[25217] in Perl-Users-Digest
Perl-Users Digest, Issue: 7462 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Mon Nov 29 18:06:08 2004
Date: Mon, 29 Nov 2004 15:05:09 -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 Mon, 29 Nov 2004 Volume: 10 Number: 7462
Today's topics:
Re: Beginners question. $_ Variable. <joe@inwap.com>
Buy Programming Books <webmaster@qubitcode.com>
FAQ 6.13: How do I process each word on each line? <comdog@panix.com>
Re: how to define a variable to hold a multiline text i <mritty@gmail.com>
Re: how to define a variable to hold a multiline text i <spamtrap@dot-app.org>
Re: List::Util::shuffle - where did the algorithm come <jgibson@mail.arc.nasa.gov>
Re: Minimize black screen <yorhel@gmail.com>
Re: Minimize black screen <flavell@ph.gla.ac.uk>
Re: Minimize black screen <joe@inwap.com>
Re: Minimize black screen <bik.mido@tiscalinet.it>
PAR problems Win32 (Can't Spawn, line 372) (solved) <postmaster@castleamber.com>
Re: Perl Executable and Script Name -- NOT Args <apeiron@comcast.net>
Re: Perl Executable and Script Name -- NOT Args <mritty@gmail.com>
replace words in string with hash values (wana)
Re: replace words in string with hash values <noreply@gunnar.cc>
Re: replace words in string with hash values <mritty@gmail.com>
Re: replace words in string with hash values <bik.mido@tiscalinet.it>
Re: Unix commands and perl <joe@inwap.com>
Re: Unix commands and perl <bik.mido@tiscalinet.it>
Re: Unix commands and perl <bik.mido@tiscalinet.it>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Mon, 29 Nov 2004 21:17:25 GMT
From: Joe Smith <joe@inwap.com>
Subject: Re: Beginners question. $_ Variable.
Message-Id: <FlMqd.166420$HA.134626@attbi_s01>
Mitchell Hulscher wrote:
> I thought of a theory that the $_ variable gets assigned to the
> latest scalar assigned.
Think of it as input, not output.
Many built-in perl functions use $_ as their input if you don't
specify any arguments and the function needs one.
Some operators use $_ for both input and output.
$_ = 'abcde';
tr /bc/12/;
s/e/EEEEE/;
print;
------------------------------
Date: Mon, 29 Nov 2004 22:27:01 GMT
From: Rich <webmaster@qubitcode.com>
Subject: Buy Programming Books
Message-Id: <Xns95B0B175AEB6webmasterqubitcodeco@63.223.5.241>
QubitCode.com
Offering programming books related to:
C++
C#
Java
Javascript
HTML
Perl
and much more...
Check it out for great deals!
http://www.qubitcode.com/
------------------------------
Date: Mon, 29 Nov 2004 23:03:02 +0000 (UTC)
From: PerlFAQ Server <comdog@panix.com>
Subject: FAQ 6.13: How do I process each word on each line?
Message-Id: <cog9r6$3bg$1@reader1.panix.com>
This message is one of several periodic postings to comp.lang.perl.misc
intended to make it easier for perl programmers to find answers to
common questions. The core of this message represents an excerpt
from the documentation provided with Perl.
--------------------------------------------------------------------
6.13: How do I process each word on each line?
Use the split function:
while (<>) {
foreach $word ( split ) {
# do something with $word here
}
}
Note that this isn't really a word in the English sense; it's just
chunks of consecutive non-whitespace characters.
To work with only alphanumeric sequences (including underscores), you
might consider
while (<>) {
foreach $word (m/(\w+)/g) {
# do something with $word here
}
}
--------------------------------------------------------------------
Documents such as this have been called "Answers to Frequently
Asked Questions" or FAQ for short. They represent an important
part of the Usenet tradition. They serve to reduce the volume of
redundant traffic on a news group by providing quality answers to
questions that keep coming up.
If you are some how irritated by seeing these postings you are free
to ignore them or add the sender to your killfile. If you find
errors or other problems with these postings please send corrections
or comments to the posting email address or to the maintainers as
directed in the perlfaq manual page.
Note that the FAQ text posted by this server may have been modified
from that distributed in the stable Perl release. It may have been
edited to reflect the additions, changes and corrections provided
by respondents, reviewers, and critics to previous postings of
these FAQ. Complete text of these FAQ are available on request.
The perlfaq manual page contains the following copyright notice.
