Add some pre-existing scripts.

dircompare

@@ -0,0 +1,47 @@
+#!/usr/bin/env python3
+# ft=python
+
+import os, sys
+
+def compare_dirs(d1: "old directory name", d2: "new directory name"):
+    def print_local(a, msg):
+        print('DIR ' if a[2] else 'FILE', a[1], msg)
+    # ensure validity
+    for d in [d1,d2]:
+        if not os.path.isdir(d):
+            raise ValueError("not a directory: " + d)
+    # get relative path
+    l1 = [(x,os.path.join(d1,x)) for x in os.listdir(d1)]
+    l2 = [(x,os.path.join(d2,x)) for x in os.listdir(d2)]
+    # determine type: directory or file?
+    l1 = sorted([(x,y,os.path.isdir(y)) for x,y in l1])
+    l2 = sorted([(x,y,os.path.isdir(y)) for x,y in l2])
+    i1 = i2 = 0
+    common_dirs = []
+    while i1<len(l1) and i2<len(l2):
+        if l1[i1][0] == l2[i2][0]:      # same name
+            if l1[i1][2] == l2[i2][2]:  # same type
+                if l1[i1][2]:           # remember this folder for recursion
+                    common_dirs.append((l1[i1][1], l2[i2][1]))
+            else:
+                print_local(l1[i1],'type changed')
+            i1 += 1
+            i2 += 1
+        elif l1[i1][0]<l2[i2][0]:
+            print_local(l1[i1],'removed')
+            i1 += 1
+        elif l1[i1][0]>l2[i2][0]:
+            print_local(l2[i2],'added')
+            i2 += 1
+    while i1<len(l1):
+        print_local(l1[i1],'removed')
+        i1 += 1
+    while i2<len(l2):
+        print_local(l2[i2],'added')
+        i2 += 1
+    # compare subfolders recursively
+    for sd1,sd2 in common_dirs:
+        compare_dirs(sd1, sd2)
+
+if __name__=="__main__":
+    compare_dirs(sys.argv[1], sys.argv[2])