email regex

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

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Re: email regex by Abigail-II (Bishop) on Aug 19, 2003 at 11:02 UTC
`s/\@domain\.com$//;` [download] However, if your question really is, "how do I remove the domain name from an email address using a regexp", then the answer is "you don't". Email addresses can be very complex, and you are better off parsing them. Abigail	[reply] [d/l]
Re: email regex by hardburn (Abbot) on Aug 19, 2003 at 13:35 UTC
As others noted, this problem isn't nearly as simple as it first appears. To be safe, use Mail::Address instead of trying to create your own solution: `use Mail::Address; my $addr = 'name@domain.com'; my $ma = Mail::Address->new('', $addr); my $user = $ma->user;` [download] ---- I wanted to explore how Perl's closures can be manipulated, and ended up creating an object system by accident. -- Schemer Note: All code is untested, unless otherwise stated	[reply] [d/l]
Re: email regex by jonnyfolk (Vicar) on Aug 19, 2003 at 11:13 UTC
This isn't a regex but is one way to do it: `#!/usr/bin/perl -w use strict; use CGI ':standard'; my $email = param('email'); (my $name, my $domain)=split(/\@/, $email); print "Content-type: text/html\n\n"; print "$name";` [download]	[reply] [d/l]
Re: email regex by Abigail-II (Bishop) on Aug 19, 2003 at 11:23 UTC
Eh, no, it doesn't. As I said in an earlier reply, email addresses can be complicated. Here's an example were your approach will fail: `"@"@example.com` [download] Abigail	[reply] [d/l]
Re: Re: email regex by rob_au (Abbot) on Aug 19, 2003 at 11:57 UTC
Okay, looking at this in another light ... How does this substitution, which in theory strips the domain and route portion of the email address, fair. `( $domain ) = $email =~ /\@([^\@]+)$/;` [download] ~~Note that this substitution does not handle RFC822 addresses which contains elements beyond the local_part@domain atoms (however this may be considered beyond the scope of this question).~~ Update - Okay, updated using a subset of the RFC822 email address regular expression from Mastering Regular Expressions to strip off the trailing domain portion to leave the "username" element ... $email =~ s/(?:\@[\040\t](?:(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xf +f]\|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]))+(?!(?:[^(\040)<>@,;: +"\\\[\]\000-\037\x80-\xff]\|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff +])))\|\[(?:[^\\\x80-\xff\n\015\[\]]\|\\[^\x80-\xff])\])[\040\t](?:$[ +^\\\x80-\xff\n\015()](?:(?:\\[^\x80-\xff]\|\([^\\\x80-\xff\n\015()]( +?:\\[^\x80-\xff][^\\\x80-\xff\n\015()])$)[^\\\x80-\xff\n\015()])* +\)[\040\t])(?:\.[\040\t](?:$[^\\\x80-\xff\n\015()](?:(?:\\[^\x80 +-\xff]\|\([^\\\x80-\xff\n\015()](?:\\[^\x80-\xff][^\\\x80-\xff\n\015( +)])$)[^\\\x80-\xff\n\015()])\)[\040\t])(?:(?:[^(\040)<>@,;:"\\ +\[\]\000-\037\x80-\xff]\|(?:\[(\040)<>@,;:"\\\[\]\000-\037\x80-\xff])) ++(?!(?:[^(\040)<>@,;:"\\\[\]\000-\037\x80-\xff]\|(?:\[(\040)<>@,;:"\\\ +[\]\000-\037\x80-\xff])))\|\[(?:[^\\\x80-\xff\n\015\[\]]\|\\[^\x80-\xff +])\])[\040\t](?:$[^\\\x80-\xff\n\015()](?:(?:\\[^\x80-\xff]\|\([^\ +\\x80-\xff\n\015()](?:\\[^\x80-\xff][^\\\x80-\xff\n\015()])$)[^\\ +\x80-\xff\n\015()])\)[\040\t])))$//; [download] `perl -le 'print+unpack"N",pack"B32","00000000000000000000001001111011"'`	[reply] [d/l] [select]
Re: email regex by Abigail-II (Bishop) on Aug 19, 2003 at 12:04 UTC
Re: Re: email regex by tbone1 (Monsignor) on Aug 19, 2003 at 13:03 UTC
If you'll pardon the self-promotion, check out this discussion for why that won't always work. -- tbone1 Ain't enough 'O's in 'stoopid' to describe that guy. - Dave "the King" Wilson	[reply]