[24124] in Perl-Users-Digest
Perl-Users Digest, Issue: 6318 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Sun Mar 28 18:15:45 2004
Date: Sun, 28 Mar 2004 15:15:10 -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 Sun, 28 Mar 2004 Volume: 10 Number: 6318
Today's topics:
Cannot reset LIBPATH in perl program on AIX <shah@typhoon.xnet.com>
Re: Cannot reset LIBPATH in perl program on AIX <No_4@dsl.pipex.com>
Re: Does anyone know what this switch does? <vunderink@t-online.de>
File handling concatenating two files (uc_sk)
Re: Filehandles Referenced with a Variable (Myron Turner)
Re: Filehandles Referenced with a Variable <mikeflan@earthlink.net>
Re: fork and wait... (Anno Siegel)
Re: Help: Deleting Entries in Flat File Database <uri@stemsystems.com>
Re: Help: Using the Reply-To: header on sending email <bik.mido@tiscalinet.it>
Re: Help: Using the Reply-To: header on sending email (Anno Siegel)
Re: Help: Using the Reply-To: header on sending email <noreply@gunnar.cc>
Included directory problem <chatiman@free.fr>
Re: Included directory problem <postmaster@castleamber.com>
Re: Included directory problem <chatiman@free.fr>
Re: Included directory problem <uri@stemsystems.com>
Re: Included directory problem <postmaster@castleamber.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Sun, 28 Mar 2004 22:23:39 +0000 (UTC)
From: Hemant Shah <shah@typhoon.xnet.com>
Subject: Cannot reset LIBPATH in perl program on AIX
Message-Id: <c47j9b$4u8$1@flood.xnet.com>
Folks,
I am having a problem with my perl module on AIX system. I cannot reset
LIBPATH variable from my perl module. I have a perl script that uses my
perl module which in turn uses DBD::DB2 to get data from a database.
When user logs in, his environment may set LIBPATH and LD_LIBRARY_PATH to
another DB2 instance.
When functions from my perl module are called I would like to reset LIBPATH
to a different DB2 instance.
Example:
User's environment has following values.
LIBPATH=/lib:/usr/lib:/home/db2inst1/sqllib/lib
LD_LIBRARY_PATH=/lib:/usr/lib:/home/db2inst1/sqllib/lib
My module uses db2inst2 which is using different version of DB2 so
I would like to set LIBPATH to LD_LIBRARY_PATH to db2inst2. I tried
following in my perl module, but it does not work.
delete @ENV{qw(LD_LIBRARY_PATH LIBPATH)};
$ENV{LIBPATH} = "/lib:/usr/lib:/home/db2inst2/sqllib/lib";
$ENV{LD_LIBRARY_PATH} = "/lib:/usr/lib:/home/db2inst2/sqllib/lib";
This does not work. I cannot connect to the database.
I ran the script in perl debugger and I can see that the values have
changed, but it still does not work.
If I change the variables from the command line
and then call the script then it works without any problem.
One option I have is to write a wrapper shell script that resets the
variables and then calls the perl script. I am trying to avoid this
because there are many scripts (most of which are not under my control)
that call functions from my perl module and all of them will have to
change. I would rather change one module that is under my control.
Is there a way around it?
Thanks.
--
Hemant Shah /"\ ASCII ribbon campaign
E-mail: NoJunkMailshah@xnet.com \ / ---------------------
X against HTML mail
TO REPLY, REMOVE NoJunkMail / \ and postings
FROM MY E-MAIL ADDRESS.
-----------------[DO NOT SEND UNSOLICITED BULK E-MAIL]------------------
I haven't lost my mind, Above opinions are mine only.
it's backed up on tape somewhere. Others can have their own.
