rsync 备份一个源目录并检查多个目录

Question

我正在尝试将“sdir”目录复制（rsync）到 tdir 目录，具体取决于日期。我想要一份完整的副本到 mon 目录，周二只有更改的内容，婚礼只有更改的内容，等等，但我没有得到我需要的结果。 参考我运行的实际命令：

[jesse@localhost test]$ tree
.
├── sdir
│   ├── file1
│   ├── file2
│   ├── file3
│   ├── file4
│   └── file5
└── tdir
    ├── fri
    ├── mon
    │   ├── file1
    │   └── file2
    ├── thu
    ├── tue
    │   └── file3
    └── wed
        ├── file3
        ├── file4
        └── file5

7 directories, 11 files
[jesse@localhost test]$ touch sdir/file6
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir//thu/ --backup-dir=/home/jesse/test/tdir/fri/
sending incremental file list
./
file3
file4
file5
file6

sent 294 bytes  received 31 bytes  650.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir//thu/ --backup-dir=/home/jesse/test/tdir/thu/
sending incremental file list
./
file3
file4
file5
file6

sent 294 bytes  received 31 bytes  650.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ --backup-dir=/home/jesse/test/tdir/thu/
sending incremental file list
./
file6

sent 208 bytes  received 22 bytes  460.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)
[jesse@localhost test]$ rsync -av --dry-run sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir/thu/ --backup-dir=/home/jesse/test/tdir/thu/
sending incremental file list
./
file3
file4
file5
file6

sent 294 bytes  received 31 bytes  650.00 bytes/sec
total size is 0  speedup is 0.00 (DRY RUN)
[jesse@localhost test]$ rsync -av  sdir/ --compare-dest=/home/jesse/test/tdir/mon/ /home/jesse/test/tdir/tue/ /home/jesse/test/tdir/wed/ /home/jesse/test/tdir/thu/ --backup-dir=/home/jesse/test/tdir/thu/
sending incremental file list
./
file3
file4
file5
file6

sent 438 bytes  received 95 bytes  1,066.00 bytes/sec
total size is 0  speedup is 0.00
[jesse@localhost test]$ tree
.
├── sdir
│   ├── file1
│   ├── file2
│   ├── file3
│   ├── file4
│   ├── file5
│   └── file6
└── tdir
    ├── fri
    ├── mon
    │   ├── file1
    │   └── file2
    ├── thu
    │   ├── file3
    │   ├── file4
    │   ├── file5
    │   └── file6
    ├── tue
    │   └── file3
    └── wed
        ├── file3
        ├── file4
        └── file5

7 directories, 16 files
[jesse@localhost test]$ 

Answer 1

我注意到 rsync 手册页明确指出“从版本 2.6.4 开始，可以提供多个 --link-dest 目录”，--compare-dest 也有类似的说明，但不适用于--backup-dir（这是有道理的）。如果您想将备份限制为“仅不在多个其他目录之一中的内容”，则可以使用--*-dest 选项。

这是我的测试和结果：

$ mkdir src mon tue wed
$ for n in {1..3}; do date > src/file$n; sleep 1; done
$ rsync -avi src/ mon/
building file list ... done
.d..t.... ./
>f+++++++ file1
>f+++++++ file2
>f+++++++ file3

sent 346 bytes  received 92 bytes  876.00 bytes/sec
total size is 87  speedup is 0.20
$ for n in {4..5}; do date > src/file$n; sleep 1; done
$ rsync -avi --compare-dest=$PWD/mon/ src/ tue/
building file list ... done
.d..t.... ./
>f+++++++ file4
>f+++++++ file5

sent 295 bytes  received 70 bytes  730.00 bytes/sec
total size is 145  speedup is 0.40
$ for n in {6..7}; do date > src/file$n; sleep 1; done
$ rsync -avi --compare-dest=$PWD/mon/ --compare-dest=$PWD/tue/ src/ wed/
building file list ... done
.d..t.... ./
>f+++++++ file6
>f+++++++ file7

sent 319 bytes  received 70 bytes  778.00 bytes/sec
total size is 203  speedup is 0.52
$

这里的显着区别是每个比较目录都需要自己的选项。符号不是：

rsync --compare-dest one/ two/ src/ dest/

而是：

rsync --compare-dest=one/ --compare-dest=two/ src/ dest/

要将其放入每天运行的代码中，您可以尝试如下（未经测试的脚本）：

#!/usr/bin/env bash

# Store our rsync arguments in an array, for easier handling.
rsync_args=(-a)

# If we're running interactively, show us rsync verbose output.
if [ -t 0 ]; then
  rsync_args+=(-vi)
fi

# Step through weekdays, adding days to our argument list, stopping at "today"
read today < <(date '+%a')
for day in Mon Tue Wed Thu Fri; do
  [ "$day" = "$today" ] && break
  rsync_args+=(--compare-dest=$PWD/${day,,})
done

# And finally, copy everything.
rsync "${rsync_args[@]}" src/ "${day,,}"/

请注意，bash 在参数扩展中的大小写控制（${s,,} 和 ${s^^}）是 bash 版本 4 的功能。