AUTHOR AND COPYRIGHT
Copyright (c) 1997-2002 Tom Christiansen and Nathan
Torkington, and other contributors as noted. All rights
reserved.
This posting is provided in the hope that it will be useful but
does not represent a commitment or contract of any kind on the part
of the contributers, authors or their agents.
------------------------------
Date: Mon, 29 Nov 2004 20:55:45 GMT
From: "Paul Lalli" <mritty@gmail.com>
Subject: Re: how to define a variable to hold a multiline text input in perl from html multiline textbox
Message-Id: <l1Mqd.3545$%R1.1254@trndny03>
"dale zhang" <zhangd@tycoelectronics.com> wrote in message
news:60460471.0411291238.22fe6793@posting.google.com...
> Here is my script:
>
> #!/usr/bin/perl
<snip>
> sub populatePostFields {
> %postFields = ();
> read( STDIN, $tmpStr, $ENV{ "CONTENT_LENGTH" } );
> @parts = split( /\&/, $tmpStr );
> foreach $part (@parts) {
> ( $name, $value ) = split( /\=/, $part );
> $value =~ ( s/%23/\#/g );
> $value =~ ( s/%2F/\//g );
> $postFields{ "$name" } = $value;
> }
> }
>
> Any suggestions? -Dale
Yes, get rid of this entirely. Use CGI.pm;. Also use strict; and use
warnings;. Read about CGI.pm (and how much easier this code suddenly
becomes once you use it) by typing
perldoc CGI
Paul Lalli
------------------------------
Date: Mon, 29 Nov 2004 15:56:10 -0500
From: Sherm Pendley <spamtrap@dot-app.org>
Subject: Re: how to define a variable to hold a multiline text input in perl from html multiline textbox
Message-Id: <4budneK2D9BxETbcRVn-1w@adelphia.com>
dale zhang wrote:
> #!/usr/bin/perl
use strict;
use warnings;
use CGI qw(fatalsToBrowser);
> &populatePostFields;
my $q = new CGI;
my %postFields = $q->Vars();
> I can not print $question, so I comment it out. My guess is $question
> is not properly assigned since the textfield7 has multiline (it is a
> textarea in HTML).
>
> Any suggestions? -Dale
Delete the buggy homemade populatePostFields subroutine and use one that
works properly.
Also, learn to call subroutines correctly. The '&' was needed for Perl
4, but in Perl 5 it's supported for compatibility only, and has side
effects you probably don't want. See 'perldoc perlsub'.
sherm--
--
Cocoa programming in Perl: http://camelbones.sourceforge.net
Hire me! My resume: http://www.dot-app.org
------------------------------
Date: Mon, 29 Nov 2004 13:20:01 -0800
From: Jim Gibson <jgibson@mail.arc.nasa.gov>
Subject: Re: List::Util::shuffle - where did the algorithm come from?
Message-Id: <291120041320017737%jgibson@mail.arc.nasa.gov>
In article <pan.2004.11.25.19.03.04.44915@zync.co.uk>, Richard Gration
<richard@zync.co.uk> wrote:
> Hi all,
>
> I was just looking at List::Util::shuffle (reproduced below) and wondered
> where the algorithm came from. Was this invented by the module author? Is
> it a known good algorithm for shuffling lists?
>
> It wasn't immediately obvious to me that all elements of the list would be
> returned, but I understand what's going on now. Visualising pigeon holes
> and bits of paper helps. A bit.
>
> So does anyone know its provenance?
>
> Rich
>
> sub shuffle (@) {
> my @a=\(@_);
> my $n;
> my $i=@_;
> map {
> $n = int rand($i--);
> (${$a[$n]}, $a[$n] = $a[$i])[0];
> } @_;
> }
See "Seminumerical Algorithms", 2nd Ed., D. Knuth, Section 3.4.2
"Random Sampling and Shuffling", Algorithm P (Shuffling), p. 139, and
references therein.
------------------------------
Date: 29 Nov 2004 11:38:55 -0800
From: "YorHel" <yorhel@gmail.com>
Subject: Re: Minimize black screen
Message-Id: <1101757135.174005.6210@f14g2000cwb.googlegroups.com>
"black screen" -> The windows console, Linux console? what "black
screen"?
