| #!/usr/bin/env bash |
| |
| # |
| # Licensed to the Apache Software Foundation (ASF) under one |
| # or more contributor license agreements. See the NOTICE file |
| # distributed with this work for additional information |
| # regarding copyright ownership. The ASF licenses this file |
| # to you under the Apache License, Version 2.0 (the |
| # "License"); you may not use this file except in compliance |
| # with the License. You may obtain a copy of the License at |
| # |
| # http://www.apache.org/licenses/LICENSE-2.0 |
| # |
| # Unless required by applicable law or agreed to in writing, software |
| # distributed under the License is distributed on an "AS IS" BASIS, |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| # See the License for the specific language governing permissions and |
| # limitations under the License. |
| |
| # For each filespec FS given (one per line) on stdin, rename FS (if it exists) to FS.old, then rename FS.new to |
| # FS. |
| |
| if [[ "$*" = "--help" ]] ; then |
| echo "For each filespec FS read from stdin, rename FS.new to FS. If FS already exists, rename to FS.old" >&2 |
| exit 0 |
| fi |
| |
| while read F |
| do |
| python3 - "$F" << THE_END |
| |
| import sys |
| import os |
| |
| def eprint(*args, **kwargs): |
| print(*args, file=sys.stderr, **kwargs) |
| |
| def rename_file(old_path, new_path): |
| try: |
| os.rename(old_path, new_path) |
| except: |
| eprint(f"fatal error: failure renaming {old_path} to {new_path}\n") |
| sys.exit(1) |
| |
| def rename_to_old(pathspec): |
| op = pathspec + ".old" |
| |
| if os.access(op, os.F_OK): |
| last = 2 |
| while os.access(op + ".{}".format(last), os.F_OK): |
| last += 1 |
| while last > 2: |
| rename_file(op + ".{}".format(last - 1), op + ".{}".format(last)) |
| last -= 1 |
| rename_file(op, op + ".2") |
| |
| rename_file(pathspec, op) |
| |
| filespec = sys.argv[1] |
| if os.access(filespec, os.F_OK): |
| rename_to_old(filespec) |
| rename_file(filespec + ".new", filespec) |
| |
| sys.exit(0) |
| |
| THE_END |
| done |