use os.open and os.write instead of regular file

Author: joshuaboud

navigator/scripts/write-chunks.py3

@@ -1,28 +1,28 @@
 #!/usr/bin/env python3
 
 """
-    Cockpit Navigator - A File System Browser for Cockpit.
-    Copyright (C) 2021 Josh Boudreau <jboudreau@45drives.com>
+	Cockpit Navigator - A File System Browser for Cockpit.
+	Copyright (C) 2021 Josh Boudreau <jboudreau@45drives.com>
 
-    This file is part of Cockpit Navigator.
-    Cockpit Navigator is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-    Cockpit Navigator is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-    You should have received a copy of the GNU General Public License
-    along with Cockpit Navigator.  If not, see <https://www.gnu.org/licenses/>.
+	This file is part of Cockpit Navigator.
+	Cockpit Navigator is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+	Cockpit Navigator is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+	You should have received a copy of the GNU General Public License
+	along with Cockpit Navigator.  If not, see <https://www.gnu.org/licenses/>.
 """
 
 """
 Synopsis: `echo <newline delimited JSON objects> | write-chunks.py3`
 JSON objects are of form:
 obj = {
-    seek: <byte offset>
-    chunk: <base64 encoded data chunk>
+	seek: <byte offset>
+	chunk: <base64 encoded data chunk>
 }
 """
 
@@ -31,53 +31,48 @@ import os
 import sys
 import json
 
-def write_chunk(chunk, file):
-    if not file:
-        path = sys.argv[1]
-        parent_path = os.path.dirname(path)
-        try:
-            if not os.path.exists(parent_path):
-                os.makedirs(parent_path, exist_ok=True)
-            elif os.path.isfile(parent_path):
-                print(parent_path + ": exists and is not a directory.")
-                sys.exit(1)
-            file = open(path, "wb")
-        except Exception as e:
-            print(e)
-            sys.exit(1)
-    seek = chunk["seek"]
-    data = base64.b64decode(chunk["chunk"])
-    try:
-        file.seek(seek)
-        file.write(data)
-    except Exception as e:
-        print(e)
-        sys.exit(1)
+def write_chunk(chunk, fd):
+	seek = chunk["seek"]
+	data = base64.b64decode(chunk["chunk"])
+	os.lseek(fd, seek, os.SEEK_SET)
+	os.write(fd, data)
+
+def create_path(path):
+	try:
+		if not os.path.exists(path):
+			os.makedirs(path, exist_ok=True)
+		elif os.path.isfile(path):
+			print(path + ": exists and is not a directory.")
+			sys.exit(1)
+	except Exception as e:
+		print(e)
+		sys.exit(1)
 
 def main():
-    file = None
-    if len(sys.argv) != 2:
-        print("Invalid number of arguments.")
-        sys.exit(1)
-    while True:
-        try:
-            json_in = input()
-        except EOFError:
-            break
-        json_list = json_in.split("\n") # need to split in case writes happen faster than reads
-        for json_obj in json_list:
-            try:
-                obj_in = json.loads(json_obj)
-            except Exception as e:
-                print(e)
-                log = open("/var/log/navigator.log", "w")
-                log.write(json_in)
-                log.close()
-                sys.exit(1)
-            write_chunk(obj_in, file)
-    if file:
-        file.close()
-    sys.exit(0)
+	if len(sys.argv) != 2:
+		print("Invalid number of arguments.")
+		sys.exit(1)
+	fd = None
+	path = sys.argv[1]
+	parent_path = os.path.dirname(path)
+	create_path(parent_path)
+	try:
+		fd = os.open(sys.argv[1], os.O_WRONLY | os.O_TRUNC | os.O_CREAT)
+		while True:
+			try:
+				json_in = input()
+			except EOFError:
+				break
+			json_list = json_in.split("\n") # need to split in case writes happen faster than reads
+			for json_obj in json_list:
+				obj_in = json.loads(json_obj)
+				write_chunk(obj_in, fd)
+	except Exception as e:
+		print(e)
+		os.close(fd)
+		sys.exit(1)
+	os.close(fd)
+	sys.exit(0)
 
 if __name__ == "__main__":
-    main()
+	main()