------------------------------
Date: Mon, 29 Mar 2004 00:01:28 +0100
From: Big and Blue <No_4@dsl.pipex.com>
Subject: Re: Cannot reset LIBPATH in perl program on AIX
Message-Id: <4067590c$0$6550$cc9e4d1f@news-text.dial.pipex.com>
Hemant Shah wrote:
>
> I am having a problem with my perl module on AIX system. I cannot reset
> LIBPATH variable from my perl module.
You can set it. What you mean is that setting it doesn't have any
effect. This is true. The value used is that at program startup.
> I have a perl script that uses my
> perl module which in turn uses DBD::DB2 to get data from a database.
>
> When user logs in, his environment may set LIBPATH and LD_LIBRARY_PATH to
> another DB2 instance.
Bad practice. The values in here will refer to SPECIFIC APPLICATIONS,
so should not be set in a global context. (I trust that your Perl scripts
don't use global variables everywhere, but instead use correctly-scoped ones?)
> When functions from my perl module are called I would like to reset LIBPATH
> to a different DB2 instance.
a) If you know where the dynamic libraries will be at the time you compile
the extension then set the relevant link-time options so that the Perl
extensions knows where to look.
b) if you can't do a) then run *your* application through a simple sehll
interlude script that does set LD_LIBRARY_PATH/LIBPATH to the value you
want and the exec your perl script.
> One option I have is to write a wrapper shell script that resets the
> variables and then calls the perl script. I am trying to avoid this
> because there are many scripts (most of which are not under my control)
> that call functions from my perl module and all of them will have to
> change. I would rather change one module that is under my control.
>
> Is there a way around it?
Yes.
c) similar to b) but you pass in the name of the script you wish to run as
well, so that you only have one interlude script, but it can exec any DB2
script.
--
-*- Just because I've written it here doesn't -*-
-*- mean that you should, or I do, believe it. -*-
------------------------------
Date: Sun, 28 Mar 2004 20:01:04 +0100
From: Rob Vunderink <vunderink@t-online.de>
Subject: Re: Does anyone know what this switch does?
Message-Id: <BC8CDF80.201F%vunderink@t-online.de>
Thanks, Joe, this is the most complete and clear answer I got.
Rob Vunderink
= - = - = - = - = - = - =
in article 1aw9c.21936$K91.66988@attbi_s02, Joe Smith at Joe.Smith@inwap.com
wrote on 28-03-2004 09:38:
> Rob Vunderink wrote:
>
>> http://www.opstartpagina.nl/cgi-bin/ipadres.cgi
>> It works.
>
> Check.
>
>> Now check out this url:
>> http://angel.regioportals.nl/gelderlander/cgi-bin/ipadres.cgi
>
> Opening ipadres.cgi
> The file "padres.cgi is of type application/x-httpd-php, and Mozilla does no
> know how to handle this file type. This file is located at:
> http://angel.regioportals.nl/gelderlander/cgi-bin/
> What should Mozilla do with this file?
> ( ) Open it with the default application
> ( ) Open it with ___________________________ [Choose...]
> (*) Save it to disk
>
>> It does not work, although the scripts are the same in both cases:
>>
>> = - = - = - = - = - = - = - = -
>> #!/usr/bin/perl
>>
>> http://angel.regioportals.nl/gelderlander/cgi-bin/ipadres2.cgi
>>
>> It works. The script is:
>> #!/usr/bin/perl --
>
> Clearly an end-of-line upload problem.
>
> It fails because "/usr/bin/perl^M" does not exist (where ^M represents
> the Classic Mac end-of-line and one half of the MS-DOS end-of-line).
>
> Changing the shebang line to include a space and any switch ("-w", "-T")
> works because the program loader stops at the space, and therefore
> knows the right interpreter to load.
>
> It appears that the web server at angel.regioportals.nl is configured
> to not produce a "500 Server Error" when the shebang line is bad, and
> outputs "Content-type: application/x-httpd-php" instead.
> I'd say the server is misconfigured, in that it does not invoke the
> php-handler in this case.
>
> The fix is to tell your FTP client to use ASCII mode instead if IMAGE
> (binary) mode when uploading your scripts.
