Using url_param()s with &

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

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Re: Using url_param()s with & by jonadab (Parson) on Apr 14, 2005 at 17:08 UTC
If you want to include an ampersand in a query string argument, the easiest way is to hex-encode it, the same way spaces are done. Spaces (decimal 32, hex 20) are encoded as %20 in URIs, which I'm sure you've seen at some point (here on Perlmonks if nowhere else). I think ampersand would be %26 if I've done the conversion correctly. Of course, whatever you use to get the query args has to know how to unencode this; if you are using a well-known module, that should not be a problem. HTH.HAND update: I neglected to mention that the browser should do this conversion automatically, if you put the thing in the value attribute of a hidden field (or, for that matter, any form field at all (update2: though yes, you'd need to encode the entities in that case (presumably with HTML::Entities))). However, if you're putting it in an href, then you have to (hex) encode it first. Some of the CGI-related modules ~~may~~ provide functions for doing this (update3: such as URI::Escape), but it's also pretty trivial to do by hand, along the lines of this (which, however, I have not extensively tested): `$foo =~ s/(\W)/"%".sprintf "%02x",ord$1/eg;` "In adjectives, with the addition of inflectional endings, a changeable long vowel (Qamets or Tsere) in an open, propretonic syllable will reduce to Vocal Shewa. This type of change occurs when the open, pretonic syllable of the masculine singular adjective becomes propretonic with the addition of inflectional endings." — Pratico & Van Pelt, BBHG, p68	[reply] [d/l]
Re^2: Using url_param()s with & by dmorelli (Scribe) on Apr 14, 2005 at 18:00 UTC
There's no need to reinvent this wheel. `URI::Escape` is part of the Perl "core" `perl -MURI::Escape -le 'print uri_escape "search&l=phone&s=$query&r=10 +0&m=&p=\$cnt"' __OUTPUT__ search%26l%3Dphone%26s%3D%26r%3D100%26m%3D%26p%3D%24cnt` [download] Watch out for that `$cnt` though. I escaped it with \ to keep it from being interpolated, which may or may not be what the OP needs.	[reply] [d/l] [select]
Re^3: Using url_param()s with & by Anonymous Monk on Apr 15, 2005 at 13:07 UTC
URI::Escape is not part of the Perl core	[reply]
Re^2: Using url_param()s with & by jhourcle (Prior) on Apr 14, 2005 at 23:07 UTC
The automatic encoding can actually get you into trouble -- because you need to HTML encode the ampersands as `&` -- so, either of these two would be valid: `<input type='hidden' value='search&l=phone&s=$query&r=100& +amp;m=&p=$cnt'> <a href='$url?search%26l%3dphone%26s%3d%24query%26r%3d100%26m%3d%26p%3 +d%24cnt'>` [download] And once you realize that, it makes perfect sense why there's the push to use `;` as its seperator (which you don't need to HTML escape)	[reply] [d/l] [select]
Re: Using url_param()s with & by sulfericacid (Deacon) on Apr 14, 2005 at 17:19 UTC
Really all you would need to do is change the ampersands to some character or small series of characters you know will never appear in the string (say: XAS;) and just do a little s/// when you need to extract the param to return it to its original form. "Age is nothing more than an inaccurate number bestowed upon us at birth as just another means for others to judge and classify us" sulfericacid	[reply]