[31795] in Perl-Users-Digest
Perl-Users Digest, Issue: 3058 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Aug 3 00:09:29 2010
Date: Mon, 2 Aug 2010 21:09:10 -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 Mon, 2 Aug 2010 Volume: 11 Number: 3058
Today's topics:
Re: CGI Program Questions <tzz@lifelogs.com>
Re: CGI Program Questions <edgrsprj@ix.netcom.com>
Re: CGI Program Questions <jurgenex@hotmail.com>
Re: Help with regular expression <tzz@lifelogs.com>
Re: If Perl is compiled on a 32-bit system, and the sys <nospam-abuse@ilyaz.org>
Re: piped open and shell metacharacters <ben@morrow.me.uk>
Re: piped open and shell metacharacters (Randal L. Schwartz)
Re: piped open and shell metacharacters <tzz@lifelogs.com>
Re: piped open and shell metacharacters <hjp-usenet2@hjp.at>
Re: piped open and shell metacharacters <jak@isp2dial.com>
Re: piped open and shell metacharacters <ben@morrow.me.uk>
Re: piped open and shell metacharacters <nospam-abuse@ilyaz.org>
Re: piped open and shell metacharacters <derykus@gmail.com>
Re: piped open and shell metacharacters <uri@StemSystems.com>
Plot Module Question <edgrsprj@ix.netcom.com>
Re: Plot Module Question <jimsgibson@gmail.com>
Re: Plot Module Question <edgrsprj@ix.netcom.com>
Re: Plot Module Question <netnews@invalid.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Mon, 02 Aug 2010 10:07:53 -0500
From: Ted Zlatanov <tzz@lifelogs.com>
Subject: Re: CGI Program Questions
Message-Id: <87tyndf3xy.fsf@lifelogs.com>
On Sat, 31 Jul 2010 23:15:05 -0500 "E.D.G." <edgrsprj@ix.netcom.com> wrote:
EDG> "Randal L. Schwartz" <merlyn@stonehenge.com> wrote in message
EDG> news:867hkbt4ee.fsf@red.stonehenge.com...
>> It's not CGI if it isn't being invoked from a web page hit. You're
>> talking about a mail handler.
EDG> A goal here is to eventually have a single Internet Bulletin Board
EDG> program that will:
EDG> --- Accept and process data submitted to it through Web page input screens.
EDG> --- Accept and process data submitted to it via E-mail letters. As
EDG> you said, a mail handler is involved.
EDG> --- Accept and process data submitted to it by other programs running
EDG> at my domain Web site that will run one or more times a day and
EDG> collect scientific data from other Web sites.
EDG> The effort to get such a bulletin board running at my domain Web site
EDG> is gradually moving along a step at a time.
It's amazing how people manage to avoid discovering NNTP.
Ted
------------------------------
Date: Mon, 2 Aug 2010 17:04:54 -0500
From: "E.D.G." <edgrsprj@ix.netcom.com>
Subject: Re: CGI Program Questions
Message-Id: <wridnd6b7PyY3MrRnZ2dnUVZ_h2dnZ2d@earthlink.com>
"Ted Zlatanov" <tzz@lifelogs.com> wrote in message
news:87tyndf3xy.fsf@lifelogs.com...
> It's amazing how people manage to avoid discovering NNTP.
This is a fairly complex project involving a number of people. And
Perl is being used exclusively for everything possible. Other types of
applications are being developed and used when necessary. But if possible,
and as soon as possible, they are converted to Perl language code.
The computer programs being developed need to be able to run on both a
Windows PC and a Web server.
------------------------------
Date: Mon, 02 Aug 2010 20:56:35 -0700
From: Jürgen Exner <jurgenex@hotmail.com>
Subject: Re: CGI Program Questions
Message-Id: <mf4f56hg94nlmuj3bij26bgmudq8d28rq3@4ax.com>
Ted Zlatanov <tzz@lifelogs.com> wrote:
>On Sat, 31 Jul 2010 23:15:05 -0500 "E.D.G." <edgrsprj@ix.netcom.com> wrote:
>
>EDG> "Randal L. Schwartz" <merlyn@stonehenge.com> wrote in message
>EDG> news:867hkbt4ee.fsf@red.stonehenge.com...
