added a dependencies section

imap_unseen.sh

#!/bin/bash
#
# connects to a remote host and counts the unseen entries on an imap box
#+
#+ Usage: ./imap_unseen.sh [host] [mailbox]
#+
#+ Dependencies:
#+  - on the localhost: ssh
#+  - on the remote host: ssh, dovecot

# host to connect to
IU_HOST="localhost";

# use first parameter als IU_HOST
if [ ! -z "$1" ]; then
    IU_HOST="$1";
fi;

# Inbox to check
IU_INBOX="INBOX";

# use second parameter as IU_INBOX
if [ ! -z "$2" ]; then
    IU_INBOX="$2";
fi;

# sources an script, that adds an ssh-key to your keychain.
#+ you have to write that script
IU_SSH_KEY="";

# unread entries in the inbox
IU_UNSEEN_COUNT=0;

# cleans the namespace
cleanup () {

    unset IU_HOST;
    unset IU_INBOX;
    unset IU_SSH_KEY;
    unset IU_UNSEEN_COUNT;
}

# reads the unseen entries
#+ result ist available throug $COUNT
#+ @param $1 host
#+ @param $2 inbox
#+ @param $3 sshkeychain
imap_unseen_count () {

    if [ -z $1 ]; then
        echo "Parameter host is missing. Fial";
        exit 1;
    fi
    local host="${1}";

    if [ -z "$2" ]; then
        echo "Parameter inbox is missing. Fial";
        exit 1;
    fi
    local inbox="${2}";

    if [ -z "$3" ]; then
        echo "Parameter sshkeychain is missing. Fial";
        exit 1;
    fi
    local sshkeychain="${3}";

    local imap_command='? status '"$inbox"' (unseen)';

    # todo: test the existence of the host

    if [ -f "$sshkeychain" ]; then
        . "$sshkeychain";
    fi

    local imap_status=$(printf '%s' "${imap_command}" |
                        ssh -q $host /usr/sbin/dovecot --exec-mail imap);

    IU_UNSEEN_COUNT=$(printf '%s' "$imap_status" |
                   grep UNSEEN |
                   awk '{ print substr($5,0,length($5) - 2); }');

    return 0;
}

imap_unseen_count "$IU_HOST" "$IU_INBOX" "$IU_SSH_KEY";

if [ $? -eq 1 ]; then
    echo "Could not get the unseen mail count. Sorry";
    cleanup;
    exit 1;
fi;

printf '%s\n' $IU_UNSEEN_COUNT;

cleanup;
exit 0

Original author is http://github.com/rtwo