Hello Monks,

I'm having an issue i wasn't planning on running into this morning.... thought i've done it before in the past... but i guess i'm reducing to asking for master-help.

I want to have multiple actions occur if an open statement doesn't work. Check out my code below and you'll see what i'm talking about.

thanks!

#!/tps/bin/perl -s

open (my $log_FH, '>', './testlogfile.txt')
    || {
           print "failure to open log file...........";
           die 'Failure to open log file.....';
       }

close($log_FH);
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The issue i get from the above is:

syntax error at ./test.pl line 6, near "die"

Execution of ./test.pl aborted due to compilation errors.

Hi All, brand new to perlmonks here, from few days ago and it is my first post. I came to Perl last spring (from Linux and bash scripting), really love it, learned a bit and finished some small projects, but still a begginner. My question is: Is it correct to use few if loops one after the other, as I did in this code? So, loops are not nestled and the midle if loop is with else. All that is a content of a foreach loop.

    if ($char eq "a") {
        some code …
    }

    if ($k ==2)  {
        some code …
    }
    else {
        some code …
    }

    if ($char eq "b") {
        some code …
    }
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I know standard use of loops, but somehow, while trying to make my script work, I've came to this solution, that works well in my case. There is only few similar examples of using if loops such way I've found on the web, so I don't know if it is ok and maybe it is considered something to avoid or a dirty code? If it is ok, I would like to hear your comments about the whole script, but maybe that should be sent with other title. If not ok, I will begin to write the other code.

use Date::Manip;
my $dt1='2016080100:00:00';
my $dt2='2016123100:00:00';
my $dtopt= DateCalc($dt1,$dt2);
print $dtopt;
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This is more of a curiosity thing than anything as I must admit, I don't know a whole lot of C.

Can someone explain what I'm missing in the below code? In the C num() function, I have a uint8_t argument, which causes an error:

Undefined subroutine &main::num called at perl.pl line 6.
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The broken code:

use warnings;
use strict;

use Inline 'C';

num(1);

__END__
__C__

#include <stdio.h>
#include <inttypes.h>

void num(uint8_t number){
    printf("%d\n", number);
}
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However, if I accept the argument as an int, and then cast it to uint8_t, it works fine:

void num(int number){
    number = (uint8_t)number;
    printf("%d\n", number);
}
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The code that breaks in Perl (uint8_t in the function definition) works fine when compiling/running it as a straight up C program.

I've tried to use "-|" pipe option on "perl v5.8.4 built for MSWin32-x86-multi-thread" as below :

use strict;
use warnings;
use threads;

#sub sub1{-
my $pid = open(HCIDUMP, "-|");
defined($pid) || die "can't fork: $!";

if($pid){
    while(<HCIDUMP>){
        my $test = readline(<HCIDUMP>);
        print "this is priting from open - $test\n";
    }
    close(HCIDUMP);
}else{
    exec("sdb shell hcidump") || die "can't exec program: $!";
}
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"'-' is not recognized as an internal or external command,operable pro
+gram or batch file."
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Thanks Br

David Lim

The code turns on the perl debugger in a separate thread at the XS level, this allows the debugger to be used to step through running perl code in that separate thread. It's hard to explain, but works well:)

It seems (given my limited understanding) that the correct way to do this in later perl's is to use the Perl_init_debugger function, but it doesn't seem to be available? Using the raw source code for this function works well but that would mean that my code would only works on that specific version of perl, something that I want to avoid...

An example of a module that uses this function is Enbugger:

https://metacpan.org/source/JJORE/Enbugger-2.016/Enbugger.xs

However, this module doesn't actually compile under ActiveState 5.22 or Stawberry 5.24

Enbugger.o:Enbugger.c:(.text+0x852): undefined reference to `__imp_Perl_init_debugger'

Does anyone know the 'correct' way to use this function?

Any hints would be gratefully appreciated.

In the script

#!/usr/bin/perl

use warnings;
use strict;


my $sod='ip6 is used for...';
my $i=0;
my @baza_tek=qw( (?^u:ip(\d)) "internet_protocol-$1$2" );

$sod=~s#$baza_tek[$i]#$baza_tek[$i+1]#gee;
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i have such an error on execution:

Use of uninitialized value $2 in concatenation (.) or string at...

My question is,

How to tell PERL to show the values of current baza_tek[$i] or $baza_tek[$i+1] at the time, when the error occured?

I curate a repository of cpan modules @WORK that is shared across the enterprise. Unfortunately, I am trying to serve two masters: "run the biz" and "change the biz". The RTB folks don't like changes to their environment, and fight vehemently when modules upgrade (b/c they have production systems dependent upon old code). By contrast, the CTB folks love the bleeding edge and want to try new things, build new tools, etc.

