tmux_attach_or_new

#!/usr/bin/env sh

# A useful wrapper to invoke tmux that I got from a guy on IRC #tmux
# 5/20/2016 -- Modified by David Parkinson
# Basically invokes a new sesion if no argument, and group attaches to an existing session
# and kills any group sessions that are unattached.  Very useful.  
# from https://ntnn.de/plain//tmux_attach_or_new
# Now added tmuxifier logic

link=0
# Give me a random # between 0 & 9999
NUMBER=$(shuf -i 0-9999 -n 1)
#!/usr/bin/env sh

link=0

case $1 in
    (-l|--link)
        link=1
        shift
        ;;
esac

tmuxifier_has() {
    if command -v tmuxifier > /dev/null $2 &>/dev/null; then
      return 1;
    fi

    if tmuxifier list-${1} | grep $2 &>/dev/null; then
        return 0;
    fi
    return 1;
}

session_is_attached() {
    if tmux list-sessions | grep "^$1" | grep attached; then
        return 0;
    fi
    return 1;
}

if [ $# -eq 0 ]; then
    # no parameter given, starting new session with tmux' naming scheme
    tmux new-session

elif [ $# -eq 1 ]; then

    if tmux has-session -t "$1"; then
        # attach and link if --link was passed or the session has no
        # attached client - otherwise group-attach
        if [ $link -eq 1 ] || ! session_is_attached "$1"; then
            tmux -2 attach-session -t "$1"
        else
            # get a random number from /dev/random to prevent attaching
            # to an existing grouped session
            random=$(od -An -d -N2 /dev/random)

            # define grouped session name
            group_sess_name="${1}-group-${random## }"

            tmux -2 new-session -t "$1" -s "$group_sess_name"

            # kill session if it exists after exiting the client
            if tmux has-session -t "$group_sess_name"; then
                tmux kill-session -t "$group_sess_name"
            fi
        fi

    elif tmuxifier_has sessions $1; then
        # if the parameter is the name of a session layout start that
        tmuxifier load-session "$1"

    elif tmuxifier_has windows $1; then
        # if the parameter is the name of a window layout start that
        tmuxifier load-window "$1"

    else
        # the parameter is not a running session nor a layout - start
        # a new session with that name
        tmux -2 new-session -s "$1"
    fi

else
    exit 1
fi