>
>>> It's not CGI if it isn't being invoked from a web page hit. You're
>>> talking about a mail handler.
>
>EDG> A goal here is to eventually have a single Internet Bulletin Board
>EDG> program that will:
Those are readily available a dozen a dime...
>EDG> --- Accept and process data submitted to it through Web page input screens.
Standard feature. How else would you submit contributions?
>EDG> --- Accept and process data submitted to it via E-mail letters. As
>EDG> you said, a mail handler is involved.
Why email? While certainly possible and easy enough to do, post and put
have been invented already for a reason..
>EDG> --- Accept and process data submitted to it by other programs running
>EDG> at my domain Web site that will run one or more times a day and
>EDG> collect scientific data from other Web sites.
There are many tools readily available for this purpose.
jue
------------------------------
Date: Mon, 02 Aug 2010 10:05:39 -0500
From: Ted Zlatanov <tzz@lifelogs.com>
Subject: Re: Help with regular expression
Message-Id: <87y6cpf41o.fsf@lifelogs.com>
On Mon, 02 Aug 2010 10:06:12 +0300 Eric Pozharski <whynot@pozharski.name> wrote:
EP> with <slrni5bs74.bff.hjp-usenet2@hrunkner.hjp.at> Peter J. Holzer wrote:
EP> *SKIP*
>> I agree with Eric: Write a proper grammar and use that to parse your
>> expressions. If you've ever heard of BNF, using Parse::Yapp or
>> Parse::RecDescent shouldn't be too hard (I prefer the former, although
>> the docs assume that you are already familiar with yacc).
EP> Passed to Ted (Zlatanov). I've learned that from him.
I don't understand, do you mean I should answer? I haven't been
following this thread carefully.
Ted
------------------------------
Date: Mon, 2 Aug 2010 21:19:45 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: If Perl is compiled on a 32-bit system, and the system is upgraded to 64-bit...
Message-Id: <slrni5edjh.gtf.nospam-abuse@powdermilk.math.berkeley.edu>
On 2010-08-02, Peter J. Holzer <hjp-usenet2@hjp.at> wrote:
>> What is important is the ratio of data/text.
>
> No. What is important is the ratio between code and the usable address
> space.
I see (below) that we discuss different scenarios.
>> In your case, it is less than 10. (With more memory, you run more of
>> OTHER monsters. ;-)
> Yes, but those other monsters get their own virtual address space, so
> they don't matter in this discussion.
They do on OS/2: the DLL's-related memory is loaded into shared
address region. (This way one does not need any "extra"
per-process-context patching or redirection of DLL address accesses.)
> No, you misunderstood. If you now have an address space of 2 GB for
> code+data, and you move the code to a different segment, you win 40MB
> for data. But if the OS is changed to give each process a 4 GB address
> space, then you win 2 GB, which is a lot more than 40 MB.
I do not see how one would lift this limit (without a segmented
architecture ;-). I expect that (at least) this would make context
switch majorly costlier...
Thanks,
Ilya
------------------------------
Date: Mon, 2 Aug 2010 11:07:07 +0100
From: Ben Morrow <ben@morrow.me.uk>
Subject: Re: piped open and shell metacharacters
Message-Id: <bvhii7-aab2.ln1@osiris.mauzo.dyndns.org>
Quoth merlyn@stonehenge.com (Randal L. Schwartz):
> >>>>> "John" == John Kelly <jak@isp2dial.com> writes:
>
> John> It's easy to force a shell with some no-op metacharacters:
>
> John> perl -e 'system ":; eval ls /"'
>
> Even simpler, just append ";". Never changes the meaning, and it forces
> /bin/sh in the mix.
Um, what exactly is wrong with
perl -e 'system "/bin/sh", -c => "eval ls /"'
? If you *want* the shell, ask for it.
