JSH(1)

NAME
jsh - run scheduled commands on remote machines

SYNOPSIS
jsh [-aeiv] [-l username] [-p port] [-o port] [-h hostname] [command ...]

DESCRIPTION
The jsh program connects to a 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 jsd daemon for future use by other jsh 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.

The following options are available:

-a  The -a option modifies the behavior of jsh when dealing with stdin. Normally all commands from stdin are run on the same machine. Specifying the -a option causes each command to be run on the next node in the seqence.

-e  Unless the -e option is specified, stderr from remote commands will not be reported to the user.

-i  The -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 -l option.

-v  Prints the version of ClusterIt to the stdout, and exits.

-l  If the -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.

-p  The -p option can be used to set the port number which jsd will listen to replies from jsh processes indicating completion of processing on remote nodes. This option overrides the JSD_IPORT environment variable. The default listen port is 2001.

-o  The -o option can be used to set the port number which jsd will listen to requests from jsh processes for remote nodes. This option overrides the JSD_OPORT environment variable. The default listen port is 2002.

-h  The -h option can be used to set the remote hostname where a jsd daemon is running. jsh defaults to contacting a jsd daemon on the local machine, but can be set up to talk to a remote daemon. The -h option will override the JSD_HOST environment variable.

ENVIRONMENT
jsh utilizes the following environment variables:

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 ssh.

RCMD_CMD_ARGS
    Arguments to pass to the remote shell command. Defaults to none.

JSD_OPORT
    When set, overrides the default port which jsd listens on for jsh processes requesting nodes. This environment setting can be overriden by the -o option.

JSD_IPORT
    When set, overrides the default port which jsd listens on for jsh processes reporting back that it has completed processing on a node. This environment setting can be overriden by the -p option.

JSD_HOST
    When set, contains the hostname of the remote machine that the jsd daemon is listening on. This environment setting can be overriden by the -h option.

SEE ALSO
dsh(1), ssh(1), kerberos(3), hosts.equiv(5), rhosts(5), jsd(1).

HISTORY
The jsh command first appeared in clusterit 2.0.

AUTHOR
Jsh was written by Tim Rightnour.