[30037] in Perl-Users-Digest
Perl-Users Digest, Issue: 1280 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Feb 15 14:09:50 2008
Date: Fri, 15 Feb 2008 11:09:10 -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 Fri, 15 Feb 2008 Volume: 11 Number: 1280
Today's topics:
Can't locate object method err <dw149@acmex.gatech.edu>
Re: Can't locate object method err <joost@zeekat.nl>
Re: Can't locate object method err <yankeeinexile@gmail.com>
Re: Can't locate object method err xhoster@gmail.com
Re: Can't locate object method err <joost@zeekat.nl>
Re: Can't locate object method err <dw149@acmex.gatech.edu>
Re: Can't locate object method err <dw149@acmex.gatech.edu>
Re: Can't locate object method err <joost@zeekat.nl>
dump POST data to screen <contact@myname.com>
Re: dump POST data to screen <noreply@gunnar.cc>
Re: dump POST data to screen <contact@myname.com>
Re: how to find how many items are in a reference? <wsmith60@cinci.rr.com>
Re: how to find how many items are in a reference? <hjp-usenet2@hjp.at>
JendaRex and Perl 5.10 <Bruce.Axtens@gmail.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Serving Large Data From Files or From Blobs FeelLikeANut@gmail.com
Re: Serving Large Data From Files or From Blobs xhoster@gmail.com
Re: Serving Large Data From Files or From Blobs <luiheidsgoeroe@hotmail.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 15 Feb 2008 17:28:58 +0000 (UTC)
From: David Williams <dw149@acmex.gatech.edu>
Subject: Can't locate object method err
Message-Id: <fp4i4q$el7$1@news-int.gatech.edu>
Hello all,
I am getting the following error and need help. As a disclaimer,
I am heavily versed in php but not perl so if this is a simple error,
please forgive me:
Can't locate object method "new" via package "Net::Telnet" (perhaps you forgot to load "Net::Telnet"?) at ./check.pl line 5.
_
#!/usr/bin/perl
use strict;
use warnings;
use lib "/netmod/lib/site_perl/Net/";
my $t= new Net::Telnet('Telnet.pm') or die();
From the package, the syntax/spelling is correct:
package Net::Telnet
I installed the package in a non standard location because I do not
have root on the box. Telnet.pm is under
/netmod/lib/site_perl/Net/
but perl is acting like it cannot find it.
Anybody have any ideas?
thx,
David
--
------------------------------
Date: Fri, 15 Feb 2008 18:34:28 +0100
From: Joost Diepenmaat <joost@zeekat.nl>
Subject: Re: Can't locate object method err
Message-Id: <87zlu22kez.fsf@zeekat.nl>
David Williams <dw149@acmex.gatech.edu> writes:
> Hello all,
> I am getting the following error and need help. As a disclaimer,
> I am heavily versed in php but not perl so if this is a simple error,
> please forgive me:
>
> Can't locate object method "new" via package "Net::Telnet" (perhaps
> you forgot to load "Net::Telnet"?) at ./check.pl line 5.
The error is correct. You've not loaded Net::Telnet before you call the
new() method.
> #!/usr/bin/perl
> use strict;
> use warnings;
> use lib "/netmod/lib/site_perl/Net/";
> my $t= new Net::Telnet('Telnet.pm') or die();
Net::Telnet's new() method does not take a 'Telnet.pm' argument.
Replace that last line with something like this:
use Net::Telnet;
my $t = Net::Telnet->new(
# your arguments here
);
As far as I can tell, the new() method should die() automatically if
anything goes wrong when connecting.
--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/
------------------------------
Date: 15 Feb 2008 11:41:59 -0600
From: Lawrence Statton <yankeeinexile@gmail.com>
Subject: Re: Can't locate object method err
Message-Id: <87ve4q6rrs.fsf@hummer.cluon.com>
David Williams <dw149@acmex.gatech.edu> writes:
> Hello all,
> I am getting the following error and need help. As a disclaimer,
> I am heavily versed in php but not perl so if this is a simple error,
> please forgive me:
>
> Can't locate object method "new" via package "Net::Telnet" (perhaps
> you forgot to load "Net::Telnet"?) at ./check.pl line 5. _
>
>
> #!/usr/bin/perl
> use strict;
> use warnings;
> ## use lib "/netmod/lib/site_perl/Net";
use lib '/netmod/lib/site_perl';
use Net::Telnet;
> my $t= new Net::Telnet('Telnet.pm') or die();
I am reasonably certain that 'Telnet.pm' is not a meaningful parameter
for Telnet's constructor.