If you don't know where your shell lives, it's in $Config{sh}.
Ben
------------------------------
Date: Mon, 02 Aug 2010 04:32:17 -0700
From: merlyn@stonehenge.com (Randal L. Schwartz)
Subject: Re: piped open and shell metacharacters
Message-Id: <86ocdlntby.fsf@red.stonehenge.com>
>>>>> "Ben" == Ben Morrow <ben@morrow.me.uk> writes:
Ben> Um, what exactly is wrong with
Ben> perl -e 'system "/bin/sh", -c => "eval ls /"'
1) complexity
2) using => as a bizarro-world comma
Please. Don't. A certain individual started that, and like JAPHs, it's
a meme that deserves to die.
Having said that:
print "Just another Perl hacker,"; # the original
--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/>
Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc.
See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion
------------------------------
Date: Mon, 02 Aug 2010 10:11:27 -0500
From: Ted Zlatanov <tzz@lifelogs.com>
Subject: Re: piped open and shell metacharacters
Message-Id: <87pqy1f3s0.fsf@lifelogs.com>
On Mon, 02 Aug 2010 04:32:17 -0700 merlyn@stonehenge.com (Randal L. Schwartz) wrote:
RLS> 2) using => as a bizarro-world comma
RLS> Please. Don't. A certain individual started that, and like JAPHs, it's
RLS> a meme that deserves to die.
I find => much better than commas in shell argument lists and many other
places:
1) it quotes the left side--less typing
2) it's much harder to mistype and misread as a period (I've scratched
my head more than once staring at that kind of bug in the source code)
Ted
------------------------------
Date: Mon, 2 Aug 2010 17:14:06 +0200
From: "Peter J. Holzer" <hjp-usenet2@hjp.at>
Subject: Re: piped open and shell metacharacters
Message-Id: <slrni5do5v.pas.hjp-usenet2@hrunkner.hjp.at>
On 2010-08-02 11:32, Randal L. Schwartz <merlyn@stonehenge.com> wrote:
>>>>>> "Ben" == Ben Morrow <ben@morrow.me.uk> writes:
>
>Ben> Um, what exactly is wrong with
>
>Ben> perl -e 'system "/bin/sh", -c => "eval ls /"'
>
> 1) complexity
It looks more complex than
system "eval ls /;"
but it really isn't and that ";" is really easy to miss. So that would
have to be something like
system "eval ls /;"; # ; forces shell
and then you can write
system "/bin/sh", "-c", "eval ls /"
too. It even saves two characters ;-).
> 2) using => as a bizarro-world comma
>
> Please. Don't. A certain individual started that, and like JAPHs, it's
> a meme that deserves to die.
I agree about the "=>".
hp
------------------------------
Date: Mon, 02 Aug 2010 16:24:27 +0000
From: John Kelly <jak@isp2dial.com>
Subject: Re: piped open and shell metacharacters
Message-Id: <svrd56995c0rk2ubeehkr3j694etsn81kg@4ax.com>
On Mon, 2 Aug 2010 17:14:06 +0200, "Peter J. Holzer"
<hjp-usenet2@hjp.at> wrote:
>On 2010-08-02 11:32, Randal L. Schwartz <merlyn@stonehenge.com> wrote:
>>>>>>> "Ben" == Ben Morrow <ben@morrow.me.uk> writes:
>>
>>Ben> Um, what exactly is wrong with
>>
>>Ben> perl -e 'system "/bin/sh", -c => "eval ls /"'
>>
>> 1) complexity
>
>It looks more complex than
>
> system "eval ls /;"
>
>but it really isn't and that ";" is really easy to miss.
That's why I suggested:
system ":; eval ls /"
It's easy miss ";" at the end, but hard to miss ":;" at the beginning.
>So that would have to be something like
>
> system "eval ls /;"; # ; forces shell
>
>and then you can write
>
> system "/bin/sh", "-c", "eval ls /"
>
>too. It even saves two characters ;-).
