[31360] in Perl-Users-Digest
Perl-Users Digest, Issue: 2612 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Sep 25 14:10:11 2009
Date: Fri, 25 Sep 2009 11:09:08 -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, 25 Sep 2009 Volume: 11 Number: 2612
Today's topics:
each - iterator clash <bugbear@trim_papermule.co.uk_trim>
Re: each - iterator clash <jurgenex@hotmail.com>
Re: each - iterator clash <ben@morrow.me.uk>
FAQ 4.55 How do I process an entire hash? <brian@theperlreview.com>
FAQ 8.20 How can I call my system's unique C functions <brian@theperlreview.com>
FAQ 8.32 How can I write expect in Perl? <brian@theperlreview.com>
Re: How to check if a module is installed in Strawberry <RedGrittyBrick@spamweary.invalid>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Re: problem with IO:Socket <c7eqjyg02@sneakemail.com>
Re: problem with IO:Socket perldba@dba.invalid.com
Re: Trying to parse/match a C string literal <hjp-usenet2@hjp.at>
Re: Trying to parse/match a C string literal <uri@StemSystems.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Fri, 25 Sep 2009 17:45:16 +0100
From: bugbear <bugbear@trim_papermule.co.uk_trim>
Subject: each - iterator clash
Message-Id: <u_qdnZ1rcPgAbiHXnZ2dnUVZ8uKdnZ2d@brightview.co.uk>
I have deduced (by elimination) that I have some
iterator stomping going on. The documentation
for each says that:
There is a single iterator for each hash,
shared by all "each", "keys", and "values"
function calls in the program; it can be reset by
reading all the elements from the hash, or by evalu-
ating "keys HASH" or "values HASH".
I have an "each" loop that terminates early,
and I suspect that a nested each/keys/values
call is responsible.
I deduce this because if the outer "each" loop
is replaced by iterating over the array of keys
returned by a "keys" loop, all is well.
So - is there any convenient way to satisfy my curiosity
and FIND the nested keys/values/each call
doing the damage?
I thought I understood my code (which *is*
quite large), and do not understand why such a nested
call would be present.
BugBear
------------------------------
Date: Fri, 25 Sep 2009 10:10:59 -0700
From: Jürgen Exner <jurgenex@hotmail.com>
Subject: Re: each - iterator clash
Message-Id: <kbupb51o14a0okdvn7mrt87p4us9u96jou@4ax.com>
bugbear <bugbear@trim_papermule.co.uk_trim> wrote:
>So - is there any convenient way to satisfy my curiosity
>and FIND the nested keys/values/each call
>doing the damage?
>
>I thought I understood my code (which *is*
>quite large), and do not understand why such a nested
>call would be present.
Please post a minimal sample program that exhibits the issue you
described.
jue
------------------------------
Date: Fri, 25 Sep 2009 18:50:15 +0100
From: Ben Morrow <ben@morrow.me.uk>
Subject: Re: each - iterator clash
Message-Id: <nfcvo6-u1n2.ln1@osiris.mauzo.dyndns.org>
Quoth bugbear <bugbear@trim_papermule.co.uk_trim>:
> I have deduced (by elimination) that I have some
> iterator stomping going on. The documentation
> for each says that:
>
> There is a single iterator for each hash,
> shared by all "each", "keys", and "values"
> function calls in the program; it can be reset by
> reading all the elements from the hash, or by evalu-
> ating "keys HASH" or "values HASH".
>
> I have an "each" loop that terminates early,
> and I suspect that a nested each/keys/values
> call is responsible.
>
> I deduce this because if the outer "each" loop
> is replaced by iterating over the array of keys
> returned by a "keys" loop, all is well.
>
> So - is there any convenient way to satisfy my curiosity
> and FIND the nested keys/values/each call
> doing the damage?
You could try tying the hash to a class derived from Tie::StdHash (in
the Tie::Hash module) with an overriden FIRSTKEY method that logs where
it was called from. I don't know whether this counts as 'convenient' :).
