[31427] in Perl-Users-Digest
Perl-Users Digest, Issue: 2679 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Nov 17 06:09:40 2009
Date: Tue, 17 Nov 2009 03:09:06 -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 Tue, 17 Nov 2009 Volume: 11 Number: 2679
Today's topics:
Converting images without Image::Magick <jwcarlton@gmail.com>
Re: Converting images without Image::Magick <newsojo@web.de>
How to upper case letters in a pair of parenthesis by P <ken.sofin@gmail.com>
Re: How to upper case letters in a pair of parenthesis <derykus@gmail.com>
Re: Image::Magick->Write() doesn't want to write <source@netcom.com>
Re: iterating with a substitution sln@netherlands.com
Re: iterating with a substitution <tadmc@seesig.invalid>
Re: mingw Perl: no long doubles? <nospam-abuse@ilyaz.org>
Re: mingw Perl: no long doubles? <nospam-abuse@ilyaz.org>
My perl script to run arbitrary tasks in parallel <ignoramus30118@NOSPAM.30118.invalid>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Re: Question about using chomp and other functions toge sln@netherlands.com
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 17 Nov 2009 00:39:01 -0800 (PST)
From: Jason Carlton <jwcarlton@gmail.com>
Subject: Converting images without Image::Magick
Message-Id: <b0db4d34-ef26-4225-949d-205d2aa2fe8a@s15g2000yqs.googlegroups.com>
Like so many others, I can't get Image::Magick to install on my
server. I found where someone had posted (in 2007) that you can first
install graphviz RPM, then the module IPC-Run, then the module
GraphViz, and THEN you might be able to install Image::Magick, but
that's a lot of work if there's an easier way around my problem.
All that I'm using it for is to convert BMP, GIF, and PNG files to
JPG. Is there another way to do this? I've been using Imager; I don't
suppose that you can convert an image with that module, can you?
------------------------------
Date: 17 Nov 2009 09:15:55 GMT
From: Oliver 'ojo' Bedford <newsojo@web.de>
Subject: Re: Converting images without Image::Magick
Message-Id: <4b0269cb$0$6566$9b4e6d93@newsspool4.arcor-online.net>
Am Tue, 17 Nov 2009 00:39:01 -0800 schrieb Jason Carlton:
> All that I'm using it for is to convert BMP, GIF, and PNG files to JPG.
> Is there another way to do this? I've been using Imager; I don't suppose
> that you can convert an image with that module, can you?
From the man page Imager::Files:
The "type" parameter is a lowercase representation of the file type,
and can be any of the following:
bmp Windows BitMaP (BMP)
gif Graphics Interchange Format (GIF)
jpeg JPEG/JFIF
png Portable Network Graphics (PNG)
pnm Portable aNyMap (PNM)
raw Raw
sgi SGI .rgb files
tga TARGA
tiff Tagged Image File Format (TIFF)
Oliver
------------------------------
Date: Tue, 17 Nov 2009 02:21:35 -0800 (PST)
From: sofin <ken.sofin@gmail.com>
Subject: How to upper case letters in a pair of parenthesis by PERL?
Message-Id: <9018ea4e-ad17-450a-bf41-17f723d3dc3a@b25g2000prb.googlegroups.com>
Input:
"Modeltest: testing the model of (dna)-substitution"
Output:
"Modeltest: testing the model of DNA-substitution"
Anyone knows how to do it by PERL? Thanks.
------------------------------
Date: Tue, 17 Nov 2009 02:36:40 -0800 (PST)
From: "C.DeRykus" <derykus@gmail.com>
Subject: Re: How to upper case letters in a pair of parenthesis by PERL?
Message-Id: <0b98c507-3597-458f-807f-3935ea9d4286@y10g2000prg.googlegroups.com>
On Nov 17, 2:21=A0am, sofin <ken.so...@gmail.com> wrote:
> Input:
> "Modeltest: testing the model of (dna)-substitution"
>
> Output:
> "Modeltest: testing the model of DNA-substitution"
>
> Anyone knows how to do it by PERL? Thanks.
perldoc -f uc
perldoc perlop (see \U in Quote and quote-like operators)
--
Charles DeRykus
------------------------------
Date: Mon, 16 Nov 2009 20:01:37 -0800
From: David Harmon <source@netcom.com>
Subject: Re: Image::Magick->Write() doesn't want to write
Message-Id: <a6mdnZVTOND4vZ_WnZ2dnUVZ_sqdnZ2d@earthlink.com>
On Mon, 16 Nov 2009 21:10:29 +0000 (UTC) in comp.lang.perl.misc,
dgriffi@cs.csbuak.edu (Dave Griffith) wrote,
> My problem is that
>$magick_image->Write('$upload_dir/$outfile'); never seems to output
>anything.
