[11423] in Perl-Users-Digest
Perl-Users Digest, Issue: 5023 Volume: 8
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Mon Mar 1 14:07:26 1999
Date: Mon, 1 Mar 99 11:01:42 -0800
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, 1 Mar 1999 Volume: 8 Number: 5023
Today's topics:
multi-threaded question brz@hotmail.com
multi-threaded question brz@hotmail.com
multi-threaded question brz@hotmail.com
Nifty little expression (Sean McAfee)
Re: Numeric Sort (Larry Rosler)
Re: Perl comment <emschwar@mail.uccs.edu>
Perl on Windows NT <Jean-Daniel.Bonjour@epfl.ch>
Re: Proper idiom for split(/,/) outside parentheses? (Greg Kuperberg)
regexp help (Mark P.)
Re: regexp help <ebohlman@netcom.com>
replace { with space <seugenio@man.amis.com>
Re: replace { with space <ebohlman@netcom.com>
Re: The dumbest newbie question ever..THANKS EVERYBODY <uri@home.sysarch.com>
trapping errors in DBD (Sybase/HP-UX 10.2) <thewheel@stlnet.com>
Re: trapping errors in DBD (Sybase/HP-UX 10.2) (Abigail)
Re: Using a glob with sort (Andrew M. Langmead)
Re: Using Perl to resize image? <jeromeo@atrieva.com>
Re: Using Perl to resize image? <bw@cs3.ecok.EDU>
Special: Digest Administrivia (Last modified: 12 Dec 98 (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Sun, 28 Feb 1999 17:51:21 GMT
From: brz@hotmail.com
Subject: multi-threaded question
Message-Id: <7bbvmo$oh6$1@nnrp1.dejanews.com>
Hi all:
How do I achieve multi-threaded operation in perl? I would like one thread
to work on the main applications and a second thread to send the generated
events at pre-defined time-intervals. So if I use sleep and my application
is single-threaded, the main application would be held up by the sleep thing.
Hope I am making myself clear
Thanks
brz@hotmail.com
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
------------------------------
Date: Sun, 28 Feb 1999 17:50:33 GMT
From: brz@hotmail.com
Subject: multi-threaded question
Message-Id: <7bbvl8$ogu$1@nnrp1.dejanews.com>
Hi all:
How do I achieve multi-threaded operation in perl? I would like one thread
to work on the main applications and a second thread to send the generated
events at pre-defined time-intervals. So if I use sleep and my application
is single-threaded, the main application would be held up by the sleep thing.
Hope I am making myself clear
Thanks
brz@hotmail.com
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
------------------------------
Date: Sun, 28 Feb 1999 17:51:13 GMT
From: brz@hotmail.com
Subject: multi-threaded question
Message-Id: <7bbvmf$oh3$1@nnrp1.dejanews.com>
Hi all:
How do I achieve multi-threaded operation in perl? I would like one thread
to work on the main applications and a second thread to send the generated
events at pre-defined time-intervals. So if I use sleep and my application
is single-threaded, the main application would be held up by the sleep thing.
Hope I am making myself clear
Thanks
brz@hotmail.com
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
------------------------------
Date: Sun, 28 Feb 1999 07:33:44 GMT
From: mcafee@waits.facilities.med.umich.edu (Sean McAfee)
Subject: Nifty little expression
Message-Id: <sj6C2.9308$Ge3.36676473@news.itd.umich.edu>
I've been working recently on a program for which I found it convenient to
introduce a couple of classes. At first I put each class into its own .pm
file, but I wasn't quite comfortable with this approach since the modules
only really made sense when used in conjunction with the main program. So
I combined all of the files into one, but was then faced with the problem
of exporting a couple of functions from one package to another without
using Exporter.