I like mine best. :-)
--
Web mail, POP3, and SMTP
http://www.beewyz.com/freeaccounts.php
------------------------------
Date: Mon, 2 Aug 2010 17:20:57 +0100
From: Ben Morrow <ben@morrow.me.uk>
Subject: Re: piped open and shell metacharacters
Message-Id: <9s7ji7-fho.ln1@osiris.mauzo.dyndns.org>
Quoth merlyn@stonehenge.com (Randal L. Schwartz):
> >>>>> "Ben" == Ben Morrow <ben@morrow.me.uk> writes:
>
> Ben> Um, what exactly is wrong with
>
> Ben> perl -e 'system "/bin/sh", -c => "eval ls /"'
>
> 2) using => as a bizarro-world comma
>
> Please. Don't. A certain individual started that, and like JAPHs, it's
> a meme that deserves to die.
=> *is* a bizarro-world comma. That is its sole function. I tend to use
it in all circumstances where I am listing (name, value) pairs; since -c
takes a single argument I see it as the key of such a pair.
Ben
------------------------------
Date: Mon, 2 Aug 2010 21:12:28 +0000 (UTC)
From: Ilya Zakharevich <nospam-abuse@ilyaz.org>
Subject: Re: piped open and shell metacharacters
Message-Id: <slrni5ed5r.gtf.nospam-abuse@powdermilk.math.berkeley.edu>
On 2010-08-02, Randal L. Schwartz <merlyn@stonehenge.com> wrote:
>Ben> perl -e 'system "/bin/sh", -c => "eval ls /"'
> 1) complexity
> 2) using => as a bizarro-world comma
> Please. Don't. A certain individual started that, and like JAPHs, it's
> a meme that deserves to die.
[I presume (by proximity of JAPH) that this "certain individual" is
you (no, I would not remember myself). I think there is nothing to
be shameful about for this meme.]
When in "random position" in a list, => MAY be confusing. On the
other hand, it may be a tool to attract attention to most important
element(s) of the list.
When used between two "logically connected" parts of the list (as in
$^X, -I => $INC, ...), it is, IMO, very appropriate.
Yours,
Ilya
------------------------------
Date: Mon, 2 Aug 2010 19:33:48 -0700 (PDT)
From: "C.DeRykus" <derykus@gmail.com>
Subject: Re: piped open and shell metacharacters
Message-Id: <076fc87f-c7ba-4026-83c3-9cf2a8fc25fa@l25g2000prn.googlegroups.com>
On Aug 2, 2:12=A0pm, Ilya Zakharevich <nospam-ab...@ilyaz.org> wrote:
> On 2010-08-02, Randal L. Schwartz <mer...@stonehenge.com> wrote:
>
> >Ben> =A0 =A0 perl -e 'system "/bin/sh", -c =3D> "eval ls /"'
> > 1) complexity
> > 2) using =3D> as a bizarro-world comma
> > Please. =A0Don't. =A0A certain individual started that, and like JAPHs,=
it's
> > a meme that deserves to die.
>
> ...
> When in "random position" in a list, =3D> MAY be confusing. =A0On the
> other hand, it may be a tool to attract attention to most important
> element(s) of the list.
>
> When used between two "logically connected" parts of the list (as in
> $^X, -I =3D> $INC, ...), it is, IMO, very appropriate.
>
some non-word cautions for the unwary:
perl -wle ' %h =3D( 12:00 =3D> "lunch")'
syntax error at ... near "12:"
perl -MO=3DDeparse -wle ' x( area-54 =3D> 'verboten' );'
Unquoted string "area" may clash ...
x('area' - 54, 'verboten');
-e syntax OK
--
Charles DeRykus
Charles DeRykus
------------------------------
Date: Mon, 02 Aug 2010 23:07:27 -0400
From: "Uri Guttman" <uri@StemSystems.com>
Subject: Re: piped open and shell metacharacters
Message-Id: <87pqy0e6mo.fsf@quad.sysarch.com>
>>>>> "CD" == C DeRykus <derykus@gmail.com> writes:
CD> On Aug 2, 2:12 pm, Ilya Zakharevich <nospam-ab...@ilyaz.org> wrote:
>> When in "random position" in a list, => MAY be confusing. On the
>> other hand, it may be a tool to attract attention to most important
>> element(s) of the list.