--
Lawrence Statton - lawrenabae@abaluon.abaom s/aba/c/g
Computer software consists of only two components: ones and
zeros, in roughly equal proportions. All that is required is to
place them into the correct order.
------------------------------
Date: 15 Feb 2008 17:43:42 GMT
From: xhoster@gmail.com
Subject: Re: Can't locate object method err
Message-Id: <20080215124344.402$hm@newsreader.com>
David Williams <dw149@acmex.gatech.edu> wrote:
> Hello all,
> I am getting the following error and need help. As a disclaimer,
> I am heavily versed in php but not perl so if this is a simple error,
> please forgive me:
>
> Can't locate object method "new" via package "Net::Telnet" (perhaps you
> forgot to load "Net::Telnet"?) at ./check.pl line 5. _
I'm not sure why Perl doesn't just try to do an implicit "use %s" as
a last resort before failing with a 'perhaps you for forgot to lead "%s"'
message. It seems to me like it would be a nice convenience, but it
doesn't do that; and there is probably a reason that that would be a bad
idea that I have overlooked.
>
> #!/usr/bin/perl
> use strict;
> use warnings;
> use lib "/netmod/lib/site_perl/Net/";
This tells perl to add the above to the list of paths which are searched
to find the requested module. But you never tell perl to actually load any
module that might be found therein. Also, because the "Net" is part of the
module name and automatically gets added to each path when searching, it
probably shouldn't be explicitly included in the path, so:
use lib "/netmod/lib/site_perl/";
Then you need to actually load the module, by adding a line like:
use Net::Telnet;
> my $t= new Net::Telnet('Telnet.pm') or die();
I don't know what the 'Telnet.pm' above is suppose to accomplish. I
suspect it shouldn't be there.
>
> From the package, the syntax/spelling is correct:
> package Net::Telnet
>
> I installed the package in a non standard location because I do not
> have root on the box. Telnet.pm is under
>
> /netmod/lib/site_perl/Net/
>
> but perl is acting like it cannot find it.
> Anybody have any ideas?
You told perl where to search for a module, in case it needs to search for
one. But you never told it to actually do that search and load the module.
Xho
--
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this fact.
------------------------------
Date: Fri, 15 Feb 2008 18:50:36 +0100
From: Joost Diepenmaat <joost@zeekat.nl>
Subject: Re: Can't locate object method err
Message-Id: <87ve4q2jo3.fsf@zeekat.nl>
xhoster@gmail.com writes:
> David Williams <dw149@acmex.gatech.edu> wrote:
> I'm not sure why Perl doesn't just try to do an implicit "use %s" as
> a last resort before failing with a 'perhaps you for forgot to lead "%s"'
> message. It seems to me like it would be a nice convenience, but it
> doesn't do that; and there is probably a reason that that would be a bad
> idea that I have overlooked.
Well, it's also likely that the package name is misspelled, and blindly
loading the wrong module could theoretically lead to much more
problematic issues than simply failing.
--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/
------------------------------
Date: Fri, 15 Feb 2008 17:57:46 +0000 (UTC)
From: David Williams <dw149@acmex.gatech.edu>
Subject: Re: Can't locate object method err
Message-Id: <fp4jqq$ets$1@news-int.gatech.edu>
David Williams <dw149@acmex.gatech.edu> wrote:
Hi and thanks,
However,
I cannot use
use Net::Telnet;
because the module is not local.
so I put
use lib "netmod/lib/site_perl/Net";
which I thought loaded the module.
Is that not right?
David
> Hello all,
> I am getting the following error and need help. As a disclaimer,
> I am heavily versed in php but not perl so if this is a simple error,
> please forgive me:
> Can't locate object method "new" via package "Net::Telnet" (perhaps you forgot to load "Net::Telnet"?) at ./check.pl line 5.
