[26846] in Perl-Users-Digest
Perl-Users Digest, Issue: 8869 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Thu Jan 19 18:05:31 2006
Date: Thu, 19 Jan 2006 15:05:05 -0800 (PST)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Thu, 19 Jan 2006 Volume: 10 Number: 8869
Today's topics:
Re: randomly choose some uniq elements of an array <news@chaos-net.de>
Reference Confusion <bob@dont.spam.me>
Re: Validating massive amounts of external links <glex_no-spam@qwest-spam-no.invalid>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Thu, 19 Jan 2006 23:20:08 +0100
From: Martin Kissner <news@chaos-net.de>
Subject: Re: randomly choose some uniq elements of an array
Message-Id: <slrndt044o.605.news@maki.homeunix.net>
xhoster@gmail.com wrote :
> Martin Kissner <news@chaos-net.de> wrote:
>> I want to choose a number of files from a directory randomly.
>
> Is "a number" always going to be 3, or at least small?
For the purpose I need the script now, it's always 3.
I had a working solution. I mainly posted to expand my understanding of
Perl.
> Apparently you have read the FAQ. So why did you implement the method the
> FAQ said was bad, rather than one of the methods that it said were good?
> Reading the FAQ so that you can do exactly what they tell you *not* to do
> seems like an odd programming strategy.
I needed the script for a CGI based website (for showing random images
of the alps to be precise ;) )
Implemented the method wich I understood quickly enough to go on.
Since my array is not very large I was satisfied for the moment.
Thank you for your feedback.
Martin
--
perl -e '$S=[[73,116,114,115,31,96],[108,109,114,102,99,112],
[29,77,98,111,105,29],[100,93,95,103,97,110]];
for(0..3){for$s(0..5){print(chr($S->[$_]->[$s]+$_+1))}}'
------------------------------
Date: Thu, 19 Jan 2006 19:05:15 GMT
From: Bob <bob@dont.spam.me>
Subject: Reference Confusion
Message-Id: <pan.2006.01.19.19.05.07.841467@dont.spam.me>
The perl scritpt below is attempting to set some variables from the
contents of a datbase. I can make it work fine if I explicitly and
directly set each variable by name. Because, unlike the demo script below,
there are many variables I tried to be clever with a loop and references.
It almost works.
The print statement within the loop shows that I am getting the correct
data and putting it into a variable with a the name I want, that is a name
that matches the database field name. But, once outside the loop the
contents of the variable disappear or perhaps there is a scoping problem
and I never set the right variable in the first place.
Yes, I am aware that this techniqueue can be unsafe.
I hope the following comes through without getting line-wrapped!
============================= the script =========================
#!/usr/bin/perl use warnings;
use strict;
use DBI;
my $DB_CONNECT="DBI:Pg:dbname=stable-db";
my $DB_USER="postgres";
my $DB_PASS="passwd";
my $dbh = DBI->connect($DB_CONNECT, $DB_USER, $DB_PASS);
my $id=561;
my $title;
my $query = "SELECT title FROM jobs WHERE id = $id";
my $sth = $dbh->prepare($query);
$sth->execute;
while ( my $row_hash = $sth->fetchrow_hashref ) {
foreach my $key (sort keys %$row_hash) {
no strict 'refs';
$row_hash->{$key} and $$key=$row_hash->{$key} or $$key="";
print "Here is $key: $$key\n";
}
if ( ! $title ) { print "Where did \$title go?\n"; }
else { print "Title is still $title\n"; }
}
=====================================================================================
Output:
Here is title: My favorite job title
Where did $title go?
------------------------------
Date: Thu, 19 Jan 2006 16:39:23 -0600
From: "J. Gleixner" <glex_no-spam@qwest-spam-no.invalid>
Subject: Re: Validating massive amounts of external links
Message-Id: <wyUzf.35$rc5.790@news.uswest.net>
Lars Haugseth wrote:
> I have a database with a table containing (among others) the columns
> URL, STATUS and LASTCHECKED. Stored in the table are thousand of records
> containg links to external resources (all using the HTTP protocol.)
Randal has an article about checking bookmarked links, which might help:
http://www.stonehenge.com/merlyn/UnixReview/col56.html
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
From: Perl-Users-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Digest Administrivia (Last modified: 6 Apr 01)
Message-Id: <null>
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End of Perl-Users Digest V10 Issue 8869
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