The obvious way was:
*SRan3 = \&OtherPkg::Random::SRan3;
*Ran3 = \&OtherPkg::Random::Ran3;
...which works, but looks kind of awkward. I thought "This is Perl I'm
using here. There must be a more succinct way to write this!" After a
bit of thought, I found it:
(*SRan3, *Ran3) = @OtherPkg::Random::{'SRan3', 'Ran3'};
This aliases the whole typeglobs, not just the function part, but this is
rarely a problem. Pretty slick.
--
Sean McAfee mcafee@umich.edu
print eval eval eval eval eval eval eval eval eval eval eval eval eval eval
q!q@q#q$q%q^q&q*q-q=q+q|q~q:q? Just Another Perl Hacker ?:~|+=-*&^%$#@!
------------------------------
Date: Sat, 27 Feb 1999 23:27:35 -0800
From: lr@hpl.hp.com (Larry Rosler)
Subject: Re: Numeric Sort
Message-Id: <MPG.11428fc4e0639a2a9896ab@nntp.hpl.hp.com>
[Posted and a courtesy copy mailed.]
In article <36d8d902.11330469@news.flash.net>, on Sun, 28 Feb 1999
05:50:58 GMT golfer@usa.net says...
> Was wondering if someone could help me. I have a tab delimited text
> file with the following on each line (example):
>
> Pete 56 23 88 99 23 2 8
> Mike 99 32 45 12 11 8 90
>
> What I want to do is sort these numerically from highest to lowest
> written to a tab delimited file resulting in
>
> Pete 99 88 56 etc
> Mike 99 90 45 etc
#!/usr/local/bin/perl -w
use strict;
while (<DATA>) {
chomp;
my ($name, @vals) = split /\t/;
print join("\t", $name, sort { $b <=> $a } @vals), "\n";
}
__END__
Pete 56 23 88 99 23 2 8
Mike 99 32 45 12 11 8 90
--
Larry Rosler
Hewlett-Packard Company
http://www.hpl.hp.com/personal/Larry_Rosler/
lr@hpl.hp.com
------------------------------
Date: 01 Mar 1999 11:23:43 -0700
From: Eric The Read <emschwar@mail.uccs.edu>
Subject: Re: Perl comment
Message-Id: <xkfn21xm5lc.fsf@valdemar.col.hp.com>
lr@hpl.hp.com (Larry Rosler) writes:
> CRUNCH 3. n. The character "#". Usage: used at Xerox and CMU, among
> other places. Other names for "#" include SHARP, NUMBER, HASH, PIG-PEN,
> POUND-SIGN, and MESH. GLS adds: I recall reading somewhere that most of
> these are names for the # symbol IN CONTEXT. The name for the sign
> itself is "octothorp".
Just to be excessively pedantic, it's "octothorpe", and there's a fair
amount of evidence to show that that particular name was invented in the
late 60s or early 70s by a Bell Labs engineer, as a joke.
Go troll dejanews on alt.usage.english; we've done this one to death.
(Several times, alas!)
-=Eric
------------------------------
Date: Mon, 01 Mar 1999 09:42:57 +0100
From: Jean-Daniel Bonjour <Jean-Daniel.Bonjour@epfl.ch>
Subject: Perl on Windows NT
Message-Id: <36DA5311.F209436C@epfl.ch>
Within a Perl script written on Windows NT4 (using ActiveState Perl),
I want to enter a pasword without echoing the password-string
on the Command-Prompt Window (DOS Window).
On Unix, the solution is to execute a "stty -echo" before reading
<STDIN>, and a "stty echo" after reading <STDIN>, like that :
system "stty -echo" ;
print "Enter password : " ;
chomp ($password = <STDIN>) ;
system "stty echo" ;
So, how can I get the same result on Windows NT ?
( using Windows commands equivalent to "stty -echo" ??? )
---
Jean-Daniel BONJOUR (Jean-Daniel.Bonjour@epfl.ch)
SI-DGR, EPFL
CH-1015 Lausanne
------------------------------
Date: 28 Feb 1999 09:17:09 -0800
From: greg@manifold.math.ucdavis.edu (Greg Kuperberg)
Subject: Re: Proper idiom for split(/,/) outside parentheses?
