Despite plenty of similar cases having been discussed here, this exact issue is thornier than it may seem at first sight and I couldn't find a close enough match to this: Simply stated, the problem is, given a string, determine whether it is safe enough to print the string without doing anything nasty to just about any screen or printer oon the basis of this being assumed to be a text file (especially if we are talking about printing large files where a typical binary file being let through would cause mayhem). I refined the problem statement to this:

Using a regexp, filter the following character types: \x08 \x09 \x0B \x0C \x20 and any symbolic character (punctuation, numbers, letters, standard symbols...) and detect whether anything is left over. I can conceive of an ugly way to do this using ranges of characters - but is that really the best?

Many thanks in advance for any suggestions,

-M

Free your mind


In reply to Testing for unprintable characters by Moron

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.