first commit

.gitignore

@@ -0,0 +1 @@
+examplefolder

cmd/overlayneaten/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+   "os"
+   "fmt"
+	"path/filepath"
+)
+
+func DirSize(path string) (int64, error) {
+    var size int64
+    err := filepath.Walk(path, func(_ string, info os.FileInfo, err error) error {
+        if err != nil {
+            return err
+        }
+        if !info.IsDir() {
+            size += info.Size()
+        }
+        return err
+    })
+    return size, err
+}
+
+func main() {
+   bytes,_ := DirSize(".")
+   if bytes < 1024 {
+      fmt.Println("Directory size:", bytes, "bytes")
+   } else if bytes < 1024*1024 {
+      fmt.Println("Directory size:", bytes/1024, "kbytes")
+   } else if bytes < 1024*1024*1024 {
+      fmt.Println("Directory size:", bytes/1024/1024, "mbytes")
+   } else if bytes < 1024*1024*1024*1024 {
+      fmt.Println("Directory size:", bytes/1024/1024/1024, "mbytes")
+   } else {
+      fmt.Println("Directory size:", bytes/1024/1024/1024/1024, "gbytes")
+   }
+}

scripts/script.sh

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+#!/bin/bash
+SCRIPTDIR=`dirname $(realpath $0)`
+DEFAULTEXAMPLEFOLDER=${SCRIPTDIR}/../examplefolder
+EXAMPLEFOLDER=$(realpath ${1:-$DEFAULTEXAMPLEFOLDER})
+mkdir -p $EXAMPLEFOLDER 2>/dev/null
+if [ ! -f lower1/Jan/01 ]; then
+    mkdir $EXAMPLEFOLDER/lower1
+    mkdir $EXAMPLEFOLDER/lower2
+    mkdir $EXAMPLEFOLDER/upper
+    mkdir $EXAMPLEFOLDER/merged
+    mkdir $EXAMPLEFOLDER/workdir
+    for month in 01-Jan 02-Feb 03-Mar 04-Apr; do 
+        mkdir $EXAMPLEFOLDER/lower1/$month; for day in `seq -w 01 03`; do
+            dd if=/dev/urandom of=$EXAMPLEFOLDER/lower1/$month/$day bs=1M count=1
+        done
+    done
+    for month in 05-May 06-Jun 07-Jul 08-Aug; do 
+        mkdir $EXAMPLEFOLDER/lower2/$month; for day in `seq -w 01 03`; do
+            dd if=/dev/urandom of=$EXAMPLEFOLDER/lower2/$month/$day bs=1M count=1
+        done
+    done
+fi
+if ! mount | grep 'examplefolder/merged'; then
+    sudo mount -t overlay overlay $EXAMPLEFOLDER/merged -olowerdir=$EXAMPLEFOLDER/lower1:$EXAMPLEFOLDER/lower2,upperdir=$EXAMPLEFOLDER/upper,workdir=$EXAMPLEFOLDER/workdir
+fi
+if [ ! -f $EXAMPLEFOLDER/merged/09-Sep ]; then
+    for month in 09-Sep 10-Oct 11-Nov 12-Dec; do 
+        mkdir $EXAMPLEFOLDER/merged/$month; for day in `seq -w 01 03`; do
+            dd if=/dev/urandom of=$EXAMPLEFOLDER/merged/$month/$day bs=1M count=1
+        done
+    done
+fi