> _
> #!/usr/bin/perl
> use strict;
> use warnings;
> use lib "/netmod/lib/site_perl/Net/";
> my $t= new Net::Telnet('Telnet.pm') or die();
> From the package, the syntax/spelling is correct:
> package Net::Telnet
> I installed the package in a non standard location because I do not
> have root on the box. Telnet.pm is under
> /netmod/lib/site_perl/Net/
> but perl is acting like it cannot find it.
> Anybody have any ideas?
> thx,
> David
> --
--
David Williams
Georgia Institute of Technology, Atlanta Georgia, 30332
Email: dw149@prism.gatech.edu
------------------------------
Date: Fri, 15 Feb 2008 18:07:03 +0000 (UTC)
From: David Williams <dw149@acmex.gatech.edu>
Subject: Re: Can't locate object method err
Message-Id: <fp4kc7$f9m$1@news-int.gatech.edu>
Problem solved and thank you to all.
It came down to taking the Net off of the end of this string
#wrong
use lib '/netmod/lib/site_perl/Net';
#right
use lib '/netmod/lib/site_perl/';
and then actually using the module which I thought use lib did.
use Net::Telnet;
This is why I focused on php for 3 years and counting but
I need to learn perl clearly.
--
David Williams
Georgia Institute of Technology, Atlanta Georgia, 30332
Email: dw149@prism.gatech.edu
------------------------------
Date: Fri, 15 Feb 2008 19:12:40 +0100
From: Joost Diepenmaat <joost@zeekat.nl>
Subject: Re: Can't locate object method err
Message-Id: <87r6fe2inb.fsf@zeekat.nl>
David Williams <dw149@acmex.gatech.edu> writes:
> David Williams <dw149@acmex.gatech.edu> wrote:
> Hi and thanks,
> However,
> I cannot use
>
> use Net::Telnet;
> because the module is not local.
>
> so I put
>
> use lib "netmod/lib/site_perl/Net";
> which I thought loaded the module.
> Is that not right?
Not quite. You should do:
use lib "netmod/lib/site_perl/";
use Net::Telnet;
the 'use lib' statement adds the given *directory* to the @INC array
(this is a list of directories where modules should be loaded from).
the 'use Net::Telnet' command then searches for the 'Net/Telnet.pm' file
in the directories in the global @INC array. That way you can install as
many modules as you need to the "netmod/lib/site_perl" directory and
still use them without having to remember if they're locally or globally
installed.
--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/
------------------------------
Date: 15 Feb 2008 14:41:11 GMT
From: henribaeyens <contact@myname.com>
Subject: dump POST data to screen
Message-Id: <47b5a487$0$849$ba4acef3@news.orange.fr>
Hello,
I'm trying to figure out a way to output, for debugging purposes, the
contents of a multipart form-data. The posted data consists of both text
type inputs and file types input. In php, one can invoke print_r($_POST)
and print_r($_FILES), how do I achieve this using perl, especially for
the $_FILES data; I can do the $_POST by parsing the query string but how
do I do it for the files?
Thanks much for any help
Henri
------------------------------
Date: Fri, 15 Feb 2008 18:16:38 +0100
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: dump POST data to screen
Message-Id: <61lvjtF1vp4r2U1@mid.individual.net>
henribaeyens wrote:
> I'm trying to figure out a way to output, for debugging purposes, the
> contents of a multipart form-data.
print <STDIN>;
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: 15 Feb 2008 18:39:40 GMT
From: henribaeyens <contact@myname.com>
Subject: Re: dump POST data to screen
Message-Id: <47b5dc6c$0$906$ba4acef3@news.orange.fr>
On Fri, 15 Feb 2008 18:16:38 +0100, Gunnar Hjalmarsson wrote:
> henribaeyens wrote:
>> I'm trying to figure out a way to output, for debugging purposes, the
>> contents of a multipart form-data.
>
> print <STDIN>;
nice guru shit!
I managed to come up with
while(<STDIN>) {
chomp($_);
print "$_<br>\n";
}
thanks
------------------------------
Date: Fri, 15 Feb 2008 00:43:28 -0500
From: "Bill Smith" <wsmith60@cinci.rr.com>
Subject: Re: how to find how many items are in a reference?
