如何在目录及其所有子目录中使用Perl找到最新的.pl文件？ [英] How can I find the newest .pl file in a directory and all its subdirectories using Perl?

问题描述

$ b $如何扫描整个目录的内容，包括其子目录内容，并使用Perl查找最新的 .pl 文件？

我想在目录树中构建所有 .pl 文件的完整文件路径的排序数组/列表。

所以，例如，如果我的基本目录是 / home / users / cheeseconqueso / 我想搜索 .pl 该目录中的文件和该路径中的任何子目录，然后按日期排序 .pl 文件。

最终结果将是一个数组， @pl_paths ，其中 $ pl_paths [0] 会像 /home/users/cheeseconqueso/maybe_not_newest_directory/surely_newest_file.pl

这样的结果，我想要执行文件，但是我想一旦我得到排序的数组，在 $ pl_paths [0] 中执行该文件将不会是一个问题。 p>

有一个相似关于SO的问题，我一直在努力修改以适应我的需要但是我现在在这里有明显的原因。

我用于在一个目录中获取最新文件NAME的代码是：

  opendir（我的$ DH，$ DIR）或死打开$ DIR：$！ 
我的％files = map {$ _ => （stat（$ DIR / $ _））[9]} grep（！/^\.\.?$/，readdir（$ DH））; 
 closedir（$ DH）; 
我的@sorted_files = sort {$ files {$ b}< => $ files {$ a}}（键％文件）; 
 print $ sorted_files [0]。\\\
; 
  

解决方案

您可以使用文件：找到，如果你想要一个核心模块，但我宁愿使用文件:Find::Rule 。

要开始，我们可以找到

 使用文件的目录下的所有 .pl  ::查找::规则; 
 my @files = File :: Find :: Rule-> file 
  - > name（'*。pl'）
  - > in（$ directory）; 
  

然后让我们使用 map 将文件名与修改次数：

 我的@files_with_mtimes = map + {name => $ _，mtime => （stat $ _）[9]}，@files; 
  

并按mtime排序：

  my @sorted_files = reverse sort {$ a-> {mtime}< => $ b-> {mtime}} 
 @files_with_mtimes; 
  

从那里，最新的名称在 $ sorted_files [ 0] {name} 。

如果你只想找到顶级的，实际上不需要做一个完整的排序，但是最好的解决方案我可以想到涉及一些稍微高级的FP，所以如果看起来很奇怪，不要担心：

 使用List :: Util'reduce'; 
我的（$ top_file）= reduce {$ a-> {mtime}> = $ b-> {mtime}？ $ a：$ b} 
 @files_with_mtimes; 
  

How can I scan an entire directory's contents, including its subdirectories' contents, and find the newest .pl file within them using Perl?

I want to build a sorted array/list of the full file paths of all .pl files within a directory tree.

So, for example, if my base directory is /home/users/cheeseconqueso/ I want to search for .pl files in that directory and any subdirectory within that path and then sort the .pl files by date.

The end result would be an array, @pl_paths, where $pl_paths[0] would be something like /home/users/cheeseconqueso/maybe_not_newest_directory/surely_newest_file.pl

From that result, I want to execute the file, but I think once I get the sorted array figured out, executing the file in $pl_paths[0], won't be a problem.

There is a similar question on SO that I have been trying to modify to suit my needs, but I am here now for obvious reasons.

The code I'm using to get the newest file NAME only in one directory is:

opendir(my $DH, $DIR) or die "Error opening $DIR: $!";
my %files = map { $_ => (stat("$DIR/$_"))[9] } grep(! /^\.\.?$/, readdir($DH));
closedir($DH);
my @sorted_files = sort { $files{$b} <=> $files{$a} } (keys %files);
print $sorted_files[0]."\n";

解决方案

You can use File::Find if you want a core module for this, but I would prefer to use File::Find::Rule.

To start off, we can find all of the .pl files under a directory with

use File::Find::Rule;
my @files = File::Find::Rule->file
                            ->name('*.pl')
                            ->in($directory);

Then let's use map to associate filenames with their modification times:

my @files_with_mtimes = map +{ name => $_, mtime => (stat $_)[9] }, @files;

And sort them by mtime:

my @sorted_files = reverse sort { $a->{mtime} <=> $b->{mtime} } 
                @files_with_mtimes;

And from there, the name of the newest one is in $sorted_files[0]{name}.

If you only want to find the top one, there's actually no need to do a complete sort, but the nicest solution I can think of involves some slightly advanced FP, so don't worry about it at all if it looks strange to you:

use List::Util 'reduce';
my ($top_file) = reduce { $a->{mtime} >= $b->{mtime} ? $a : $b } 
  @files_with_mtimes;

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