Message-Id: <7bbtml$l06$1@manifold.math.ucdavis.edu>
In article <7ba5tc$je5$1@manifold.math.ucdavis.edu>,
Greg Kuperberg <greg@manifold.math.ucdavis.edu> wrote:
>I am working on cleaning up a Perl code that needs to divide an author
>list into authors. The authors may be separated by commas or by the word
>"and". The idea is illustrated by the syntax
>
>@authorlist = split(/, *|,? *\band\b */i,$allauthors);
>
>*except* that the authors may have affiliations in parentheses, and there
>may even be nested parentheses, and I don't want to chop the string at
>conjunctions that are in parentheses.
To answer my own question, I looked up "How can I split a [character]
delimited string except when inside [character]?" in the Perl FAQ.
(I did a Deja News search before writing my posting, but I did not
find this particular thing before.) This FAQ entry does not answer my
question, but the code it does have gave me this idea:
$depth = 0;
@authorlist = ();
$auth = "";
while($allauthors =~ /(.*?)(\(|\)|, *|$)/g)
{
if($2 eq ")")
{ $auth .= $&; $depth--; }
elsif($2 eq "(")
{ $auth .= $&; $depth++; }
elsif($depth > 0)
{ $auth .= $&; }
else
{ push(@authorlist,"$auth$1") if "$auth$1"; $auth = ""; }
}
For clarity in this sample code I am only splitting on commas and not
on the word "and". If anyone has a better idea, I'm still interested.
Please send a copy of your reply by e-mail.
--
/\ Greg Kuperberg (UC Davis)
/ \
\ / Visit the xxx Math Archive Front at http://front.math.ucdavis.edu/
\/ * 7446+1509 articles and counting! *
------------------------------
Date: Sun, 28 Feb 1999 17:14:52 GMT
From: mag@imchat.com (Mark P.)
Subject: regexp help
Message-Id: <36d97758.596468666@news.ionet.net>
Well, I'm still very green when it comes to regexps. I'm
attempting to learn, but the darn things make my brain hurt.<G>
Anyway, I need a regexp that will take a url like so,
http://www.whatever.com/what/index.html#what and just get the
index.html. Then I need to replace the index.html to index.txt. I know
how to do the replace, but I'm getting bogged down with getting the
index.html. I'm embarrassed to show what I have so far, but oh
well.<G>
s/.*\\([^http:\/\/]+[^#]+)$/$1/ig;
s/.html/.txt/ig;
I appreciate any help in this.
------------------------------
Date: Sun, 28 Feb 1999 17:38:33 GMT
From: Eric Bohlman <ebohlman@netcom.com>
Subject: Re: regexp help
Message-Id: <ebohlmanF7vL09.2CE@netcom.com>
Mark P. <mag@imchat.com> wrote:
: Anyway, I need a regexp that will take a url like so,
: http://www.whatever.com/what/index.html#what and just get the
: index.html. Then I need to replace the index.html to index.txt. I know
: how to do the replace, but I'm getting bogged down with getting the
: index.html. I'm embarrassed to show what I have so far, but oh
: well.<G>
Don't reinvent the wheel. Use the URI::URL module, which gives you all
sorts of methods for splitting and composing URLs.
------------------------------
Date: 1 Mar 1999 08:22:02 GMT
From: "Sheila Eugenio" <seugenio@man.amis.com>
Subject: replace { with space
Message-Id: <01be63bc$7a11f030$2bbe10ac@amipnet>
How can I replace any occurrence of the left bracket with a white space? I
did the following comparison:
$newsubtype = ~ s/[{]/ /g;
and everytime i print ("$newsubtype\n"); it replaces { with 4294967295.
Thanks!