> -Joe
------------------------------
Date: 28 Mar 2004 13:52:08 -0800
From: kshagun@hotmail.com (uc_sk)
Subject: File handling concatenating two files
Message-Id: <e2766e96.0403281352.68b74dc0@posting.google.com>
Hi All,
I have the task of comparing two text files line by line and
outputting it after concatenating it. For example:
In my File1 I have 2 RECORDS:
abcdecf 7 {2,3,4,6} 4
>{2,3}
>{6}
lmno-qr 6 {12,16,29} 3
>{12}
>{16}
>{29}
and in File2 I have again 2 RECORDS (if you will see and compare the
records of File1 and File2, the first line i.e the first pattern is
the same):
abcdecf 7 {2,3,4,6} 4
(1,2,3,4,5,6,7) 7 {0,1,2,3,4,5,6} 7
lmno-qr 6 {12,16,29} 3
(1,2,3,4,6,7) 6 {11,12,16,17,29} 5
So now i want the output after concatenating them as:
abcdecf 7 {2,3,4,6} 4
(1,2,3,4,5,6,7) 7 {0,1,2,3,4,5,6} 7
>{2,3}
>{6}
lmno-qr 6 {12,16,29} 3
(1,2,3,4,6,7) 6 {11,12,16,17,29} 5
>{12}
>{16}
>{29}
So basically in my final result I want the first two lines of File2
and want all the lines of File1 except the first line FOR EACH RECORD.
I am a newbie with Perl, so dont have idea about most of the
things but i feel that PERL will be the better opion to do this.
thanks in advance for your help!
~uc_sk
------------------------------
Date: Sun, 28 Mar 2004 15:52:10 GMT
From: mturner@ms.umanitoba.ca (Myron Turner)
Subject: Re: Filehandles Referenced with a Variable
Message-Id: <4066ee07.2117402223@news.wp.shawcable.net>
On Sat, 27 Mar 2004 18:06:44 GMT, Mike Flannigan
<mikeflan@earthlink.net> wrote:
>
>Myron Turner wrote:
>
>> I know this topic has been gone over, but this is based on
>> "Programming Perl", page 249, which I've known about but have never
>> used:
>>
>> my %handles;
>>
>> for my $file(@names) {
>> my $fh;
>> $handles{$file} = $fh;
>> }
>
>This confuses me. It's seems like $fh would not
>be defined as anything useful, but I'll give it a try.
>
>
There are lots of things in perl which are done behind the scenes.
For instance, when you pass a filehandle as *FILE to a subroutine,
perl you are not passing the file handle itself but a typeglob which
can have one of six values--it can be a reference to a scalar, a hash,
an array, a filehandle, a subroutine or a format specifier. When your
subroutine assigns the glob to $fh and then uses it in a place
requring a filehandle, perl treats it as a filehandle,not as a hash,
an array, etc.
In the above code, because of the my in
my $fh
each time you go through the loop, perl creates a new scalar and
assigns it to the hash. In perl you can say:
open $fh, "myfile"
It doesn't have to be
open FH, "myfile"
When you extract $fh from the hash and use it in a position requiring
a filehandle perl goes to the type glob which holds $fh (*fh) and
fetches the filehandle for you.
Myron
Myron Turner
www.room535.org
------------------------------
Date: Sun, 28 Mar 2004 19:59:26 GMT
From: Mike Flannigan <mikeflan@earthlink.net>
Subject: Re: Filehandles Referenced with a Variable
Message-Id: <40672EB9.1A2BD36@earthlink.net>
Joe Smith wrote:
> But you should be.
>
> our %handles; # Open file handles, indexed by state
>
> foreach (@states) {
> my $fh; # Start with a scalar variable whose value is undef
> open $fh, '>', "$_.txt" or die "Cannot open $_.txt - $!\n";
> $handles{$_} = $fh; # open() magically makes $fh into a filehandle!
