Add -r option support for reattach only

mca.sh

@@ -4,15 +4,16 @@ set -e
 
 EXEC_NAME="$(basename -- "$0")"
 
-options="$(getopt -n "$EXEC_NAME" -s sh  -o hvfdx -l help -l version -- "$@")"
+options="$(getopt -n "$EXEC_NAME" -s sh  -o hvfdxr -l help -l version -- "$@")"
 eval set -- "$options"
 
 SCREEN_OPTS=
+REATTACH_ONLY=0
 
 while :; do
     case "$1" in
         -h|--help)
-            echo "Usage: $EXEC_NAME [-fdx] [MCA_NAME|MCA_JAR|MCA_DIR] [--] [INPUT]…"
+            echo "Usage: $EXEC_NAME [-fdxr] [MCA_NAME|MCA_JAR|MCA_DIR] [--] [INPUT]…"
             exit
             ;;
         -v|--version)
@@ -28,6 +29,9 @@ while :; do
         -x)
             SCREEN_OPTS=x
             ;;
+        -r)
+            REATTACH_ONLY=1
+            ;;
         --)
             shift
             break
@@ -74,6 +78,8 @@ elif screen -S "$MCA_NAME" -X select . > /dev/null 2>&1; then
     exit 2
 fi
 
+[ "$REATTACH_ONLY" -eq 1 ] && { echo "$EXEC_NAME: $MCA_NAME: no such a screen was found" >&2; exit 2; }
+
 [ -d "$MCA_DIR" ] || { echo "$EXEC_NAME: $MCA_DIR: not found" >&2; exit 2; }
 
 cd "$MCA_DIR"