------------------------------
Date: Mon, 1 Mar 1999 08:57:34 GMT
From: Eric Bohlman <ebohlman@netcom.com>
Subject: Re: replace { with space
Message-Id: <ebohlmanF7wrJy.7Fy@netcom.com>
Sheila Eugenio <seugenio@man.amis.com> wrote:
: How can I replace any occurrence of the left bracket with a white space? I
: did the following comparison:
: $newsubtype = ~ s/[{]/ /g;
: and everytime i print ("$newsubtype\n"); it replaces { with 4294967295.
That's because your code is doing the following:
1) Replace every occurrence of '{' in $_ with two spaces (the s// part).
2) Take the bitwise complement of the number of replacements (the ~ part).
3) Assign the complemented number of replacements to $newsubtype (the =
part).
An = followed by whitespace followed by ~ is an assignment of a bitwise
complement. An = followed *immediately* by ~ is a pattern-match binding,
which is what you want. Take out your stray space.
------------------------------
Date: 01 Mar 1999 02:46:55 -0500
From: Uri Guttman <uri@home.sysarch.com>
Subject: Re: The dumbest newbie question ever..THANKS EVERYBODY
Message-Id: <x7pv6tfy8g.fsf@home.sysarch.com>
>>>>> "ME" == Mike Eley <mapman@frii.com> writes:
ME> WOW
ME> this has got to be the most helpful newsgroup ever
ME> my faith has been restored
ME> i think i can in fact learn the Perl thing
ME> THANKS AGAIN EVERYONE
show this to all the other newbies who flame us for being coldhearted
bastards. most perl hackers i know are pretty helpful. they just don't
like being asked to do everything for a newbie and over and over again.
uri
--
Uri Guttman ----------------- SYStems ARCHitecture and Software Engineering
Perl Hacker for Hire ---------------------- Perl, Internet, UNIX Consulting
uri@sysarch.com ------------------------------------ http://www.sysarch.com
The Best Search Engine on the Net ------------- http://www.northernlight.com
------------------------------
Date: Sun, 28 Feb 1999 01:30:50 -0600
From: "T. Wheeler" <thewheel@stlnet.com>
Subject: trapping errors in DBD (Sybase/HP-UX 10.2)
Message-Id: <36D8F0AA.EE29E522@stlnet.com>
I have a problem trapping errors while accessing a Sybase
System 11 database on HP-UX 10.2. I am not at that
computer now, so I can't tell you what version of DBI/DBD I
am using, but I built it last week with the latest sources
from CPAN. I'm running perl 5.004.
I have created a few subroutines that simplify database
access. One such function is db_connect(), which looks
like:
sub db_connect {
# this function returns a handle to the db.
my $dbh = DBI->connect($CONN_STR);
return $dbh;
}
This program is running as a FastCGI, so I can't use
statements like DBI->connect($CONN_STR) || die. Instead, I
need to do something more like warn(), where I can trap
errors and handle them appropriately.
I have seen this in the past done like:
eval {
my $dbh = db_connect();
};
handle_error("Connection error $@") if $@;
But that is not working. In this case $@ is never
populated, even if the connect fails (and $dbh is not
valid).
Any ideas on how to handle this? Stability is more of a
concern than speed to me.
Thanks,
Tom Wheeler
thewheel@stlnet.com
------------------------------
Date: 28 Feb 1999 08:17:50 GMT
From: abigail@fnx.com (Abigail)
Subject: Re: trapping errors in DBD (Sybase/HP-UX 10.2)
Message-Id: <7bau3e$ski$1@client2.news.psi.net>
T. Wheeler (thewheel@stlnet.com) wrote on MMVII September MCMXCIII in
<URL:news:36D8F0AA.EE29E522@stlnet.com>:
`` I have a problem trapping errors while accessing a Sybase
`` System 11 database on HP-UX 10.2. I am not at that
`` computer now, so I can't tell you what version of DBI/DBD I
`` am using, but I built it last week with the latest sources
`` from CPAN. I'm running perl 5.004.
