[perlre] 4-digit hex code in regexp? How to specify?

princepawn has asked for the wisdom of the Perl Monks concerning the following question:

As you might be able to tell from the Basic Unicode Chart, a $ sign has hex value 0024. However, in Perl, I cannot write 0024, but must only write 24. This could problem problematic when dealing with a larger hex code than 2 digits. How can I specify a hex code in Perl using 4 digits instead of 2?

$delimiter = 'Y';

$_ = q(this has $100 worth of salt in it) ;

warn $_;

s/([\x0024])/$delimiter/gm;

warn $_;

s/([\x24])/$delimiter/gm;

warn $_;
[download]

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Re: [perlre] 4-digit hex code in regexp? How to specify? by nothingmuch (Priest) on Nov 14, 2002 at 21:21 UTC
`\x{decaf}` - Damn, that's five. Update: Retrospectively I think it's worth a mention that this is off the Camel Book, from one of the reference sections. Thanks for enlightening \msgs tho... =) -nuffin zz zZ Z Z #!perl	[reply] [d/l]
Re: [perlre] 4-digit hex code in regexp? How to specify? by hawtin (Prior) on Nov 14, 2002 at 21:38 UTC
According to the docs the following should allow 4 byte Unicode defs: `s/([\x{1F24}])/$delimiter/gm;` [download] Update: Sorry did not spot that this had been dismissed. How about the clunky `{ my($temp); $temp1 = "\x{0024}"; $temp2 = "\x{1F45}"; s/([$temp1,$temp2])/$delimiter/gm; }` [download]	[reply] [d/l] [select]
Re^2: [perlre] 4-digit hex code in regexp? How to specify? by Aristotle (Chancellor) on Nov 15, 2002 at 16:41 UTC
Except you don't want the comma in the character class. And why use two variables? `{ my $temp = "\x{0024}\x{1F45}"; s/([$temp])/$delimiter/gm; }` [download] Which if often used might be better written as `# somewhere in init code my $descriptive_charclass_name = do { my $wide = "\x{0024}\x{1F45}"; qr/[$widechars]/; }; # ... later s/($descriptive_charclass_name)/$delimiter/gm;` [download] Makeshifts last the longest.	[reply] [d/l] [select]
Re: [perlre] 4-digit hex code in regexp? How to specify? by Mr. Muskrat (Canon) on Nov 14, 2002 at 21:16 UTC
This works great until you try to put it into brackets... `s/(\x{0024})/$delimiter/gm;`	[reply] [d/l]
Re: Re: [perlre] 4-digit hex code in regexp? How to specify? by jreades (Friar) on Nov 14, 2002 at 21:43 UTC
There appear to be two ways to handle hex codes -- one is the one that you are using: `\x1B` The other is the method used by Mr. Muskrat: `\x{263a}` If you're using 'wide' hex digits (as I assume is the case since you're talking about four digits in this example) then you probably need to use the \x{...} approach. If you'll tell us a little more about what you're doing, we might be able to move beyond a single substitution. Unless that's all you need, in which case this appears to work: `s/\x{0024}/$delimiter/` [download] And you don't need to make it part of a character class	[reply] [d/l] [select]