screen_ssh

#!/bin/bash
# script to ssh to boxes
#
# accepted patterns:
#   abc[01-05].xyz.com
#   abc[09-11].{colo1,colo2}.company.com
#   abc01.{colo1,colo2}.company.com
#   abc[02,05-07,11].company.com
#   abc[09-11].company.com*2    -> opens two shells each to the given boxes
#
# Multiple patterns can be given space separated
# Author: Jemshad O K - jemshad dot ok at gmail dot com
#

expand_hosts() {

    local pat="$1"
    local hostpart multiplier prefix suffix range i start end num host 

    # if there is "*" in the pattern, multiply the pattern that many times
    # ex: "abc[01-03]*2" should open two terminals each of the three boxes
    if [[ $pat == *\** ]]; then
        hostpart="${pat%%\**}"
        multiplier="${pat##*\*}"

        for ((i=1;i<=multiplier;i++)); do
            expand_hosts "$hostpart"
        done
    elif [[ $pat == *{*}* ]]; then
        # expand the braces first
        prefix="${pat%%\{*}"
        suffix="${pat##*\}}"

        splits="${pat##*\{}"
        splits="${splits%%\}*}"

        for range in ${splits//,/ }; do
            expand_hosts "${prefix}${range}${suffix}"
        done
    elif [[ $pat == *\[*\]* ]]; then
        # expand the abc-[01,02-05,10].xyz cases
        prefix="${pat%%[*}"
        suffix="${pat##*]}" 
 
        splits="${pat##*[}"
        splits="${splits%%]*}"

        for range in ${splits//,/ }; do
            # expand the [02-05] format 
            if [[ $range ==  *-* ]]; then
                # get start and end number
                start="${range%-*}"
                end="${range#*-}"
                num="${#end}"  # no.of digits in the number

                # remove leading zeroes
                shopt -s extglob
                start="${start##+(0)}"
                end="${end##+(0)}"
                shopt -u extglob

                for ((i=start;i<=end;i++));do
                    host=$(printf "${prefix}%0${num}d$suffix\n" $i)
                    expand_hosts "$host"
                done
            else
                expand_hosts "${prefix}${range}${suffix}"
            fi
        done
    else
        echo "$pat"
    fi
}

## main ##
while :;do
        unset hostpat hosts host
        read -p "Host(s) to SSH> " -a hostpat
        if [[ $hostpat == "" ]];then
            continue
        fi
        for hostpattern in "${hostpat[@]}";do
            hosts=(${hosts[@]} $(expand_hosts "$hostpattern"))
        done

        (for host in "${hosts[@]}";do
            if [[ -z $host ]]; then
                continue
            fi
            screen -t "${host%.inmobi.com}" ssh "${host}"
        # designed to work with just shell where sleep(1) is not available
        # work around with a busy loop
            for i in {1..1000}; do :; done 
        done) &
done