stdin使用perl检查文件中的字

igetnqfo 于 2022-11-15 发布在 Perl

关注(0)|答案(2)|浏览(145)

我有一个文件aa.txt：

Nothing is worth more than the truth.
I like to say hello to him.
Give me peach or give me liberty.
Please say hello to strangers.
I'ts ok to say Hello to strangers.

我试着用代码：

use strict;
use warnings;

my $input_aa='aa.txt';

while (1) {
    print "Enter the word you are looking for (or 'quit' to exit): ";
    my $answer = <STDIN>;
    chomp $answer;
    last if $answer =~/quit/i; #
    print "Looking for '$answer'\n";
    my $found = 0;
    open my $f, "<", $input_aa or die "ERROR: Cannot open '$input_aa': $!";
    while (<$f>) {
        m/$answer/ or next;
        $found=1;
        last;
    }
    close $f;
    if ($found) {
        print "Found $answer!\n";
        while ( my $line = <$input_aa> ) {
            print $line;
         }
    } else {
        print "Sorry - $answer was not found\n";
    }
}

我希望当我从键盘输入一个关键字时，在文件中进行比较，并输出带有该单词的行。例如，当我输入单词Nothing时，它应该输出行Nothing is worth more than the truth.。
我试着输入代码，但是当我从钥匙串输入关键字时，它没有输出该行。问题在哪里？

perl

来源：https://stackoverflow.com/questions/74250301/stdin-check-word-in-file-with-perl

2条答案

按热度按时间

4bbkushb1#

您的代码可以正常工作，直到您尝试打印匹配行。您的代码尝试读取<$input_aa>，这不是一个有效的文件句柄。
相反，您可以使用$found变量在找到匹配行时简单地保存它，例如：

use strict;
use warnings;

my $input_aa='aa.txt';

while (1) {
    print "Enter the word you are looking for (or 'quit' to exit): ";
    my $answer = <STDIN>;
    chomp $answer;
    last if $answer =~/quit/i; #
    print "Looking for '$answer'\n";
    my $found;
    open my $f, "<", $input_aa or die "ERROR: Cannot open '$input_aa': $!";
    while (<$f>) {
        m/$answer/ or next;
        $found=$_;
        last;
    }
    close $f;
    if (defined($found)) {
        print "Found $answer! in this line: $found";
    } else {
        print "Sorry - $answer was not found\n";
    }
}

更改是不初始化$found，因此检查是否定义了$found。如果定义了，则打印$found。

赞(0）回复(0）举报 2022-11-15

46scxncf2#

看来问题就出在这一行：

while ( my $line = <$input_aa> )

当你找到该行时，试着保存它，例如用以下内容替换$found = 1：

$found = $_;

然后你可以打印$found

赞(0）回复(0）举报 2022-11-15

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stdin使用perl检查文件中的字

2条答案

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