Message-Id: <47b59182$0$4958$4c368faf@roadrunner.com>
"Tomasz Chmielewski" <tch@nospam.syneticon.net> wrote in message
news:fp1brl$jh4$1@online.de...
> How can I find how many items are there in a reference?
>
>
> Let's say we first make:
>
> my $data = $db->selectall_arrayref("SELECT * FROM table");
>
>
> Now, I can access any data with:
>
> print $$hardware[X][Y];
>
>
> How can I find the maximum element for X, Y?
I am not certain what your question means.
Let me simulate the structure returned from
db->selectall_arrayref
and demonstrate how to reference the data.
use strict;
use warnings;
my $hardware = [
# type diam(in). length(in) finish
[ "hex", "1/4", "1", "brass", ],
[ "slot", "1/8", "1/2", "chrome",],
[ "pan", "3/16", "3/4", "black", ],
];
local $, = " ";
for my $screw (@$hardware){
print @$screw, "\n";
}
my $number_screws = @$hardware;
my $number_columns = @{${$hardware}[0]};
print "Number of screws: $number_screws Number of columns:
$number_columns\n";
__END__
use strict;
use warnings;
my $hardware = [
# type diam. length finish
[ "hex", "1/4", "1", "brass", ],
[ "slot", "1/8", "1/2", "chrome",],
[ "pan", "3/16", "3/4", "black", ],
];
local $, = " ";
for my $screw (@$hardware){
print @$screw, "\n";
}
my $number_screws = @$hardware;
my $number_columns = @{${$hardware}[0]};
print "Number of screws: $number_screws Number of columns:
$number_columns\n";
__END__
Former C programmers do find it easier to read perl's alternate syntax
($array[X][Y]) for arrays. I find it much easier to write perl in its
normal syntax expecially when using features unique to perl such as the "@"
operator and array cross sections.
------------------------------
Date: Fri, 15 Feb 2008 17:52:52 +0100
From: "Peter J. Holzer" <hjp-usenet2@hjp.at>
Subject: Re: how to find how many items are in a reference?
Message-Id: <slrnfrbgr4.jvl.hjp-usenet2@hrunkner.hjp.at>
On 2008-02-15 05:43, Bill Smith <wsmith60@cinci.rr.com> wrote:
> "Tomasz Chmielewski" <tch@nospam.syneticon.net> wrote in message
> news:fp1brl$jh4$1@online.de...
>> How can I find how many items are there in a reference?
>>
>> Let's say we first make:
>>
>> my $data = $db->selectall_arrayref("SELECT * FROM table");
>>
>>
>> Now, I can access any data with:
>>
>> print $$hardware[X][Y];
Or somewhat more readable:
print $hardware->[X][Y];
>> How can I find the maximum element for X, Y?
>
> I am not certain what your question means.
> Let me simulate the structure returned from
> db->selectall_arrayref
> and demonstrate how to reference the data.
>
> use strict;
> use warnings;
>
> my $hardware = [
> # type diam(in). length(in) finish
> [ "hex", "1/4", "1", "brass", ],
> [ "slot", "1/8", "1/2", "chrome",],
> [ "pan", "3/16", "3/4", "black", ],
> ];
>
> local $, = " ";
> for my $screw (@$hardware){
> print @$screw, "\n";
> }
>
> my $number_screws = @$hardware;
> my $number_columns = @{${$hardware}[0]};
This assumes that all the rows have the same number of elements. That's
always true for the return value of selectall_arrayref, but in the more
general case you might need to loop over the rows to determine the
maximum.
> print "Number of screws: $number_screws Number of columns:
> $number_columns\n";
> __END__
[ second copy of the same script snipped - took me some time to see that
it differed only in formatting ]
> Former C programmers do find it easier to read perl's alternate syntax
> ($array[X][Y]) for arrays. I find it much easier to write perl in its
> normal syntax expecially when using features unique to perl such as the "@"
> operator and array cross sections.