So, when I built Perl for the next operating system, I added a new directory to the default @INC where I can put additional, non-core, modules (or new versions of existing modules) for the CTB folks. This works fine if the "newer version" of a module comes earliest in the @INC list. But what happens when something in the corelist is updated? DHOH!

So after much GIYF, I found this very troubling statement:

"Please recall that Perl interpreter will STOP trying to search [additional directories in @INC] once it finds the file in one of the locations, without trying to see if the file is in later locations as well. E.g. if /usr/lib/perl/This/Here/MyModule2.pm exists, then Perl will not look for, nor care about the existence, of /opt/custom/lib/This/Here/MyModule2.pm." Stack Overflow

Is there a better solution than "use lib reverse @INC" to get the newer module that is further in the @INC list?

For example, autodie v.2.23 is in the core for perl. So I build the newest autodie v.2.29, and it now lives in the non-core extras modules path, which is part of the default @INC.

 
--> perl -MData::Dumper -E 'say "INC: ", Dumper( \@INC )'
  INC: $VAR1 = [
          '/usr/foss/packages/perl/perl-5.20.3/lib/site_perl/5.20.3/x8
+6_64-linux-thread-multi',
          '/usr/foss/packages/perl/perl-5.20.3/lib/site_perl/5.20.3',
          '/usr/foss/packages/perl/perl-5.20.3/lib/5.20.3/x86_64-linux
+-thread-multi-ld',
          '/usr/foss/packages/perl/perl-5.20.3/lib/5.20.3',
          '/usr/foss/packages/cpan-basics/perl-5.20.3/lib/perl5/x86_64
+-linux-thread-multi-ld',
          '/usr/foss/packages/cpan-basics/perl-5.20.3/lib/perl5',
          '/usr/foss/packages/cpan-basics/perl-5.20.3/lib/perl5/site_p
+erl',
          '/usr/foss/packages/foss-perllib',
          '.'
        ];

--> perl -E 'use autodie; 
say q[version: ], $autodie::VERSION; 
say q[location: ], $INC{q[autodie.pm]}; '
  version: 2.23
  location: /usr/foss/packages/perl/perl-5.20.3/lib/5.20.3/autodie.pm

--> perl -E 'use lib reverse @INC; 
use autodie; 
say q[version: ], $autodie::VERSION; 
say q[location: ], $INC{q[autodie.pm]};'
  version: 2.29
  location: /usr/foss/packages/cpan-basics/perl-5.20.3/lib/perl5/autod
+ie.pm

--> perl -E 'use autodie 2.29; 
say q[version: ], $autodie::VERSION; 
say q[location: ], $INC{q[autodie.pm]}; '
    autodie version 2.29 required--this is only version 2.23 at -e lin
+e 1.
    BEGIN failed--compilation aborted at -e line 1.
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So again, I ask: is there a better solution than "use lib reverse @INC" to get the newer module that is further in the @INC list? Is there a way to change the module search heuristic in Perl so that all the locations are scanned when you specify a VERSION (and/or a LIST)? Am I missing a new feature that solves this problem?

TIA for your wisdom and insights.

Reading more and more about Perl, I'm having doubts about how I organized my modules on my current project.

I have a main namespace - let's call it "MyProject". I have objects from class A that are composed of objects of class B, C and D. Classes B, C and D are used by class A only, so it made sense to me to organize the modules as follows:

• MyProject::A
• MyProject::A::B
• MyProject::A::C
• MyProject::A::D

But I'm starting to think that it will make sense to me only if I ever dare to relase parts of my project in CPAN. I think people will believe that B, C and D are inheriting A and not composing it.

So: shall I reorganize my modules this way?

• MyProject::A
• MyProject::B
• MyProject::C
• MyProject::D

Or maybe indicate that B, C and D are parts of A by appending their names?

