[28418] in Perl-Users-Digest
Perl-Users Digest, Issue: 9782 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Sep 29 09:05:42 2006
Date: Fri, 29 Sep 2006 06:05:05 -0700 (PDT)
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, 29 Sep 2006 Volume: 10 Number: 9782
Today's topics:
Re: can't locate method new IO::Socket::INET <sisyphus1@nomail.afraid.org>
Re: FAQ 3.1 How do I do (anything)? <bik.mido@tiscalinet.it>
Re: FAQ 3.1 How do I do (anything)? usenet@DavidFilmer.com
Re: FTP from Perl script on Windows <ilackic@yahoo.com>
Re: ImageMagick and Perl <noreply@gunnar.cc>
Re: ImageMagick and Perl <bik.mido@tiscalinet.it>
Re: ImageMagick and Perl <zentara@highstream.net>
Re: ImageMagick and Perl <noreply@gunnar.cc>
Re: Is LaTeX the tool I'm looking for? <bik.mido@tiscalinet.it>
Re: list vs. array <bik.mido@tiscalinet.it>
Re: My first socket question <bik.mido@tiscalinet.it>
Re: My first socket question <bik.mido@tiscalinet.it>
Re: Perl 64 bit solaris - Strange Errors <nospam-abuse@ilyaz.org>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: Reading from standard input <harpreet.saluja@gmail.com>
Re: Reading from standard input <bik.mido@tiscalinet.it>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 29 Sep 2006 17:01:21 +1000
From: "Sisyphus" <sisyphus1@nomail.afraid.org>
Subject: Re: can't locate method new IO::Socket::INET
Message-Id: <451cc5d3$0$25207$afc38c87@news.optusnet.com.au>
"ten8ciousb" <brent.honadel@lawson.com> wrote in message
.
.
>
> use IO::Socket;
> use IO::Socket::INET;
>
> $sock = IO::Socket::INET->new(
> PeerAddr => $host,
> PeerPort => $port,
> Proto => 'tcp',
> );
>
Pretty much stumped by this. (The *full* error message as a copy'n'paste
could be helpful as that would remove *all* guesswork on our part.)
Normally you don't 'use IO::Socket::INET;' - you just 'use IO::Socket;'. I
can't think of why that would stuff things up, but it's a change you could
try.
Cheers,
Rob
------------------------------
Date: 29 Sep 2006 09:21:06 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: FAQ 3.1 How do I do (anything)?
Message-Id: <mohph2tr13ud3pv0tjf6nlu16m183iams7@4ax.com>
On Thu, 28 Sep 2006 13:38:57 -0500, brian d foy
<brian.d.foy@gmail.com> wrote:
>> How 'bout an ironic answer in terms of the Everything bundle?
>
>Heh, but, no. :)
Well I meant something like:
How do I do (anything)?
Use the Everything bundle from CPAN. No, seriously, have you
looked at CPAN (see perlfaq2)? [...]
But id it's no, it's no!
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: 29 Sep 2006 00:40:46 -0700
From: usenet@DavidFilmer.com
Subject: Re: FAQ 3.1 How do I do (anything)?
Message-Id: <1159515645.846788.158790@h48g2000cwc.googlegroups.com>
Michele Dondi wrote:
> Use the Everything bundle from CPAN.
Has anyone EVER actually installed that? Without force, I mean...
--
David Filmer (http://DavidFilmer.com)
------------------------------
Date: Fri, 29 Sep 2006 10:11:05 +0000 (UTC)
From: Ivan L <ilackic@yahoo.com>
Subject: Re: FTP from Perl script on Windows
Message-Id: <Xns984D7B6DC1F92ivanlac@213.191.133.136>
I know about %windir% environment variable. However, there is no protocol file (or
folder) in the c:\Windows\System32\drivers\etc\ There are, however, several files
named services (services, services01, services02 ...) that happen to be empty.
"Dr.Ruud" <rvtol+news@isolution.nl> wrote in news:efhvc9.1go.1@news.isolution.nl:
> l v schreef:
>> Ivan L:
>>> [attribution corrupted]
>>>> [attribution corrupted]
>
>>>>> "Cannot connect to host: Net::FTP: Bad protocol 'tcp' at
>>>>> ftptest1.pl line 3."
>>>>
>>>> Check out the file "%windir%\system32\drivers\etc\protocol".
>>>
>>> There is no "%windir%\system32\drivers\etc\protocol" file on my
>>> machine.
>>
>> s/protocol/services/
>
> The error message was "Bad protocol 'tcp'".
> The "services" file contains a list of names for selected port/protocol
> combinations.
>
> Ivan, did you understand "%windir%"? It's an environment variable that
> has the value "C:\WINNT" on some systems, "C:\Windows" on other systems,
> and other values on yet other systems. Go to a command prompt and enter
> "set" to get the value on your system.