------------------------------
Date: Mon, 29 Nov 2004 19:58:07 +0000
From: "Alan J. Flavell" <flavell@ph.gla.ac.uk>
Subject: Re: Minimize black screen
Message-Id: <Pine.LNX.4.61.0411291955300.23785@ppepc56.ph.gla.ac.uk>
On Mon, 29 Nov 2004, jim simpson wrote:
> Is there anyway to minimize the black screen while a Perl script is
> running
Hmmm. Crystal ball time. I suspect we might have here a PoB
("prisoner of Bill") who hadn't realised that mention of their OS and
other environment details would be useful.
Maybe you're looking for wperl.exe
> an then return it to normal just before the script comcludes?
Dunno about that part. You could google for wperl.exe and see if it's
part of the answer, anyhow.
------------------------------
Date: Mon, 29 Nov 2004 20:59:15 GMT
From: Joe Smith <joe@inwap.com>
Subject: Re: Minimize black screen
Message-Id: <D4Mqd.688639$8_6.11025@attbi_s04>
jim simpson wrote:
> Is there anyway to minimize the black screen while a Perl script is running
If you are talking about the MS-DOS command window that pops up on
Windows, wperl.exe will prevent that. It will also supress any output
going to SDTOUT and STDERR.
> an then return it to normal just before the script comcludes?
So, you want something that will create an MS-DOS command window when
the perl script starts, minimize that window while running, and at the
end of the script restore the window to its usual size and wait while
the user has a chance to look at any messages, right?
I can't help you with the minimize/restore part, but the last bit is
print "Press ENTER when done\n";
$_ = <STDIN>;
exit;
------------------------------
Date: Mon, 29 Nov 2004 22:18:39 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Minimize black screen
Message-Id: <072nq0h31qsjdarl62d9mh06p1cinr7q1p@4ax.com>
On Mon, 29 Nov 2004 10:56:42 -0500, "jim simpson" <jimsimpson@cox.net>
wrote:
>Is there anyway to minimize the black screen while a Perl script is running
>an then return it to normal just before the script comcludes?
You're talking Windoze, aren't you? Well, your headers tell me so...
then not a *real* answer to your question, but you may be interested
in wperl.exe.
Michele
--
{$_=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 Nov 2004 20:55:22 GMT
From: John Bokma <postmaster@castleamber.com>
Subject: PAR problems Win32 (Can't Spawn, line 372) (solved)
Message-Id: <Xns95B097CC37FDEcastleamber@130.133.1.4>
ASPerl: v5.8.3 built for MSWin32-x86-multi-thread
I installed PAR today. I downloaded PAR-0.85.tar.gz
Used ppm to install Module::ScanDeps, Parse::Binary, Win32::Exe,
PAR::Dist
perl Makefile.pl
nmake test
nmake install
Since it didn't find parl, I read the FAQ:
http://par.perl.org/index.cgi?FAQ
Used bribes:
ppm> upgrade -install PAR
PAR 0.75: new version 0.85 available in bribes
====================
Upgrade 'PAR' version 0.75 in ActivePerl 5.8.3.809.
====================
Downloaded 778464 bytes.
Extracting 22/22: blib/arch/auto/PAR/.exists
Successfully upgraded PAR version 0.75 in ActivePerl 5.8.3.809.
ppm> quit
After many attempst, I kept getting 0.75, so I did the following:
ppm> install http://www.bribes.org/perl/ppm/PAR-Dist.ppd
====================
Install 'PAR-Dist' version 0.07 in ActivePerl 5.8.3.809.
====================
Downloaded 6561 bytes.
Extracting 19/19: blib/lib/PAR/Dist.pm
Installing C:\Perl\html\site\lib\PAR\Dist.html
Installing C:\Perl\site\lib\PAR\Dist.pm
Successfully installed PAR-Dist version 0.07 in ActivePerl 5.8.3.809.
ppm> install http://www.bribes.org/perl/ppm/PAR.ppd
====================
Install 'File-Temp' version 0.12 in ActivePerl 5.8.3.809.
====================
Downloaded 21438 bytes.
Extracting 5/5: blib/arch/auto/File/Temp/.exists
Installing C:\Perl\html\site\lib\File\Temp.html
Installing C:\Perl\site\lib\File\Temp.pm
Successfully installed File-Temp version 0.12 in ActivePerl 5.8.3.809.
====================
Install 'PAR' version 0.85 in ActivePerl 5.8.3.809.
====================
Downloaded 852069 bytes.
