Add batch homework download tool

tools/homework_downloadall.py

@@ -0,0 +1,44 @@
+import os,sys
+import multiprocessing
+
+"""
+download all homework from given student name, id, url description file
+
+txt file format:
+```
+name, id, git rep url
+```
+"""
+
+def homework_download(git_rep, dir_name):
+    cmd = "git clone %s %s" % (git_rep, dir_name)
+    print("exec command: %s" % cmd)
+    os.system(cmd)
+
+def homework_download_all(fname):
+    pool = multiprocessing.Pool()
+
+    lns = open(fname).readlines()
+    for l in lns:
+        items = l.split(",")
+        if( len(items) >= 3 ):
+            n = items[0].strip()
+            id = items[1].strip()
+            url = items[2].strip()
+
+            git_rep = url + ".git"
+            dir_name = id + "_" + n
+
+            print("%s : %s" % (dir_name, git_rep))
+            print("")
+
+            pool.apply_async(homework_download, (git_rep, dir_name))
+
+    pool.close()
+    pool.join()
+    
+if( __name__ == "__main__" ):
+    if( len(sys.argv) > 1 ):
+        fn = sys.argv[1]
+        homework_download_all(fn)
+