Adding the ability to specify tmux session name.

Change-Id: Iee7f34de4448e9ab5d383e6e2eb871639271fdb5

modules/tmux/README.md

@@ -20,25 +20,19 @@ following line to *zpreztorc*:
 
     zstyle ':prezto:module:tmux:auto-start' remote 'yes'
 
-In both cases the tmux server will be started and a background session
-named _prezto_ will be created if a session doesn't already exist.
+In both cases, it will create a background session named _prezto_ if the tmux
+server is not started.
 
-By default every shell shares a set of windows but has an independent
-view. Detaching from one of these sessions removes the view but the
-open windows persist. This is accomplished by setting the
-`destroy-unattached` option to `on` for each session.
+You can change the default session name with:
 
-Some users prefer that all new shells share the same session so that
-the view for each shell is in sync. This useful for advanced users
-that create multiple sessions and want to manually navigate between
-them. To accomplish this behavior set the `mode` option to `shared` in
-*zpreztorc*,
+    zstyle ':prezto:module:tmux' session 'YOUR DEFAULT SESSION NAME'
 
-    zstyle ':prezto:module:tmux:auto-start' mode shared
-
-You can customize the background session by creating a new session in
-your `.tmux.conf` file.
+With `auto-start` enabled, you may want to control how multiple sessions are
+managed. The `destroy-unattached` option of tmux controls if the unattached
+sessions must be kept alive, making sessions available for later use, configured
+in *tmux.conf*:
 
+    set-option -g destroy-unattached [on | off]
 
 Aliases
 -------

modules/tmux/init.zsh

@@ -25,21 +25,14 @@ if [[ -z "$TMUX" && -z "$EMACS" && -z "$VIM" ]] && ( \
 
   # Create a 'prezto' session if no session has been defined in tmux.conf.
   if ! tmux has-session 2> /dev/null; then
+    zstyle -s ':prezto:module:tmux' session 'session' || session='prezto'
     tmux \
-      new-session -d -s prezto \; \
-      set-option -t prezto destroy-unattached off &> /dev/null
-  else
-    tmux_session
+      new-session -d -s "$session" \; \
+      set-option -t "$session" destroy-unattached off &> /dev/null
   fi
 
-  if zstyle -t ':prezto:module:tmux:auto-start' mode shared; then
-      # Attach to the 'prezto' session or to the last session used.
-      exec tmux attach
-  else
-      # Find a session to share windows with.
-      tmux_session=`tmux list-sessions -F '#S' | head -n 1`
-      exec tmux new-session -t "$tmux_session"\; set-option destroy-unattached on
-  fi
+  # Attach to the 'prezto' session or to the last session used.
+  exec tmux attach-session
 fi
 
 #