Sometimes, it's just easier to try it out:

$_       = 'foo bah bar';
$find    = 'bah';
$replace = '[\1]';
s/(\Q$find\E)/$replace/g;

$\ = "\n";
print;      # "foo [\1] bar" and not "foo [bah] bar"

[download]

But there is indeed a (more efficient?) way:

$_       = 'foo bah bar';
$find    = 'bah';
$replace = '[\1]';

$idx = index($_, $find);
substr($_, $idx, length($find), $replace) if $idx >= 0;

$\ = "\n";
print;

[download]

Update: Here's a version that does mutliple matches:

$_       = 'foo bah bah bar';
$find    = 'bah';
$replace = '[\1]';

$idx = length($_);
while (($idx = rindex($_, $find, $idx-1)) >= 0) {
   substr($_, $idx, length($find), $replace);
}

$\ = "\n";
print;

[download]

In reply to Re: Does s/\Q$find\E/$replace/g really a plain string replace ? by ikegami
in thread Does s/\Q$find\E/$replace/g really a plain string replace ? by MSoegtrop

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