这应该适合你.

#!/usr/bin/perl

use strict;
use warnings;

use List::Util qw/sum/;
sub avg { sum(@_) / @_ }

my $fileName = shift;

open my $fh, "<", $fileName
    or die "Unable to open $fileName: $!\n";

my %monthData;

chomp(my @headers = split /\t+/, <$fh>);

while (<$fh>) {
    chomp;
    my %rec;
    @rec{@headers} = split /\t+/;
    my ($hour) = split /:/, $rec{TIME}, 2;

    for my $key (grep { not /^(DATE|TIME)$/ } keys %rec) {
        push @{ $monthData{$key}{$rec{DATE}}{$hour} }, $rec{$key};
    }
}

for my $column (keys %monthData) {
    for my $date (keys %{ $monthData{$column} }) {
        for my $hour (keys %{ $monthData{$column}{$date} }) {
            my $avg = avg @{ $monthData{$column}{$date}{$hour} };
            print "average of $column for $date $hour is $avg\n";
        }
    }
}

注意事项:

• strict 和 警告 pragmas
• List::Util 模块获取求和函数
• 将数组放入标量上下文中以获取数组中的项数(在 avg 函数中)
• 更安全的三个参数版本的 open
• 词法文件句柄(而不是旧的裸字样式文件句柄)
• 首先在循环外读取头文件，以避免在循环内有特殊的逻辑
• 使用 hash slice 将文件数据放入结构化记录中立>
• 避免使用 split 的第三个参数分割不必要的时间立>
• 通过只在列表赋值中指定我们想要捕获的变量来避免无用的变量
• 使用 grep 防止将 DATE 和 TIME 键放入 %monthData
• 嵌套的 for 循环每个处理哈希中的一个级别

• strict and warnings pragmas
• List::Util module to get the sum function
• putting an array in scalar context to get the number of items in the array (in the avg function)
• the safer three argument version of open
• the lexical filehandle (rather than the old bareword style filehandle)
• reading the headers first outside the loop to avoid having to have special logic inside it
• using a hash slice to get the file data into a structured record
• avoiding splitting the time more than necessary with the third argument to split
• avoiding useless variables by only specifying the variable we want to catch in the list assignment
• using grep to prevent the DATE and TIME keys from being put in %monthData
• the nested for loops each dealing with a level in the hash