You could also try running a debugging build of perl under a (C)
debugger and setting a breakpoint on Perl_hv_iterinit.
Ben
------------------------------
Date: Fri, 25 Sep 2009 04:00:24 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 4.55 How do I process an entire hash?
Message-Id: <sfXum.143811$nL7.11309@newsfe18.iad>
This is an excerpt from the latest version perlfaq4.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
4.55: How do I process an entire hash?
(contributed by brian d foy)
There are a couple of ways that you can process an entire hash. You can
get a list of keys, then go through each key, or grab a one key-value
pair at a time.
To go through all of the keys, use the "keys" function. This extracts
all of the keys of the hash and gives them back to you as a list. You
can then get the value through the particular key you're processing:
foreach my $key ( keys %hash ) {
my $value = $hash{$key}
...
}
Once you have the list of keys, you can process that list before you
process the hash elements. For instance, you can sort the keys so you
can process them in lexical order:
foreach my $key ( sort keys %hash ) {
my $value = $hash{$key}
...
}
Or, you might want to only process some of the items. If you only want
to deal with the keys that start with "text:", you can select just those
using "grep":
foreach my $key ( grep /^text:/, keys %hash ) {
my $value = $hash{$key}
...
}
If the hash is very large, you might not want to create a long list of
keys. To save some memory, you can grab one key-value pair at a time
using "each()", which returns a pair you haven't seen yet:
while( my( $key, $value ) = each( %hash ) ) {
...
}
The "each" operator returns the pairs in apparently random order, so if
ordering matters to you, you'll have to stick with the "keys" method.
The "each()" operator can be a bit tricky though. You can't add or
delete keys of the hash while you're using it without possibly skipping
or re-processing some pairs after Perl internally rehashes all of the
elements. Additionally, a hash has only one iterator, so if you use
"keys", "values", or "each" on the same hash, you can reset the iterator
and mess up your processing. See the "each" entry in perlfunc for more
details.
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Fri, 25 Sep 2009 10:00:02 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 8.20 How can I call my system's unique C functions from Perl?
Message-Id: <Cw0vm.143827$nL7.103068@newsfe18.iad>
This is an excerpt from the latest version perlfaq8.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
8.20: How can I call my system's unique C functions from Perl?
In most cases, you write an external module to do it--see the answer to
"Where can I learn about linking C with Perl? [h2xs, xsubpp]". However,
if the function is a system call, and your system supports syscall(),
you can use the syscall function (documented in perlfunc).
Remember to check the modules that came with your distribution, and CPAN
as well--someone may already have written a module to do it. On Windows,
try Win32::API. On Macs, try Mac::Carbon. If no module has an interface
to the C function, you can inline a bit of C in your Perl source with
Inline::C.
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Fri, 25 Sep 2009 16:00:05 GMT
From: PerlFAQ Server <brian@theperlreview.com>
Subject: FAQ 8.32 How can I write expect in Perl?
Message-Id: <9O5vm.71531$u76.7019@newsfe10.iad>
This is an excerpt from the latest version perlfaq8.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .
--------------------------------------------------------------------
8.32: How can I write expect in Perl?
Once upon a time, there was a library called chat2.pl (part of the
standard perl distribution), which never really got finished. If you
find it somewhere, *don't use it*. These days, your best bet is to look
at the Expect module available from CPAN, which also requires two other
modules from CPAN, IO::Pty and IO::Stty.
--------------------------------------------------------------------
The perlfaq-workers, a group of volunteers, maintain the perlfaq. They
are not necessarily experts in every domain where Perl might show up,
so please include as much information as possible and relevant in any
corrections. The perlfaq-workers also don't have access to every
operating system or platform, so please include relevant details for
corrections to examples that do not work on particular platforms.
Working code is greatly appreciated.
If you'd like to help maintain the perlfaq, see the details in
perlfaq.pod.
