如何在 Perl 中插入非内插字符串

Question

一旦确定其中包含“$”，如何对下面的字符串进行插值？

use strict;

my $yrs;
my $stg = 'He is $yrs years old.';

if ($stg =~ /[@#$\%\/]/) {

    print "Matched dollar sign.\n";
    $yrs = '4';
    
} else {

    print "No Match.\n";

}

print "Year's scalar: $yrs\n";
print $stg . "\n";

我得到：

He is $yrs years old.

我想得到：

He is 4 years old.

Answer 1

您正在尝试编写模板系统。周围有很多这样的东西，所以你不必费心自己写。

use Template qw( );

my $template = 'He is [% years %] years old.';

my $vars = {
   years => 4,
};

my $tt = Template->new();
$tt->process($template, $vars, \my $output)
   or die($tt->error());

say $output;

Answer 2

我可能会用 sprintf:

来写

my $template = 'He is %d years old.';
my $output = sprintf $template, $years;

如何在 Perl 中插入非内插字符串

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