RegEx question

[der.hans]

Am 17. Sep, 2009 schwätzte Paul Mooring so:

> This is probably a really obvious question but how can I match
> everything up to a character not including that character with regex?
> For example:
> person at email.tld => person
> me at here.com => me

Use parenthesis to create a back reference.

For sed it's important to use the -r flag for this.

$ echo person at email.tld | sed -re 's/(.+)@.+/\1/'
person

If you're doing this in perl you can reference the match later.

If you're just trying to strip off the remainder it might be easier to do
that rather than pulling up the match.

$ echo person at email.tld | sed -re 's/@.+//'
person

In any case, you might want to search for not the delimiter rather than
any character.

$ echo person at email@.tld | sed -re 's/(.+)@.+/\1/'
person at email

$ echo person at email@.tld | sed -re 's/([^@]+)@.+/\1/'
person

ciao,

der.hans
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