repetition operator +

[robslang]

Shouldn't "a\n" match the regular expression a+ in the following case?

$ echo a | grep 'a'
a
$ echo a | grep 'a*'
a
$ echo a | grep 'a+'
$

--Robert

[Matthew Wakeling]

On Fri, 3 Jul 2009, robslang@... wrote:
> Shouldn't "a\n" match the regular expression a+ in the following case?
>
> $ echo a | grep 'a'
> a
> $ echo a | grep 'a*'
> a
> $ echo a | grep 'a+'
> $

See the section "Basic vs Extended Regular Expressions" in the grep man
page.

$ echo a | grep "a\+"
a
$ echo a | grep -E "a+"
a


Matthew

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