文件读入使用Perl数组 [英] Read a file into an array using Perl

问题描述

我目前正在读的文件，并在名为阵列中存储数据 @lines 。然后，我遍历这个数组用为循环，我对某些值相匹配的循环中：

I am currently reading a file and storing the data in an array named @lines. Then, I loop through this array using a for loop and inside the loop I match on certain values:

$find = "fever";

if ($_ =~ /$find/) {
    print "$_\n";
    $number++;
    #@lines =
    #print ("there are : " . $number);
}

目前，我使用的是标量， $找到与发热值而不是执行重复的语句每个过滤器。

At the moment, I am using a scalar, $find, with a value of fever instead of performing the repetitive statements for each filter.

我可以传递一个数组进行比较，而不是一个标量的关键字？

Can I pass an array for comparison instead of a scalar keyword?

推荐答案

如果你读一个文件到列表，它会立刻一切

If you read a file into a list it will take everything at once

@array = <$fh>;  # Reads all lines into array

通过读入标量上下文对比度此

Contrast this with reading into a scalar context

$singleLine = <$fh>;  # Reads just one line

读取整个文件一次可以是一个问题，但你的想法。

Reading the whole file at once can be a problem, but you get the idea.

然后你可以使用的grep 来过滤阵列。

Then you can use grep to filter your array.

@filteredArray = grep /fever/, @array;

然后你就可以得到使用标，迫使标过滤的行数（即单个值）的阵列间pretation的背景下，在这种情况下，返回的计数。

Then you can get the count of filtered lines using scalar, which forces scalar (that is, single value) context on the interpretation of the array, in this case returning a count.

print scalar @filteredArray;

全部放在一起......

Putting it all together...

C:\temp>cat test.pl
use strict; use warnings;  # always

my @a=<DATA>;  # Read all lines from __DATA__

my @f = grep /fever/, @a;  # Get just the fevered lines

print "Filtered lines = ", scalar @f;  # Print how many filtered lines we got

__DATA__
abc
fevered
frier
forever
111fever111
abc

C:\temp>test.pl
Filtered lines = 2
C:\temp>

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