The following gets rid of non-alphanumerics and underscores: 

$user_name =~ s/[\W_]//g;

[download]

The pattern [\W_] breaks down as follows:

However, instead of just silently cleaning data, I'd prefer to check the string for undesirable characters and notify the user if it is bad, so that they can fix it: 

$user_name =~ /[\W_]/ and 
    warn "user name is bad\n"

[download]

In reply to Re: How do I keep anything other than alphanumeric out of a variable? by DrHyde
in thread How do I keep anything other than alphanumeric out of a variable? by Anonymous Monk

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