add readonly flag to folder snapshot

add new function snapshot_send to send a snapshot to another mounted partition or drive

modules/filesystem/btrfs/btrfs.mod

@@ -101,17 +101,50 @@ find_subvolumes() {
 }
 
 folder_snapshot() {
-
+  if [[ $1 == "-r" ]];then 
+    readonly=-r
+    shift 1
+   else 
+   readonly=""
+  fi 
   for sv in $(find_subvolumes $1 1); do
     if [[ -d $2/$sv ]]; then
       echo snapshot $sv already exists in $2. You must manually delete target snapshots!
     else
-      sudo $BTRFS_BIN sub snap $1/$sv $2
+      sudo $BTRFS_BIN sub snap $readonly $1/$sv $2
     fi
   done
 
 }
 
+
+snapshot_send() {
+  if [[ $1 == "-e" ]];then 
+    dr=""
+    shift 1
+   else 
+    echo "snapshot_send <-e> <souce snapshot path> <destination folder on different partition> <destination extension>"
+    echo preface with -e to execute 
+    dr="echo"
+  fi
+  temp="$(dirname $1)/tmp_send"
+  name=$(basename $1)
+  name=$(echo $name | cut -f 1 -d '.') 
+  ext="$(echo $name | cut -s -f 2 -d '.')"
+  [[ $ext ]] && ext=".$ext"
+  [[ $3 ]] && ext=".$3" 
+  sudo mkdir $temp 
+  $dr sudo $BTRFS_BIN sub snap -r $1 $temp/$name$ext
+  if [[ $dr ]]; then
+  $dr "sudo $BTRFS_BIN send $temp/$name$ext | btrfs receive $2"
+  else 
+  sudo $BTRFS_BIN send $temp/$name$ext | btrfs receive $2
+  fi
+  $dr sudo $BTRFS_BIN sub del $temp/$name$ext
+  ls -la $2
+  sudo rm -r $temp
+}
+
 mount_subvolume () {
   # echo sudo mount $1 -o subvol=$2 $3
   if mountpoint $3 &> /dev/null; then