Perl is one of the things I never quite had the justification to get into. Unfortunately, I've got a very specific (looks like a bug to me) bit of Perl code, and I need to define it's operation provably. This code is written and in production already, I wish to have it removed. I believe it's impossible to successfully match, but it'...
In Perl, the array index -1 means the last element: @F=(1,2,3); print $F[-1]; # result: 3 You can also use the $# notation instead, here $#F: @F=(1,2,3); print $F[$#F]; # result: 3 So why don't -1 and $#F give the same result when I want to specify the last element in a range: print @F[1..$#F]; # 23 print @F[1..-1]; # <empty> T...
Given that the roles Fooable and Barable have both been defined, how do I say that class FooBar does Fooable and Barable? I have no problem saying #!/usr/bin/perl use MooseX::Declare; role Fooable { method foo { print "foo\n" } } role Barable { method bar { print "bar\n" } } class Foo with Fooable {} class Bar with Barable ...
I have a shell script, pretty big one. Now my boss says I must rewrite it in Perl. Is there any way to write a Perl script and use the existing shell code as is in my Perl script. Something similar to Inline::C. Is there something like Inline::Shell? I had a look at inline module, but it supports only languages. ...
The content of condition.conf: condition1=$a>$b Example Perl code: $cnd_ConfFile = $ARGV[0]; open(CONDITIONS, '<', $cndConfFile); $cndCount=0; while ( <CONDITIONS> ) { chomp; # no newline s/#.*//; # no comments s/^\s+//; # no leading white s/\s+$//; # no trailing white next unless length; ...
I'm seeing some occasional (one time in five), momentary (5-10 seconds) "freezing" when it dragspossibly as part of the -startcommand callback. It never happens on the first drag. The callback is simple enough; it just sets the text of the dragging cursor to the value that is being dragged: sub DragStart { my( $token ) = @_; my $w...
I posted "How to undersand the POE-Tk use of destroy?" in an attempt to reduce the bug in my production code to a test case. But it seems that the solution to the test case is not working in the full program. The program is 800+ lines long so I am hesitant to post it in full. I realize that the snippets I provide here may be too shor...
What is the best way to log an error when testing in Perl? I prefer a one-liner solution such as return 0 if $var!=3 and $logger->error("Var is not 3")) Can something like the example shown be implemented? ...
Is there an OS-agnostic Perl module that puts a hard limit on the amount of virtual memory a process can use; e.g. so that the process will be killed if it starts eating up too much memory? I see Apache::SizeLimit, which is obviously Apache specific; and Process::MaxSize, which requires you to call a check function (and also has a hacky...
I am having difficulty with the BUILD method in MooseX::Declare. If I say: #!/usr/bin/perl use MooseX::Declare; class Foo { has foo => (is => "rw", isa => "Str", default => "foo"); method BUILD { print "I was called\n"; } } Foo->new; I get the following less than helpful error message: Reference found where even...
Input: F1 F2 F3 F4 F5 F6 4 ABCDEF1234 1111111111 20090101 00:00:00 XYZ 123 Output: 4 ABCDEF1234 1111111111 20090101-00:00:00 XYZ 123 F represents fields. F4 and F5 are date fields which needs to be concatenated with a hyphen. Is there a quick Perl script that does this? ...
Hello friends, I have encountered a difficulty in understanding the subroutine syntax. using the following code: sub build_dyne_file{ open(DYNAP, "+>$veri_dir/$dyna_para") or die $!; for (keys %hash){ print DYNAP "#define ",$_," ",$hash{$_}->[$i],"\n"; } close(DYNAP); } for (my $i = 0 ; $i <$TEST_QUOTA ; $i++){ b...
I have a problem in Perl I don't understand. I stripped it down to this very short code. Why does Perl's map function return an empty array? Shouldn't it return an array with 9 undefs? sub mySub{ return; } my @arr = (1 .. 9); my @arr2 = map( mySub($_), @arr ); print @arr . ' ' . @arr2, "\n"; It prints "9 0". It is probably som...
I was asked to modify some existing code to add some additional functionality. I have searched on Google and cannot seem to find the answer. I have something to this effect... %first_hash = gen_first_hash(); %second_hash = gen_second_hash(); do_stuff_with_hashes(%first_hash, %second_hash); sub do_stuff_with_hashes { my %first_hash ...
What is the difference between doing use My::Module and require My::Module? ...
I have some simple Perl code: #!/usr/bin/perl use strict; # not in the OP, recommended use warnings; # not in the OP, recommended my $val = 1; for ( 1 .. 100 ) { $val = ($val * $val + 1) % 8051; print ($val / 8050) . " \n"; } But when I run it, the output is: bash-3.2$ perl ./rand.pl 0.0002484472049689440.0006211180124223...
I keep printing my hash as # of buckets / # allocated. How do I print the contents of my hash? Without using a while loop would be most preferable (ex: a one-line would be best) ...
Seeing some strange behavior, whereby connecting to Oracle database, and then calling external function, the value of $? is always -1. Problem machine is running standard AIX5.3, with DBD::Oracle 1.20 and DBI 1.602. #!/usr/bin/perl -w use DBI; CORE::system "pwd"; print "Before connect: $?\n"; DBI->connect('dbi:Oracle:', 'pwd', 'pwd'); ...
Are there any examples I can look at that use HTML::FormFu with AJAX form validation and submission? I would really not like to write my validation routines three times (once in JS, once in FormFu constraints, and once in DBIC models), so I'd really like a way that's integrated with HTML::FormFu::Model::DBIC if possible. ...
How would I start a long-running job from within a Catalyst app? I want a page from which the user can upload a list of URLs, and the application would then go and download these URLs. I need to implement an AJAX progress indicator that would then show the status of this job. ...