What does the error message returned by $magick_image->Write say?
------------------------------
Date: Mon, 16 Nov 2009 17:05:46 -0800
From: sln@netherlands.com
Subject: Re: iterating with a substitution
Message-Id: <oct3g5tod44rvd8m66vc7gffihmcum4mij@4ax.com>
On Mon, 16 Nov 2009 23:15:39 +0100, Martijn Lievaart <m@rtij.nl.invlalid> wrote:
>On Mon, 16 Nov 2009 13:38:17 -0800, sln wrote:
>
>> (my $str=<DATA>) =~ s/<(\d+)>(?{ print "$^N removed\n" })//g; print
>
>Why use an experimental feature when perfect standard idioms are known?
>
>M4
In the regex? Which is the experimental feature and what does that mean
to you? Did it work on your build?
Which of these extended features are experimental, why or why not?
Extended Patterns:
(?#text)
(?pimsx-imsx)
(?:pattern)
(?imsx-imsx:pattern)
(?|pattern)
(?=pattern)
(?!pattern)
(?<=pattern) \K
(?<!pattern)
(?'NAME'pattern)
(?<NAME>pattern) ) >>
\k<NAME>
\k'NAME'
(?{ code })
(??{ code })
(?PARNO) (?-PARNO) (?+PARNO) (?R) (?0)
(?&NAME)
(?(condition)yes-pattern|no-pattern)
(?(condition)yes-pattern)
(?>pattern)
-sln
------------------------------
Date: Mon, 16 Nov 2009 20:06:42 -0600
From: Tad McClellan <tadmc@seesig.invalid>
Subject: Re: iterating with a substitution
Message-Id: <slrnhg4147.av9.tadmc@tadbox.sbcglobal.net>
sln@netherlands.com <sln@netherlands.com> wrote:
> On Mon, 16 Nov 2009 23:15:39 +0100, Martijn Lievaart <m@rtij.nl.invlalid> wrote:
>
>>On Mon, 16 Nov 2009 13:38:17 -0800, sln wrote:
>>
>>> (my $str=<DATA>) =~ s/<(\d+)>(?{ print "$^N removed\n" })//g; print
>>
>>Why use an experimental feature when perfect standard idioms are known?
>>
>>M4
>
> In the regex? Which is the experimental feature
(?{ })
> and what does that mean
> to you?
It means that the documentation for the feature labels it so.
> Which of these extended features are experimental,
Read their docs yourself:
perldoc perlre
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Tue, 17 Nov 2009 04:05:27 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: mingw Perl: no long doubles?
Message-Id: <slrnhg4887.bfb.nospam-abuse@powdermilk.math.berkeley.edu>
On 2009-11-16, Peter J. Holzer <hjp-usenet2@hjp.at> wrote:
> On 2009-11-14 22:56, Shmuel Metz <spamtrap@library.lspace.org.invalid> wrote:
>>>P.S. Due to a bug in test suite, today it has come to my attension
>>> that similar restrictions exist on s390 and alpha linuxes; but
>>> there it is hardware limitation;
>>
>> Does "s390" refer only to IBM's old S/390 line or also to the current
>> zSeries line? Certainly all current zSeries processors have 64-bit
>> arithmetic, and I believe that the earliest ones did as well.
[Do not get the original yet, so I answer at this place in the thread.]
I never physically touched s390. However, smoke testers DO run tests
on (one? some?) s390 machines (I saw Linux and IIRC NetBSD personalities).
Their perl-config can be seen in individual reports; e.g., follow
almost any Linux red link in
http://matrix.cpantesters.org/?dist=Audio-FindChunks+1.01
(the FreeBSD failure is on alpha). I do not know what generation they
are; but it looks like z:
uname='linux cpan02.zseries.org 2.6.18-92.el5 #1 smp tue apr 29
13:16:58 edt 2008 s390x s390x s390x gnulinux '
(BTW, this failure is still undebugged... This module of mine had
"more than the expented" ;-] share of very embarassing bugs...
Especially given that the XS part takes whooping 5588 bytes. ;-)
Yours,
Ilya
------------------------------
Date: Tue, 17 Nov 2009 05:40:49 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: mingw Perl: no long doubles?