------------------------------
Date: Fri, 25 Sep 2009 11:51:30 +0100
From: RedGrittyBrick <RedGrittyBrick@spamweary.invalid>
Subject: Re: How to check if a module is installed in Strawberry?
Message-Id: <4abca0b4$0$2524$da0feed9@news.zen.co.uk>
Tad J McClellan wrote:
> RedGrittyBrick <RedGrittyBrick@spamweary.invalid> wrote:
>> Water Lin wrote:
>>> If I am using Strawberry in my Windows, I need to find out if a module
>>> is already installed in Strawberry.
>>>
>>> The command
>>> $ perldoc perllocal
>>> doesn't work under strawberry.
>>>
>> The word "module" has a special meaning in Perl.
>
>
> And the OP is using "module" with that special meaning in mind...
>
>
>> Your problem with
>> `perldoc perllocal` is probably unrelated.
>
>
> Errr, no.
>
> "perldoc perllocal" should list all of the locally installed modules.
>
>
Thanks for the correction.
--
RGB
------------------------------
Date: Fri, 25 Sep 2009 02:23:31 -0500
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.9 $)
Message-Id: <_d2dnbPwaZNu8iHXnZ2dnUVZ_vCdnZ2d@giganews.com>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($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: Fri, 25 Sep 2009 05:02:54 -0700 (PDT)
From: linuxlover <c7eqjyg02@sneakemail.com>
Subject: Re: problem with IO:Socket
Message-Id: <357303f4-f54f-4c94-9fbd-497bca9b833c@o21g2000vbl.googlegroups.com>
On 25 sep, 01:30, perl...@dba.invalid.com wrote:
[...]
> Server program
>
> #! /usr/bin/perl -w
> use strict ;
> use warnings;
> use DBI ;
> my $new_sock ;
>
> use IO::Socket;
> my $sock =3D new IO::Socket::INET (
> =A0 =A0LocalHost =3D> '127.0.0.1',
> =A0 =A0LocalPort =3D> '7070',
> =A0 =A0Proto =3D> 'tcp',
> =A0 =A0Listen =3D> 10,
> =A0 =A0Reuse =3D> 1);
> die "Could not create socket: $!\n" unless $sock;
> $sock->autoflush(1);
> $SIG{CHLD} =3D 'IGNORE' ;
> while ( $new_sock =3D $sock->accept()) {
> =A0 =A0 my $pid =3D fork();
> =A0 =A0 die "Cannot fork: $!" unless defined($pid);
> =A0 =A0 if ($pid =3D=3D 0) { =A0# only child process
> =A0 =A0 =A0 =A0 $sock->autoflush(1);
> =A0 =A0 =A0 =A0 &process_sql();
> =A0 =A0 =A0 =A0 system("kill -9 $$") ;
> =A0 =A0 }}
>
> close ($sock);
[...]
> What I did was to change the port of the above mentioned server program t=
o 7071
> and introduced another program. This program will act as server to the cl=
ient
> programs (on port 7070) and as a client to the db server running on port =
7071.
>
> #! /usr/bin/perl -w
> use strict ;
> use warnings;
> use IO::Socket ;
> my $new_sock ;
>
> my $ssock =3D new IO::Socket::INET (
> =A0 =A0 =A0 =A0LocalHost =3D> '127.0.0.1',
> =A0 =A0 =A0 =A0LocalPort =3D> '7071',
> =A0 =A0 =A0 =A0Proto =3D> 'tcp',
> =A0 =A0 =A0 ) ;
> die "Could not create socket 7071 for app server: $!\n" unless $ssock;
>
> my $sock =3D new IO::Socket::INET (
> =A0 =A0LocalHost =3D> '127.0.0.1',
> =A0 =A0LocalPort =3D> '7070',
> =A0 =A0Proto =3D> 'tcp',
> =A0 =A0Listen =3D> 10,
> =A0 =A0Reuse =3D> 1);
> die "Could not create socket: $!\n" unless $sock;
>
> The server program on 7071 starts fine. (the same code pasted before as "=
server
> program"). But when the above mentioned new program app.pl tries to start=
, it
> errors out "Could not create 7071 for app server: Address already in use"=
.