I don't know which syntax is "normal" for perl, but I do find
> my $number_columns = @{${$hardware}[0]};
very hard to read. I very much prefer
my $number_columns = @{ $hardware->[0] };
here.
hp
------------------------------
Date: Fri, 15 Feb 2008 04:19:39 -0800 (PST)
From: axtens <Bruce.Axtens@gmail.com>
Subject: JendaRex and Perl 5.10
Message-Id: <24474ec2-6ae9-4e0d-af19-07fd61dda055@s12g2000prg.googlegroups.com>
G'day everyone
I've been trying unsuccessfully to compile (using PerlCtrl)
JendaRex.pm, using the latest PDK (7.1) and the latest Perl (5.10).
Everything seems to compile okay, whether I use PerlCtrl as is, or
with Jenda's own PDKcompile, and the resulting DLL seems to register
okay with RegSvr32.
After that, nothing works. This VBScript code
Set re = CreateObject("Jenda.Rex")
gives me
Microsoft VBScript runtime error: ActiveX component can't
create object: 'Jenda.Rex'
I get a similar report from VB.
Has anyone got any idea why? Is it that I'm doomed to comb through
perldelta for some change in Perl syntax?
Please, anyone, help!
Kind regards,
Bruce.
------------------------------
Date: Fri, 15 Feb 2008 08:15:56 GMT
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
Message-Id: <0Tbtj.3341$Ru4.2516@newssvr19.news.prodigy.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
This newsgroup, commonly called clpmisc, is a technical newsgroup
intended to be used for discussion of Perl related issues (except job
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As you would expect, clpmisc discussions are usually very technical in
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The article at:
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describes how to get answers from technical people in general.
This article describes things that you should, and should not, do to
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Lurk for a while before posting
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One such searchable archive is:
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If You Like
This section describes things that you *can* do before posting to
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Check Other Resources
You may want to check in books or on web sites to see if you can
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Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
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Is there a better place to ask your question?
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should decide to read your article.
Do not spend them indicating "experience level" (guru, newbie...).
Do not spend them pleading (please read, urgent, help!...).
Do not spend them on non-Subjects (Perl question, one-word
Subject...)
For more information on choosing a Subject see "Choosing Good
Subject Lines":
http://www.cpan.org/authors/id/D/DM/DMR/subjects.post
Part of the beauty of newsgroup dynamics, is that you can contribute
to the community with your very first post! If your choice of
Subject leads a fellow Perler to find the thread you are starting,
then even asking a question helps us all.
Use an effective followup style
When composing a followup, quote only enough text to establish the
context for the comments that you will add. Always indicate who
wrote the quoted material. Never quote an entire article. Never
quote a .signature (unless that is what you are commenting on).
Intersperse your comments *following* each section of quoted text to
which they relate. Unappreciated followup styles are referred to as
"top-posting", "Jeopardy" (because the answer comes before the
question), or "TOFU" (Text Over, Fullquote Under).
Reversing the chronology of the dialog makes it much harder to
understand (some folks won't even read it if written in that style).
For more information on quoting style, see:
http://web.presby.edu/~nnqadmin/nnq/nquote.html
Speak Perl rather than English, when possible
Perl is much more precise than natural language. Saying it in Perl
instead will avoid misunderstanding your question or problem.
Do not say: I have variable with "foo\tbar" in it.
Instead say: I have $var = "foo\tbar", or I have $var = 'foo\tbar',
or I have $var = <DATA> (and show the data line).
Ask perl to help you
You can ask perl itself to help you find common programming mistakes
by doing two things: enable warnings (perldoc warnings) and enable
"strict"ures (perldoc strict).
You should not bother the hundreds/thousands of readers of the
newsgroup without first seeing if a machine can help you find your
problem. It is demeaning to be asked to do the work of a machine. It
will annoy the readers of your article.
You can look up any of the messages that perl might issue to find
out what the message means and how to resolve the potential mistake
(perldoc perldiag). If you would like perl to look them up for you,
you can put "use diagnostics;" near the top of your program.
Do not re-type Perl code
Use copy/paste or your editor's "import" function rather than
attempting to type in your code. If you make a typo you will get
followups about your typos instead of about the question you are
trying to get answered.
Provide enough information
If you do the things in this item, you will have an Extremely Good
chance of getting people to try and help you with your problem!
These features are a really big bonus toward your question winning
out over all of the other posts that you are competing with.
