regexp - how to embed a "/" within the executable part of the regexp when using /e

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

The following program:

$_ = '22C';
s/(\d+)C/($1*9/5)+32 . "F"/ge;
print;
[download]

is a verbatim reproduction of slide 31of gnat's Stages of a Perl programmer. However the / in the executable part of the regexp is being misinterpreted.

How does one embed a slash in a regexp?

Edited: ~Fri Sep 27 15:00:32 2002 (GMT) by footpad: Removed incomplete <A HREF> tag, per Consideration.

Comment on regexp - how to embed a "/" within the executable part of the regexp when using /e Select or Download Code

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Re: regexp - how to embed a "/" within the executable part of the regexp when using /e by diotalevi (Canon) on Sep 27, 2002 at 06:15 UTC
Either escape it as `s/(\d+)C/($19\/5)+32 . "F"/ge;` or change the delimiter so there isn't a conflict like `s\|(\d+)C\|($19/5)+32 . "F"\|ge;`. perlre has more examples of this.	[reply] [d/l] [select]
Re: regexp - how to embed a "/" within the executable part of the regexp when using /e by Juerd (Abbot) on Sep 27, 2002 at 08:15 UTC
s/(\d+)C/($19/5)+32 . "F"/ge;* I like `[]` for matches, and `{}` for code. Maybe the Apocalypses inspired me... `s[ (\d+) C ] { $1 * 9 / 5 + 32 . 'F' }gex;` [download] - Yes, I reinvent wheels. - Spam: Visit eurotraQ.	[reply] [d/l] [select]
Re: Re: regexp - how to embed a "/" within the executable part of the regexp when using /e by diotalevi (Canon) on Sep 27, 2002 at 13:03 UTC
I'm reconsidering my normal useage of both toothpicks and pipes. Of course - once you start writing your regular expressions more like a grammar then it starts to make sense to use balanced delimiters, stylisticly even. Of course grammars (using regular expressions, not Parse::RecDescent) are still fugly in perl5 but hey.	[reply]
Re: regexp - how to embed a "/" within the executable part of the regexp when using /e by Dedalus (Scribe) on Sep 27, 2002 at 10:57 UTC
One simply escapes it, this works even if it is part of code to be executed: `$_ = '22C'; s/(\d+)C/($1*9\/5)+32 . "F"/ge; print;` [download] produces 71.6F. Dedalus.	[reply] [d/l]
Re: regexp - how to embed a "/" within the executable part of the regexp when using /e by trs80 (Priest) on Sep 29, 2002 at 05:35 UTC
You could also do it without division. `$_ = '22C'; s/(\d+)C/($19.2)+32 . "F"/ge; print; print "\n"; $_ = '0C'; s/(\d+)C/($19.2)+32 . "F"/ge; print; print "\n";` [download]	[reply] [d/l]


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