>
------------------------------
Date: Fri, 29 Sep 2006 09:13:40 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: ImageMagick and Perl
Message-Id: <4o3vd8FchadvU1@individual.net>
kjhjhjhjadsasda@urbanhabit.com wrote:
> Im trying to get ImageMagick working on my VPS. Below code used to work
> on a previous VPS, but now all I get written is $file1, never $file2.
> Problem is, I dont even know how to debug it... Any clues?
First clue:
use strict;
use warnings;
<snip>
> $img->Write(filename=>$file2);
my $err = $img->Write($file2) and die $err;
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: 29 Sep 2006 12:27:17 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: ImageMagick and Perl
Message-Id: <86qph2pk4h3iseq5d8ijrsl52hf5id52fi@4ax.com>
On 28 Sep 2006 16:36:18 -0700, kjhjhjhjadsasda@urbanhabit.com wrote:
>Im trying to get ImageMagick working on my VPS. Below code used to work
>on a previous VPS, but now all I get written is $file1, never $file2.
>Problem is, I dont even know how to debug it... Any clues?
[snip]
>$img->Write(filename=>$file2);
How 'bout checking the return value of Write(), which should be the
number of images (successfully) written?
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 29 Sep 2006 10:58:15 GMT
From: zentara <zentara@highstream.net>
Subject: Re: ImageMagick and Perl
Message-Id: <ohuph25mta9lrv6nv1bd2ashjvju5d2n1f@4ax.com>
On 28 Sep 2006 16:36:18 -0700, kjhjhjhjadsasda@urbanhabit.com wrote:
>Hi,
>
>Im trying to get ImageMagick working on my VPS. Below code used to work
>on a previous VPS, but now all I get written is $file1, never $file2.
>Problem is, I dont even know how to debug it... Any clues?
>
>$url="someimage.jpg";
>$file1="pathonmyserver/something1.jpg";
>$file2="pathonmyserver/something2.jpg";
>
>my $response=LWP::UserAgent->new->get($url,':content_file'=>$file1);
>$img=Image::Magick->new;
>$img->Read($file1);
>$img->Scale(geometry=>'548x308');
>$img->Resize(width => 548, height => 308);
>$img->Write(filename=>$file2);
>undef $img;
>
>Thanks!
Here is a thumbnail script, written by Merlyn, which shows how
to use IM in a loop cleanly, and see the error messages if any.
It's a bit tricky.
#!/usr/bin/perl
# by Merlyn
use strict;
use Image::Magick;
my $im = Image::Magick->new;
umask 0022;
my @names = @ARGV ? @ARGV : grep { -f and -B } <*>;
for (@names) {
if (/ /) {
my $old = $_;
tr, ,_,s;
$_ .= ".jpg" unless /\.jpg$/;
!-e and rename $old, $_ or next;
warn "renaming $old to $_\n";
}
next if /\.thumb\.jpg$/;
my $thumb = "$_.thumb.jpg";
next if -e $thumb;
undef @$im;
my $ret;
$ret = $im->Read($_)
and warn($ret), next;
$ret = $im->Scale( geometry => '100x100' )
and warn($ret), next;
$ret = $im->Write($thumb)
and warn($ret), next;
warn "thumbnail made for $_\n";
}
__END__
--
I'm not really a human, but I play one on earth.
http://zentara.net/japh.html
------------------------------
Date: Fri, 29 Sep 2006 14:02:45 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: ImageMagick and Perl
Message-Id: <4o4gb9FcgnmeU1@individual.net>
Michele Dondi wrote:
> On 28 Sep 2006 16:36:18 -0700, kjhjhjhjadsasda@urbanhabit.com wrote:
>>Im trying to get ImageMagick working on my VPS. Below code used to work
>>on a previous VPS, but now all I get written is $file1, never $file2.
>>Problem is, I dont even know how to debug it... Any clues?
>
> [snip]
>
>>$img->Write(filename=>$file2);
>
> How 'bout checking the return value of Write(), which should be the
> number of images (successfully) written?
Are you sure of that? Please see the examples posted by me and zentara.
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: 29 Sep 2006 12:27:19 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Is LaTeX the tool I'm looking for?
Message-Id: <7gqph2p96c9aj7anfsnn98nlc9qemsc1nf@4ax.com>
[xposted to clpmisc]
On Fri, 29 Sep 2006 00:17:13 +0100, Peter Flynn
<peter.nosp@m.silmaril.ie> wrote:
>If you get Perl to turn
>"George","Adams","g_adams27@example.net","555-1212"
>into
>\address{George}{Adams}{g_adams27@example.net}{555-1212}
>then it's fairly straightforward to write the macro \address
>that will format those four items of information, eg
If the csv's entries do not contain commas or double quotes, then this
may be as simple as
local $\="\n";
while (<$csv>) {
print join '', '\\address',
map { s/^"//; s/"$//; "{$_}" }
split /,/
}
But it's not reliable in case the csv is not that simple, and
generally it isn't. So it's always recommended to use Text::CSV_XS
instead, which only takes a few more keystrokes.
