dtcsh

DSH with patterns, regexps.

What is it ?

dtcsh is a wrapper for
the dancer shell. It
allows user to specify host names by regular expressions, or specify
group names by pattern

It’s technically safe to do

alias dsh=dtcsh

However, it still relies on the original dsh.

How to install it ?

Prerequisites

You need to install zsh, dsh, and cssh (for interactive shells) first of all.

Note that your cssh package is probably named clusterssh

dtcsh installation

Get (git clone, or copy) the dtcsh script from this repository, and place it somewhere in your $PATH.

Configuration

Just use dsh configuration.

Use man dsh.conf for detailled information.

DSH enhancements

Imagine you have multiple node00{1,2,3,…}.mydomain servers located in multiple group files and you want to contact them.

# Instead of 
$ dsh -m node001.mydomain -m node002.mydomain -m .... uptime
# Do this
dtcsh -m 'node[0-9]+.mydomain' uptime

Or if there’s a pattern in group files :

# Instead of 
$ dsh -g 'prod/node' -g 'dev/node' uptime
# You can do this
$ dtcsh h -g '*/node' ls

More features

Search for group files

# All groups named node
$ dtcsh ls '**/node'
# All groups underneath prod subdir
$ dtcsh ls 'prod/**/*'

All zsh extended patterns are allowed

Search for hostnames

# You want to look for all hostnames containing keyword john
$ dtcsh grep keyword

cssh wrapping

For people fond of interactivity, dtcsh can combine dsh groups power
with clusterssh.

# Open an interactive shell on every node.
$ dtcsh cssh 'node[0-9]+.mydomain'

More

$ dtcsh -h
DTCsh-wrapped Distributed Shell / Dancer's shell version 0.25.10 
Copyright 2001-2005 Junichi Uekawa, 
distributed under the terms and conditions of GPL version 2
-v --verbose                   Verbose output
-q --quiet                     Quiet
-M --show-machine-names        Prepend the host name on output
-H --hide-machine-names        Do not prepend host name on output
-i --duplicate-input           Duplicate input given to dsh
-b --bufsize                   Change buffer size used in input duplication
-m --machine [machinename]     Execute on machine
-n --num-topology              How to divide the machines
-a --all                       Execute on all machines
-g --group [groupname]         Execute on group member
-f --file [file]               Use the file as list of machines
-r --remoteshell [shellname]   Execute using shell (rsh/ssh)
-o --remoteshellopt [option]   Option to give to shell 
-h --help                      Give out this message
-w --wait-shell                Sequentially execute shell
-c --concurrent-shell          Execute shell concurrently
-F --forklimit [fork limit]    Concurrent with limit on number
-V --version                   Give out version information
Alternative syntaxes in which none of the above options apply:
dtcsh ls 'group_pattern'
        Prints the dsh group names matching given pattern.
dtcsh cat 'group_pattern'
        Prints the (uniq) hostnames contained in dsh group names
        matching given pattern.
dtcsh match 'hostname_regexp' [ 'group' ]
        Prints dsh group names containing hostnames matching given 'grep
        -E'-styled regular expression. If given, 'group' represents the
        beginning of a dsh group name, restricting the research to that
        'group' tree.
dtcsh grep 'hostname_regexp' [ 'group' ]
        Same as the 'match' command, but prints matching host names (and
        not dsh groups) instead.
dtcsh cssh [ <cssh option> ... ] '[login@](group|file|regexp|hostname)[:port]'
        Acts like cssh. Parameters can be either dsh groups, file names,
        hostname regular expression pattern or plain host names, with
        optional '<username>@' prefix and optional ':<port number>'
        suffix.  If 'dtcsh' is called as 'cssh' or 'dcssh', 'dtcsh' acts
        as if called as 'dtcsh cssh'.
dtcsh clean-keys '(group|regexp|hostname)'
        Remove entries from your ~/.ssh/known_hosts file. Parameters can be
        either dsh groups, hostname or hostname regular expressions. The
        IP address will also be removed from the known_hosts file.
dtcsh update-keys '(group|regexp|hostname)'
        Like clean-keys action but also attempt to connect the expanded
        list of hostnames so that latest version of host keys will be
        re-added to the known_hosts file.
dtcsh remove 'regexp'
        Removes all hostnames matching given regular expression from dsh
        groups.
dtcsh whatever '(group|regexp|hostname)'
        Expands arguments into a list of host names, whatever their
        nature: group pattern, host name regular expression or plain host
        name. It's the exact same subroutines used in clean-keys,
        update-keys and in the cssh wrapper.