☰

检查多个文件夹的文件差异

tag-icon • tag-icon backup diff snapshot file-comparison
检查多个文件夹的文件差异

我想使用快照检查备份系统内的文件何时不同。

我有几个内部具有相同架构的文件夹

ls -1 .snapshot
4-hourly.2024-04-14_0405
4-hourly.2024-04-14_0805
4-hourly.2024-04-14_1205
4-hourly.2024-04-14_1605
4-hourly.2024-04-14_2005
4-hourly.2024-04-15_0405
4-hourly.2024-04-15_0805
4-hourly.2024-04-15_1205
daily.2024-04-08_0010
daily.2024-04-09_0010
daily.2024-04-10_0010
daily.2024-04-11_0010
daily.2024-04-12_0010
daily.2024-04-13_0010
daily.2024-04-14_0010
daily.2024-04-15_0010
monthly.2024-01-01_0020
monthly.2024-02-01_0020
monthly.2024-03-01_0020
monthly.2024-04-01_0020
weekly.2024-02-25_0015
weekly.2024-03-03_0015
weekly.2024-03-10_0015
weekly.2024-03-17_0015
weekly.2024-03-24_0015
weekly.2024-03-31_0015
weekly.2024-04-07_0015
weekly.2024-04-14_0015

我必须检查每个文件夹中的文件。

例如，目标是查看是否 .snapshot/weekly.2024-04-14_0015/my/path/to/the/file.php与 week.2024-04-07_0015/my/path/to/the/file.php 或 from .snapshot/weekly.2024-03-31_0015/my/path/to/the/file.php、 或 from.snapshot/weekly.2024-04-07_0015/my/path/to/the/file.php等不同。

有一个明显简单的方法吗？

PS：此文件夹内还有其他文件/文件夹发生了更改，我不能只比较整个文件夹。

答案1

对于 shell 循环来说，这听起来是一件容易的事。这应该可以在 zsh、bash、dash 中工作...

cd .snapshot
original="weekly.2024-04-14_0015/my/path/to/the/file.php"
pathonly="$(echo "${original}" | sed 's;^[^/]*/\(.*\)$;\1;')" # cut off head directory

orig_hash=$(sha1sum "${original}" | sed 's/^\([^ ]*\) .*$/\1/')

for candidate in */"${pathonly}" ; do
  # don't compare file to itself, that'd be silly
  [[ "${candidate}" = "${original}" ]] && continue 

  cand_hash=$(sha1sum "${candidate}" | sed 's/^\([^ ]*\) .*$/\1/')

  # check hashes, so that we don't have to read the original N times
  ( [[ "${orig_hash}" = "${cand_hash}" ]] && \
  # if the hashes match, use the cmp tool to compare files byte by byte
    cmp -- "${candidate}" "${original}" ) || \
    # if either the hash equality or the content equality fail, print file name
    printf '%s differs\n' "${candidate}"
done

相关内容