>>
>> When used between two "logically connected" parts of the list (as in
>> $^X, -I => $INC, ...), it is, IMO, very appropriate.
CD> some non-word cautions for the unwary:
CD> perl -wle ' %h =( 12:00 => "lunch")'
CD> syntax error at ... near "12:"
CD> perl -MO=Deparse -wle ' x( area-54 => 'verboten' );'
CD> Unquoted string "area" may clash ...
CD> x('area' - 54, 'verboten');
CD> -e syntax OK
well the docs say => quotes perl word (also words starting with -) to its
left and those aren't perl words. i don't use => except for real pairs
in hashes or arrays (that will eventually be copied to hashes). i also
find the cute style of using it with some args to be wrong.
uri
--
Uri Guttman ------ uri@stemsystems.com -------- http://www.sysarch.com --
----- Perl Code Review , Architecture, Development, Training, Support ------
--------- Gourmet Hot Cocoa Mix ---- http://bestfriendscocoa.com ---------
------------------------------
Date: Mon, 2 Aug 2010 17:47:06 -0500
From: "E.D.G." <edgrsprj@ix.netcom.com>
Subject: Plot Module Question
Message-Id: <mr2dnW1gttZ618rRnZ2dnUVZ_g-dnZ2d@earthlink.com>
Question: What Perl language plotting modules would be good candidates for
the following applications?
ActiveState Perl 5.10 is being used with PCs running XP and Vista.
The Perl programs being developed will also be running on a Web server
computer.
The PC versions of Perl programs that are presently running send plot
data to the Gnuplot plotting program. However, an effort is underway to
modify the Perl programs so that they will run on a Web server. I don't
believe that Gnuplot can run on a Web server though I am not certain of
that. And even if it would run there, for a number of reasons it would be
better to do the plotting using a Perl plotting module if possible.
--- The plotting module needs to be able to run on a Windows PC with XP,
Vista, or Windows 7 in both pl and exe Perl programs. I already know how to
generate standalone exe programs using the original Perl code.
--- It needs to run on a Web sever that runs Perl programs.
--- It would be nice if it would also run using other versions of Perl on
other types of computers with other operating systems.
--- The plotting functions will not be especially complex. The plotting
module does not need to do 3D work. However, it should be able to do
relatively simple things such as draw hollow or filled circles.
--- On the PC it needs to be able to both generate plots that display on the
computer monitor and produce copies of those plots as PNG, GIF, and BMP
picture files. However, if it could generate PNG and not BMP files for
example, that might still work. The files can be converted if necessary.
--- On the Web server computer it needs to be able to generate some type of
fairly high quality picture file such as PNG.
--- When it creates plots for the Windows computer monitor it should have
the ability to automatically display the plots as full window (maximum) or
partial window (normal) plots.
------------------------------
Date: Mon, 02 Aug 2010 16:26:43 -0700
From: Jim Gibson <jimsgibson@gmail.com>
Subject: Re: Plot Module Question
Message-Id: <020820101626433712%jimsgibson@gmail.com>
In article <mr2dnW1gttZ618rRnZ2dnUVZ_g-dnZ2d@earthlink.com>, E.D.G.
<edgrsprj@ix.netcom.com> wrote:
> Question: What Perl language plotting modules would be good candidates for
> the following applications?
>
> ActiveState Perl 5.10 is being used with PCs running XP and Vista.
> The Perl programs being developed will also be running on a Web server
> computer.
>
> The PC versions of Perl programs that are presently running send plot
> data to the Gnuplot plotting program. However, an effort is underway to
> modify the Perl programs so that they will run on a Web server. I don't
> believe that Gnuplot can run on a Web server though I am not certain of
> that. And even if it would run there, for a number of reasons it would be
> better to do the plotting using a Perl plotting module if possible.
