refactor bunkdeck with some add'l error handling and fixed format

bunkdeck

@@ -1,25 +1,30 @@
-#!/bin/bash
-set -e
+#!/bin/sh -e
 
+sessionname=bunkdeck
 heedPane="bunkdeck:0.0"
 proclaimPane="bunkdeck:0.1"
 shellPane="bunkdeck:0.2"
 
-function isExistingDeck {
-	set +e
-	sessions=$(tmux list-sessions)
-	set -e
+isExistingDeck () {
+    # format `-F '#S' # formats the result as just the session name`
+    # filter `-f "{==:#S,${sessionname}}` # only returns sessions named $sessionname
+    # capture error and redirect
+	  sessions=$(tmux list-sessions -F '#S' -f "#{==:#S,${sessionname}}" 2>/dev/null)
 
-	if [[ $sessions == *"bunkdeck"* ]]; then
+	  if [ "${sessions}" = "${sessionname}" ] ; then
 		    return 0
     else
 		    return 1
 	  fi
 }
 
-function startNewDeck {
-	tmux new -d -s bunkdeck heed
-	tmux split-window -h -t bunkdeck -p 70
+attachToDeck () {
+    tmux attach-session -t bunkdeck
+}
+
+startNewDeck () {
+	  tmux new -d -s $sessionname heed
+	  tmux split-window -h -t $sessionname -p 70
 	  tmux split-window -t $heedPane -v -p 3
 	  tmux send-keys -t $proclaimPane 'proclaim' C-m
 	  tmux send-keys -t $shellPane 'cowsay "press [CTRL+b then o] to cycle through panes"' C-m
@@ -32,11 +37,25 @@ function startNewDeck {
 	  tmux attach -t $shellPane
 }
 
-function killDeck {
-	tmux kill-session -t bunkdeck
+killDeck () {
+    if isExistingDeck; then
+        tmux kill-session -t $sessionname
+    else
+        echo "you don't have bunkdeck running!"
+    fi
 }
 
-function growPane {
+leaveDeck () {
+    # currently assumes that bunkdeck is only session running
+    # if bunkdeck leave is issued from within another session, silent failure occurs
+    if isExistingDeck && [ "${TMUX}" != "" ]; then
+        tmux detach -s $sessionname
+        echo "you are not inside bunkdeck! for help:"
+        echo "$ bunkdeck help"
+    fi
+}
+
+growPane () {
 	  case $2 in
 		    shell)
 			      tmux resize-pane -t $shellPane -L "$3"
@@ -62,7 +81,7 @@ function growPane {
 	  esac
 }
 
-function shrinkPane {
+shrinkPane () {
 	  case $2 in
 		    shell)
 			      tmux resize-pane -t $shellPane -R "$3"
@@ -88,6 +107,28 @@ function shrinkPane {
 	  esac
 }
 
+helpText () {
+    usageText
+    echo
+    echo "help:"
+    echo
+    echo "  movement:"
+    echo "    bunkdeck gives you three panes, 'proclaim' to chat, 'heed' to read chats"
+    echo "    and 'shell' to do whatever you want!"
+    echo "    to move between panes you press [CTL + b] at the same time"
+    echo "    then [arrow key] to move to a new pane, or 'o' to cycle around"
+}
+
+usageText () {
+		echo "usage: bunkdeck [COMMAND]"
+		echo
+		echo "commands:"
+		echo "  (none)      attach to existing bunkdeck or start new one"
+		echo "  kill        kill running bunkdeck"
+    echo "  leave       close bunkdeck without killing it"
+    echo "  grow        grow the size of a bunkdeck window"
+		echo "  shrink      shrink the size of a bunkdeck window"
+}
 
 case $1 in
 
@@ -96,26 +137,24 @@ case $1 in
 	      ;;
 	  "")
 		    if isExistingDeck; then
-			tmux attach-session -t bunkdeck
+			      attachToDeck
 		    else
 			      startNewDeck
 		    fi
 	      ;;
+    leave)
+        leaveDeck
+        ;;
 	  grow)
 		    growPane "$@"
 	      ;;
 	  shrink)
 		    shrinkPane "$@"
 	      ;;
+    help)
+        helpText
+        ;;
 	  *)
-		echo "usage: bunkdeck [COMMAND]"
-		echo
-		echo "commands:"
-		echo "  (none)      attach to existing bunkdeck or start new one"
-		echo "  kill        kill running bunkdeck"
-		echo "  grow        grow the size of a bunkdeck window"
-		echo "  shrink      shrink the size of a bunkdeck window"
-		exit 1
+        usageText
         ;;
 esac
-