Overview

Tclssh is a package of pure Tcl functions for executing Tcl scripts in a remote host. It is used by Nbsp and the WRFPak to offload some long-time running jobs in parallel to other computers.

The remote host must be accessible via ssh keys without a password; that is, for example, the contents of your ./ssh/id_rsa.pub must be added to the .ssh/authorized_keys file in the remote host.

The directory

<prefix>/share/doc/examples

has several examples that can be used for testing and documentation.

Example

The best way to explain how to use is by looking at one of them, ex-1.tcl.

#!/usr/bin/tclsh

package require ssh

#
# Collect in the string "script" the script that will be sent to the
# remote (slave) host.
#
set script {
puts "I am a remote host named [info hostname] executing a script
that my master sent me. I am going to sent him back the results of some
commands. Here they are:

    The date is: [exec date]
    My info is: [exec uname -a]

Now I need to inform my master that I have finished.

DONE 0"
};

set slave "is.1-loop.net";     # This is the remote host

#
# If the tcl shell in the remote host is just "tclsh"
(e.g. a linux system)
# the -t option (and its argment) can be omitted; otherwise it can be
# used to specify the name of the remote tcl shell.
#
::ssh::connect -t tclsh8.6 -- $slave
::ssh::push $slave $script
::ssh::send $slave;
while {[::ssh::pop_line $slave line] >= 0} {
    if {[regexp {^DONE\s+(\d+)} $line match code]} {
    break;
    }
    puts $line;
}
::ssh::disconnect $slave;

puts "Slave finished with code: $code";

Below is the output of executing ex-1.tcl from a machine named elite:

[nieves@elite examples]$ ./ex-1.tcl
I am a remote host named is.1-loop.net executing a script
that my master sent me. I am going to sent him back the results of some
commands. Here they are:

    The date is: Sun Dec  9 17:35:43 AST 2012
    My info is: Linux is 2.6.32-308.8.2.el5.028stab101.1 #1 SMP Sun Jun 24 20:25:35 MSD 2012 i686 GNU/Linux

Now I need to inform my master that I have finished.

Slave finished with code: 0
[nieves@elite examples]$

Several other examples in the

<prefix>/share/doc/examples

directory illustrate more capabilities of this package.