>
> Why? I am using the same logic on what is working, except that this new s=
cript
> app.pl is both a server and a client.
>
> Is there a restriction on IO::Socket as only port it can use in a script.
In the server program, you changed the listen-port LocalPort to 7071,
which will bind the server to port 7071. Next, in the client program,
you also specify LocalPort =3D> 7071, which also tries to bind to the
same port, which of course fails, because it is already in use by the
server.
You should specify PeerHost and PeerPort in the client program, and
let the socket call fiddle out the Local address by itself.
------------------------------
Date: 25 Sep 2009 05:38:46 -0700
From: perldba@dba.invalid.com
Subject: Re: problem with IO:Socket
Message-Id: <h9idkm01a0c@drn.newsguy.com>
In article <357303f4-f54f-4c94-9fbd-497bca9b833c@o21g2000vbl.googlegroups.com>,
>In the server program, you changed the listen-port LocalPort to 7071,
>which will bind the server to port 7071. Next, in the client program,
>you also specify LocalPort =3D> 7071, which also tries to bind to the
>same port, which of course fails, because it is already in use by the
>server.
>
>You should specify PeerHost and PeerPort in the client program, and
>let the socket call fiddle out the Local address by itself.
yup that was the cause. thanks. Looks like I did cut-n-paste badly,
took the code from my working server script instead of taking it
from the client script.
------------------------------
Date: Fri, 25 Sep 2009 17:53:04 +0200
From: "Peter J. Holzer" <hjp-usenet2@hjp.at>
Subject: Re: Trying to parse/match a C string literal
Message-Id: <slrnhbppr1.not.hjp-usenet2@hrunkner.hjp.at>
On 2009-09-24 18:56, Uri Guttman <uri@StemSystems.com> wrote:
>>>>>> "jpc" == jl post@hotmail com <jl_post@hotmail.com> writes:
>
> jpc> I'm trying to write Perl code that scans through a C/C++ and
> jpc> matches string literals. I want to use a regular expression for this,
> jpc> so that if given these inputs, it will extract these outputs:
>
> that can't be done easily with a single regex so don't even try. look at
> text::balanced on cpan which is designed to match c strings and similar things.
At the translation stage where string literals are recognised by a C
compiler there are no nesting constructs, so I don't see why you would
want to use Text::Balanced.
(For a real solution you would need to take comments into account, but
they don't nest either)
hp
------------------------------
Date: Fri, 25 Sep 2009 12:38:46 -0400
From: "Uri Guttman" <uri@StemSystems.com>
Subject: Re: Trying to parse/match a C string literal
Message-Id: <87zl8jvv1l.fsf@quad.sysarch.com>
>>>>> "PJH" == Peter J Holzer <hjp-usenet2@hjp.at> writes:
PJH> On 2009-09-24 18:56, Uri Guttman <uri@StemSystems.com> wrote:
>>>>>>> "jpc" == jl post@hotmail com <jl_post@hotmail.com> writes:
>>
jpc> I'm trying to write Perl code that scans through a C/C++ and
jpc> matches string literals. I want to use a regular expression for this,
jpc> so that if given these inputs, it will extract these outputs:
>>
>> that can't be done easily with a single regex so don't even try. look at
>> text::balanced on cpan which is designed to match c strings and similar things.
PJH> At the translation stage where string literals are recognised by
PJH> a C compiler there are no nesting constructs, so I don't see why
PJH> you would want to use Text::Balanced.
PJH> (For a real solution you would need to take comments into account, but
PJH> they don't nest either)
but you can have a string literal inside a comment and it needs to be
skipped. there are other cases i bet. ask damian why it is better. :)
uri
------------------------------
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 V11 Issue 2612
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