Message-Id: <slrnhg4dr0.cpi.nospam-abuse@powdermilk.math.berkeley.edu>
On 2009-11-17, Ilya Zakharevich <nospam-abuse@ilyaz.org> wrote:
> Their perl-config can be seen in individual reports; e.g., follow
> almost any Linux red link in
> http://matrix.cpantesters.org/?dist=Audio-FindChunks+1.01
> (the FreeBSD failure is on alpha). I do not know what generation they
> are; but it looks like z:
>
> uname='linux cpan02.zseries.org 2.6.18-92.el5 #1 smp tue apr 29
> 13:16:58 edt 2008 s390x s390x s390x gnulinux '
Hmm, this particular report
http://www.nntp.perl.org/group/perl.cpan.testers/2009/01/msg3077340.html
is on an architecture WITH long double! So they run tests on quite
different personalities (other tests I saw had longdblsize=8).
Ilya
------------------------------
Date: Tue, 17 Nov 2009 00:13:38 -0600
From: Ignoramus30118 <ignoramus30118@NOSPAM.30118.invalid>
Subject: My perl script to run arbitrary tasks in parallel
Message-Id: <KOadnVRzhI2Pop_WnZ2dnUVZ_gBi4p2d@giganews.com>
#!/usr/bin/perl
#
# This script reads its standard input, or from files given on
# command line (<>).
#
# It executes every line as a separate shell command. If --parallel
# argument is given, it executes as many jobs in parallel, as
# possible, but no more tham "--parallel" at any given time.
#
# This can be helpful to speed up some tasks.
#
# You need module Parallel::ForkManager. It is available as
# an ubuntu package.
#
# Copyright(C) Igor Chudov, 2009. All rights reserved.
# This script is made available to the public under the latest
# GPL Version found at http://www.gnu.org/licenses/gpl.html
#
# No warranty is given or implied. Refunds will not be provided.
#
# Igor Chudov, http://igor.chudov.com/
#
use strict;
use warnings;
use Getopt::Long;
use Parallel::ForkManager;
my $parallel = 0;
my $pm = new Parallel::ForkManager( $parallel );
GetOptions(
"parallel=i" => \$parallel,
);
while( <> ) {
chomp;
my $pid = $pm->start and next;
system( $_ );
$pm->finish;
}
$pm->wait_all_children;
------------------------------
Date: Tue, 17 Nov 2009 02:12:54 -0600
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.9 $)
Message-Id: <ntmdnVr9pY-bxp_WnZ2dnUVZ_sCdnZ2d@giganews.com>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.9 $)
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
nature and there are conventions for conduct in technical newsgroups
going somewhat beyond those in non-technical newsgroups.
The article at:
http://www.catb.org/~esr/faqs/smart-questions.html
describes how to get answers from technical people in general.
This article describes things that you should, and should not, do to
increase your chances of getting an answer to your Perl question. It is
available in POD, HTML and plain text formats at:
http://www.rehabitation.com/clpmisc.shtml
For more information about netiquette in general, see the "Netiquette
Guidelines" at:
http://andrew2.andrew.cmu.edu/rfc/rfc1855.html
A note to newsgroup "regulars":
Do not use these guidelines as a "license to flame" or other
meanness. It is possible that a poster is unaware of things
discussed here. Give them the benefit of the doubt, and just
help them learn how to post, rather than assume that they do
know and are being the "bad kind" of Lazy.
A note about technical terms used here:
In this document, we use words like "must" and "should" as
they're used in technical conversation (such as you will
encounter in this newsgroup). When we say that you *must* do
something, we mean that if you don't do that something, then
it's unlikely that you will benefit much from this group.
We're not bossing you around; we're making the point without
lots of words.
Do *NOT* send email to the maintainer of these guidelines. It will be
discarded unread. The guidelines belong to the newsgroup so all
discussion should appear in the newsgroup. I am just the secretary that
writes down the consensus of the group.
Before posting to comp.lang.perl.misc
Must
This section describes things that you *must* do before posting to
clpmisc, in order to maximize your chances of getting meaningful replies
to your inquiry and to avoid getting flamed for being lazy and trying to
have others do your work.
The perl distribution includes documentation that is copied to your hard
drive when you install perl. Also installed is a program for looking
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
standard documentation.
Check the Perl Frequently Asked Questions (FAQ)
Checking the FAQ before posting is required in Big 8 newsgroups in
general, there is nothing clpmisc-specific about this requirement.
You are expected to do this in nearly all newsgroups.