``
`` I have created a few subroutines that simplify database
`` access. One such function is db_connect(), which looks
`` like:
``
`` sub db_connect {
`` # this function returns a handle to the db.
`` my $dbh = DBI->connect($CONN_STR);
`` return $dbh;
`` }
``
`` This program is running as a FastCGI, so I can't use
`` statements like DBI->connect($CONN_STR) || die. Instead, I
`` need to do something more like warn(), where I can trap
`` errors and handle them appropriately.
So, what's wrong with
DBI->connect($CONN_STR) || warn
then?
I use Sybase::DBlib to connect to Sybase, and its connection method
just returns false if the connection fails. Alternatively, the
DBlibrary has callback functions that are called whenever Sybase
throws an error or message.
I use it in my monitor program that connects to 15 SQL servers and
10 backup servers every minute, on a 24x7 scedule and that pages
or emails me with the appropriate reason if a connection fails.
Abigail
--
perl -e '$_ = q *4a75737420616e6f74686572205065726c204861636b65720a*;
for ($*=******;$**=******;$**=******) {$**=*******s*..*qq}
print chr 0x$& and q
qq}*excess********}'
------------------------------
Date: Sun, 28 Feb 1999 17:23:56 GMT
From: aml@world.std.com (Andrew M. Langmead)
Subject: Re: Using a glob with sort
Message-Id: <F7vKBw.MK5@world.std.com>
moseley@best.com (Bill Moseley) writes:
>In article <F7tBLG.JBw@world.std.com>, Andrew Langmead says...
>> {
>> local(*sub_sort);
>> die "Invalid sort criteria\n" unless exists $sortroutines{$sortby};
>> *sub_sort = $sortroutines{$sortby};
>> @sorted = sort sort_sub keys %students;
>> }
>Why the enclosing braces? This is already in a subroutine so the scope
>is not very big (long?).
So the scope of the new subroutine sort_sub only lasts until the call
to sort() is over. If you are sure that it won't be used later within
the next enclosing block, and you know that there is not variable
called $sort_sub that might get munged, I suppose you can remove them,
but then you run the risk of some later maintenance programmer messing
things up.
>Another question which shows my lack of experience: how is it that I can
>use 'sub_sort' under use strict without use vars? sub_sort is a package
>var, well the glob for all the package vars named sub_sort, right?
Since we are assigning a code reference to the typeglob, only the
package subroutine &sort_sub gets redefined (or defined in this case.)
The scalar, array, hash, and filehandle named sort_sub stay the
same. Since this isn't dealing with any of the variables, the strict
pragma does nothing.
--
Andrew Langmead
------------------------------
Date: Mon, 01 Mar 1999 10:00:01 -0800
From: Jerome O'Neil <jeromeo@atrieva.com>
To: John <john@terminalreality.com>
Subject: Re: Using Perl to resize image?
Message-Id: <36DAD5A1.2BBCB791@atrieva.com>
John wrote:
>
> Is there a way, using Perl or some UNIX program that I can execute through
> Perl that I could take a GIF or JPG image and make a thumbnail of it at a
> size that I specify?
I wrote something like this using ImageMagik. Works great! And the
library comes with some usefull tools. If you want to manipulate many
different image formats, you will need to compile those libraries when
you build to toolkit.
Good Luck!
--
Jerome O'Neil, Operations and Information Services
Atrieva Corporation, 600 University St., Ste. 911, Seattle, WA 98101
jeromeo@atrieva.com - Voice:206/749-2947
The Atrieva Service: Safe and Easy Online Backup http://www.atrieva.com
------------------------------
Date: 1 Mar 1999 18:41:33 GMT
From: Bill Walker <bw@cs3.ecok.EDU>
Subject: Re: Using Perl to resize image?
