wrapper for ssh and scp to connect to temporary servers

sshtmp.sh

#alias sshtmp='ssh -oUserKnownHostsFile="$HOME/.ssh/tmp_known_hosts"'
#alias scptmp='scp -oUserKnownHostsFile="$HOME/.ssh/tmp_known_hosts"'
alias sshtmpreset='>$HOME/.ssh/tmp_known_hosts ;#'
alias sshtmp='__sshtmp_cmd ssh'
alias scptmp='__sshtmp_cmd scp'

__sshtmp_cmd() {
        local cmd="$1";shift
        local host="$1"
        local user=''
        case "$1" in
                (-*) echo >&2 "first argument must be [user@]host"; return 1 ;;
                (*?@?*)
                        user="${1%%@*}"
                        host="${1#*@}"
                ;;
                (?*)
                        user=''
                        host="$1"
                ;;
        esac
        local newhost="$(grep -- '^[^[:space:]]\+[[:space:]]\+\<'"$1"'\>' "$HOME/.ssh/tmp_hosts" | cut -d\  -f1 | cut -d $'\t' -f1)"
        newhost="$user${user:+@}${newhost:-$1}"
        shift
        "$cmd" -oUserKnownHostsFile="$HOME/.ssh/tmp_known_hosts" "$newhost" "$@"
}