Shell script for mounting remote dir by sshfs and obtaining SSH console

gistfile1.sh

#!/bin/bash

if [ -z "$1" ]; then
    echo No user@host specified!
    exit 1
fi

if [[ ! "$1" =~ ^[^@:]+@[^@:]+:[^@:]+$ ]]; then
    echo Invalid user@host!
    exit 2
fi

mntdir="$HOME/remote/`echo "$1" | cut -d':' -f1 | sed -e 's#@#.at.#'`"

if [ `cat /etc/mtab | grep "$mntdir" | wc -l` -gt 0 ]; then
    echo Point is already mounted!
    exit 3
fi

[ ! -d "$mntdir" ] && mkdir "$mntdir"
sshfs "$1" "$mntdir"
ssh "`echo "$1" | cut -d':' -f1`"