You can use the "-q" switch with perldoc to do a word search of the
questions in the Perl FAQs.
Check the other standard Perl docs (*.pod)
The perl distribution comes with much more documentation than is
available for most other newsgroups, so in clpmisc you should also
see if you can find an answer in the other (non-FAQ) standard docs
before posting.
It is *not* required, or even expected, that you actually *read* all of
Perl's standard docs, only that you spend a few minutes searching them
before posting.
Try doing a word-search in the standard docs for some words/phrases
taken from your problem statement or from your very carefully worded
"Subject:" header.
Really Really Should
This section describes things that you *really should* do before posting
to clpmisc.
Lurk for a while before posting
This is very important and expected in all newsgroups. Lurking means
to monitor a newsgroup for a period to become familiar with local
customs. Each newsgroup has specific customs and rituals. Knowing
these before you participate will help avoid embarrassing social
situations. Consider yourself to be a foreigner at first!
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_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
too, of course.
Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
read every article. They must decide somehow which articles they are
going to read, and which they will skip.
Your post is in competition with 199 other posts. You need to "win"
before a person who can help you will even read your question.
These sections describe how you can help keep your article from being
one of the "skipped" ones.
Is there a better place to ask your question?
Question should be about Perl, not about the application area
It can be difficult to separate out where your problem really is,
but you should make a conscious effort to post to the most
applicable newsgroup. That is, after all, where you are the most
likely to find the people who know how to answer your question.
Being able to "partition" a problem is an essential skill for
effectively troubleshooting programming problems. If you don't get
that right, you end up looking for answers in the wrong places.
It should be understood that you may not know that the root of your
problem is not Perl-related (the two most frequent ones are CGI and
Operating System related), so off-topic postings will happen from
time to time. Be gracious when someone helps you find a better place
to ask your question by pointing you to a more applicable newsgroup.
How to participate (post) in the clpmisc community
Carefully choose the contents of your Subject header
You have 40 precious characters of Subject to win out and be one of
the posts that gets read. Don't waste them. Take care while
composing them, they are the key that opens the door to getting an
answer.
Spend them indicating what aspect of Perl others will find if they
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: Mon, 16 Nov 2009 15:52:52 -0800
From: sln@netherlands.com
Subject: Re: Question about using chomp and other functions together
Message-Id: <t4i3g5t8qms9nou7sifogo02abeduhjo6t@4ax.com>
On Mon, 16 Nov 2009 17:45:54 +0000, George <me@me.com> wrote:
>Dear All,
>
>I wrote a function to mimic the behavior of the trim function in
>Javascript as follows:
>
>sub trim($)
>{
> my $string = shift;
> $string =~ s/^\s+//;
> $string =~ s/\s+$//;
> return $string;
>}
>
>Then I am using it as follows:
>
>$finalstate = chomp(trim(<STDIN>));
>
>When I try and run it, I get the following message:
>Can't modify non-lvalue subroutine call in chomp at ./trans2autnew.pl
>line 63, near "))"
>Execution of ./trans2autnew.pl aborted due to compilation errors.
>(of course, strict and warnings are on).
>
>Could you help me resolving this as I new to Perl (but not in
>programming in general)?
>
>Regards,
>George
\s will remove trailing \n
Perldocs: "\s is a whitespace character and represents [\ \t\r\n\f]"
If you want to generalize it even more you could do something like below.
You should avoid passing around copies of unknown length strings.
Trim() act's on the existing string (instead of a copy), the last two
return the modified string.
-sln
---------------------
use strict;
use warnings;
sub trim($)
{
$_[0] =~ s/^\s+//;
$_[0] =~ s/\s+$//;
# wantarray() returns
# true = list, false = scalar, undefined = void context
return $_[0] if defined wantarray;
}
my $finalstate = <STDIN>;
trim($finalstate);
print $finalstate, "<-1-\n\n";
$finalstate = trim(<STDIN>);
print $finalstate, "<-2-\n\n";
print trim(<STDIN>), "<-3-\n\n";
------------------------------
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:
To submit articles to comp.lang.perl.announce, send your article to
clpa@perl.com.
Back issues are available via anonymous ftp from
ftp://cil-www.oce.orst.edu/pub/perl/old-digests.
#For other requests pertaining to the digest, send mail to
#perl-users-request@ruby.oce.orst.edu. Do not waste your time or mine
#sending perl questions to the -request address, I don't have time to
#answer them even if I did know the answer.
------------------------------
End of Perl-Users Digest V11 Issue 2679
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