It is a bit tricky. Just tried it and Perl warned:
The string is: The black cat is.
Can't do {n,m} with n > m in regex; marked by <-- HERE in m/ \A ( .{19,18}
<-- HERE ?\s+ \b ) / at substr.pl line 10.
My strings are not fixed length, but I do they are normally longer that the
offset I used, so I should be fine I think.
Mimi
-----Original Message-----
From: John W. Krahn [mailto:[email protected]]
Sent: 18 April 2010 17:03
To: Perl Beginners
Subject: Re: Extract substring from offset to space or full stop
Mimi Cafe wrote:
> I used MySQL substr function to extra 100 characters from the result of a
> query, but understandably, I don't get what I want.
>
> Now I looked at Perl's substr function and it doesn't look like it can
help
> me achieve what I need to.
>
> Let's say I have:
>
> $s = "The black cat climbed the green tree";
>
> $substring = substr( $s, 1, 15); # this will return "The black cat c".
No it will not. It will return "he black cat cl" because in perl
offsets start at 0 and not 1:
$ perl -le'
my $s = "The black cat climbed the green tree";
my $substring = substr( $s, 1, 15 );
print $substring;
'
he black cat cl
> How can I have this return the whole word climbed rather than the c (i.e.
I
> need to get "The black cat climbed")? I need to get the remaining
characters
> from the length till the next white space or end of a phrase.
>
> Any other way to overcome this limitation? How can I use regex here?
$ perl -le'
my $s = "The black cat climbed the green tree";
my $length = length $s;
my ( $substring ) = $s =~ / \A ( .{15,$length}? \b ) /x;
print $substring;
'
The black cat climbed
John
--
The programmer is fighting against the two most
destructive forces in the universe: entropy and
human stupidity. -- Damian Conway
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