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Postings from April 2010
Mimi Cafe wrote:
>
>> From: John W. Krahn [mailto:jwkrahn@shaw.ca]
>>
>> 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";
>>>
>>> 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
>
> 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.
$ perl -le'
my $s = "The black cat climbed the green tree";
my $end = length $s;
my $start = $end < 15 ? $end : 15;
my ( $substring ) = $s =~ / \A ( .{$start,$end}? \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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