Hi,

The demo: 
#!perl -l
use strict;
use warnings;

my $orig =        'a.dll';
my $replacement = 'b.dll';

my $str1 = "foo $orig bar";
my $str2 = $str1;

$str1 =~ s/\Q$orig\E/\Q$replacement\E/g;
$str2 =~ s/\Q$orig/$replacement/g;

print $str1;
print $str2;

[download]
I expected $str1 and $str2 to be identical after the substitution regexes, but they're not (on both perl-5.16.0 and 5.20.0 at least). For me, the demo outputs: 
foo b\.dll bar
foo b.dll bar

[download]
Why does the first regex put that backslash in there ?
Are we allowed a maximium of *one* \Q per regex ?
Is there documentation that explains this ?

Supposing that instead of the first regex, I had wanted to do: 
$str1 =~ s/\Q$orig\E.+/\Q$replacement\E/g;

[download]
$str1 would then have become foo b\.dll, whereas I expected foo b.dll.

Cheers,
Rob

In reply to A misunderstanding of quotemeta ? by syphilis

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