First make a short (less than 20-30 lines) and *complete* program
that illustrates the problem you are having. People should be able
to run your program by copy/pasting the code from your article. (You
will find that doing this step very often reveals your problem
directly. Leading to an answer much more quickly and reliably than
posting to Usenet.)
Describe *precisely* the input to your program. Also provide example
input data for your program. If you need to show file input, use the
__DATA__ token (perldata.pod) to provide the file contents inside of
your Perl program.
Show the output (including the verbatim text of any messages) of
your program.
Describe how you want the output to be different from what you are
getting.
If you have no idea at all of how to code up your situation, be sure
to at least describe the 2 things that you *do* know: input and
desired output.
Do not provide too much information
Do not just post your entire program for debugging. Most especially
do not post someone *else's* entire program.
Do not post binaries, HTML, or MIME
clpmisc is a text only newsgroup. If you have images or binaries
that explain your question, put them in a publically accessible
place (like a Web server) and provide a pointer to that location. If
you include code, cut and paste it directly in the message body.
Don't attach anything to the message. Don't post vcards or HTML.
Many people (and even some Usenet servers) will automatically filter
out such messages. Many people will not be able to easily read your
post. Plain text is something everyone can read.
Social faux pas to avoid
The first two below are symptoms of lots of FAQ asking here in clpmisc.
It happens so often that folks will assume that it is happening yet
again. If you have looked but not found, or found but didn't understand
the docs, say so in your article.
Asking a Frequently Asked Question
It should be understood that you may have missed the applicable FAQ
when you checked, which is not a big deal. But if the Frequently
Asked Question is worded similar to your question, folks will assume
that you did not look at all. Don't become indignant at pointers to
the FAQ, particularly if it solves your problem.
Asking a question easily answered by a cursory doc search
If folks think you have not even tried the obvious step of reading
the docs applicable to your problem, they are likely to become
annoyed.
If you are flamed for not checking when you *did* check, then just
shrug it off (and take the answer that you got).
Asking for emailed answers
Emailed answers benefit one person. Posted answers benefit the
entire community. If folks can take the time to answer your
question, then you can take the time to go get the answer in the
same place where you asked the question.
It is OK to ask for a *copy* of the answer to be emailed, but many
will ignore such requests anyway. If you munge your address, you
should never expect (or ask) to get email in response to a Usenet
post.
Ask the question here, get the answer here (maybe).
Beware of saying "doesn't work"
This is a "red flag" phrase. If you find yourself writing that,
pause and see if you can't describe what is not working without
saying "doesn't work". That is, describe how it is not what you
want.
Sending a "stealth" Cc copy
A "stealth Cc" is when you both email and post a reply without
indicating *in the body* that you are doing so.
Be extra cautious when you get upset
Count to ten before composing a followup when you are upset
This is recommended in all Usenet newsgroups. Here in clpmisc, most
flaming sub-threads are not about any feature of Perl at all! They
are most often for what was seen as a breach of netiquette. If you
have lurked for a bit, then you will know what is expected and won't
make such posts in the first place.
But if you get upset, wait a while before writing your followup. I
recommend waiting at least 30 minutes.
Count to ten after composing and before posting when you are upset
After you have written your followup, wait *another* 30 minutes
before committing yourself by posting it. You cannot take it back
once it has been said.
AUTHOR
Tad McClellan and many others on the comp.lang.perl.misc newsgroup.
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Fri, 15 Feb 2008 09:44:50 -0800 (PST)
From: FeelLikeANut@gmail.com
Subject: Serving Large Data From Files or From Blobs
Message-Id: <43a6351b-c607-44ea-88eb-c1a1718e4071@i29g2000prf.googlegroups.com>
My question is partly a language issue (memory) and partly a Web issue
(where the program runs), so I hope everyone will be open to helping.
Users may submit and store pictures with my program. I have the choice
of storing these pictures either as files on the server or as a blob
in the database. The pictures are just user data, and it seems logical
to keep them in the database with all the other data. But I'm
concerned about how to serve these pictures. I can write a program to
handle image requests and return the appropriate picture from the
database. But it seems to me this means the picture will need to be
read from the database and stored in memory, in a variable, then
written from the variable to the HTTP response.