Michele
--
>It's because the universe was programmed in C++.
No, no, it was programmed in Forth. See Genesis 1:12:
"And the earth brought Forth ..."
- Robert Israel in sci.math, thread "Why numbers?"
------------------------------
Date: 29 Sep 2006 09:54:17 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: list vs. array
Message-Id: <l8kph2thmg84k5kpgq4p9cd3q5sbgahq01@4ax.com>
On Thu, 28 Sep 2006 16:51:06 +0100, Ben Morrow
<benmorrow@tiscali.co.uk> wrote:
>Well, yes, you are correct. I was ignoring prototypes (and functions
Wow! Lucky day. My name-day...
:-)
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: 29 Sep 2006 12:27:13 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: My first socket question
Message-Id: <5eoph258u8u1jitk659h8vkc2qd66v4j95@4ax.com>
On 28 Sep 2006 15:47:00 -0700, "jl_post@hotmail.com"
<jl_post@hotmail.com> wrote:
> If you're asking how to handle a client request while, at the same
>time, continue to listen for other clients trying to connect, you might
>want to try fork()ing, like this:
Or use threads (which I'm not familiar with), but no, that's not what
I was asking...
>
> # Untested:
> while ( my $client=$server->accept ) {
> last unless fork; # parent keeps listening; child breaks out
> }
ITYM s/last/next/; s/unless/if/;
> # Child process runs this code:
> (my $cmd=<$client>) =~ tr/\r\n//d;
> my %answer=(foo => "foo: that's what I wanted!");
> print $client
> $answer{$cmd} || "Unknown command: `$cmd'", "\r\n";
> ...
Indeed, although in the real world I think I'd keep track of generated
childs. And have the child die after he's done its job. Because this
way it will also re-enter the loop possibly leading to incontrollable
proliferation. And then check for fork() to return undef, because in
that case there would be no child and the parent process would also
terminate. And I would wait for dead children to avoid accumulating
zombies.
> Either way, I hope you find something that works for you, Michele.
Well, thank you for taking interest in my question.
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: 29 Sep 2006 12:27:15 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: My first socket question
Message-Id: <pcpph2trfkgflfatbmuusk0pt5hdi3gsih@4ax.com>
On 28 Sep 2006 21:35:53 -0700, "DJ Stunks" <DJStunks@gmail.com> wrote:
>My next client/server script will make use of the Perl Object
>Environment. After reading the chapter on POE in _Advanced Perl
>Programming_ (2nd Ed) I'm sold - the event driven model seems much
>better suited to socket communication.
>
>check out http://poe.perl.org/?Evolution_of_a_POE_Server for a brief
>TCP server tutorial.
For the moment I would like to stay at a lower level and getting
familiar with it, but thank you for supplying this piece of
information. I had of course already hear about POE, but had never
taken real interest in it due to the fact that I was not much
interested in networking stuff at all. Certainly I will read the
supplied link, first or later...
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Fri, 29 Sep 2006 09:28:37 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: Perl 64 bit solaris - Strange Errors
Message-Id: <efip05$q6r$1@agate.berkeley.edu>
[A complimentary Cc of this posting was sent to
<josephshibu.francis@gmail.com>], who wrote in article <1159495839.634311.307450@m7g2000cwm.googlegroups.com>:
> while debugging,
>
> ./miniperl -Ilib -W -d -e ' use IO::Handle' ;
>
> also dumps the core.
You need to debug C, not Perl. Use gdb/dbx.
> brk(0x1002D26C0) = 0
> Incurred fault #5, FLTACCESS %pc = 0x10007ABE4
> siginfo: SIGBUS BUS_ADRALN addr=0x1002D0704
> Received signal #10, SIGBUS [default]
> siginfo: SIGBUS BUS_ADRALN addr=0x1002D0704
> *** process killed ***
E2LITTLEINFO. perl -v is the minimum. Do you use MYMALLOC with wrong
alignment flags?
Hope this helps,
Ilya
------------------------------
Date: 29 Sep 2006 07:22:14 GMT
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.6 $)
Message-Id: <451cc9a5$0$47255$ae4e5890@news.nationwide.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: 1.6 $)
This newsgroup, commonly called clpmisc, is a technical newsgroup
intended to be used for discussion of Perl related issues (except job
postings), whether it be comments or questions.
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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Must
This section describes things that you *must* do before posting to
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have others do your work.
The perl distribution includes documentation that is copied to your hard
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things up in that (and other) documentation named 'perldoc'.