• MyProject::A
• MyProject::AB
• MyProject::AC
• MyProject::AD

My question: What is the currently considered a best practices for module organization and naming when it comes to composition?

package SO;

use DynaLoader;

sub new {
    my $class = shift;
    my $libname = shift;
    my $so = DynaLoader::dl_findfile( $libname );
    die 'Failed to find .so for '.$libname unless defined( $so );
    my $lib = DynaLoader::dl_load_file( $so, @_ );
    die 'Failed to load '.$so unless $lib;

    return bless [ $lib, $so ], $class;
};

sub AUTOLOAD {
    my $self = shift;
    my $sub = $AUTOLOAD;
    $sub =~ s/.*\:\://;

    warn 'called DL';
    return $self->call( $sub, @_ );
};

sub DESTROY {
    my $self = shift;
    DynaLoader::dl_unload_file( $self->[0] );
};

sub call {
    my $self = shift;
    my $sym = shift;
    my $symref = DynaLoader::dl_find_symbol( $self->[0], $sym );
    die 'failed to find '.$sym.' in '.$self->[1] unless $symref;

    DynaLoader::dl_install_xsub( $sym, $symref );
    return &$sym( @_ );
};

1;
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use SO;
my $so = SO->new('some.so');
my $string = $so->get_some_string();#correct result
my $x = { a => 'b', c => 123 };
my $r = $so->change_this_argument( $x );#get error from .so about wron
+g arguments, but the arguments definetly correct.
my $r2 = $so->accept_this_argument( $x );#get same error.
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perl -e '$a = "-4.84900000E+001"; $a += 0; $b = -48.49; print "EQ\n" i
+f ($a == $b); print "$a\n$b\n";'
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EQ
-48.49
-48.49
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perl -e '$a = "-4.84800000E+001"; $a += 0; $b = -48.48; print "EQ\n" i
+f ($a == $b); print "$a\n$b\n";'
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-48.48
-48.48
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perl -v
This is perl 5, version 22, subversion 2 (v5.22.2) built for x86_64-li
+nux-thread-multi
(with 33 registered patches, see perl -V for more detail)
[download]

Dear Monks

Given the following snippet which adds a record into a simple Sqlite Database perfectly working

my $Tag1="hallo";
my $Tag2="bye";

my $dbh = DBI->connect( "dbi:SQLite:$DbFullPath", '', '', { sqlite_uni
+code => 1 }  ) || die "Cannot connect: $DBI::errstr";
$dbh->do('INSERT INTO Data (Tag1, Tag2) VALUES (?, ?)',
undef,
standardize($Tag1), standardize($Tag1));
$dbh->disconnect;

sub standardize{
 my $string=shift;
 #manipulating string
 $string=~ s/\'/\'\'/g;
 $string=~ s/^\s+|\s+$//g;
 $string=~ s/\t/ /g;
 return $string;
}
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Why is the following (updatin an entry) not working? (Error message "syntax error")

my $ID_read=1;
my $dbh = DBI->connect( "dbi:SQLite:$DbFullPath", '', '', { sqlite_uni
+code => 1 }  ) || die "Cannot connect: $DBI::errstr";
$dbh->do ('UPDATE Data SET Tag1=?, Tag2=? WHERE ID=$ID_read VALUES (?,
+ ?)',
undef,
standardize($Tag1), standardize($Tag1));
$dbh->disconnect;
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Fellow Monks,

I've just made the first public release of a tool I've been working on called relink (Update: it's GPLv3), and I wanted to tell you about it in the form of a short narrative, below. But first, just to whet your appetite:

  # Rewrite the targets of symlinks with Perl
$ relink rewrite 's/foo/bar/' PATH(s)
  # Convert between absolute and relative targets
$ relink abs2rel PATH(s)
$ relink rel2abs PATH(s)
  # List links  [only certain symlinks]
$ relink list [-t '/foo/'] PATH(s)
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Regards,
-- Hauke D

I just wrote a reply to "Re^2: how to improve: use MODULE VERSION LIST" (id://1179142). I previewed twice then created. All looked good and perfectly normal up to this point.

When the "created" page appeared, I followed the link to the start of the thread: "how to improve: use MODULE VERSION LIST" (id://1179107). This appeared but, when I scrolled down, my post was nowhere to be seen.

I went to Newest Nodes and a post by me was at the top of the Notes list. I followed that link "Reaped: Re^3: how to improve: use MODULE VERSION LIST (id://1179154) but found an orphaned page (i.e. no "in reply to" or "in thread" links at the top). The page also had no content. It did have what appeared to be the correct title ("Re^3: how to improve: use MODULE VERSION LIST"): small consolation.

I went back to the tab where I'd created my response. I hit the back button and the content of my response was there BUT it said "by 1nickt" followed by "on Jan 08, 2017 at 09:00 AEDT ( #1179146=note: print w/replies, xml )". Note, that ID (1179146) is different from the one in Newest Nodes (1179154).

I followed that link: it was an earlier reply by 1nickt to a different node in the same thread.

Hitting the back button again (on the tab where I'd created my response) took me back to my final edit prior to posting. I've saved the content: I can post it again when the problem's fixed.