If you are working in regular expressions, non-alphanumeric characters are recognised
only if they are preceded by a backslash (\) else it will be treated as:

• perl operators or
• popups an error or
• you will get undesired results.

Lets take a look at your problem.

\ (backslash is a non-alphanumeric character).

\\ (in regular expression, two backslashs are recognised as single backslash)

while trying the below segment...

$txt=~s/\\/\\\\/g;

\\\\ (FOUR backslashs becomes 2 backslashs)

therefore your results will be...

__\\U//__

For your desired output try the below one:

    $txt = ' __\\U//__ ';
    $txt =~s/\\/\\\\\\\\/g;
    print $txt;

[download]

regards
Franklin

Don't put off till tomorrow, what you can do today.

In reply to Re: Escaping multiple escape chars by l.frankline
in thread Escaping multiple escape chars by JamesNC

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