Message-Id: <7ben0t$lbg$1@sunhub-tulsa.onenet.net>
In comp.lang.perl.misc Jerome O'Neil <jeromeo@atrieva.com> wrote:
> John wrote:
>>
>> Is there a way, using Perl or some UNIX program that I can execute through
>> Perl that I could take a GIF or JPG image and make a thumbnail of it at a
>> size that I specify?
> I wrote something like this using ImageMagik. Works great! And the
> library comes with some usefull tools. If you want to manipulate many
> different image formats, you will need to compile those libraries when
> you build to toolkit.
----------------------------------
try this:
#!/usr/local/bin/perl
use GD;
################################# main stuff here #######################
# name of thumbnail directory
$SMALLDIR = "./THUMBS";
$thumbnailfile = "./thumbnail.html";
mkdir ($SMALLDIR, 0755);
$smallx = 100;
$smally = 100;
$smaller = 90;
$smallimage = new GD::Image($smallx, $smally);
$blankimage = new GD::Image($smallx, $smally);
$red = $blankimage->colorAllocate(255,0,0);
$smallimage->copy($blankimage,0,0,0,0,$smallx,$smally);
$smallimage->transparent($red);
open (HTML, ">"."$thumbnailfile");
select (HTML);
$|=1;
printf(HTML "<html><body bgcolor=red>\n");
################# now we should make a loop ##################
opendir (DIR, ".");
while ($filename = readdir(DIR)) {
if (($filename =~ /gif/)
|| ($filename =~ /GIF/) ) {
& procfile($filename,$filename);
}
if ($filename =~ /jpg|jpg/) { #convert it
$tempfile = $filename.".gif";
$conversion = `djpeg -gif $filename > $tempfile`;
&procfile($filename,$tempfile);
$conversion = `rm $tempfile`;
}
}
closedir (DIR);
################# finish it off ##############################
select(HTML);
$|=1;
printf (HTML "\n<br></body></html>\n");
close (HTML);
chmod (0744, $thumbnailfile);
exit 0;
sub procfile {
local ($filename,$tempname) = @_;
open (GIF, $tempname);
$fullimage = newFromGif GD::Image(GIF);
close (GIF);
($largex, $largey) = $fullimage->getBounds();
# resize the fullimage to fit in at most a $smaller x $smaller box, with
# perspective added
$maxdim = $largex;
if ($largey > $maxdim) {
$maxdim = $largey;
}
$resizedx = $largex / $maxdim * $smaller;
$resizedy = $largey / $maxdim * $smaller;
# copy resized to small image
$smallimage->copy($blankimage,0,0,0,0,$smallx,$smally);
$smallimage->transparent($red);
$smallimage->copyResized($fullimage,5,5,0,0,$resizedx, $resizedy,$largex,$largey);
# create the small image filename
$smallfilename = $SMALLDIR."/small-"."$tempname";
open (SMALL, ">"."$smallfilename") || die "cant create small file $smallfilename";
print SMALL $smallimage->gif;
close (SMALL);
chmod (0744, $smallfilename);
select(STDOUT);
printf("finished with %s\n",$filename);
select(HTML);
$|=1;
printf ( HTML "<a href=\"%s\"><img src=\"%s\"></a>\n",$filename,$smallfilename);
}
-------------------
73 de Bill W5GFE
------------------------------
Date: 12 Dec 98 21:33:47 GMT (Last modified)
From: Perl-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Special: Digest Administrivia (Last modified: 12 Dec 98)
Message-Id: <null>
Administrivia:
Well, after 6 months, here's the answer to the quiz: what do we do about
comp.lang.perl.moderated. Answer: nothing.
]From: Russ Allbery <rra@stanford.edu>
]Date: 21 Sep 1998 19:53:43 -0700
]Subject: comp.lang.perl.moderated available via e-mail
]
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------------------------------
End of Perl-Users Digest V8 Issue 5023
**************************************