> }
>
> Notice the third paragraph in "perldoc -f open" where it says
>
> If FILEHANDLE is an undefined scalar variable (or array or hash
> element) the variable is assigned a reference to a new anony-
> mous filehandle ...
>
> so the open() could be written as
>
> open $handles{$_}, '>', "$_.txt" or die;
>
> Note that this uses a freshly created anonymous handle that is stored
> in a hash indexed by state name, as Uri said over and over.
>
> The print() section can be written as
>
> my $fh = $handles{$st};
> print $fh $line;
>
> or
>
> print {$handles{$st}} $line;
>
> -Joe
>
> P.S. The autovivification of file handles for undef values was added
> during the development of perl version 5.6, back in 1999.
Thanks to all - Joe, Uri, Myron (& others?). It's working as
supplied, with 'use strict' in place. Doesn't even use a
module, which is nice.
I've read the pod and am convinced that I could not have
gotten there on my own. Even in hindsight, I can't figure
out how it's put together. I probably understand less
than 10% of it. I hope it makes sense someday.
For kicks, I printed out the hash elements and got:
SC => GLOB(0x1a8a1e8)
LA => GLOB(0x1a8741c)
NC => GLOB(0x1a89f18)
MS => GLOB(0x1a89eb8)
GU => GLOB(0x1a8729c)
OK => GLOB(0x1a8a0c8)
NY => GLOB(0x1a8a068)
VA => GLOB(0x1a8d78c)
HI => GLOB(0x1a872cc)
PA => GLOB(0x1a8a128)
NE => GLOB(0x1a89f78)
SD => GLOB(0x1a8d69c)
PR => GLOB(0x1a8a158)
DC => GLOB(0x1a871ac)
OH => GLOB(0x1a8a098)
WV => GLOB(0x1a8d87c)
WI => GLOB(0x1a8d84c)
NM => GLOB(0x1a8a008)
etc.
A little bit of the magic revealed, I guess :-)
There is something about this statement from Myron that
I don't understand:
"When you extract $fh from the hash and use it in a position requiring a
filehandle perl goes to the type glob which holds
$fh (*fh) and fetches the filehandle for you."
I guess that "extract $fh from the hash" is happening behind
the scenes, and I shouldn't really expect to see it directly
in my code below. Right or wrong, I have a lot to learn.
foreach (@states) {
my $fh; # Start with a scalar variable whose value is undef
open $fh, '>', "$_.txt" or die "Cannot open $_.txt: $!";
$handles{$_} = $fh; # open() magically makes $fh into a filehandle!
}
Mike
------------------------------
Date: 28 Mar 2004 14:45:28 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: fork and wait...
Message-Id: <c46oe8$8j8$1@mamenchi.zrz.TU-Berlin.DE>
svetj <svetjNO@SPAMtiscali.it> wrote in comp.lang.perl.misc:
> Hi,
> I wrote a perl script that do one query to many db at the same time.
> this is the code with fork (from "Programming Perl"):
> my @countries=('IT'
> ,'BE'
> ,'ES'
> ,'NL'
> ,'NO)
>
> foreach my $ct (@countries) {
>
> FORK: {
> if ($pid = fork){
> #codice processo padre
> print "$ct - $pid\n";
> #waitpid($pid,80);
>
> } elsif (defined $pid) {#qui $pid è zero se è definito
> &report ($ct);
There's no need for the "&" in front of "report()", and in fact it can
mess things up for you. Leave it off.
> print "\n sono $ct figlio!!!\n";
> } elsif ($! =~ /No more process/) {
> #errore recuperabile
> sleep 5;
> redo FORK;
> } else {
> #strano errore di fork
> die "$ct - Nn riesco a fare il fork: $!\n";
> }
> }
> }
>
> So, if I uncomment "waitpid($pid,80);" parten process wait for the end of a
> child,
> and if child don't stops, can't start next child..