You should either find out where the docs got installed on your system,
or use perldoc to find them for you. Type "perldoc perldoc" to learn how
to use perldoc itself. Type "perldoc perl" to start reading Perl's
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Checking the FAQ before posting is required in Big 8 newsgroups in
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You are expected to do this in nearly all newsgroups.
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Check the other standard Perl docs (*.pod)
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Try doing a word-search in the standard docs for some words/phrases
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Really Really Should
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Lurk for a while before posting
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customs. Each newsgroup has specific customs and rituals. Knowing
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Search a Usenet archive
There are tens of thousands of Perl programmers. It is very likely
that your question has already been asked (and answered). See if you
can find where it has already been answered.
One such searchable archive is:
http://groups.google.com/advanced_group_search
If You Like
This section describes things that you *can* do before posting to
clpmisc.
Check Other Resources
You may want to check in books or on web sites to see if you can
find the answer to your question.
But you need to consider the source of such information: there are a
lot of very poor Perl books and web sites, and several good ones
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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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For more information on choosing a Subject see "Choosing Good
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Speak Perl rather than English, when possible
Perl is much more precise than natural language. Saying it in Perl
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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 <tadmc@augustmail.com> and many others on the
comp.lang.perl.misc newsgroup.
------------------------------
Date: 29 Sep 2006 00:13:44 -0700
From: "Harpreet" <harpreet.saluja@gmail.com>
Subject: Re: Reading from standard input
Message-Id: <1159514023.978785.151320@i42g2000cwa.googlegroups.com>
Hi Michele,
I didn't understand what you said earlier but I experimented with the
code you had posted and it works exactly the way I wanted. But since I
have just started exploring perl, things like Mfatal and Mdata don't
make much sense to me. I hope to read all that in due time and
understand what you said. Do you have a good soft document or pointer
to an online resource through which I can learn perl.
regards,
Harpreet
Michele Dondi wrote:
> (I don't have John's post so I'm replying to you)
>
> On 26 Sep 2006 21:40:18 -0700, "Harpreet" <harpreet.saluja@gmail.com>
> wrote:
>
> >> You are trying to open the file '-', standard input is not involved when
> >> opening a plain file.
> >>
> >> The *only* time that '-' has anything to do with standard input is when @ARGV
> >> and <> are used:
>
> I thought so too. But that is *not* the case, and the docs confirm
> that:
>
> : In the 2-arguments (and 1-argument) form opening '-' opens STDIN
> : and opening '>-' opens STDOUT.
>
> Yet, not a particularly good reason to use it, especially when you
> already have STDIN.
>
>
> Michele
> --
> {$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
> (($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
> .'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
> 256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: 29 Sep 2006 12:27:10 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Reading from standard input
Message-Id: <nhrph2tguaivbrnrssjh2nqe08vl5vf9q4@4ax.com>
On 29 Sep 2006 00:13:44 -0700, "Harpreet" <harpreet.saluja@gmail.com>
wrote:
>I didn't understand what you said earlier but I experimented with the
>code you had posted and it works exactly the way I wanted. But since I
>have just started exploring perl, things like Mfatal and Mdata don't
Caveat: there are *no* things like "Mfatal and Mdata", since for one
thing capitalization does matter and the second module is
Data::Dumper.
Here I'm making use of the -M command line switch. Learn more about
it, and all the other ones reading
perldoc perlrun
Basically it's a shortcut for use()ing modules. In a "regular" script,
as opposed to a one-liner you would write:
use Fatal 'open';
It's a module designed to make certain operations cause the script to
die with an informative message in case they fail. This was not
strictly required in a one-liner, but I also (like another poster) had
erroneusly thought that
open F, '-';
would try open()ing a file named '-' in the cwd. So I used that as a
"workaround" for not having to explicitly check the return value of
open() and report something significative accordingly.
Similarly, Data::Dumper is a module giving you "stringified perl data
structures". It's handy to inspect some variables, like I did here for
a certain array. Indeed in many cases
print "@a";
would suffice. But in other ones, especially when you actually have
complex data structures, D::D is much better if not absolutely
necessary. (Although then there are other modules with similar
functionality.)
To learn more about these two modules you can check their
documentation:
perldoc Fatal
perldoc Data::Dumper
>make much sense to me. I hope to read all that in due time and
>understand what you said. Do you have a good soft document or pointer
>to an online resource through which I can learn perl.
I can point you to a good document that *you* have: it's already in
your system and you can reach it with the perldoc program, as you may
have inferred from the above. Indeed perl comes with extensive
documentation. As a starter, you {may,should} look into
perldoc perl
perldoc perldoc
to know about core Perl documentation and perldoc's self
functionality: the latter is much and can be substituted by man (if
you're under *NIX) for regular modules, but it can do much more: in
particular give you documentation about single functions and search
the FAQ for you.
HTH,
Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
.'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,
------------------------------
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 9782
***************************************