The part where the whole picture is stored in a variable is the part
that worries me. Is this impractical? Or merely a bad idea? Is storing
the pictures as files, allowing the server to serve them as it would
server anything else, the best option?
------------------------------
Date: 15 Feb 2008 18:00:07 GMT
From: xhoster@gmail.com
Subject: Re: Serving Large Data From Files or From Blobs
Message-Id: <20080215130009.258$HC@newsreader.com>
FeelLikeANut@gmail.com wrote:
> My question is partly a language issue (memory) and partly a Web issue
> (where the program runs), so I hope everyone will be open to helping.
>
> Users may submit and store pictures with my program. I have the choice
> of storing these pictures either as files on the server or as a blob
> in the database. The pictures are just user data, and it seems logical
> to keep them in the database with all the other data. But I'm
> concerned about how to serve these pictures. I can write a program to
> handle image requests and return the appropriate picture from the
> database. But it seems to me this means the picture will need to be
> read from the database and stored in memory, in a variable, then
> written from the variable to the HTTP response.
Databases that support blob types generally support ways to either stream
those blobs or efficiently read them in chunks. How to do that would
depend on the specifics of the database being used.
How are you getting the data into the database in the first place without
having it all in memory at once?
> The part where the whole picture is stored in a variable is the part
> that worries me. Is this impractical?
It depends on the maximum practical size of the image, and the amount of
memory your server has. Only you can know those things.
> Or merely a bad idea? Is storing
> the pictures as files, allowing the server to serve them as it would
> server anything else, the best option?
Do the file contents need the same transactional behavior (ACID, etc.)
as the rest of the stuff in database?
Xho
--
-------------------- http://NewsReader.Com/ --------------------
The costs of publication of this article were defrayed in part by the
payment of page charges. This article must therefore be hereby marked
advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate
this fact.
------------------------------
Date: Fri, 15 Feb 2008 19:17:57 +0100
From: "Rik Wasmus" <luiheidsgoeroe@hotmail.com>
Subject: Re: Serving Large Data From Files or From Blobs
Message-Id: <op.t6kvr7dj5bnjuv@metallium.lan>
On Fri, 15 Feb 2008 18:44:50 +0100, <FeelLikeANut@gmail.com> wrote:
> My question is partly a language issue (memory) and partly a Web issue=
> (where the program runs), so I hope everyone will be open to helping.
>
> Users may submit and store pictures with my program. I have the choice=
> of storing these pictures either as files on the server or as a blob
> in the database. The pictures are just user data, and it seems logical=
> to keep them in the database with all the other data. But I'm
> concerned about how to serve these pictures. I can write a program to
> handle image requests and return the appropriate picture from the
> database. But it seems to me this means the picture will need to be
> read from the database and stored in memory, in a variable, then
> written from the variable to the HTTP response.
>
> The part where the whole picture is stored in a variable is the part
> that worries me. Is this impractical? Or merely a bad idea? Is storing=
> the pictures as files, allowing the server to serve them as it would
> server anything else, the best option?
Insertion & retrieving is very much streamlined (huhu, pun not intended,=
=
but it indeed uses streams) with PDO, look at the Large Objects (LOB) =
example at <http://nl.php.net/pdo>:
Insertion:
<?php
$db =3D new PDO();//put your connections variables here
$stmt =3D $db->prepare("INSERT INTO tablename (image) values (?)");
$fp =3D fopen($_FILES['file']['tmp_name'], 'rb');
$stmt->bindParam(1, $fp, PDO::PARAM_LOB);
$stmt->execute();
fclose($fp);
?>
Retrieval:
<?php
$db =3D new PDO();//put your connections variables here
$stmt =3D $db->prepare("SELECT image FROM tablename WHERE id =3D ?");
$stmt->bindParam(1,$_GET['id'],PDO::PARAM_INT);
$stmt->execute();
$stmt->bindColumn(1, $lob, PDO::PARAM_LOB);
$stmt->fetch(PDO::FETCH_BOUND);
header("Content-Type: image/png");//or other format...
fpassthru($lob);
?>
-- =
Rik Wasmus
------------------------------
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>
Administrivia:
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------------------------------
End of Perl-Users Digest V11 Issue 1280
***************************************
