find命令的结果顺序是什么

1. 目的

在研读 doxygen 源码时，在不同电脑、不同操作系统上使用了 find 命令，发现对于相同的 doxygen 源码目录、相同的 find 命令参数，得到了不同顺序的结果。尝试了解下 find 命令的参数，希望得到统一一致的结果，对不同结果的原因稍作分析。

简单的结论: find . -maxdepth 1 -type d 这样的命令后，接入管道和 sort -V 得到自然排序结果:

find . -maxdepth 1 -type d | sort -V

2. 准备：克隆 doxygen 源码

git clone https://gitee.com/mirrors/doxygen
git checkout 79a9efb
* 79a9efb 2023-05-18 | Merge pull request #10052 from albert-github/feature/bug_regr_ca65fd0bbb717a3f65e64bfcebe36a5debba66fa (grafted, HEAD -> master, origin/master, origin/HEAD) [Dimitri van Heesch]

我们希望用 find 命令，打印出 doxygen 目录下的第一级子目录。

3. ubuntu22.04 结果

(base) zz@localhost-43% cat /etc/issue
Ubuntu 22.04.1 LTS \\n \\l
(base) zz@localhost% find –version
find (GNU findutils) 4.8.0
Copyright (C) 2021 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Eric B. Decker, James Youngman, and Kevin Dalley.
开启的特性: D_TYPE O_NOFOLLOW(enabled) LEAF_OPTIMISATION FTS(FTS_CWDFD) CBO(level=2)
(base) zz@localhost% find . -maxdepth 1 -type d
.
./.git
./templates
./libxml
./deps
./libversion
./.github
./examples
./testing
./doc_internal
./addon
./winbuild
./doc
./src
./cmake
./vhdlparser

4. ubuntu16.04 结果

(base) zz@localhost-04% cat /etc/issue
Ubuntu 16.04.1 LTS \\n \\l
(base) zz@localhost-04% find –version
find (GNU findutils) 4.7.0-git
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Eric B. Decker, James Youngman, and Kevin Dalley.
Features enabled: D_TYPE O_NOFOLLOW(enabled) LEAF_OPTIMISATION FTS(FTS_CWDFD) CBO(level=2)
(base) zz@localhost-04% find . -maxdepth 1 -type d
.
./.github
./src
./doc
./addon
./doc_internal
./libxml
./testing
./deps
./.git
./examples
./libversion
./templates
./cmake
./winbuild
./vhdlparser

5. git bash 结果

$ find –version
find (GNU findutils) 4.9.0
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by Eric B. Decker, James Youngman, and Kevin Dalley.
Features enabled: D_TYPE O_NOFOLLOW(enabled) LEAF_OPTIMISATION FTS(FTS_CWDFD) CBO(level=2)
$ find . -maxdepth 1 -type d
.
./.git
./.github
./addon
./cmake
./deps
./doc
./doc_internal
./examples
./libversion
./libxml
./src
./templates
./testing
./vhdlparser
./winbuild

6. 三路比较

7. 保持一样的结果：用自然排序

传入 | sort -V 参数即可:

find . -maxdepth 1 -type d | sort -V
(base) zz@localhost% find . -maxdepth 1 -type d | sort -V
.
./.git
./.github
./addon
./cmake
./deps
./doc
./doc_internal
./examples
./libversion
./libxml
./src
./templates
./testing
./vhdlparser
./winbuild

8. References

https://www.baeldung.com/linux/find-default-sorting-order

关于find命令查找的排序规则探索以及排序方法

1、linux中find命令的排序规则

find命令的搜寻条件直接关系到输出结果，默认应该是按从左到右的的顺序判断，如果有逻辑运算（-not、-and、-or）还得再判断条件组合。find查询的结果是找到一个匹配的项就立即输出结果，一边查找一边输出，查找到的内容不是一次性输出的，所以可能没有统一排序。但是具体排序规则需要分析find命令的底层实现了。