Extracting 61/61: blib/script/tkpp.bat
Installing C:\Perl\html\bin\par.html
[ ... ]
Installing C:\Perl\bin\tkpp
Installing C:\Perl\bin\tkpp.bat
Successfully installed PAR version 0.85 in ActivePerl 5.8.3.809.
ppm>
Seems to work :-D I guess you can jump to the part after the "many
attempts". No idea what I did wrong in the first place (probably 12 hrs
perl programming the prev day doesn't help either).
--
John Small Perl scripts: http://johnbokma.com/perl/
Perl programmer available: http://castleamber.com/
Happy Customers: http://castleamber.com/testimonials.html
------------------------------
Date: 29 Nov 2004 19:23:55 GMT
From: Christopher Nehren <apeiron@comcast.net>
Subject: Re: Perl Executable and Script Name -- NOT Args
Message-Id: <slrncqmtqb.5nk.apeiron@prophecy.dyndns.org>
On 2004-11-29, Paul Lalli scribbled these
curious markings:
> perldoc perlvar is the place to go to find a list of all global Perl
> variables.
Note that it covers more than just _global_ variables; it also documents
package variables such as $a and $b, and the dynamically-scoped regular
expression match variables -- among others.
--
I abhor a system designed for the "user", if that word is a coded
pejorative meaning "stupid and unsophisticated". -- Ken Thompson
Linux: "How rebellious ... in a conformist sort of way."
Unix is user friendly. However, it isn't idiot friendly.
------------------------------
Date: Mon, 29 Nov 2004 19:39:33 GMT
From: "Paul Lalli" <mritty@gmail.com>
Subject: Re: Perl Executable and Script Name -- NOT Args
Message-Id: <VVKqd.354$Xd.130@trndny02>
"Christopher Nehren" <apeiron@comcast.net> wrote in message
news:slrncqmtqb.5nk.apeiron@prophecy.dyndns.org...
> On 2004-11-29, Paul Lalli scribbled these
> curious markings:
> > perldoc perlvar is the place to go to find a list of all global
Perl
> > variables.
>
> Note that it covers more than just _global_ variables; it also
documents
> package variables such as $a and $b, and the dynamically-scoped
regular
> expression match variables -- among others.
True. That was a poor choice of words on my part. "built-in Perl
variables" may be better. Basically, all the variables that exist by
default without the programmer creating them.
Paul Lalli
------------------------------
Date: 29 Nov 2004 12:23:16 -0800
From: ioneabu@yahoo.com (wana)
Subject: replace words in string with hash values
Message-Id: <bf0b47ca.0411291223.18580da6@posting.google.com>
foreach (keys %h)
{
$a =~ s/\b$_\b/$h{$_}/g;
}
I want to replace matches in string to hash key with hash value. I am
replacing acronyms with phrases where acronym is hash key. Is there a
better or different way?
thanks!
wana (on pda)
------------------------------
Date: Mon, 29 Nov 2004 21:44:06 +0100
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: replace words in string with hash values
Message-Id: <311g7dF371e6oU1@uni-berlin.de>
wana wrote:
> foreach (keys %h)
> {
> $a =~ s/\b$_\b/$h{$_}/g;
> }
>
> I want to replace matches in string to hash key with hash value. I am
> replacing acronyms with phrases where acronym is hash key. Is there a
> better or different way?
You have Perl search the whole string as many times as there are keys in
the hash. With this approach, searching the string once is sufficient:
my $keys = join '|', keys %h;
$a =~ s/($keys)/$h{$1}/g;
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: Mon, 29 Nov 2004 20:53:12 GMT
From: "Paul Lalli" <mritty@gmail.com>
Subject: Re: replace words in string with hash values
Message-Id: <Y_Lqd.2047$_C2.671@trndny01>
"wana" <ioneabu@yahoo.com> wrote in message
news:bf0b47ca.0411291223.18580da6@posting.google.com...
> foreach (keys %h)
> {
> $a =~ s/\b$_\b/$h{$_}/g;
> }
>
> I want to replace matches in string to hash key with hash value. I am
> replacing acronyms with phrases where acronym is hash key. Is there a
> better or different way?
Well, here's one that's different, though not necessarily better (in
fact, quite likely worse)
$a=~ s/\b(\B+)\b/$h{$1} or $1/ge;
Rather than searching the string for each hash key, this one would
search each word in the string to determine if it is in the hash (more
correctly stated: if it has a true value in the hash). If so, replace
it with the hash value, if not, leave it as is.