Gnuplot can indeed run on a server, as the gnuplot program is available
for many platforms, including the two most popular web server
platforms: windows and unix. Whether or not gnuplot is available on
your particular server is up to your service provider. I do not have a
feel for the probability of gnuplot being available in commercial web
servers. I suspect it is low, however.
A CGI program desiring to display gnuplot-generated graphs would start
a gnuplot session, send it commands to generate a graph and send the
output to a PNG file, then put a link in a returned HTML page to
display the PNG file as an image.
<http://www.ibm.com/developerworks/aix/library/au-gnuplot/index.html?ca=
dgr-lnxw07dth-AIX&S_TACT=105AGX59&S_CMP=grlnxw07>
Other than gnuplot, your best bet is probably the GD module, if it is
available. I have never had any luck installing GD on my system. The
Perl GD module is an interface to the GD library, and the library must
be installed on your server for the module to work.
--
Jim Gibson
------------------------------
Date: Mon, 2 Aug 2010 19:10:00 -0500
From: "E.D.G." <edgrsprj@ix.netcom.com>
Subject: Re: Plot Module Question
Message-Id: <ZYGdnUywD_DFw8rRnZ2dnUVZ_oWdnZ2d@earthlink.com>
"Jim Gibson" <jimsgibson@gmail.com> wrote in message
news:020820101626433712%jimsgibson@gmail.com...
>> Question: What Perl language plotting modules would be good candidates
>> for the following applications?
> Gnuplot can indeed run on a server, as the gnuplot program is available
> Other than gnuplot, your best bet is probably the GD module, if it is
> available. I have never had any luck installing GD on my system. The
Hi Jim,
Thanks for the input. I will take a look at what the GD module offers.
So far I have not seen any information regarding Gnuplot on the Web
server I am using. In a day or two I am planning to ask some of the Web
specialists about that. I need to also get some Perl application
information from them.
One of the problems with using Gnuplot with Perl on a Windows machine
pertains to sending Gnuplot information. Perl has to store the plot data in
a file and then tell Gnuplot to start running and process those data. Perl
can send Gnuplot commands through a pipe. That works quite well. However,
it has been my experience that sending Gnuplot large amounts of plot data
though the pipe is not a good idea. The process is slow and prone to
errors.
Windows experts have told me that this can also be done by having
Perl and Gnuplot use a shared section of the computer memory. But that
might then not work with other operating systems etc.
So, if the right Perl plotting module can be found then that would
seem to me to be the way to go. Also, this is part of a proposed effort
that involves creating a type of SCIENCE module for Perl. It would not
actually have to be a true module but might instead be a text file
containing information regarding which modules researchers would need to
install with their Perl program so that they can do various things such as
use certain math functions that don't come with the original Perl program,
and generate PNG files using plot data.
Perhaps it would be a good idea to even create a Perl FAQ section
that was specifically intended for science researchers. It would discuss
all of those things in detail. Right now they need to search through the
various FAQ sections looking for that information instead of having it in a
single location. And, certain topics such as generating PNG files from plot
data etc. might not even be discussed at the present time in any of the FAQ
sections. I went looking for information regarding that in the FAQ files
and could not find anything. It can probably be found in the documentation
for different modules. But a person would first need to know which modules
to check.
These are personal opinions.
------------------------------
Date: Mon, 02 Aug 2010 18:31:47 -0700
From: HASM <netnews@invalid.com>
Subject: Re: Plot Module Question
Message-Id: <m3eiego518.fsf@127.0.0.1>
Jim Gibson <jimsgibson@gmail.com> writes:
> A CGI program desiring to display gnuplot-generated graphs would start
> a gnuplot session, send it commands to generate a graph and send the
> output to a PNG file, then put a link in a returned HTML page to
> display the PNG file as an image.
I do exactly as above, but I run the webserver in a linux box I control, so
gnuplot is available ...
-- HASM
------------------------------
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------------------------------
End of Perl-Users Digest V11 Issue 3058
***************************************
