESCRIPTION
The
.Nm
program connects to a
.Em jsd
daemon, and requests a node for processing.  It will then connect to
that remote node and execute the command or commands given to it.
Once it has completed work on the remote machine, it will return the
node to the
.Em jsd
daemon for future use by other
.Nm
processes.  The primary use of this is to ensure that no more than one 
remote process is running on any single machine at a point in time.
This can be used to better facilitate bulk parallel compiling.
.Pp
The following options are available:
.Bl -tag -width www
.It Fl a
The
.Fl a
option modifies the behavior of
.Nm
when dealing with stdin.  Normally all commands from stdin are run on
the same machine.  Specifying the
.Fl a
option causes each command to be run on the next node in the seqence.
.It Fl e
Unless the
.Fl e
option is specified, stderr from remote commands will not be reported
to the user.
.It Fl i
The
.Fl i
option will list information about the current cluster, and command
groupings. It will also show you which command you are about to run,
and your username if specified with the
.Fl l
option.
.It Fl l
If the
.Fl l
option is specified, followed by a username, the commands will be run under 
that userid on the remote machines.  Consideration must be taken for proper 
authentication, for this to work.
.It Fl p
The
.Fl p
option can be used to set the port number which jsd will listen to
replies from
.Em jsh
processes indicating completion of processing on remote nodes.  This
option overrides the
.Ev JSD_IPORT
environment variable.  The default listen port is 2001.
.It Fl o
The
.Fl o
option can be used to set the port number which jsd will listen to
requests from
.Em jsh
processes for remote nodes.  This option overrides the
.Ev JSD_OPORT
environment variable.  The default listen port is 2002.
.It Fl h
The
.Fl h
option can be used to set the remote hostname where a
.Em jsd
daemon is running.
.Nm
defaults to contacting a
.Em jsd
daemon on the local machine, but can be set up to talk to a remote
daemon.  The
.Fl h
option will override the
.Ev JSD_HOST
environment variable.
.El
.Sh ENVIRONMENT
.Nm
utilizes the following environment variables:
.Bl -tag -width "JSD_BENCH_CMD"
.It Ev RCMD_CMD
Command to use to connect to remote machines.  The command chosen must
be able to connect with no password to the remote host.  Defaults to
.Ic rsh .
.It Ev JSD_OPORT
When set, overrides the default port which jsd listens on for
.Em jsh
processes requesting nodes.  This environment setting can be overriden 
by the
.Fl o
option.
.It Ev JSD_IPORT
When set, overrides the default port which jsd listens on for
.Em jsh
processes reporting back that it has completed processing on a node.
This environment setting can be overriden
by the
.Fl p
option.
.It Ev JSD_HOST
When set, contains the hostname of the remote machine that the
.Em jsd
daemon is listening on.  This environment setting can be overriden by
the
.Fl h
option.
.El
.Sh SEE ALSO
.Xr dsh 1 ,
.Xr rsh 1 ,
.Xr kerberos 3 ,
.Xr hosts.equiv 5 ,
.Xr rhosts 5 ,
.Xr jsd 1 .
.Sh HISTORY
The
.Nm
command first appeared in clusterit 2.0.
.Sh AUTHOR
.Nm Jsh
was written by Tim Rightnour.