shell utility functions: add, improve

Add a function to open 4 common osmo vtys and make sure these tmux functions
don't open new sessions if the session already exists

modules/rhizo_base/templates/rccn-functions.sh.erb

@@ -79,6 +79,11 @@ o() {
 }
 
 f() {
+  tmux has-session -t SIP 2>/dev/null
+  if [ $? -eq 0 ] ; then
+    tmux a -t SIP
+    return
+  fi
   tmux new-session -n SIP "sudo sngrep -d any" \; splitw -p 60 "fs_cli -r" \; select-window -t SIP \;
 }
 
@@ -110,8 +115,41 @@ b<%= index %>() {
 }
 <% end -%>
 
+vt ()
+{
+  tmux has-session -t vtys 2>/dev/null
+  if [ $? -eq 0 ] ; then
+    tmux a -t vtys
+    return
+  fi
+  tmux start-server;
+  tmux new -s vtys -d -n VTY "vty bsc $*";
+  for vty in msc mgw hlr;
+    do
+      if [ "$vty" == "msc" ]; then
+        pane=0;
+      fi;
+      if [ "$vty" == "hlr" ]; then
+        pane=2;
+      fi;
+      if [ "$vty" == "mgw" -o "$vty" == "hlr" ]; then
+        split=h;
+      else
+        split=v;
+      fi;
+      tmux split-window -t $pane -$split "vty $vty $*";
+    done;
+  tmux select-pane -t:.0
+  tmux attach -t vtys ;
+}
+
 bA() {
   source /home/rhizomatica/bin/vars.sh
+  tmux has-session -t bts 2>/dev/null
+  if [ $? -eq 0 ] ; then
+    tmux a -t bts
+    return
+  fi
   tmux start-server
   tmux new -s bts -d -n BTS0 "source /etc/profile.d/rccn-functions.sh ; b0 $*"
   # This won't look great for more than 4 windows, but