Benchmarking is left as an excercise to the OP. ;-)
One comment, however: Be careful about the use of \b. While \b does
mean 'word boundary', it means Perl's definition of a 'word', which is:
[0-9a-zA-Z_]+ That means that "don't" is two words: "don" and "t".
This may or may not be what you actually want.
Paul Lalli
------------------------------
Date: Mon, 29 Nov 2004 22:18:40 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: replace words in string with hash values
Message-Id: <ke2nq0djr5ifakschgm5bst7grub88r157@4ax.com>
On 29 Nov 2004 12:23:16 -0800, ioneabu@yahoo.com (wana) wrote:
>foreach (keys %h)
>{
> $a =~ s/\b$_\b/$h{$_}/g;
>}
>
>I want to replace matches in string to hash key with hash value. I am
>replacing acronyms with phrases where acronym is hash key. Is there a
>better or different way?
Don't know if it's "better" (depends on far too many different
things!), but
s/\b\w+\b/$h{$&}||$&/ge;
should do the job. Of course if your acronyms follow some convention
(e.g. 2 to 4 uppercase letters only) it could be improved
performance-wise:
s/\b[A-Z]{2,4}\b/$h{$&}||$&/ge;
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/?$/:"\r";print,redo}#JAPH,
------------------------------
Date: Mon, 29 Nov 2004 21:07:58 GMT
From: Joe Smith <joe@inwap.com>
Subject: Re: Unix commands and perl
Message-Id: <OcMqd.166355$HA.39680@attbi_s01>
AS wrote:
> My point is -- what do I need to do to run multiple commands taking
> the output from one command into another?
The example you gave works as long as you use the correct quoting
characters, and remember to put a backslash in front of the dollar
signs otherwise perl will do variable substitution.
my $cmd = "prog1 | prog2 '\$1' | prog3";
print "Command = $cmd\n";
(system $cmd) == 0 or die 'Command failed';
-Joe
------------------------------
Date: Mon, 29 Nov 2004 22:18:38 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Unix commands and perl
Message-Id: <2n3nq0pncprtdd9ge5sscqa2mrjrcccngq@4ax.com>
On Mon, 29 Nov 2004 12:37:19 -0500, James Willmore
<jwillmore@fastmail.us> wrote:
>[jim@localhost jim]$ perl -e 'print [getgrgid($<)]->[0],"\n";'
Not that I find it disturbing or incorrect, but what is this business
of referencing and dereferencing?
perl -le 'print +(getgrgid $<)[0]'
Michele
--
{$_=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: Mon, 29 Nov 2004 22:18:41 +0100
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Unix commands and perl
Message-Id: <aq3nq0tmsabemuh8bhhmql2irvo0tnq68d@4ax.com>
On 29 Nov 2004 08:47:50 -0800, solanki1961@yahoo.com (AS) wrote:
>My point is -- what do I need to do to run multiple commands taking
>the output from one command into another? I am comparatively new to
>Perl and am just getting back into programming. Michele, I would
You don't need anything particular. I think you just want to read
perldoc -q 'output of a command'
>appreciate it if you would add "how to do it" rather than just telling
>me it can be done in Perl better. In this example if someone explains
>to me what to do to make it work, I will be very thankful.
Well, any introductory reading on perl, including what you can find in
the docs would help you to find "how to do it". However, let me see...
in your post you had:
: system ('id | awk '{print $2}' | cut -d\( -f2 | cut -d\) -f1');
then incorrect quoting apart and notwithstanding the fact that another
user already suggested a "pure perl" solution, let's suppose that we
want to parse the output of id anyway: one of the many possible ways
could be (untested)
print do {
local $_=qx/id/;
(split)[0] =~ /\((\w+)\)/g;
}
or
{
local $_=qx/id/;
print +(split)[0] =~ /\((\w+)\)/g;
}
or...
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>
Administrivia:
#The Perl-Users Digest is a retransmission of the USENET newsgroup
#comp.lang.perl.misc. For subscription or unsubscription requests, send
#the single line:
#
# subscribe perl-users
#or:
# unsubscribe perl-users
#
#to almanac@ruby.oce.orst.edu.
NOTE: due to the current flood of worm email banging on ruby, the smtp
server on ruby has been shut off until further notice.
To submit articles to comp.lang.perl.announce, send your article to
clpa@perl.com.
#To request back copies (available for a week or so), send your request
#to almanac@ruby.oce.orst.edu with the command "send perl-users x.y",
#where x is the volume number and y is the issue number.
#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 V10 Issue 7462
***************************************