> But i want to start all childs at the same time,
> and after the parent process must wait end of all childs for 80 seconds (for
> example).
> So where I must write waitpid?
In the main program, after the loop that creates the children, or in a
SIGCHLD handler. The first one is simpler, but it leaves your main program
unresponsive, except possibly to other signals. If you need the handler,
look up %SIG in perlvar.
You should also have asked *how* to write waitpid(). The form you are
using will wait for one specific child and ignore all others. Since you
have more than one child, that is insufficient. See "perldoc -f waitpid"
for alternatives.
Anno
------------------------------
Date: Sun, 28 Mar 2004 14:46:11 GMT
From: Uri Guttman <uri@stemsystems.com>
Subject: Re: Help: Deleting Entries in Flat File Database
Message-Id: <x7ekrduj0s.fsf@mail.sysarch.com>
>>>>> "JS" == Joe Smith <Joe.Smith@inwap.com> writes:
JS> ... convoluted code snipped ...
JS> @newarray = grep !/$del1/, @array;
JS> exit if $#newarray == $#array; # Nothing to do if no changes
exit if @newarray == @array; # Nothing to do if no changes
i prefer @foo for that. i stay away from $#foo unless it is really
needed. it is just too fugly and i feel misleading to too many. i hate
to see it used when not needed as well like in if $#foo > -1 instead of
if @foo.
uri
--
Uri Guttman ------ uri@stemsystems.com -------- http://www.stemsystems.com
--Perl Consulting, Stem Development, Systems Architecture, Design and Coding-
Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
------------------------------
Date: Sun, 28 Mar 2004 20:27:12 +0200
From: Michele Dondi <bik.mido@tiscalinet.it>
Subject: Re: Help: Using the Reply-To: header on sending email
Message-Id: <tu4e60p8bfe8ecithev5qvplvh2d550pqu@4ax.com>
On Sun, 28 Mar 2004 09:27:22 +0200, Gunnar Hjalmarsson
<noreply@gunnar.cc> wrote:
>X-Reply-To is not the same as Reply-To. Try saying:
>
> Reply-To => "$reply_to",
or (as is always worth reminding!)
Reply-To => $reply_to,
Michele
--
you'll see that it shouldn't be so. AND, the writting as usuall is
fantastic incompetent. To illustrate, i quote:
- Xah Lee trolling on clpmisc,
"perl bug File::Basename and Perl's nature"
------------------------------
Date: 28 Mar 2004 21:07:59 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: Help: Using the Reply-To: header on sending email
Message-Id: <c47erf$k6s$1@mamenchi.zrz.TU-Berlin.DE>
Michele Dondi <bik.mido@tiscalinet.it> wrote in comp.lang.perl.misc:
> On Sun, 28 Mar 2004 09:27:22 +0200, Gunnar Hjalmarsson
> <noreply@gunnar.cc> wrote:
>
> >X-Reply-To is not the same as Reply-To. Try saying:
> >
> > Reply-To => "$reply_to",
>
> or (as is always worth reminding!)
>
> Reply-To => $reply_to,
...but quotes are needed on the other side of "=>". "Reply-To" is not a
valid identifier, so
'Reply-To' => $reply_to,
Anno
------------------------------
Date: Sun, 28 Mar 2004 23:13:56 +0200
From: Gunnar Hjalmarsson <noreply@gunnar.cc>
Subject: Re: Help: Using the Reply-To: header on sending email
Message-Id: <c47f70$2capk8$1@ID-184292.news.uni-berlin.de>
Anno Siegel wrote:
> Michele Dondi wrote:
>> Gunnar Hjalmarsson wrote:
>>> X-Reply-To is not the same as Reply-To. Try saying:
>>>
>>> Reply-To => "$reply_to",
>>
>> or (as is always worth reminding!)
>>
>> Reply-To => $reply_to,
>
> ...but quotes are needed on the other side of "=>".
> "Reply-To" is not a valid identifier, so
>
> 'Reply-To' => $reply_to,
Time to go to sleep, I suppose. :(
Thanks!
--
Gunnar Hjalmarsson
Email: http://www.gunnar.cc/cgi-bin/contact.pl
------------------------------
Date: Sun, 28 Mar 2004 18:39:04 +0200
From: "chatiman" <chatiman@free.fr>
Subject: Included directory problem
Message-Id: <4066ffa4$0$14042$626a14ce@news.free.fr>
Hello,
I'm trying to build an installation procedure for a script.
The script require some aditional modules
which will be installed on the base "prefix=/my_prefix".
How can I know which path to include in my script ?
As you know the modules get installed in a directory
which depends on the perl version and other
parameters. It's sometimes:
my_prefix/lib/site_perl/5.005
my_prefix/lib/5.00503/
...
Thanks
------------------------------
Date: Sun, 28 Mar 2004 11:54:26 -0600
From: John Bokma <postmaster@castleamber.com>
Subject: Re: Included directory problem
Message-Id: <40671152$0$24340$58c7af7e@news.kabelfoon.nl>
chatiman wrote:
> Hello,
>
> I'm trying to build an installation procedure for a script.
Reinventing the wheel, or do you use the available tools?
--
John personal page: http://johnbokma.com/
Freelance Perl / Java developer available - http://castleamber.com/
------------------------------
Date: Sun, 28 Mar 2004 20:48:03 +0200
From: "chatiman" <chatiman@free.fr>
Subject: Re: Included directory problem
Message-Id: <40671ddf$0$14065$626a14ce@news.free.fr>
"John Bokma" <postmaster@castleamber.com> a écrit dans le message de news:
40671152$0$24340$58c7af7e@news.kabelfoon.nl...
> Reinventing the wheel, or do you use the available tools?
>
I don't think so. I don't know any standard way to install
a script and its modules as a non root user
Is there some ?
------------------------------
Date: Sun, 28 Mar 2004 20:28:42 GMT
From: Uri Guttman <uri@stemsystems.com>
Subject: Re: Included directory problem
Message-Id: <x7zna0u35x.fsf@mail.sysarch.com>
>>>>> "c" == chatiman <chatiman@free.fr> writes:
c> "John Bokma" <postmaster@castleamber.com> a écrit dans le message de news:
c> 40671152$0$24340$58c7af7e@news.kabelfoon.nl...
>> Reinventing the wheel, or do you use the available tools?
>>
c> I don't think so. I don't know any standard way to install
c> a script and its modules as a non root user
c> Is there some ?
FAQ. did you think you were the first person (or even the thousandth) to
ask this?
uri
--
Uri Guttman ------ uri@stemsystems.com -------- http://www.stemsystems.com
--Perl Consulting, Stem Development, Systems Architecture, Design and Coding-
Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
------------------------------
Date: Sun, 28 Mar 2004 15:21:34 -0600
From: John Bokma <postmaster@castleamber.com>
Subject: Re: Included directory problem
Message-Id: <406741df$0$24356$58c7af7e@news.kabelfoon.nl>
chatiman wrote:
> "John Bokma" <postmaster@castleamber.com> a écrit dans le message de news:
> 40671152$0$24340$58c7af7e@news.kabelfoon.nl...
>
>>Reinventing the wheel, or do you use the available tools?
>
> I don't think so. I don't know any standard way to install
> a script and its modules as a non root user
> Is there some ?
For ages, what do you think the modules at CPAN modules use, for
example? And yes, you can install as a non root user, in your local
directory. You can specify a path where the install should be put. And
no, you can not install as a non root user in a dir you haven´t got
access to.
--
John personal page: http://johnbokma.com/
Freelance Perl / Java developer available - http://castleamber.com/
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
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Subject: Digest Administrivia (Last modified: 6 Apr 01)
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------------------------------
End of Perl-Users Digest V10 Issue 6318
***************************************
